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Expression profiling of EWS/FLI identifies NKX2.2 as a critical target gene in Ewing's sarcoma. Our understanding of Ewing's sarcoma development mediated by the EWS/FLI fusion protein has been limited by a lack of knowledge regarding the tumor cell of origin. To circumvent this, we analyzed the function of EWS/FLI in Ewing's sarcoma itself. By combining retroviral-mediated RNA interference with reexpression studies, we show that ongoing EWS/FLI expression is required for the tumorigenic phenotype of Ewing's sarcoma. We used this system to define the full complement of EWS/FLI-regulated genes in Ewing's sarcoma. Functional analysis revealed that NKX2.2 is an EWS/FLI-regulated gene that is necessary for oncogenic transformation in this tumor. Thus, we developed a highly validated transcriptional profile for the EWS/FLI fusion protein and identified a critical target gene in Ewing's sarcoma development.

Which are the genes thought to be regulated by EWS/FLI?

552faa43bc4f83e828000004_007

Expression profiling of EWS/FLI identifies NKX2.2 as a critical target gene in Ewing's sarcoma. Our understanding of Ewing's sarcoma development mediated by the EWS/FLI fusion protein has been limited by a lack of knowledge regarding the tumor cell of origin. To circumvent this, we analyzed the function of EWS/FLI in Ewing's sarcoma itself. By combining retroviral-mediated RNA interference with reexpression studies, we show that ongoing EWS/FLI expression is required for the tumorigenic phenotype of Ewing's sarcoma. We used this system to define the full complement of EWS/FLI-regulated genes in Ewing's sarcoma. Functional analysis revealed that NKX2.2 is an EWS/FLI-regulated gene that is necessary for oncogenic transformation in this tumor. Thus, we developed a highly validated transcriptional profile for the EWS/FLI fusion protein and identified a critical target gene in Ewing's sarcoma development.

Which are the genes thought to be regulated by EWS/FLI?

552faa43bc4f83e828000004_008

The Ews/Fli-1 fusion gene changes the status of p53 in neuroblastoma tumor cell lines. One hallmark of Ewing's sarcoma/peripheral neuroectodermal tumors is the presence of the Ews/Fli-1 chimeric oncogene. Interestingly, infection of neuroblastoma tumor cell lines with Ews/Fli-1 switches the differentiation program of neuroblastomas to Ewing's sarcoma/peripheral neuroectodermal tumors. Here we examined the status of cytoplasmically sequestered wt-p53 in neuroblastomas after stable expression of Ews/Fli-1. Immunofluorescence revealed that in the neuroblastoma-Ews/Fli-1 infectant cell lines, p53 went from a punctate-pattern of cytoplasmic sequestration to increased nuclear localization. Western blot analysis revealed that PARC was down-regulated in one neuroblastoma cell line but not expressed in the second. Therefore, decreased PARC expression could not fully account for relieving p53 sequestration in the neuroblastoma tumor cells. Neuroblastoma-Ews/Fli-1 infectant cell lines showed marked increases in p53 protein expression without transcriptional up-regulation. Interestingly, p53 was primarily phosphorylated, without activation of its downstream target p21(WAF1). Western blot analysis revealed that whereas MDM2 gene expression does not change, p14(ARF), a negative protein regulator of MDM2, increases. These observations suggest that the downstream p53 pathway may be inactivated as a result of abnormal p53. We also found that p53 has an extended half-life in the neuroblastoma-Ews/Fli-1 infectants despite the retention of a wild-type sequence in neuroblastoma-Ews/Fli-1 infectant cell lines. We then tested the p53 response pathway and observed that the neuroblastoma parent cells responded to genotoxic stress, whereas the neuroblastoma-Ews/Fli-1 infectants did not. These results suggest that Ews/Fli-1 can directly abrogate the p53 pathway to promote tumorigenesis. These studies also provide additional insight into the relationship among the p53 pathway proteins.

Which are the genes thought to be regulated by EWS/FLI?

552faa43bc4f83e828000004_009

The Ews/Fli-1 fusion gene changes the status of p53 in neuroblastoma tumor cell lines. One hallmark of Ewing's sarcoma/peripheral neuroectodermal tumors is the presence of the Ews/Fli-1 chimeric oncogene. Interestingly, infection of neuroblastoma tumor cell lines with Ews/Fli-1 switches the differentiation program of neuroblastomas to Ewing's sarcoma/peripheral neuroectodermal tumors. Here we examined the status of cytoplasmically sequestered wt-p53 in neuroblastomas after stable expression of Ews/Fli-1. Immunofluorescence revealed that in the neuroblastoma-Ews/Fli-1 infectant cell lines, p53 went from a punctate-pattern of cytoplasmic sequestration to increased nuclear localization. Western blot analysis revealed that PARC was down-regulated in one neuroblastoma cell line but not expressed in the second. Therefore, decreased PARC expression could not fully account for relieving p53 sequestration in the neuroblastoma tumor cells. Neuroblastoma-Ews/Fli-1 infectant cell lines showed marked increases in p53 protein expression without transcriptional up-regulation. Interestingly, p53 was primarily phosphorylated, without activation of its downstream target p21(WAF1). Western blot analysis revealed that whereas MDM2 gene expression does not change, p14(ARF), a negative protein regulator of MDM2, increases. These observations suggest that the downstream p53 pathway may be inactivated as a result of abnormal p53. We also found that p53 has an extended half-life in the neuroblastoma-Ews/Fli-1 infectants despite the retention of a wild-type sequence in neuroblastoma-Ews/Fli-1 infectant cell lines. We then tested the p53 response pathway and observed that the neuroblastoma parent cells responded to genotoxic stress, whereas the neuroblastoma-Ews/Fli-1 infectants did not. These results suggest that Ews/Fli-1 can directly abrogate the p53 pathway to promote tumorigenesis. These studies also provide additional insight into the relationship among the p53 pathway proteins.

Which are the genes thought to be regulated by EWS/FLI?

552faa43bc4f83e828000004_010

The Ews/Fli-1 fusion gene changes the status of p53 in neuroblastoma tumor cell lines. One hallmark of Ewing's sarcoma/peripheral neuroectodermal tumors is the presence of the Ews/Fli-1 chimeric oncogene. Interestingly, infection of neuroblastoma tumor cell lines with Ews/Fli-1 switches the differentiation program of neuroblastomas to Ewing's sarcoma/peripheral neuroectodermal tumors. Here we examined the status of cytoplasmically sequestered wt-p53 in neuroblastomas after stable expression of Ews/Fli-1. Immunofluorescence revealed that in the neuroblastoma-Ews/Fli-1 infectant cell lines, p53 went from a punctate-pattern of cytoplasmic sequestration to increased nuclear localization. Western blot analysis revealed that PARC was down-regulated in one neuroblastoma cell line but not expressed in the second. Therefore, decreased PARC expression could not fully account for relieving p53 sequestration in the neuroblastoma tumor cells. Neuroblastoma-Ews/Fli-1 infectant cell lines showed marked increases in p53 protein expression without transcriptional up-regulation. Interestingly, p53 was primarily phosphorylated, without activation of its downstream target p21(WAF1). Western blot analysis revealed that whereas MDM2 gene expression does not change, p14(ARF), a negative protein regulator of MDM2, increases. These observations suggest that the downstream p53 pathway may be inactivated as a result of abnormal p53. We also found that p53 has an extended half-life in the neuroblastoma-Ews/Fli-1 infectants despite the retention of a wild-type sequence in neuroblastoma-Ews/Fli-1 infectant cell lines. We then tested the p53 response pathway and observed that the neuroblastoma parent cells responded to genotoxic stress, whereas the neuroblastoma-Ews/Fli-1 infectants did not. These results suggest that Ews/Fli-1 can directly abrogate the p53 pathway to promote tumorigenesis. These studies also provide additional insight into the relationship among the p53 pathway proteins.

Which are the genes thought to be regulated by EWS/FLI?

552faa43bc4f83e828000004_011

BCL11B is up-regulated by EWS/FLI and contributes to the transformed phenotype in Ewing sarcoma. The EWS/FLI translocation product is the causative oncogene in Ewing sarcoma and acts as an aberrant transcription factor. EWS/FLI dysregulates gene expression during tumorigenesis by abnormally activating or repressing genes. The expression levels of thousands of genes are affected in Ewing sarcoma, however, it is unknown which of these genes contribute to the transformed phenotype. Here we characterize BCL11B as an up-regulated EWS/FLI target that is necessary for the maintenance of transformation in patient derived Ewing sarcoma cells lines. BCL11B, a zinc finger transcription factor, acts as a transcriptional repressor in Ewing's sarcoma and contributes to the EWS/FLI repressed gene signature. BCL11B repressive activity is mediated by the NuRD co-repressor complex. We further demonstrate that re-expression of SPRY1, a repressed target of BCL11B, limits the transformation capacity of Ewing sarcoma cells. These data define a new pathway downstream of EWS/FLI required for oncogenic maintenance in Ewing sarcoma.

Which are the genes thought to be regulated by EWS/FLI?

552faa43bc4f83e828000004_012

BCL11B is up-regulated by EWS/FLI and contributes to the transformed phenotype in Ewing sarcoma. The EWS/FLI translocation product is the causative oncogene in Ewing sarcoma and acts as an aberrant transcription factor. EWS/FLI dysregulates gene expression during tumorigenesis by abnormally activating or repressing genes. The expression levels of thousands of genes are affected in Ewing sarcoma, however, it is unknown which of these genes contribute to the transformed phenotype. Here we characterize BCL11B as an up-regulated EWS/FLI target that is necessary for the maintenance of transformation in patient derived Ewing sarcoma cells lines. BCL11B, a zinc finger transcription factor, acts as a transcriptional repressor in Ewing's sarcoma and contributes to the EWS/FLI repressed gene signature. BCL11B repressive activity is mediated by the NuRD co-repressor complex. We further demonstrate that re-expression of SPRY1, a repressed target of BCL11B, limits the transformation capacity of Ewing sarcoma cells. These data define a new pathway downstream of EWS/FLI required for oncogenic maintenance in Ewing sarcoma.

Which are the genes thought to be regulated by EWS/FLI?

552faa43bc4f83e828000004_013

Phenotype diversity in familial cylindromatosis: a frameshift mutation in the tumor suppressor gene CYLD underlies different tumors of skin appendages. Familial cylindromatosis (turban tumor syndrome; Brooke-Spiegler syndrome) (OMIM numbers 123850, 132700, 313100, and 605041) is a rare autosomal dominantly inherited tumor syndrome. The disorder can present with cutaneous adnexal tumors such as cylindromas, trichoepitheliomas, and spiradenomas, and tumors preferably develop in hairy areas of the body such as head and neck. In affected families, mutations have been demonstrated in the CYLD gene located on chromosome 16q12-13 and reveal the characteristic attributes of a tumor suppressor. Here, we studied familial cylindromatosis in a multigeneration family of German origin. Clinically, some individuals only revealed discrete small skin-colored tumors localized in the nasolabial region whereas one family member showed expansion of multiple big tumors on the trunk and in a turban-like fashion on the scalp. Histologically, cylindromas as well as epithelioma adenoides cysticum were found. We detected a frameshift mutation in the CYLD gene, designated 2253delG, underlying the disorder and were able to show that a single mutation can result in distinct clinical and histologic expression in familial cylindromatosis. The reasons for different expression patterns of the same genetic defect in this disease remain elusive, however. Identification of mutations in the CYLD gene enable us to rapidly confirm putative diagnoses on the genetic level and to provide affected families with genetic counseling.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_001

CYLD mutation causes multiple familial trichoepithelioma in three Chinese families. Multiple familial trichoepithelioma (MFT) and familial cylindromatosis are two clinically distinct cancer syndromes. MFT patients developed mostly trichoepithelioma in the face while cylindromatosis patients developed cylindromas predominantly (approximately 90%) on the head and neck. However, multiple familial trichoepithelioma is occasionally associated with familial cylindromatosis while cylindromatosis patients can also develop trichoepithelioma. This has led to the speculation that the 2 types of dermatoses may be caused by dysfunction of a common pathway. Previously, a candidate MTF locus has been mapped to 9p21 while disease gene for familial cylindromatosis, the CYLD gene located on 16q21-13 has been identified. Here, we show that mutations in the CYLD gene are also the genetic basis for three different Chinese families with MFT. Sequence analysis reveal a single nucleotide deletion, c.1462delA (P.Ile488fsX9) in exon 9, a nonsense mutation, c.2128C>T (p. Gln710X) in exon 17, and a missense mutation, c.2822A>T (p. Asp941Val) in exon 21 in each of the three families respectively. This provides direct evidence that the mutations in CYLD can cause two clinically distinct cancer syndromes.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_002

CYLD mutation causes multiple familial trichoepithelioma in three Chinese families. Multiple familial trichoepithelioma (MFT) and familial cylindromatosis are two clinically distinct cancer syndromes. MFT patients developed mostly trichoepithelioma in the face while cylindromatosis patients developed cylindromas predominantly (approximately 90%) on the head and neck. However, multiple familial trichoepithelioma is occasionally associated with familial cylindromatosis while cylindromatosis patients can also develop trichoepithelioma. This has led to the speculation that the 2 types of dermatoses may be caused by dysfunction of a common pathway. Previously, a candidate MTF locus has been mapped to 9p21 while disease gene for familial cylindromatosis, the CYLD gene located on 16q21-13 has been identified. Here, we show that mutations in the CYLD gene are also the genetic basis for three different Chinese families with MFT. Sequence analysis reveal a single nucleotide deletion, c.1462delA (P.Ile488fsX9) in exon 9, a nonsense mutation, c.2128C>T (p. Gln710X) in exon 17, and a missense mutation, c.2822A>T (p. Asp941Val) in exon 21 in each of the three families respectively. This provides direct evidence that the mutations in CYLD can cause two clinically distinct cancer syndromes.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_004

CYLD mutation causes multiple familial trichoepithelioma in three Chinese families. Multiple familial trichoepithelioma (MFT) and familial cylindromatosis are two clinically distinct cancer syndromes. MFT patients developed mostly trichoepithelioma in the face while cylindromatosis patients developed cylindromas predominantly (approximately 90%) on the head and neck. However, multiple familial trichoepithelioma is occasionally associated with familial cylindromatosis while cylindromatosis patients can also develop trichoepithelioma. This has led to the speculation that the 2 types of dermatoses may be caused by dysfunction of a common pathway. Previously, a candidate MTF locus has been mapped to 9p21 while disease gene for familial cylindromatosis, the CYLD gene located on 16q21-13 has been identified. Here, we show that mutations in the CYLD gene are also the genetic basis for three different Chinese families with MFT. Sequence analysis reveal a single nucleotide deletion, c.1462delA (P.Ile488fsX9) in exon 9, a nonsense mutation, c.2128C>T (p. Gln710X) in exon 17, and a missense mutation, c.2822A>T (p. Asp941Val) in exon 21 in each of the three families respectively. This provides direct evidence that the mutations in CYLD can cause two clinically distinct cancer syndromes.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_005

Mild phenotype of familial cylindromatosis associated with an R758X nonsense mutation in the CYLD tumour suppressor gene. Familial cylindromatosis is a rare dominantly inherited disease characterized by the development of multiple benign tumours of the skin appendages, including cylindromas, trichoepitheliomas and spiradenomas. The gene responsible was positionally cloned recently, and was designated CYLD. We describe a family with cylindromatosis, in which affected individuals have an inherited R758X nonsense mutation of CYLD. Affected members of this family manifest a relatively mild tumour phenotype; the largest tumour was only 30 mm in diameter. Thus far, there is no evident genotype-phenotype relationship in cylindromatosis, although the number of families reported with both phenotypic and genotypic data remains small.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_008

Mild phenotype of familial cylindromatosis associated with an R758X nonsense mutation in the CYLD tumour suppressor gene. Familial cylindromatosis is a rare dominantly inherited disease characterized by the development of multiple benign tumours of the skin appendages, including cylindromas, trichoepitheliomas and spiradenomas. The gene responsible was positionally cloned recently, and was designated CYLD. We describe a family with cylindromatosis, in which affected individuals have an inherited R758X nonsense mutation of CYLD. Affected members of this family manifest a relatively mild tumour phenotype; the largest tumour was only 30 mm in diameter. Thus far, there is no evident genotype-phenotype relationship in cylindromatosis, although the number of families reported with both phenotypic and genotypic data remains small.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_009

CYLD mutations underlie Brooke-Spiegler, familial cylindromatosis, and multiple familial trichoepithelioma syndromes. Brooke-Spiegler syndrome (BSS), familial cylindromatosis (FC), and multiple familial trichoepithelioma (MFT), originally described as distinct inherited disorders, are characterized by a variety of skin appendage neoplasms. Mutations in the CYLD gene are found in individuals with these syndromes. We describe a single family with affected members exhibiting either the FC or the MFT phenotypes associated with a mutation in the CYLD gene. These findings support the notion that BSS, FC, and MFT represent phenotypic variation of a single defect. Of interest, one of the affected individuals described in this report exhibits a severe phenotype illustrating the morbidity of the disorder.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_010

CYLD mutations underlie Brooke-Spiegler, familial cylindromatosis, and multiple familial trichoepithelioma syndromes. Brooke-Spiegler syndrome (BSS), familial cylindromatosis (FC), and multiple familial trichoepithelioma (MFT), originally described as distinct inherited disorders, are characterized by a variety of skin appendage neoplasms. Mutations in the CYLD gene are found in individuals with these syndromes. We describe a single family with affected members exhibiting either the FC or the MFT phenotypes associated with a mutation in the CYLD gene. These findings support the notion that BSS, FC, and MFT represent phenotypic variation of a single defect. Of interest, one of the affected individuals described in this report exhibits a severe phenotype illustrating the morbidity of the disorder.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_011

A novel germline mutation in the CYLD gene in a Slovak patient with Brooke-Spiegler syndrome. The authors report a 64-year-old female with Brooke-Spiegler syndrome who presented with multiple cutaneous nodules and tumors mostly involving the scalp. Histopathological examination of one of the lesions located in a periauricular area revealed a typical cylindroma. In some neoplastic nodules ductal differentiation and occasional bilayered glands composed of the dark abluminal basal/myoepithelial cells and luminal mucinous cells might be recognized. Apocrine secretion was focally noted. Molecular biologic study of the CYLD gene performed from the peripheral blood identified a novel splice site c.2041+1 G>T mutation. This new germline mutation in the CYLD gene of a Slovak patient with Brooke-Spiegler syndrome extends the catalogue of known CYLD germline mutations in this condition.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_013

A novel germline mutation in the CYLD gene in a Slovak patient with Brooke-Spiegler syndrome. The authors report a 64-year-old female with Brooke-Spiegler syndrome who presented with multiple cutaneous nodules and tumors mostly involving the scalp. Histopathological examination of one of the lesions located in a periauricular area revealed a typical cylindroma. In some neoplastic nodules ductal differentiation and occasional bilayered glands composed of the dark abluminal basal/myoepithelial cells and luminal mucinous cells might be recognized. Apocrine secretion was focally noted. Molecular biologic study of the CYLD gene performed from the peripheral blood identified a novel splice site c.2041+1 G>T mutation. This new germline mutation in the CYLD gene of a Slovak patient with Brooke-Spiegler syndrome extends the catalogue of known CYLD germline mutations in this condition.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_014

Brooke-Spiegler syndrome: report of two cases not associated with a mutation in the CYLD and PTCH tumor-suppressor genes. Brooke-Spiegler syndrome represents an autosomal dominant disease characterized by the occurrence of multiple cylindromas, trichoepitheliomas and (sporadically) spiroadenomas. Patients with Brooke-Spiegler syndrome are also at risk of developing tumors of the major and minor salivary glands. Patients with Brooke-Spiegler syndrome have various mutations in the CYLD gene, a tumor-suppressor gene located on chromosome 16q. To date, 68 unique CYLD mutations have been identified. We describe two families with Brooke-Spiegler syndrome, one with familial cylindromatosis and one with multiple familial trichoepithelioma, which showed wide inter-family phenotypic variability. Analysis of germline mutations of the CYLD and PTCH genes was performed using peripheral blood. In addition, formalin-fixed paraffin-embedded tumor samples were analyzed for PTCH somatic mutations and cylindroma cell cultures were obtained directly from patients for further growth and analysis. Clinically, the major features of Brooke-Spiegler syndrome include the presence of heterogeneous skin tumors and wide inter- and intra-familial phenotypic variability. Histopathologically, both cylindromas and trichoepitheliomas were found in affected individuals. Mutations or loss of heterozygosity was not found in CYLD and PTCH genes. In CYLD and PTCH mutation-negative patients, other genes may be affected and further studies are needed to clarify whether these patients may be affected by de novo germline mutations.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_015

GLI1-dependent transcriptional repression of CYLD in basal cell carcinoma. CYLD is a deubiquitination enzyme that regulates different cellular processes, such as cell proliferation and cell survival. Mutation and loss of heterozygosity of the CYLD gene causes development of cylindromatosis, a benign tumour originating from the skin. Our study shows that CYLD expression is dramatically downregulated in basal cell carcinoma (BCC), the most common cancer in humans. Reduced CYLD expression in basal cell carcinoma was mediated by GLI1-dependent activation of the transcriptional repressor Snail. Inhibition of GLI1 restored the CYLD expression-mediated Snail signaling pathway, and caused a significant delay in the G1 to S phase transition, as well as proliferation. Our data suggest that GLI1-mediated suppression of CYLD has a significant role in basal cell carcinoma progression.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_016

Identification of a large rearrangement in CYLD as a cause of familial cylindromatosis. Pathogenic mutations in CYLD can be identified in patients affected with Brooke-Spiegler syndrome, (Familial) Cylindromatosis or multiple familial trichoepithelioma. To date, only technologies which are able to identify small point mutations in CYLD, such as sequence and WAVE analysis, were used. Here we describe the identification of a larger rearrangement identified by Quantitative PCR analysis of CYLD, indicating that a combination of these technologies is necessary when searching for pathogenic mutations in CYLD.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_020

Identification of a large rearrangement in CYLD as a cause of familial cylindromatosis. Pathogenic mutations in CYLD can be identified in patients affected with Brooke-Spiegler syndrome, (Familial) Cylindromatosis or multiple familial trichoepithelioma. To date, only technologies which are able to identify small point mutations in CYLD, such as sequence and WAVE analysis, were used. Here we describe the identification of a larger rearrangement identified by Quantitative PCR analysis of CYLD, indicating that a combination of these technologies is necessary when searching for pathogenic mutations in CYLD.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_021

Identification of a large rearrangement in CYLD as a cause of familial cylindromatosis. Pathogenic mutations in CYLD can be identified in patients affected with Brooke-Spiegler syndrome, (Familial) Cylindromatosis or multiple familial trichoepithelioma. To date, only technologies which are able to identify small point mutations in CYLD, such as sequence and WAVE analysis, were used. Here we describe the identification of a larger rearrangement identified by Quantitative PCR analysis of CYLD, indicating that a combination of these technologies is necessary when searching for pathogenic mutations in CYLD.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_022

New mutation in the CYLD gene within a family with Brooke-Spiegler syndrome. Brooke-Spiegler syndrome is a rare, autosomal dominant disease characterized by multiple skin appendage tumors caused by various mutations in the CYLD gene on chromosome 16q12-q13. We describe a family, in which we performed a molecular-genetic examination and found a new mutation in exon 19 in the CYLD gene leading to a frameshift. It is important to be aware of this syndrome and its pathogenesis as its phenotypic features can vary so that apparently different diseases are caused by the same genetic defect. In addition, there may be malignant transformation of the generally benign tumors, so that a timely diagnosis is essential for appropriate monitoring and therapy.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_023

Brooke-Spiegler syndrome: report of a case with a novel mutation in the CYLD gene and different types of somatic mutations in benign and malignant tumors. The authors report a case of Brooke-Spiegler syndrome (BSS) with a novel germline CYLD mutation and various somatic mutations identified in the lesional tissues. The patient was a 46-year-old man with multiple lesions on the face. The available histopathological material included 24 trichoepitheliomas, 2 large nodular basal cell carcinomas (BCCs), 2 spiradenomas, 1 spiradenocylindroma and 1 trichoblastoma composed of large and small nodules with prominent clear cell differentiation. Whereas one of the two BCCs manifested a conventional morphology, the second neoplasm additionally showed foci with high grade cytological features characterized by marked pleomorphism and numerous mitotic figures. There were also numerous signet ring cells and cells containing intracytoplasmic eosinophilic inclusions. The germline mutation was a substitution mutation c.1684 + 1G> A. Somatic mutations were investigated in eight tissue blocks from which high quality genomic DNA had been successfully extracted. Somatic mutations included loss of heterozygosity (LOH) in four lesions and a single sequence mutation, namely a single base deletion c. 2322delA causing a frameshift mutation E774DfsX2. LOH occurred in both BCCs, one trichoepithelioma and one spiradenoma. In the remaining three lesions, the somatic event remained undetected.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_024

Tumor mapping in 2 large multigenerational families with CYLD mutations: implications for disease management and tumor induction. OBJECTIVES: To comprehensively ascertain the extent and severity of clinical features in affected individuals from 2 large families with proven heterozygous mutations in the CYLD locus and to correlate these findings with the 3 appendageal tumor predisposition syndromes (familial cylindromatosis, Brooke-Spiegler syndrome, and multiple familial trichoepitheliomas) known to be associated with such germline mutations. DESIGN: Interfamilial and intrafamilial observational study. SETTING: Tertiary genetic and dermatology referral center. PARTICIPANTS: Thirty-four individuals recruited from 2 large multigenerational families with CYLD mutations. Clinical details, history, and tumor maps were obtained from all participants; in 18, the information was corroborated by detailed clinical examination. MAIN OUTCOME MEASURES: Tumor density, distribution and histologic findings, associated medical conditions, patient symptoms, and impact of disease on quality of life. RESULTS: The severity of penetrance and phenotype varied within families. Although an approximately equal female to male predisposition was noted, 5 women and 1 man (of 26 patients surveyed [23%]) had undergone total scalp removal. The average age at onset was 16 years (range, 8-30 years). Symptoms reported by affected patients included painful tumors (in 12 of 23 patients [52%] who answered the question), conductive deafness, and sexual dysfunction. Of the 26 surveyed patients, tumors were noted on the scalp in 21 (81%), on the trunk in 18 (69%), and in the pubic area in 11 (42%). Tumor mapping provided clinical evidence that correlated with hormonally stimulated hair follicles being particularly vulnerable to loss of heterozygosity and tumor induction. CONCLUSIONS: The burden of disease at sites other than the head and neck appears to be underreported in the literature and greatly affects quality of life. Differentiation between the clinical diagnoses has little prognostic or clinical utility in genetic counseling, even within individuals from the same family. Thus, we suggest an encompassing diagnosis of "CYLD cutaneous syndrome." Finally, the clinical distribution of tumors suggests that hormonal factors may play an important role in tumor induction in these patients.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_026

Tumor mapping in 2 large multigenerational families with CYLD mutations: implications for disease management and tumor induction. OBJECTIVES: To comprehensively ascertain the extent and severity of clinical features in affected individuals from 2 large families with proven heterozygous mutations in the CYLD locus and to correlate these findings with the 3 appendageal tumor predisposition syndromes (familial cylindromatosis, Brooke-Spiegler syndrome, and multiple familial trichoepitheliomas) known to be associated with such germline mutations. DESIGN: Interfamilial and intrafamilial observational study. SETTING: Tertiary genetic and dermatology referral center. PARTICIPANTS: Thirty-four individuals recruited from 2 large multigenerational families with CYLD mutations. Clinical details, history, and tumor maps were obtained from all participants; in 18, the information was corroborated by detailed clinical examination. MAIN OUTCOME MEASURES: Tumor density, distribution and histologic findings, associated medical conditions, patient symptoms, and impact of disease on quality of life. RESULTS: The severity of penetrance and phenotype varied within families. Although an approximately equal female to male predisposition was noted, 5 women and 1 man (of 26 patients surveyed [23%]) had undergone total scalp removal. The average age at onset was 16 years (range, 8-30 years). Symptoms reported by affected patients included painful tumors (in 12 of 23 patients [52%] who answered the question), conductive deafness, and sexual dysfunction. Of the 26 surveyed patients, tumors were noted on the scalp in 21 (81%), on the trunk in 18 (69%), and in the pubic area in 11 (42%). Tumor mapping provided clinical evidence that correlated with hormonally stimulated hair follicles being particularly vulnerable to loss of heterozygosity and tumor induction. CONCLUSIONS: The burden of disease at sites other than the head and neck appears to be underreported in the literature and greatly affects quality of life. Differentiation between the clinical diagnoses has little prognostic or clinical utility in genetic counseling, even within individuals from the same family. Thus, we suggest an encompassing diagnosis of "CYLD cutaneous syndrome." Finally, the clinical distribution of tumors suggests that hormonal factors may play an important role in tumor induction in these patients.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_027

Tumor mapping in 2 large multigenerational families with CYLD mutations: implications for disease management and tumor induction. OBJECTIVES: To comprehensively ascertain the extent and severity of clinical features in affected individuals from 2 large families with proven heterozygous mutations in the CYLD locus and to correlate these findings with the 3 appendageal tumor predisposition syndromes (familial cylindromatosis, Brooke-Spiegler syndrome, and multiple familial trichoepitheliomas) known to be associated with such germline mutations. DESIGN: Interfamilial and intrafamilial observational study. SETTING: Tertiary genetic and dermatology referral center. PARTICIPANTS: Thirty-four individuals recruited from 2 large multigenerational families with CYLD mutations. Clinical details, history, and tumor maps were obtained from all participants; in 18, the information was corroborated by detailed clinical examination. MAIN OUTCOME MEASURES: Tumor density, distribution and histologic findings, associated medical conditions, patient symptoms, and impact of disease on quality of life. RESULTS: The severity of penetrance and phenotype varied within families. Although an approximately equal female to male predisposition was noted, 5 women and 1 man (of 26 patients surveyed [23%]) had undergone total scalp removal. The average age at onset was 16 years (range, 8-30 years). Symptoms reported by affected patients included painful tumors (in 12 of 23 patients [52%] who answered the question), conductive deafness, and sexual dysfunction. Of the 26 surveyed patients, tumors were noted on the scalp in 21 (81%), on the trunk in 18 (69%), and in the pubic area in 11 (42%). Tumor mapping provided clinical evidence that correlated with hormonally stimulated hair follicles being particularly vulnerable to loss of heterozygosity and tumor induction. CONCLUSIONS: The burden of disease at sites other than the head and neck appears to be underreported in the literature and greatly affects quality of life. Differentiation between the clinical diagnoses has little prognostic or clinical utility in genetic counseling, even within individuals from the same family. Thus, we suggest an encompassing diagnosis of "CYLD cutaneous syndrome." Finally, the clinical distribution of tumors suggests that hormonal factors may play an important role in tumor induction in these patients.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_028

A case of Brooke-Spiegler syndrome with a novel germline deep intronic mutation in the CYLD gene leading to intronic exonization, diverse somatic mutations, and unusual histology. We present a case of Brooke-Spiegler syndrome with a germline deep intronic mutation in the CYLD gene leading to intronic exonization. Additionally, diverse somatic mutations were identified, namely loss of heterozygosity, a recurrent nonsense mutation, and a sequence mutation causing exon skipping. These somatic aberrations were identified in 4 different cylindromas that had been removed from the patient. Additionally, we microscopically studied a spiradenocylindroma that showed unusual histology, including foci of follicular differentiation. A deep intronic mutation resulting in exonization and a somatic sequence mutations causing exon skipping are hitherto unreported genetic mechanisms involving the CYLD gene in patients with Brooke-Spiegler syndrome.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_030

A case of Brooke-Spiegler syndrome with a novel germline deep intronic mutation in the CYLD gene leading to intronic exonization, diverse somatic mutations, and unusual histology. We present a case of Brooke-Spiegler syndrome with a germline deep intronic mutation in the CYLD gene leading to intronic exonization. Additionally, diverse somatic mutations were identified, namely loss of heterozygosity, a recurrent nonsense mutation, and a sequence mutation causing exon skipping. These somatic aberrations were identified in 4 different cylindromas that had been removed from the patient. Additionally, we microscopically studied a spiradenocylindroma that showed unusual histology, including foci of follicular differentiation. A deep intronic mutation resulting in exonization and a somatic sequence mutations causing exon skipping are hitherto unreported genetic mechanisms involving the CYLD gene in patients with Brooke-Spiegler syndrome.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_031

A case of Brooke-Spiegler syndrome with a novel germline deep intronic mutation in the CYLD gene leading to intronic exonization, diverse somatic mutations, and unusual histology. We present a case of Brooke-Spiegler syndrome with a germline deep intronic mutation in the CYLD gene leading to intronic exonization. Additionally, diverse somatic mutations were identified, namely loss of heterozygosity, a recurrent nonsense mutation, and a sequence mutation causing exon skipping. These somatic aberrations were identified in 4 different cylindromas that had been removed from the patient. Additionally, we microscopically studied a spiradenocylindroma that showed unusual histology, including foci of follicular differentiation. A deep intronic mutation resulting in exonization and a somatic sequence mutations causing exon skipping are hitherto unreported genetic mechanisms involving the CYLD gene in patients with Brooke-Spiegler syndrome.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_032

A novel splicing mutation of the CYLD gene in a Taiwanese family with multiple familial trichoepithelioma. Multiple familial trichoepithelioma (MFT) is an autosomal dominant disease characterized by numerous skin-coloured papules on the central face. Mutations in the CYLD gene, which is also the gene responsible for familial cylindromatosis, have been reported recently. Recent studies indicate that CYLD is a tumour-suppressor gene. The CYLD protein is a negative regulator of the activation of transcription factor nuclear factor-kappaB, and loss of CYLD contributes to oncogenesis. We report a novel splicing mutation (IVS12 + 1 G-->A) in the CYLD gene in a Taiwanese pedigree with MFT, and discuss new developments in treatment options.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_033

A novel splicing mutation of the CYLD gene in a Taiwanese family with multiple familial trichoepithelioma. Multiple familial trichoepithelioma (MFT) is an autosomal dominant disease characterized by numerous skin-coloured papules on the central face. Mutations in the CYLD gene, which is also the gene responsible for familial cylindromatosis, have been reported recently. Recent studies indicate that CYLD is a tumour-suppressor gene. The CYLD protein is a negative regulator of the activation of transcription factor nuclear factor-kappaB, and loss of CYLD contributes to oncogenesis. We report a novel splicing mutation (IVS12 + 1 G-->A) in the CYLD gene in a Taiwanese pedigree with MFT, and discuss new developments in treatment options.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_034

Five new CYLD mutations in skin appendage tumors and evidence that aspartic acid 681 in CYLD is essential for deubiquitinase activity. Brooke-Spiegler syndrome, familial cylindromatosis, and familial trichoepithelioma are autosomal-dominant genetic predispositions for benign tumors of skin appendages caused by mutations in the CYLD gene localized on chromosome 16q12-q13. The encoded protein functions as ubiquitin-specific protease (UBP), which negatively regulates NF-kappaB and c-Jun N-terminal kinase (JNK) signaling. We investigated five families affected with these skin neoplasms and identified four premature stop codons and the novel missense mutation D681G in a family in which 11 of 12 investigated tumors were trichoepitheliomas. CYLD protein harboring this missense mutation had a significant reduced ability to inhibit TNF receptor-associated factor (TRAF)2- and TRAF6-mediated NF-kappaB activation, tumor necrosis factor-alpha (TNFalpha)-induced JNK signaling, and to deubiquitinate TRAF2. CYLD-D681G was coimmunoprecipitated by TRAF2, but was unable to cleave K63-linked polyubiquitin chains. Aspartic acid 681 is highly conserved in CYLD homologues and other members of the UBP family, but does not belong to the Cys and His boxes providing the CYLD catalytic triad (Cys601, His871, and Asp889). As reported previously, the homologous residue D295 of HAUSP/USP-7 forms a hydrogen bond with the C-terminal end of ubiquitin and is important for the enzymatic activity. These results underline that D681 in CYLD is required for cleavage of K63-linked polyubiquitin chains.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_036

Diverse phenotype of Brooke-Spiegler syndrome associated with a nonsense mutation in the CYLD tumor suppressor gene. Brooke-Spiegler syndrome (BSS) is an autosomal dominant disease characterized by cylindromas, trichoepitheliomas and occasionally spiradenomas. The disease gene was mapped to 16q12-13, and mutations in the CYLD gene were identified in families with BSS. In the present report, we describe a large consanguineous Chinese family with BSS showing an intra-family phenotypic variability. Clinically, some affected individuals only revealed discrete small skin-coloured tumors whereas the proband showed an expansion of multiple large tumors on the back of nose and numerous dome-shaped papules on her scalp. Histologically, both trichoepitheliomas and cylindromas were found in the affected individuals. By sequence analysis, we identified a recurrent mutation 2272C>T (R758X) of the CYLD gene in the affected individuals of this family, which was previously identified in other ethnic families with familial cylindromatosis. Our result provided additional information for phenotype-genotype correlation in BSS.

Which pathological conditions are caused by mutations in the CYLD gene?

533c3af6c45e13371400000d_038

Cushing syndrome. Cushing syndrome is the constellation of signs and symptoms caused by protracted exposure to glucocorticoids. The most common cause of Cushing syndrome in children and adolescents is exogenous administration of glucocorticoids. Presenting features commonly include weight gain, growth retardation, hirsutism, obesity, striae, acne and hypertension. Almost invariably, linear growth is severely diminished, a factor which may be useful in differentiating between childhood obesity and Cushing syndrome. Diagnostic approaches are based on distinguishing between adrenocorticotropic hormone (ACTH)-dependent and ACTH-independent etiologies, and consideration of the most likely diagnosis by age. Treatment modality is dependent upon etiology. After cure, important components of care include attention to linear growth, pubertal progression and body composition.

Which are the common symptoms of Cushing's syndrome?

571f3b320fd6f91b68000007_001

Cushing syndrome. Cushing syndrome is the constellation of signs and symptoms caused by protracted exposure to glucocorticoids. The most common cause of Cushing syndrome in children and adolescents is exogenous administration of glucocorticoids. Presenting features commonly include weight gain, growth retardation, hirsutism, obesity, striae, acne and hypertension. Almost invariably, linear growth is severely diminished, a factor which may be useful in differentiating between childhood obesity and Cushing syndrome. Diagnostic approaches are based on distinguishing between adrenocorticotropic hormone (ACTH)-dependent and ACTH-independent etiologies, and consideration of the most likely diagnosis by age. Treatment modality is dependent upon etiology. After cure, important components of care include attention to linear growth, pubertal progression and body composition.

Which are the common symptoms of Cushing's syndrome?

571f3b320fd6f91b68000007_002

Cushing syndrome. Cushing syndrome is the constellation of signs and symptoms caused by protracted exposure to glucocorticoids. The most common cause of Cushing syndrome in children and adolescents is exogenous administration of glucocorticoids. Presenting features commonly include weight gain, growth retardation, hirsutism, obesity, striae, acne and hypertension. Almost invariably, linear growth is severely diminished, a factor which may be useful in differentiating between childhood obesity and Cushing syndrome. Diagnostic approaches are based on distinguishing between adrenocorticotropic hormone (ACTH)-dependent and ACTH-independent etiologies, and consideration of the most likely diagnosis by age. Treatment modality is dependent upon etiology. After cure, important components of care include attention to linear growth, pubertal progression and body composition.

Which are the common symptoms of Cushing's syndrome?

571f3b320fd6f91b68000007_003

Cushing syndrome. Cushing syndrome is the constellation of signs and symptoms caused by protracted exposure to glucocorticoids. The most common cause of Cushing syndrome in children and adolescents is exogenous administration of glucocorticoids. Presenting features commonly include weight gain, growth retardation, hirsutism, obesity, striae, acne and hypertension. Almost invariably, linear growth is severely diminished, a factor which may be useful in differentiating between childhood obesity and Cushing syndrome. Diagnostic approaches are based on distinguishing between adrenocorticotropic hormone (ACTH)-dependent and ACTH-independent etiologies, and consideration of the most likely diagnosis by age. Treatment modality is dependent upon etiology. After cure, important components of care include attention to linear growth, pubertal progression and body composition.

Which are the common symptoms of Cushing's syndrome?

571f3b320fd6f91b68000007_004

Cushing syndrome. Cushing syndrome is the constellation of signs and symptoms caused by protracted exposure to glucocorticoids. The most common cause of Cushing syndrome in children and adolescents is exogenous administration of glucocorticoids. Presenting features commonly include weight gain, growth retardation, hirsutism, obesity, striae, acne and hypertension. Almost invariably, linear growth is severely diminished, a factor which may be useful in differentiating between childhood obesity and Cushing syndrome. Diagnostic approaches are based on distinguishing between adrenocorticotropic hormone (ACTH)-dependent and ACTH-independent etiologies, and consideration of the most likely diagnosis by age. Treatment modality is dependent upon etiology. After cure, important components of care include attention to linear growth, pubertal progression and body composition.

Which are the common symptoms of Cushing's syndrome?

571f3b320fd6f91b68000007_005

Cushing syndrome. Cushing syndrome is the constellation of signs and symptoms caused by protracted exposure to glucocorticoids. The most common cause of Cushing syndrome in children and adolescents is exogenous administration of glucocorticoids. Presenting features commonly include weight gain, growth retardation, hirsutism, obesity, striae, acne and hypertension. Almost invariably, linear growth is severely diminished, a factor which may be useful in differentiating between childhood obesity and Cushing syndrome. Diagnostic approaches are based on distinguishing between adrenocorticotropic hormone (ACTH)-dependent and ACTH-independent etiologies, and consideration of the most likely diagnosis by age. Treatment modality is dependent upon etiology. After cure, important components of care include attention to linear growth, pubertal progression and body composition.

Which are the common symptoms of Cushing's syndrome?

571f3b320fd6f91b68000007_006

Cushing syndrome. Cushing syndrome is the constellation of signs and symptoms caused by protracted exposure to glucocorticoids. The most common cause of Cushing syndrome in children and adolescents is exogenous administration of glucocorticoids. Presenting features commonly include weight gain, growth retardation, hirsutism, obesity, striae, acne and hypertension. Almost invariably, linear growth is severely diminished, a factor which may be useful in differentiating between childhood obesity and Cushing syndrome. Diagnostic approaches are based on distinguishing between adrenocorticotropic hormone (ACTH)-dependent and ACTH-independent etiologies, and consideration of the most likely diagnosis by age. Treatment modality is dependent upon etiology. After cure, important components of care include attention to linear growth, pubertal progression and body composition.

Which are the common symptoms of Cushing's syndrome?

571f3b320fd6f91b68000007_007

An exploratory randomised double-blind and placebo-controlled phase 2 study of a combination of baclofen, naltrexone and sorbitol (PXT3003) in patients with Charcot-Marie-Tooth disease type 1A. BACKGROUND: Charcot-Marie-Tooth type 1A disease (CMT1A) is a rare orphan inherited neuropathy caused by an autosomal dominant duplication of a gene encoding for the structural myelin protein PMP22, which induces abnormal Schwann cell differentiation and dysmyelination, eventually leading to axonal suffering then loss and muscle wasting. We favour the idea that diseases can be more efficiently treated when targeting multiple disease-relevant pathways. In CMT1A patients, we therefore tested the potential of PXT3003, a low-dose combination of three already approved compounds (baclofen, naltrexone and sorbitol). Our study conceptually builds on preclinical experiments highlighting a pleiotropic mechanism of action that includes downregulation of PMP22. The primary objective was to assess safety and tolerability of PXT3003. The secondary objective aimed at an exploratory analysis of efficacy of PXT3003 in CMT1A, to be used for designing next clinical development stages (Phase 2b/3). METHODS: 80 adult patients with mild-to-moderate CMT1A received in double-blind for 1 year Placebo or one of the three increasing doses of PXT3003 tested, in four equal groups. Safety and tolerability were assessed with the incidence of related adverse events. Efficacy was assessed using the Charcot-Marie-Tooth Neuropathy Score (CMTNS) and the Overall Neuropathy Limitations Scale (ONLS) as main endpoints, as well as various clinical and electrophysiological outcomes. RESULTS: This trial confirmed the safety and tolerability of PXT3003. The highest dose (HD) showed consistent evidence of improvement beyond stabilization. CMTNS and ONLS, with a significant improvement of respectively of 8% (0.4% - 16.2%) and 12.1% (2% - 23.2%) in the HD group versus the pool of all other groups, appear to be the most sensitive clinical endpoints to treatment despite their quasi-stability over one year under Placebo. Patients who did not deteriorate over one year were significantly more frequent in the HD group. CONCLUSIONS: These results confirm that PXT3003 deserves further investigation in adults and could greatly benefit CMT1A-diagnosed children, usually less affected than adults. TRIAL REGISTRATION: EudraCT Number: 2010-023097-40. ClinicalTrials.gov Identifier: NCT01401257. The Committee for Orphan Medicinal Products issued in February 2014 a positive opinion on the application for orphan designation for PXT3003 (EMA/OD/193/13).

List genes that have been found mutated in CMT1A (Charcot-Marie-Tooth disease type 1 A).

54d65b6b3706e8952800000c_001

Soluble neuregulin-1 modulates disease pathogenesis in rodent models of Charcot-Marie-Tooth disease 1A. Duplication of the gene encoding the peripheral myelin protein of 22 kDa (PMP22) underlies the most common inherited neuropathy, Charcot-Marie-Tooth 1A (CMT1A), a disease without a known cure. Although demyelination represents a characteristic feature, the clinical phenotype of CMT1A is determined by the degree of axonal loss, and patients suffer from progressive muscle weakness and impaired sensation. CMT1A disease manifests within the first two decades of life, and walking disabilities, foot deformities and electrophysiological abnormalities are already present in childhood. Here, we show in Pmp22-transgenic rodent models of CMT1A that Schwann cells acquire a persistent differentiation defect during early postnatal development, caused by imbalanced activity of the PI3K-Akt and the Mek-Erk signaling pathways. We demonstrate that enhanced PI3K-Akt signaling by axonally overexpressed neuregulin-1 (NRG1) type I drives diseased Schwann cells toward differentiation and preserves peripheral nerve axons. Notably, in a preclinical experimental therapy using a CMT1A rat model, when treatment is restricted to early postnatal development, soluble NRG1 effectively overcomes impaired peripheral nerve development and restores axon survival into adulthood. Our findings suggest a model in which Schwann cell differentiation within a limited time window is crucial for the long-term maintenance of axonal support.

List genes that have been found mutated in CMT1A (Charcot-Marie-Tooth disease type 1 A).

54d65b6b3706e8952800000c_002

Mutation analysis of MFN2, GJB1, MPZ and PMP22 in Italian patients with axonal Charcot-Marie-Tooth disease. Charcot-Marie-Tooth (CMT) diseases include a group of clinically heterogeneous inherited neuropathies subdivided into demyelinating (CMT1), axonal (CMT2) and intermediate CMT forms. CMTs are associated with different genes, although mutations in some of these genes may cause both clinical pictures. To date, more than 50 CMT genes have been identified, but more than half of the cases are due to mutations in MFN2, MPZ, GJB1 and PMP22. The aim of this study was to estimate the frequency of disease mutations of these four genes in the axonal form of CMT in order to evaluate their effectiveness in the molecular diagnosis of CMT2 patients. A cohort of 38 CMT2 Italian subjects was screened for mutations in the MFN2, MPZ and GJB1 genes by direct sequencing and for PMP22 rearrangements using the MLPA technique. Overall, we identified 15 mutations, 8 of which were novel: 11 mutations (28.9 %) were in the MFN2 gene, 2 (5.3 %) in MPZ and 2 (5.3 %) in PMP22. No mutations were found in GJB1. Two patients showed rearrangements in the PMP22 gene, which is commonly associated with CMT1 or HNPP phenotypes thus usually not tested in CMT2 patients. By including this gene in the analysis, we reached a molecular diagnosis rate of 39.5 %, which is one of the highest reported in the literature. Our findings confirm the MFN2 gene as the most common cause of CMT2 and suggest that PMP22 rearrangements should be considered in the molecular diagnosis of CMT2 patients.

List genes that have been found mutated in CMT1A (Charcot-Marie-Tooth disease type 1 A).

54d65b6b3706e8952800000c_003

Rer1 and calnexin regulate endoplasmic reticulum retention of a peripheral myelin protein 22 mutant that causes type 1A Charcot-Marie-Tooth disease. Peripheral myelin protein 22 (PMP22) resides in the plasma membrane and is required for myelin formation in the peripheral nervous system. Many PMP22 mutants accumulate in excess in the endoplasmic reticulum (ER) and lead to the inherited neuropathies of Charcot-Marie-Tooth (CMT) disease. However, the mechanism through which PMP22 mutants accumulate in the ER is unknown. Here, we studied the quality control mechanisms for the PMP22 mutants L16P and G150D, which were originally identified in mice and patients with CMT. We found that the ER-localised ubiquitin ligase Hrd1/SYVN1 mediates ER-associated degradation (ERAD) of PMP22(L16P) and PMP22(G150D), and another ubiquitin ligase, gp78/AMFR, mediates ERAD of PMP22(G150D) as well. We also found that PMP22(L16P), but not PMP22(G150D), is partly released from the ER by loss of Rer1, which is a Golgi-localised sorting receptor for ER retrieval. Rer1 interacts with the wild-type and mutant forms of PMP22. Interestingly, release of PMP22(L16P) from the ER was more prominent with simultaneous knockdown of Rer1 and the ER-localised chaperone calnexin than with the knockdown of each gene. These results suggest that CMT disease-related PMP22(L16P) is trapped in the ER by calnexin-dependent ER retention and Rer1-mediated early Golgi retrieval systems and partly degraded by the Hrd1-mediated ERAD system.

List genes that have been found mutated in CMT1A (Charcot-Marie-Tooth disease type 1 A).

54d65b6b3706e8952800000c_004

Computational Analysis Reveals the Association of Threonine 118 Methionine Mutation in PMP22 Resulting in CMT-1A. The T118M mutation in PMP22 gene is associated with Charcot Marie Tooth, type 1A (CMT1A). CMT1A is a form of Charcot-Marie-Tooth disease, the most common inherited disorder of the peripheral nervous system. Mutations in CMT related disorder are seen to increase the stability of the protein resulting in the diseased state. We performed SNP analysis for all the nsSNPs of PMP22 protein and carried out molecular dynamics simulation for T118M mutation to compare the stability difference between the wild type protein structure and the mutant protein structure. The mutation T118M resulted in the overall increase in the stability of the mutant protein. The superimposed structure shows marked structural variation between the wild type and the mutant protein structures.

List genes that have been found mutated in CMT1A (Charcot-Marie-Tooth disease type 1 A).

54d65b6b3706e8952800000c_005

Charcot-Marie-Tooth disease: frequency of genetic subtypes in a Southern Italy population. The objective of this study is to assess the genetic distribution of Charcot-Marie-Tooth (CMT) disease in Campania, a region of Southern Italy. We analyzed a cohort of 197 index cases and reported the type and frequency of mutations for the whole CMT population and for each electrophysiological group (CMT1, CMT2, and hereditary neuropathy with susceptibility to pressure palsies [HNPP]) and for familial and isolated CMT cases. Genetic diagnosis was achieved in 148 patients (75.1%) with a higher success rate in HNPP and CMT1 than CMT2. Only four genes (PMP22, GJB1, MPZ, and GDAP1) accounted for 92% of all genetically confirmed CMT cases. In CMT1, PMP22 duplication was the most common mutation while the second gene in order of frequency was MPZ in familial and SH3TC2 in isolated cases. In CMT2, GJB1 was the most frequent mutated gene and GJB1 with GDAP1 accounted for almost 3/4 of genetically defined CMT2 patients. The first gene in order of frequency was GJB1 in familial and GDAP1 in isolated cases. In HNPP, the majority of patients harbored the PMP22 gene deletion. The novelty of our data is the relatively high frequency of SH3TC2 and GDAP1 mutations in demyelinating and axonal forms, respectively. These epidemiological data can help in panel design for our patients' population.

List genes that have been found mutated in CMT1A (Charcot-Marie-Tooth disease type 1 A).

54d65b6b3706e8952800000c_006

Charcot-Marie-Tooth disease: frequency of genetic subtypes in a Southern Italy population. The objective of this study is to assess the genetic distribution of Charcot-Marie-Tooth (CMT) disease in Campania, a region of Southern Italy. We analyzed a cohort of 197 index cases and reported the type and frequency of mutations for the whole CMT population and for each electrophysiological group (CMT1, CMT2, and hereditary neuropathy with susceptibility to pressure palsies [HNPP]) and for familial and isolated CMT cases. Genetic diagnosis was achieved in 148 patients (75.1%) with a higher success rate in HNPP and CMT1 than CMT2. Only four genes (PMP22, GJB1, MPZ, and GDAP1) accounted for 92% of all genetically confirmed CMT cases. In CMT1, PMP22 duplication was the most common mutation while the second gene in order of frequency was MPZ in familial and SH3TC2 in isolated cases. In CMT2, GJB1 was the most frequent mutated gene and GJB1 with GDAP1 accounted for almost 3/4 of genetically defined CMT2 patients. The first gene in order of frequency was GJB1 in familial and GDAP1 in isolated cases. In HNPP, the majority of patients harbored the PMP22 gene deletion. The novelty of our data is the relatively high frequency of SH3TC2 and GDAP1 mutations in demyelinating and axonal forms, respectively. These epidemiological data can help in panel design for our patients' population.

List genes that have been found mutated in CMT1A (Charcot-Marie-Tooth disease type 1 A).

54d65b6b3706e8952800000c_007

Charcot-Marie-Tooth disease: frequency of genetic subtypes in a Southern Italy population. The objective of this study is to assess the genetic distribution of Charcot-Marie-Tooth (CMT) disease in Campania, a region of Southern Italy. We analyzed a cohort of 197 index cases and reported the type and frequency of mutations for the whole CMT population and for each electrophysiological group (CMT1, CMT2, and hereditary neuropathy with susceptibility to pressure palsies [HNPP]) and for familial and isolated CMT cases. Genetic diagnosis was achieved in 148 patients (75.1%) with a higher success rate in HNPP and CMT1 than CMT2. Only four genes (PMP22, GJB1, MPZ, and GDAP1) accounted for 92% of all genetically confirmed CMT cases. In CMT1, PMP22 duplication was the most common mutation while the second gene in order of frequency was MPZ in familial and SH3TC2 in isolated cases. In CMT2, GJB1 was the most frequent mutated gene and GJB1 with GDAP1 accounted for almost 3/4 of genetically defined CMT2 patients. The first gene in order of frequency was GJB1 in familial and GDAP1 in isolated cases. In HNPP, the majority of patients harbored the PMP22 gene deletion. The novelty of our data is the relatively high frequency of SH3TC2 and GDAP1 mutations in demyelinating and axonal forms, respectively. These epidemiological data can help in panel design for our patients' population.

List genes that have been found mutated in CMT1A (Charcot-Marie-Tooth disease type 1 A).

54d65b6b3706e8952800000c_008

CMT subtypes and disease burden in patients enrolled in the Inherited Neuropathies Consortium natural history study: a cross-sectional analysis. BACKGROUND: The international Inherited Neuropathy Consortium (INC) was created with the goal of obtaining much needed natural history data for patients with Charcot-Marie-Tooth (CMT) disease. We analysed clinical and genetic data from patients in the INC to determine the distribution of CMT subtypes and the clinical impairment associated with them. METHODS: We analysed data from 1652 patients evaluated at 13 INC centres. The distribution of CMT subtypes and pathogenic genetic mutations were determined. The disease burden of all the mutations was assessed by the CMT Neuropathy Score (CMTNS) and CMT Examination Score (CMTES). RESULTS: 997 of the 1652 patients (60.4%) received a genetic diagnosis. The most common CMT subtypes were CMT1A/PMP22 duplication, CMT1X/GJB1 mutation, CMT2A/MFN2 mutation, CMT1B/MPZ mutation, and hereditary neuropathy with liability to pressure palsy/PMP22 deletion. These five subtypes of CMT accounted for 89.2% of all genetically confirmed mutations. Mean CMTNS for some but not all subtypes were similar to those previously reported. CONCLUSIONS: Our findings confirm that large numbers of patients with a representative variety of CMT subtypes have been enrolled and that the frequency of achieving a molecular diagnosis and distribution of the CMT subtypes reflects those previously reported. Measures of severity are similar, though not identical, to results from smaller series. This study confirms that it is possible to assess patients in a uniform way between international centres, which is critical for the planned natural history study and future clinical trials. These data will provide a representative baseline for longitudinal studies of CMT. CLINICAL TRIAL REGISTRATION: ID number NCT01193075.

List genes that have been found mutated in CMT1A (Charcot-Marie-Tooth disease type 1 A).

54d65b6b3706e8952800000c_009

Severe phenotypes in a Charcot-Marie-Tooth 1A patient with PMP22 triplication. Charcot-Marie-Tooth disease (CMT) is a genetically and clinically heterogeneous hereditary motor and sensory neuropathy signified by a distal symmetric polyneuropathy. The most frequent subtype is type 1A (CMT1A) caused by duplication in chromosome 17p12 that includes PMP22. This study reports a woman with a family history of CMT1A due to PMP22 duplication. However, she presented with a more severe phenotype than her sibling or ancestors and was found to have a PMP22 triplication instead of the duplication. This was caused by de novo mutation on her affected mother's duplication chromosome. Her lower limb magnetic resonance imaging revealed severe diffused atrophy and fatty replacement. However, her affected sister with typical PMP22 duplication showed almost intact lower limb. Triplication patient's median motor nerve conduction velocity was far lower compared with her sister. Her onset age was faster (8 years) than her sister (42 years). CMT1A triplication might be generated by a female-specific chromosomal rearrangement mechanism that is different from the frequent paternal-originated CMT1A duplication. It also suggests that the wide phenotypic variation of CMT1A might be partly caused by unstable genomic rearrangement, including PMP22 triplication.

List genes that have been found mutated in CMT1A (Charcot-Marie-Tooth disease type 1 A).

54d65b6b3706e8952800000c_010

Severe neonatal parechovirus infection and similarity with enterovirus infection. BACKGROUND: Enteroviruses (EV) are an important cause of neonatal disease including hepatitis, meningoencephalitis, and myocarditis that can lead to death or severe long-term sequelae. Less is known about severe neonatal infection caused by the parechoviruses (PeV) of which type 1 (PeV1) and type 2 (PeV2) were previously known as echovirus 22 and echovirus 23. They belong to the same family of Picornaviridae as the EV. Of the PeV, so far only PeV3 has been associated in 2 recent reports with severe neonatal infection including involvement of central nervous system. METHODS: We compared the clinical signs, diagnosis, laboratory data, cerebral imaging, and neurodevelopmental outcome of 11 neonates with PeV infection with 21 infants with EV infection treated in our hospital between 1994 and 2006. The diagnosis of EV infection or PeV infection was confirmed by a positive EV and/or PeV real time-polymerase chain reaction on blood, cerebrospinal fluid, (CSF) or stool or a viral culture of stool, nasopharyngeal swab, and/or CSF. RESULTS: The 32 infants presented with sepsis-like illness and the most frequent signs were: fever, seizures, irritability, rash, and feeding problems. All patients received antibiotic treatment. Eleven of 21 infants infected with EV and 7 of 11 infants infected with PeV were full-term. Differentiation between the infants infected with EV and PeV on the basis of fever, irritability, rash, and seizures was not possible. Myocarditis was exclusively seen in 4 patients infected by EV. Eight of 11 patients with a PeV infection had meningoencephalitis of whom only 1 infant developed pleocytosis in the CSF. Serum C-reactive protein and CSF protein values were significantly higher in infants with EV infection than in those with PeV infection. Cerebral imaging of all infants with EV or PeV cerebral infection showed mild to severe white matter abnormalities. In 1 infant with EV infection and 3 infants with PeV infection, neurodevelopmental delay occurred. Mortality and long-term sequelae were mainly associated with myocarditis in the infants who were infected with EV (4 of 21). CONCLUSIONS: It is not possible to distinguish neonatal PeV from EV infection on the basis of clinical signs. Neonates with PeV or EV infection present with sepsis-like illness and the most frequent signs are fever, seizures, irritability, rash, and feeding problems.

Which viruses are best known to cause myocarditis?

517a8c918ed59a060a000043_001

[Molecular biological virus identification in dilated cardiomyopathy]. UNLABELLED: Enteroviruses have been considered to be the most common cause of acute myocarditis and possible consequence of dilated cardiomyopathy. Some publications shed light to the role of other viruses in this disease as well. Our molecular investigation has demonstrated that adeno- and herpes viruses might also frequently occur in dilated cardiomyopathy. AIM: The aim of our study was to screen virus genomes in heart tissues from heart-transplanted patients to prove their possible role in the pathogenesis of dilated cardiomyopathy. METHODS: DNA and RNA were isolated from five regions of the heart muscle. Amplification for Adenovirus Type 3, Human Herpes Virus Type 6 and Enterovirus genomes were performed by nested-Polymerase Chain Reaction. Finally the virus-positive samples were direct sequenced. RESULTS: In 2 patients Adenovirus Type 3 and in 1 patient both Adenovirus Type 3 and Human Herpes Virus Type 6 were detected. No enteroviruses were found in any heart tissue. CONCLUSIONS: In our study the adenovirus genome was found to be the most frequent virus genome in explanted heart tissues. The identified viral sequences proved previous viral infection, which could have played a role in the development of dilated cardiomyopathy. Detection of different viruses in the myocardium by molecular biological examinations might contribute to adequate treatment of these patients.

Which viruses are best known to cause myocarditis?

517a8c918ed59a060a000043_002

[Molecular biological virus identification in dilated cardiomyopathy]. UNLABELLED: Enteroviruses have been considered to be the most common cause of acute myocarditis and possible consequence of dilated cardiomyopathy. Some publications shed light to the role of other viruses in this disease as well. Our molecular investigation has demonstrated that adeno- and herpes viruses might also frequently occur in dilated cardiomyopathy. AIM: The aim of our study was to screen virus genomes in heart tissues from heart-transplanted patients to prove their possible role in the pathogenesis of dilated cardiomyopathy. METHODS: DNA and RNA were isolated from five regions of the heart muscle. Amplification for Adenovirus Type 3, Human Herpes Virus Type 6 and Enterovirus genomes were performed by nested-Polymerase Chain Reaction. Finally the virus-positive samples were direct sequenced. RESULTS: In 2 patients Adenovirus Type 3 and in 1 patient both Adenovirus Type 3 and Human Herpes Virus Type 6 were detected. No enteroviruses were found in any heart tissue. CONCLUSIONS: In our study the adenovirus genome was found to be the most frequent virus genome in explanted heart tissues. The identified viral sequences proved previous viral infection, which could have played a role in the development of dilated cardiomyopathy. Detection of different viruses in the myocardium by molecular biological examinations might contribute to adequate treatment of these patients.

Which viruses are best known to cause myocarditis?

517a8c918ed59a060a000043_003

Coxsackie B3 virus can replicate in cultured human foetal heart cells and is inhibited by interferon. Coxsackie B viruses (types 1 to 5) are the most frequent reported cause of acute viral myocarditis. To study the pathogenesis of the disease at the cellular level, we simulated an infectious situation by infecting cultured human foetal heart cells with Coxsackie B3 (CB3) virus. Successful replication of this virus could be demonstrated by the presence of virus particles inside cultivated foetal myocytes together with high titres of progeny virus of 10(8) plaque-forming units (PFU) per millilitre culture medium. Within 9 h of infection networks of myocytes lost their ability to contract spontaneously followed by disintegration and replacement by overgrowing fibroblasts which survived the infection. These cells produced CB3 virus continuously over several months, indicating carrier state infection of human myocardial fibroblasts. Human fibroblasts interferon (IFN-beta) was found to act as a potent inhibitor of the replication of this virus. Virus yields could be reduced from 1.2 x 1.8 x 10(5) PFU/ml culture medium when human heart cells were incubated with IFN-beta 20 h prior to challenge with a high input multiplicity of 50 PFU of CB3 virus per cell, demonstrating the major protective role of IFN-beta in CB3 viral infection. It thus appear that IFN-beta might become useful as an antiviral agent in the treatment of Coxsackie myocarditis.

Which viruses are best known to cause myocarditis?

517a8c918ed59a060a000043_004

Surveying genetic variants and molecular phylogeny of cerebral cavernous malformation gene, CCM3/PDCD10. The three cerebral cavernous malformations (CCMs) genes namely CCM1/KRIT1, CCM2/MGC4607 and CCM3/PDCD10 have been identified for which mutations cause cerebral cavernous malformations. However, the protein products of these genes involved in forming CCM signaling, are still poorly understood imposing an urgent need to understand these genes and their signaling processes in details. So far involvement of CCM3/PDCD10 in the cavernous angioma has been characterized from biochemical and biophysical analyses. However, there is no comprehensive study illustrating the phylogenetic history and comprehensive genetic variants of CCM3/PDCD10. Herein, we explored the phylogenetic history and genetic variants of CCM3/PDCD10 gene. Synteny analyses revealed that CCM3/PDCD10 gene shared same genomic loci from Drosophila to human and the gene structure of CCM3/PDCD10 is conserved from human to Branchiostoma floridae for about 500 MYs with some changes in sea urchin and in insects. The conserved CCM3/PDCD10 is characterized by presence of indels in the N-terminal dimerization domain. We identified 951 CCM3/PDCD10 variants by analysis of 1092 human genomes with top three variation classes belongs to 84% SNPs, 6.9% insertions and 6.2% deletions. We identified 22 missense mutations in the human CCM3/PDCD10 protein and out of which three mutations are deleterious. We also identified four stop-codon gaining mutations at the positions E34*, E68*, E97* and E140*, respectively. This study is the first comprehensive analysis of the CCM3/PDCD10 gene based on phylogenetic origin and genetic variants. This study corroborates that the evolution of CCM proteins with tubular organization evolvements by endothelial cells.

Which genes have been associated with Cerebral Cavernous Malformation?

571f2b5bbb137a4b0c000010_001

Surveying genetic variants and molecular phylogeny of cerebral cavernous malformation gene, CCM3/PDCD10. The three cerebral cavernous malformations (CCMs) genes namely CCM1/KRIT1, CCM2/MGC4607 and CCM3/PDCD10 have been identified for which mutations cause cerebral cavernous malformations. However, the protein products of these genes involved in forming CCM signaling, are still poorly understood imposing an urgent need to understand these genes and their signaling processes in details. So far involvement of CCM3/PDCD10 in the cavernous angioma has been characterized from biochemical and biophysical analyses. However, there is no comprehensive study illustrating the phylogenetic history and comprehensive genetic variants of CCM3/PDCD10. Herein, we explored the phylogenetic history and genetic variants of CCM3/PDCD10 gene. Synteny analyses revealed that CCM3/PDCD10 gene shared same genomic loci from Drosophila to human and the gene structure of CCM3/PDCD10 is conserved from human to Branchiostoma floridae for about 500 MYs with some changes in sea urchin and in insects. The conserved CCM3/PDCD10 is characterized by presence of indels in the N-terminal dimerization domain. We identified 951 CCM3/PDCD10 variants by analysis of 1092 human genomes with top three variation classes belongs to 84% SNPs, 6.9% insertions and 6.2% deletions. We identified 22 missense mutations in the human CCM3/PDCD10 protein and out of which three mutations are deleterious. We also identified four stop-codon gaining mutations at the positions E34*, E68*, E97* and E140*, respectively. This study is the first comprehensive analysis of the CCM3/PDCD10 gene based on phylogenetic origin and genetic variants. This study corroborates that the evolution of CCM proteins with tubular organization evolvements by endothelial cells.

Which genes have been associated with Cerebral Cavernous Malformation?

571f2b5bbb137a4b0c000010_002

Surveying genetic variants and molecular phylogeny of cerebral cavernous malformation gene, CCM3/PDCD10. The three cerebral cavernous malformations (CCMs) genes namely CCM1/KRIT1, CCM2/MGC4607 and CCM3/PDCD10 have been identified for which mutations cause cerebral cavernous malformations. However, the protein products of these genes involved in forming CCM signaling, are still poorly understood imposing an urgent need to understand these genes and their signaling processes in details. So far involvement of CCM3/PDCD10 in the cavernous angioma has been characterized from biochemical and biophysical analyses. However, there is no comprehensive study illustrating the phylogenetic history and comprehensive genetic variants of CCM3/PDCD10. Herein, we explored the phylogenetic history and genetic variants of CCM3/PDCD10 gene. Synteny analyses revealed that CCM3/PDCD10 gene shared same genomic loci from Drosophila to human and the gene structure of CCM3/PDCD10 is conserved from human to Branchiostoma floridae for about 500 MYs with some changes in sea urchin and in insects. The conserved CCM3/PDCD10 is characterized by presence of indels in the N-terminal dimerization domain. We identified 951 CCM3/PDCD10 variants by analysis of 1092 human genomes with top three variation classes belongs to 84% SNPs, 6.9% insertions and 6.2% deletions. We identified 22 missense mutations in the human CCM3/PDCD10 protein and out of which three mutations are deleterious. We also identified four stop-codon gaining mutations at the positions E34*, E68*, E97* and E140*, respectively. This study is the first comprehensive analysis of the CCM3/PDCD10 gene based on phylogenetic origin and genetic variants. This study corroborates that the evolution of CCM proteins with tubular organization evolvements by endothelial cells.

Which genes have been associated with Cerebral Cavernous Malformation?

571f2b5bbb137a4b0c000010_003

Deep intronic KRIT1 mutation in a family with clinically silent multiple cerebral cavernous malformations. Loss-of-function mutations in CCM1/KRIT1, CCM2/MGC4607 and CCM3/PDCD10 genes are identified in the vast majority of familial cases with multiple cerebral cavernous malformations (CCMs). However, genomic DNA sequencing combined to large rearrangement screening fails to detect a mutation in 5% of those cases. We report a family in which CCM lesions were discovered fortuitously because of the investigation of a developmental delay in a boy. Three members of the family on three generations had typical multiple CCM lesions and no clinical signs related to CCM. No mutation was detected using genomic DNA sequencing and quantitative multiplex PCR of short fluorescent fragments (QMPSF). cDNA sequencing showed a 99-nucleotide insertion between exons 5 and 6 of CCM1, resulting from a mutation located deep into intron 5 (c.262+132_262+133del) that activates a cryptic splice site. This pseudoexon leads to a premature stop codon. These data highly suggest that deep intronic mutations explain part of the incomplete mutation detection rate in CCM patients and underline the importance of analyzing the cDNA to provide comprehensive CCM diagnostic tests. This kind of mutation may be responsible for apparent sporadic presentations due to a reduced penetrance.

Which genes have been associated with Cerebral Cavernous Malformation?

571f2b5bbb137a4b0c000010_004

Deep intronic KRIT1 mutation in a family with clinically silent multiple cerebral cavernous malformations. Loss-of-function mutations in CCM1/KRIT1, CCM2/MGC4607 and CCM3/PDCD10 genes are identified in the vast majority of familial cases with multiple cerebral cavernous malformations (CCMs). However, genomic DNA sequencing combined to large rearrangement screening fails to detect a mutation in 5% of those cases. We report a family in which CCM lesions were discovered fortuitously because of the investigation of a developmental delay in a boy. Three members of the family on three generations had typical multiple CCM lesions and no clinical signs related to CCM. No mutation was detected using genomic DNA sequencing and quantitative multiplex PCR of short fluorescent fragments (QMPSF). cDNA sequencing showed a 99-nucleotide insertion between exons 5 and 6 of CCM1, resulting from a mutation located deep into intron 5 (c.262+132_262+133del) that activates a cryptic splice site. This pseudoexon leads to a premature stop codon. These data highly suggest that deep intronic mutations explain part of the incomplete mutation detection rate in CCM patients and underline the importance of analyzing the cDNA to provide comprehensive CCM diagnostic tests. This kind of mutation may be responsible for apparent sporadic presentations due to a reduced penetrance.

Which genes have been associated with Cerebral Cavernous Malformation?

571f2b5bbb137a4b0c000010_005

Signaling pathways and the cerebral cavernous malformations proteins: lessons from structural biology. Cerebral cavernous malformations (CCM) are neurovascular dysplasias that result in mulberry-shaped lesions predominantly located in brain and spinal tissues. Mutations in three genes are associated with CCM. These genes encode for the proteins KRIT1/CCM1 (krev interaction trapped 1/cerebral cavernous malformations 1), cerebral cavernous malformations 2, osmosensing scaffold for MEKK3 (CCM2/malcavernin/OSM), and cerebral cavernous malformations 3/programmed cell death 10 (CCM3/PDCD10). There have been many significant recent advances in our understanding of the structure and function of these proteins, as well as in their roles in cellular signaling. Here, we provide an update on the current knowledge of the structure of the CCM proteins and their functions within cellular signaling, particularly in cellular adhesion complexes and signaling cascades. We go on to discuss subcellular localization of the CCM proteins, the formation and regulation of the CCM complex signaling platform, and current progress towards targeted therapy for CCM disease. Recent structural studies have begun to shed new light on CCM protein function, and we focus here on how these studies have helped inform the current understanding of these roles and how they may aid future studies into both CCM-related biology and disease mechanisms.

Which genes have been associated with Cerebral Cavernous Malformation?

571f2b5bbb137a4b0c000010_006

Signaling pathways and the cerebral cavernous malformations proteins: lessons from structural biology. Cerebral cavernous malformations (CCM) are neurovascular dysplasias that result in mulberry-shaped lesions predominantly located in brain and spinal tissues. Mutations in three genes are associated with CCM. These genes encode for the proteins KRIT1/CCM1 (krev interaction trapped 1/cerebral cavernous malformations 1), cerebral cavernous malformations 2, osmosensing scaffold for MEKK3 (CCM2/malcavernin/OSM), and cerebral cavernous malformations 3/programmed cell death 10 (CCM3/PDCD10). There have been many significant recent advances in our understanding of the structure and function of these proteins, as well as in their roles in cellular signaling. Here, we provide an update on the current knowledge of the structure of the CCM proteins and their functions within cellular signaling, particularly in cellular adhesion complexes and signaling cascades. We go on to discuss subcellular localization of the CCM proteins, the formation and regulation of the CCM complex signaling platform, and current progress towards targeted therapy for CCM disease. Recent structural studies have begun to shed new light on CCM protein function, and we focus here on how these studies have helped inform the current understanding of these roles and how they may aid future studies into both CCM-related biology and disease mechanisms.

Which genes have been associated with Cerebral Cavernous Malformation?

571f2b5bbb137a4b0c000010_007

Teaching neuroimages: hypomyelinating leukodystrophy with hypodontia due to POLR3B: look into a leukodystrophy's mouth. An 18-year-old German woman presented with progressive cerebellar ataxia since early childhood, delayed cognitive development, and hypogonadotropic hypogonadism. MRI demonstrated diffuse cerebral hypomyelination, cerebellar atrophy, and thin corpus callosum; X-ray revealed persistent milk teeth and hypoplastic crowns and roots (figure), indicative of 4H syndrome (hypomyelination, hypodontia, hypogonadotropic hypogonadism). POLR3B sequencing(1) revealed 2 compound heterozygous mutations (C527R [C.1579T>C] and the common ancestral V523E [C.1568T>A](2)).

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_001

Teaching neuroimages: hypomyelinating leukodystrophy with hypodontia due to POLR3B: look into a leukodystrophy's mouth. An 18-year-old German woman presented with progressive cerebellar ataxia since early childhood, delayed cognitive development, and hypogonadotropic hypogonadism. MRI demonstrated diffuse cerebral hypomyelination, cerebellar atrophy, and thin corpus callosum; X-ray revealed persistent milk teeth and hypoplastic crowns and roots (figure), indicative of 4H syndrome (hypomyelination, hypodontia, hypogonadotropic hypogonadism). POLR3B sequencing(1) revealed 2 compound heterozygous mutations (C527R [C.1579T>C] and the common ancestral V523E [C.1568T>A](2)).

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_002

Teaching neuroimages: hypomyelinating leukodystrophy with hypodontia due to POLR3B: look into a leukodystrophy's mouth. An 18-year-old German woman presented with progressive cerebellar ataxia since early childhood, delayed cognitive development, and hypogonadotropic hypogonadism. MRI demonstrated diffuse cerebral hypomyelination, cerebellar atrophy, and thin corpus callosum; X-ray revealed persistent milk teeth and hypoplastic crowns and roots (figure), indicative of 4H syndrome (hypomyelination, hypodontia, hypogonadotropic hypogonadism). POLR3B sequencing(1) revealed 2 compound heterozygous mutations (C527R [C.1579T>C] and the common ancestral V523E [C.1568T>A](2)).

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_003

Teaching neuroimages: hypomyelinating leukodystrophy with hypodontia due to POLR3B: look into a leukodystrophy's mouth. An 18-year-old German woman presented with progressive cerebellar ataxia since early childhood, delayed cognitive development, and hypogonadotropic hypogonadism. MRI demonstrated diffuse cerebral hypomyelination, cerebellar atrophy, and thin corpus callosum; X-ray revealed persistent milk teeth and hypoplastic crowns and roots (figure), indicative of 4H syndrome (hypomyelination, hypodontia, hypogonadotropic hypogonadism). POLR3B sequencing(1) revealed 2 compound heterozygous mutations (C527R [C.1579T>C] and the common ancestral V523E [C.1568T>A](2)).

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_004

An Indian boy with a novel leukodystrophy: 4H syndrome. 4H syndrome is a rare and distinct leukodystrophy characterized by hypomyelination, hypogonadotropic hypogonadism, and hypodontia. Detecting signs of pubertal growth failure and abnormal dentition offer the clues to the diagnosis. We present an Indian boy with this novel syndrome with previously unreported feature of bilateral undescended testes. We also provide a brief overview of all published cases.

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_005

An Indian boy with a novel leukodystrophy: 4H syndrome. 4H syndrome is a rare and distinct leukodystrophy characterized by hypomyelination, hypogonadotropic hypogonadism, and hypodontia. Detecting signs of pubertal growth failure and abnormal dentition offer the clues to the diagnosis. We present an Indian boy with this novel syndrome with previously unreported feature of bilateral undescended testes. We also provide a brief overview of all published cases.

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_006

An Indian boy with a novel leukodystrophy: 4H syndrome. 4H syndrome is a rare and distinct leukodystrophy characterized by hypomyelination, hypogonadotropic hypogonadism, and hypodontia. Detecting signs of pubertal growth failure and abnormal dentition offer the clues to the diagnosis. We present an Indian boy with this novel syndrome with previously unreported feature of bilateral undescended testes. We also provide a brief overview of all published cases.

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_007

More than hypomyelination in Pol-III disorder. The 4H syndrome (hypomyelination, hypodontia, hypogonadotropic hypogonadism) is a newly recognized leukodystrophy. The classical form is characterized by the association of hypomyelination, abnormal dentition, and hypogonadotropic hypogonadism, but the recent identification of 2 genes responsible for the syndrome demonstrates that these 3 main characteristics can be variably combined among "Pol-III (polymerase III)-related leukodystrophies." The pathophysiology of this group of diseases is still to be elucidated, and there are no neuropathologic descriptions of brain tissue. We report the clinical, neuroradiologic, and neuropathologic findings of a patient affected by 4H syndrome with confirmed POLR3A mutations. We found a marked loss of oligodendrocytes, varying in severity in different brain regions, and accompanied by severe loss of myelin, moderately severe loss of axons, and patchy perivascular regions of better preserved white matter. There was relatively mild white matter astrogliosis and microgliosis. A macrophage reaction involving viable normal-appearing oligodendroglia suggests the possibility of an immunologic process in this disorder. Cortical laminar astrogliosis and mineralization of Layers I and II in particular were present. Thus, despite the uniformly hypomyelinating pattern seen on magnetic resonance imaging, neuropathologic examination reveals a complex heterogeneous leukodystrophy with prominent neuroaxonal and glial involvement in this disorder.

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_008

More than hypomyelination in Pol-III disorder. The 4H syndrome (hypomyelination, hypodontia, hypogonadotropic hypogonadism) is a newly recognized leukodystrophy. The classical form is characterized by the association of hypomyelination, abnormal dentition, and hypogonadotropic hypogonadism, but the recent identification of 2 genes responsible for the syndrome demonstrates that these 3 main characteristics can be variably combined among "Pol-III (polymerase III)-related leukodystrophies." The pathophysiology of this group of diseases is still to be elucidated, and there are no neuropathologic descriptions of brain tissue. We report the clinical, neuroradiologic, and neuropathologic findings of a patient affected by 4H syndrome with confirmed POLR3A mutations. We found a marked loss of oligodendrocytes, varying in severity in different brain regions, and accompanied by severe loss of myelin, moderately severe loss of axons, and patchy perivascular regions of better preserved white matter. There was relatively mild white matter astrogliosis and microgliosis. A macrophage reaction involving viable normal-appearing oligodendroglia suggests the possibility of an immunologic process in this disorder. Cortical laminar astrogliosis and mineralization of Layers I and II in particular were present. Thus, despite the uniformly hypomyelinating pattern seen on magnetic resonance imaging, neuropathologic examination reveals a complex heterogeneous leukodystrophy with prominent neuroaxonal and glial involvement in this disorder.

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_009

More than hypomyelination in Pol-III disorder. The 4H syndrome (hypomyelination, hypodontia, hypogonadotropic hypogonadism) is a newly recognized leukodystrophy. The classical form is characterized by the association of hypomyelination, abnormal dentition, and hypogonadotropic hypogonadism, but the recent identification of 2 genes responsible for the syndrome demonstrates that these 3 main characteristics can be variably combined among "Pol-III (polymerase III)-related leukodystrophies." The pathophysiology of this group of diseases is still to be elucidated, and there are no neuropathologic descriptions of brain tissue. We report the clinical, neuroradiologic, and neuropathologic findings of a patient affected by 4H syndrome with confirmed POLR3A mutations. We found a marked loss of oligodendrocytes, varying in severity in different brain regions, and accompanied by severe loss of myelin, moderately severe loss of axons, and patchy perivascular regions of better preserved white matter. There was relatively mild white matter astrogliosis and microgliosis. A macrophage reaction involving viable normal-appearing oligodendroglia suggests the possibility of an immunologic process in this disorder. Cortical laminar astrogliosis and mineralization of Layers I and II in particular were present. Thus, despite the uniformly hypomyelinating pattern seen on magnetic resonance imaging, neuropathologic examination reveals a complex heterogeneous leukodystrophy with prominent neuroaxonal and glial involvement in this disorder.

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_010

4H syndrome with late-onset growth hormone deficiency caused by POLR3A mutations. OBJECTIVE: To report a novel clinical and genetic presentation of a patient with 4H syndrome, which is a recently described leukodystrophy syndrome characterized by ataxia, hypomyelination, hypodontia, and hypogonadotropic hypogonadism. DESIGN: Case report. SETTING: University teaching hospital. PATIENT: A 20-year-old male patient with 4H syndrome. RESULTS: The patient was found to have delayed tooth eruption and a late-onset growth hormone deficiency without overt growth failure. He was a compound heterozygote for the novel missense mutations R1005H and A1331T of POLR3A, which codes for the largest subunit of RNA polymerase III. CONCLUSION: This is the first report of this type of leukodystrophy from southeastern Europe, which suggests that POLR3A mutations should be suspected in patients with hypomyelination and various central nervous system - based endocrine abnormalities.

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_011

4H syndrome with late-onset growth hormone deficiency caused by POLR3A mutations. OBJECTIVE: To report a novel clinical and genetic presentation of a patient with 4H syndrome, which is a recently described leukodystrophy syndrome characterized by ataxia, hypomyelination, hypodontia, and hypogonadotropic hypogonadism. DESIGN: Case report. SETTING: University teaching hospital. PATIENT: A 20-year-old male patient with 4H syndrome. RESULTS: The patient was found to have delayed tooth eruption and a late-onset growth hormone deficiency without overt growth failure. He was a compound heterozygote for the novel missense mutations R1005H and A1331T of POLR3A, which codes for the largest subunit of RNA polymerase III. CONCLUSION: This is the first report of this type of leukodystrophy from southeastern Europe, which suggests that POLR3A mutations should be suspected in patients with hypomyelination and various central nervous system - based endocrine abnormalities.

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_012

4H syndrome with late-onset growth hormone deficiency caused by POLR3A mutations. OBJECTIVE: To report a novel clinical and genetic presentation of a patient with 4H syndrome, which is a recently described leukodystrophy syndrome characterized by ataxia, hypomyelination, hypodontia, and hypogonadotropic hypogonadism. DESIGN: Case report. SETTING: University teaching hospital. PATIENT: A 20-year-old male patient with 4H syndrome. RESULTS: The patient was found to have delayed tooth eruption and a late-onset growth hormone deficiency without overt growth failure. He was a compound heterozygote for the novel missense mutations R1005H and A1331T of POLR3A, which codes for the largest subunit of RNA polymerase III. CONCLUSION: This is the first report of this type of leukodystrophy from southeastern Europe, which suggests that POLR3A mutations should be suspected in patients with hypomyelination and various central nervous system - based endocrine abnormalities.

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_013

Mutations of POLR3A encoding a catalytic subunit of RNA polymerase Pol III cause a recessive hypomyelinating leukodystrophy. Leukodystrophies are a heterogeneous group of inherited neurodegenerative disorders characterized by abnormal white matter visible by brain imaging. It is estimated that at least 30% to 40% of individuals remain without a precise diagnosis despite extensive investigations. We mapped tremor-ataxia with central hypomyelination (TACH) to 10q22.3-23.1 in French-Canadian families and sequenced candidate genes within this interval. Two missense and one insertion mutations in five individuals with TACH were uncovered in POLR3A, which codes for the largest subunit of RNA polymerase III (Pol III). Because these families were mapped to the same locus as leukodystrophy with oligodontia (LO) and presented clinical and radiological overlap with individuals with hypomyelination, hypodontia and hypogonadotropic hypogonadism (4H) syndrome, we sequenced this gene in nine individuals with 4H and eight with LO. In total, 14 recessive mutations were found in 19 individuals with TACH, 4H, or LO, establishing that these leukodystrophies are allelic. No individual was found to carry two nonsense mutations. Immunoblots on 4H fibroblasts and on the autopsied brain of an individual diagnosed with 4H documented a significant decrease in POLR3A levels, and there was a more significant decrease in the cerebral white matter compared to that in the cortex. Pol III has a wide set of target RNA transcripts, including all nuclear-coded tRNA. We hypothesize that the decrease in POLR3A leads to dysregulation of the expression of certain Pol III targets and thereby perturbs cytoplasmic protein synthesis. This type of broad alteration in protein synthesis is predicted to occur in other leukoencephalopathies such as hypomyelinating leukodystrophy-3, caused by mutations in aminoacyl-tRNA synthetase complex-interacting multifunctional protein 1 (AIMP1).

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_014

Mutations of POLR3A encoding a catalytic subunit of RNA polymerase Pol III cause a recessive hypomyelinating leukodystrophy. Leukodystrophies are a heterogeneous group of inherited neurodegenerative disorders characterized by abnormal white matter visible by brain imaging. It is estimated that at least 30% to 40% of individuals remain without a precise diagnosis despite extensive investigations. We mapped tremor-ataxia with central hypomyelination (TACH) to 10q22.3-23.1 in French-Canadian families and sequenced candidate genes within this interval. Two missense and one insertion mutations in five individuals with TACH were uncovered in POLR3A, which codes for the largest subunit of RNA polymerase III (Pol III). Because these families were mapped to the same locus as leukodystrophy with oligodontia (LO) and presented clinical and radiological overlap with individuals with hypomyelination, hypodontia and hypogonadotropic hypogonadism (4H) syndrome, we sequenced this gene in nine individuals with 4H and eight with LO. In total, 14 recessive mutations were found in 19 individuals with TACH, 4H, or LO, establishing that these leukodystrophies are allelic. No individual was found to carry two nonsense mutations. Immunoblots on 4H fibroblasts and on the autopsied brain of an individual diagnosed with 4H documented a significant decrease in POLR3A levels, and there was a more significant decrease in the cerebral white matter compared to that in the cortex. Pol III has a wide set of target RNA transcripts, including all nuclear-coded tRNA. We hypothesize that the decrease in POLR3A leads to dysregulation of the expression of certain Pol III targets and thereby perturbs cytoplasmic protein synthesis. This type of broad alteration in protein synthesis is predicted to occur in other leukoencephalopathies such as hypomyelinating leukodystrophy-3, caused by mutations in aminoacyl-tRNA synthetase complex-interacting multifunctional protein 1 (AIMP1).

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_015

Mutations of POLR3A encoding a catalytic subunit of RNA polymerase Pol III cause a recessive hypomyelinating leukodystrophy. Leukodystrophies are a heterogeneous group of inherited neurodegenerative disorders characterized by abnormal white matter visible by brain imaging. It is estimated that at least 30% to 40% of individuals remain without a precise diagnosis despite extensive investigations. We mapped tremor-ataxia with central hypomyelination (TACH) to 10q22.3-23.1 in French-Canadian families and sequenced candidate genes within this interval. Two missense and one insertion mutations in five individuals with TACH were uncovered in POLR3A, which codes for the largest subunit of RNA polymerase III (Pol III). Because these families were mapped to the same locus as leukodystrophy with oligodontia (LO) and presented clinical and radiological overlap with individuals with hypomyelination, hypodontia and hypogonadotropic hypogonadism (4H) syndrome, we sequenced this gene in nine individuals with 4H and eight with LO. In total, 14 recessive mutations were found in 19 individuals with TACH, 4H, or LO, establishing that these leukodystrophies are allelic. No individual was found to carry two nonsense mutations. Immunoblots on 4H fibroblasts and on the autopsied brain of an individual diagnosed with 4H documented a significant decrease in POLR3A levels, and there was a more significant decrease in the cerebral white matter compared to that in the cortex. Pol III has a wide set of target RNA transcripts, including all nuclear-coded tRNA. We hypothesize that the decrease in POLR3A leads to dysregulation of the expression of certain Pol III targets and thereby perturbs cytoplasmic protein synthesis. This type of broad alteration in protein synthesis is predicted to occur in other leukoencephalopathies such as hypomyelinating leukodystrophy-3, caused by mutations in aminoacyl-tRNA synthetase complex-interacting multifunctional protein 1 (AIMP1).

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_016

[Central hypomyelination, hypogonadotrophic hypogonadism and hypodontia: a new leukodystrophy]. AIM: To report one patient with slowly progressive encephalopathy, ataxia, central hypomyelination, hypodontia and hypogonadotropic hypogonadism, the 4H syndrome. This clinical picture has been described recently and there are only four patients reported previously. CASE REPORT: A girl with a previously normal early psychomotor development, presented a slowly progressive deterioration since 15 months of age. Now, she is 14 years old, and has a severe cerebellar ataxia, with tremor and dysmetria. She can't neither walk nor remain standing alone. She has lost the sphincter control and has an immature expressive language. She has no puberal development and definitive hypodontia of upper central incisors. The brain magnetic resonance imaging shows a diffuse hypomyelination, that is confirmed with diffusion and spectroscopy studies. CONCLUSION: The hypomyelinating leukoencephalopathies are disorders with abnormally low amount of myelin. The diagnosis is difficult in most of the patients. The hypomyelinating leukoencephalopathies include classic disorders and new leukoencephalopathies, described in the past few years.

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_017

[Central hypomyelination, hypogonadotrophic hypogonadism and hypodontia: a new leukodystrophy]. AIM: To report one patient with slowly progressive encephalopathy, ataxia, central hypomyelination, hypodontia and hypogonadotropic hypogonadism, the 4H syndrome. This clinical picture has been described recently and there are only four patients reported previously. CASE REPORT: A girl with a previously normal early psychomotor development, presented a slowly progressive deterioration since 15 months of age. Now, she is 14 years old, and has a severe cerebellar ataxia, with tremor and dysmetria. She can't neither walk nor remain standing alone. She has lost the sphincter control and has an immature expressive language. She has no puberal development and definitive hypodontia of upper central incisors. The brain magnetic resonance imaging shows a diffuse hypomyelination, that is confirmed with diffusion and spectroscopy studies. CONCLUSION: The hypomyelinating leukoencephalopathies are disorders with abnormally low amount of myelin. The diagnosis is difficult in most of the patients. The hypomyelinating leukoencephalopathies include classic disorders and new leukoencephalopathies, described in the past few years.

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_018

[Central hypomyelination, hypogonadotrophic hypogonadism and hypodontia: a new leukodystrophy]. AIM: To report one patient with slowly progressive encephalopathy, ataxia, central hypomyelination, hypodontia and hypogonadotropic hypogonadism, the 4H syndrome. This clinical picture has been described recently and there are only four patients reported previously. CASE REPORT: A girl with a previously normal early psychomotor development, presented a slowly progressive deterioration since 15 months of age. Now, she is 14 years old, and has a severe cerebellar ataxia, with tremor and dysmetria. She can't neither walk nor remain standing alone. She has lost the sphincter control and has an immature expressive language. She has no puberal development and definitive hypodontia of upper central incisors. The brain magnetic resonance imaging shows a diffuse hypomyelination, that is confirmed with diffusion and spectroscopy studies. CONCLUSION: The hypomyelinating leukoencephalopathies are disorders with abnormally low amount of myelin. The diagnosis is difficult in most of the patients. The hypomyelinating leukoencephalopathies include classic disorders and new leukoencephalopathies, described in the past few years.

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_019

An Indian boy with a novel leukodystrophy: 4H syndrome. 4H syndrome is a rare and distinct leukodystrophy characterized by hypomyelination, hypogonadotropic hypogonadism, and hypodontia. Detecting signs of pubertal growth failure and abnormal dentition offer the clues to the diagnosis. We present an Indian boy with this novel syndrome with previously unreported feature of bilateral undescended testes. We also provide a brief overview of all published cases.

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_020

An Indian boy with a novel leukodystrophy: 4H syndrome. 4H syndrome is a rare and distinct leukodystrophy characterized by hypomyelination, hypogonadotropic hypogonadism, and hypodontia. Detecting signs of pubertal growth failure and abnormal dentition offer the clues to the diagnosis. We present an Indian boy with this novel syndrome with previously unreported feature of bilateral undescended testes. We also provide a brief overview of all published cases.

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_021

An Indian boy with a novel leukodystrophy: 4H syndrome. 4H syndrome is a rare and distinct leukodystrophy characterized by hypomyelination, hypogonadotropic hypogonadism, and hypodontia. Detecting signs of pubertal growth failure and abnormal dentition offer the clues to the diagnosis. We present an Indian boy with this novel syndrome with previously unreported feature of bilateral undescended testes. We also provide a brief overview of all published cases.

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_022

Mutations of POLR3A encoding a catalytic subunit of RNA polymerase Pol III cause a recessive hypomyelinating leukodystrophy. Leukodystrophies are a heterogeneous group of inherited neurodegenerative disorders characterized by abnormal white matter visible by brain imaging. It is estimated that at least 30% to 40% of individuals remain without a precise diagnosis despite extensive investigations. We mapped tremor-ataxia with central hypomyelination (TACH) to 10q22.3-23.1 in French-Canadian families and sequenced candidate genes within this interval. Two missense and one insertion mutations in five individuals with TACH were uncovered in POLR3A, which codes for the largest subunit of RNA polymerase III (Pol III). Because these families were mapped to the same locus as leukodystrophy with oligodontia (LO) and presented clinical and radiological overlap with individuals with hypomyelination, hypodontia and hypogonadotropic hypogonadism (4H) syndrome, we sequenced this gene in nine individuals with 4H and eight with LO. In total, 14 recessive mutations were found in 19 individuals with TACH, 4H, or LO, establishing that these leukodystrophies are allelic. No individual was found to carry two nonsense mutations. Immunoblots on 4H fibroblasts and on the autopsied brain of an individual diagnosed with 4H documented a significant decrease in POLR3A levels, and there was a more significant decrease in the cerebral white matter compared to that in the cortex. Pol III has a wide set of target RNA transcripts, including all nuclear-coded tRNA. We hypothesize that the decrease in POLR3A leads to dysregulation of the expression of certain Pol III targets and thereby perturbs cytoplasmic protein synthesis. This type of broad alteration in protein synthesis is predicted to occur in other leukoencephalopathies such as hypomyelinating leukodystrophy-3, caused by mutations in aminoacyl-tRNA synthetase complex-interacting multifunctional protein 1 (AIMP1).

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_023

Mutations of POLR3A encoding a catalytic subunit of RNA polymerase Pol III cause a recessive hypomyelinating leukodystrophy. Leukodystrophies are a heterogeneous group of inherited neurodegenerative disorders characterized by abnormal white matter visible by brain imaging. It is estimated that at least 30% to 40% of individuals remain without a precise diagnosis despite extensive investigations. We mapped tremor-ataxia with central hypomyelination (TACH) to 10q22.3-23.1 in French-Canadian families and sequenced candidate genes within this interval. Two missense and one insertion mutations in five individuals with TACH were uncovered in POLR3A, which codes for the largest subunit of RNA polymerase III (Pol III). Because these families were mapped to the same locus as leukodystrophy with oligodontia (LO) and presented clinical and radiological overlap with individuals with hypomyelination, hypodontia and hypogonadotropic hypogonadism (4H) syndrome, we sequenced this gene in nine individuals with 4H and eight with LO. In total, 14 recessive mutations were found in 19 individuals with TACH, 4H, or LO, establishing that these leukodystrophies are allelic. No individual was found to carry two nonsense mutations. Immunoblots on 4H fibroblasts and on the autopsied brain of an individual diagnosed with 4H documented a significant decrease in POLR3A levels, and there was a more significant decrease in the cerebral white matter compared to that in the cortex. Pol III has a wide set of target RNA transcripts, including all nuclear-coded tRNA. We hypothesize that the decrease in POLR3A leads to dysregulation of the expression of certain Pol III targets and thereby perturbs cytoplasmic protein synthesis. This type of broad alteration in protein synthesis is predicted to occur in other leukoencephalopathies such as hypomyelinating leukodystrophy-3, caused by mutations in aminoacyl-tRNA synthetase complex-interacting multifunctional protein 1 (AIMP1).

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_024

Mutations of POLR3A encoding a catalytic subunit of RNA polymerase Pol III cause a recessive hypomyelinating leukodystrophy. Leukodystrophies are a heterogeneous group of inherited neurodegenerative disorders characterized by abnormal white matter visible by brain imaging. It is estimated that at least 30% to 40% of individuals remain without a precise diagnosis despite extensive investigations. We mapped tremor-ataxia with central hypomyelination (TACH) to 10q22.3-23.1 in French-Canadian families and sequenced candidate genes within this interval. Two missense and one insertion mutations in five individuals with TACH were uncovered in POLR3A, which codes for the largest subunit of RNA polymerase III (Pol III). Because these families were mapped to the same locus as leukodystrophy with oligodontia (LO) and presented clinical and radiological overlap with individuals with hypomyelination, hypodontia and hypogonadotropic hypogonadism (4H) syndrome, we sequenced this gene in nine individuals with 4H and eight with LO. In total, 14 recessive mutations were found in 19 individuals with TACH, 4H, or LO, establishing that these leukodystrophies are allelic. No individual was found to carry two nonsense mutations. Immunoblots on 4H fibroblasts and on the autopsied brain of an individual diagnosed with 4H documented a significant decrease in POLR3A levels, and there was a more significant decrease in the cerebral white matter compared to that in the cortex. Pol III has a wide set of target RNA transcripts, including all nuclear-coded tRNA. We hypothesize that the decrease in POLR3A leads to dysregulation of the expression of certain Pol III targets and thereby perturbs cytoplasmic protein synthesis. This type of broad alteration in protein synthesis is predicted to occur in other leukoencephalopathies such as hypomyelinating leukodystrophy-3, caused by mutations in aminoacyl-tRNA synthetase complex-interacting multifunctional protein 1 (AIMP1).

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_025

Teaching neuroimages: hypomyelinating leukodystrophy with hypodontia due to POLR3B: look into a leukodystrophy's mouth. An 18-year-old German woman presented with progressive cerebellar ataxia since early childhood, delayed cognitive development, and hypogonadotropic hypogonadism. MRI demonstrated diffuse cerebral hypomyelination, cerebellar atrophy, and thin corpus callosum; X-ray revealed persistent milk teeth and hypoplastic crowns and roots (figure), indicative of 4H syndrome (hypomyelination, hypodontia, hypogonadotropic hypogonadism). POLR3B sequencing(1) revealed 2 compound heterozygous mutations (C527R [C.1579T>C] and the common ancestral V523E [C.1568T>A](2)).

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_026

Teaching neuroimages: hypomyelinating leukodystrophy with hypodontia due to POLR3B: look into a leukodystrophy's mouth. An 18-year-old German woman presented with progressive cerebellar ataxia since early childhood, delayed cognitive development, and hypogonadotropic hypogonadism. MRI demonstrated diffuse cerebral hypomyelination, cerebellar atrophy, and thin corpus callosum; X-ray revealed persistent milk teeth and hypoplastic crowns and roots (figure), indicative of 4H syndrome (hypomyelination, hypodontia, hypogonadotropic hypogonadism). POLR3B sequencing(1) revealed 2 compound heterozygous mutations (C527R [C.1579T>C] and the common ancestral V523E [C.1568T>A](2)).

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_027

Teaching neuroimages: hypomyelinating leukodystrophy with hypodontia due to POLR3B: look into a leukodystrophy's mouth. An 18-year-old German woman presented with progressive cerebellar ataxia since early childhood, delayed cognitive development, and hypogonadotropic hypogonadism. MRI demonstrated diffuse cerebral hypomyelination, cerebellar atrophy, and thin corpus callosum; X-ray revealed persistent milk teeth and hypoplastic crowns and roots (figure), indicative of 4H syndrome (hypomyelination, hypodontia, hypogonadotropic hypogonadism). POLR3B sequencing(1) revealed 2 compound heterozygous mutations (C527R [C.1579T>C] and the common ancestral V523E [C.1568T>A](2)).

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_028

Teaching neuroimages: hypomyelinating leukodystrophy with hypodontia due to POLR3B: look into a leukodystrophy's mouth. An 18-year-old German woman presented with progressive cerebellar ataxia since early childhood, delayed cognitive development, and hypogonadotropic hypogonadism. MRI demonstrated diffuse cerebral hypomyelination, cerebellar atrophy, and thin corpus callosum; X-ray revealed persistent milk teeth and hypoplastic crowns and roots (figure), indicative of 4H syndrome (hypomyelination, hypodontia, hypogonadotropic hypogonadism). POLR3B sequencing(1) revealed 2 compound heterozygous mutations (C527R [C.1579T>C] and the common ancestral V523E [C.1568T>A](2)).

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_029

Mutations of POLR3A encoding a catalytic subunit of RNA polymerase Pol III cause a recessive hypomyelinating leukodystrophy. Leukodystrophies are a heterogeneous group of inherited neurodegenerative disorders characterized by abnormal white matter visible by brain imaging. It is estimated that at least 30% to 40% of individuals remain without a precise diagnosis despite extensive investigations. We mapped tremor-ataxia with central hypomyelination (TACH) to 10q22.3-23.1 in French-Canadian families and sequenced candidate genes within this interval. Two missense and one insertion mutations in five individuals with TACH were uncovered in POLR3A, which codes for the largest subunit of RNA polymerase III (Pol III). Because these families were mapped to the same locus as leukodystrophy with oligodontia (LO) and presented clinical and radiological overlap with individuals with hypomyelination, hypodontia and hypogonadotropic hypogonadism (4H) syndrome, we sequenced this gene in nine individuals with 4H and eight with LO. In total, 14 recessive mutations were found in 19 individuals with TACH, 4H, or LO, establishing that these leukodystrophies are allelic. No individual was found to carry two nonsense mutations. Immunoblots on 4H fibroblasts and on the autopsied brain of an individual diagnosed with 4H documented a significant decrease in POLR3A levels, and there was a more significant decrease in the cerebral white matter compared to that in the cortex. Pol III has a wide set of target RNA transcripts, including all nuclear-coded tRNA. We hypothesize that the decrease in POLR3A leads to dysregulation of the expression of certain Pol III targets and thereby perturbs cytoplasmic protein synthesis. This type of broad alteration in protein synthesis is predicted to occur in other leukoencephalopathies such as hypomyelinating leukodystrophy-3, caused by mutations in aminoacyl-tRNA synthetase complex-interacting multifunctional protein 1 (AIMP1).

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_030

Mutations of POLR3A encoding a catalytic subunit of RNA polymerase Pol III cause a recessive hypomyelinating leukodystrophy. Leukodystrophies are a heterogeneous group of inherited neurodegenerative disorders characterized by abnormal white matter visible by brain imaging. It is estimated that at least 30% to 40% of individuals remain without a precise diagnosis despite extensive investigations. We mapped tremor-ataxia with central hypomyelination (TACH) to 10q22.3-23.1 in French-Canadian families and sequenced candidate genes within this interval. Two missense and one insertion mutations in five individuals with TACH were uncovered in POLR3A, which codes for the largest subunit of RNA polymerase III (Pol III). Because these families were mapped to the same locus as leukodystrophy with oligodontia (LO) and presented clinical and radiological overlap with individuals with hypomyelination, hypodontia and hypogonadotropic hypogonadism (4H) syndrome, we sequenced this gene in nine individuals with 4H and eight with LO. In total, 14 recessive mutations were found in 19 individuals with TACH, 4H, or LO, establishing that these leukodystrophies are allelic. No individual was found to carry two nonsense mutations. Immunoblots on 4H fibroblasts and on the autopsied brain of an individual diagnosed with 4H documented a significant decrease in POLR3A levels, and there was a more significant decrease in the cerebral white matter compared to that in the cortex. Pol III has a wide set of target RNA transcripts, including all nuclear-coded tRNA. We hypothesize that the decrease in POLR3A leads to dysregulation of the expression of certain Pol III targets and thereby perturbs cytoplasmic protein synthesis. This type of broad alteration in protein synthesis is predicted to occur in other leukoencephalopathies such as hypomyelinating leukodystrophy-3, caused by mutations in aminoacyl-tRNA synthetase complex-interacting multifunctional protein 1 (AIMP1).

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_031

Mutations of POLR3A encoding a catalytic subunit of RNA polymerase Pol III cause a recessive hypomyelinating leukodystrophy. Leukodystrophies are a heterogeneous group of inherited neurodegenerative disorders characterized by abnormal white matter visible by brain imaging. It is estimated that at least 30% to 40% of individuals remain without a precise diagnosis despite extensive investigations. We mapped tremor-ataxia with central hypomyelination (TACH) to 10q22.3-23.1 in French-Canadian families and sequenced candidate genes within this interval. Two missense and one insertion mutations in five individuals with TACH were uncovered in POLR3A, which codes for the largest subunit of RNA polymerase III (Pol III). Because these families were mapped to the same locus as leukodystrophy with oligodontia (LO) and presented clinical and radiological overlap with individuals with hypomyelination, hypodontia and hypogonadotropic hypogonadism (4H) syndrome, we sequenced this gene in nine individuals with 4H and eight with LO. In total, 14 recessive mutations were found in 19 individuals with TACH, 4H, or LO, establishing that these leukodystrophies are allelic. No individual was found to carry two nonsense mutations. Immunoblots on 4H fibroblasts and on the autopsied brain of an individual diagnosed with 4H documented a significant decrease in POLR3A levels, and there was a more significant decrease in the cerebral white matter compared to that in the cortex. Pol III has a wide set of target RNA transcripts, including all nuclear-coded tRNA. We hypothesize that the decrease in POLR3A leads to dysregulation of the expression of certain Pol III targets and thereby perturbs cytoplasmic protein synthesis. This type of broad alteration in protein synthesis is predicted to occur in other leukoencephalopathies such as hypomyelinating leukodystrophy-3, caused by mutations in aminoacyl-tRNA synthetase complex-interacting multifunctional protein 1 (AIMP1).

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_032

More than hypomyelination in Pol-III disorder. The 4H syndrome (hypomyelination, hypodontia, hypogonadotropic hypogonadism) is a newly recognized leukodystrophy. The classical form is characterized by the association of hypomyelination, abnormal dentition, and hypogonadotropic hypogonadism, but the recent identification of 2 genes responsible for the syndrome demonstrates that these 3 main characteristics can be variably combined among "Pol-III (polymerase III)-related leukodystrophies." The pathophysiology of this group of diseases is still to be elucidated, and there are no neuropathologic descriptions of brain tissue. We report the clinical, neuroradiologic, and neuropathologic findings of a patient affected by 4H syndrome with confirmed POLR3A mutations. We found a marked loss of oligodendrocytes, varying in severity in different brain regions, and accompanied by severe loss of myelin, moderately severe loss of axons, and patchy perivascular regions of better preserved white matter. There was relatively mild white matter astrogliosis and microgliosis. A macrophage reaction involving viable normal-appearing oligodendroglia suggests the possibility of an immunologic process in this disorder. Cortical laminar astrogliosis and mineralization of Layers I and II in particular were present. Thus, despite the uniformly hypomyelinating pattern seen on magnetic resonance imaging, neuropathologic examination reveals a complex heterogeneous leukodystrophy with prominent neuroaxonal and glial involvement in this disorder.

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_033

More than hypomyelination in Pol-III disorder. The 4H syndrome (hypomyelination, hypodontia, hypogonadotropic hypogonadism) is a newly recognized leukodystrophy. The classical form is characterized by the association of hypomyelination, abnormal dentition, and hypogonadotropic hypogonadism, but the recent identification of 2 genes responsible for the syndrome demonstrates that these 3 main characteristics can be variably combined among "Pol-III (polymerase III)-related leukodystrophies." The pathophysiology of this group of diseases is still to be elucidated, and there are no neuropathologic descriptions of brain tissue. We report the clinical, neuroradiologic, and neuropathologic findings of a patient affected by 4H syndrome with confirmed POLR3A mutations. We found a marked loss of oligodendrocytes, varying in severity in different brain regions, and accompanied by severe loss of myelin, moderately severe loss of axons, and patchy perivascular regions of better preserved white matter. There was relatively mild white matter astrogliosis and microgliosis. A macrophage reaction involving viable normal-appearing oligodendroglia suggests the possibility of an immunologic process in this disorder. Cortical laminar astrogliosis and mineralization of Layers I and II in particular were present. Thus, despite the uniformly hypomyelinating pattern seen on magnetic resonance imaging, neuropathologic examination reveals a complex heterogeneous leukodystrophy with prominent neuroaxonal and glial involvement in this disorder.

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_034

More than hypomyelination in Pol-III disorder. The 4H syndrome (hypomyelination, hypodontia, hypogonadotropic hypogonadism) is a newly recognized leukodystrophy. The classical form is characterized by the association of hypomyelination, abnormal dentition, and hypogonadotropic hypogonadism, but the recent identification of 2 genes responsible for the syndrome demonstrates that these 3 main characteristics can be variably combined among "Pol-III (polymerase III)-related leukodystrophies." The pathophysiology of this group of diseases is still to be elucidated, and there are no neuropathologic descriptions of brain tissue. We report the clinical, neuroradiologic, and neuropathologic findings of a patient affected by 4H syndrome with confirmed POLR3A mutations. We found a marked loss of oligodendrocytes, varying in severity in different brain regions, and accompanied by severe loss of myelin, moderately severe loss of axons, and patchy perivascular regions of better preserved white matter. There was relatively mild white matter astrogliosis and microgliosis. A macrophage reaction involving viable normal-appearing oligodendroglia suggests the possibility of an immunologic process in this disorder. Cortical laminar astrogliosis and mineralization of Layers I and II in particular were present. Thus, despite the uniformly hypomyelinating pattern seen on magnetic resonance imaging, neuropathologic examination reveals a complex heterogeneous leukodystrophy with prominent neuroaxonal and glial involvement in this disorder.

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_035

An Indian boy with a novel leukodystrophy: 4H syndrome. 4H syndrome is a rare and distinct leukodystrophy characterized by hypomyelination, hypogonadotropic hypogonadism, and hypodontia. Detecting signs of pubertal growth failure and abnormal dentition offer the clues to the diagnosis. We present an Indian boy with this novel syndrome with previously unreported feature of bilateral undescended testes. We also provide a brief overview of all published cases.

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_036

An Indian boy with a novel leukodystrophy: 4H syndrome. 4H syndrome is a rare and distinct leukodystrophy characterized by hypomyelination, hypogonadotropic hypogonadism, and hypodontia. Detecting signs of pubertal growth failure and abnormal dentition offer the clues to the diagnosis. We present an Indian boy with this novel syndrome with previously unreported feature of bilateral undescended testes. We also provide a brief overview of all published cases.

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_037

An Indian boy with a novel leukodystrophy: 4H syndrome. 4H syndrome is a rare and distinct leukodystrophy characterized by hypomyelination, hypogonadotropic hypogonadism, and hypodontia. Detecting signs of pubertal growth failure and abnormal dentition offer the clues to the diagnosis. We present an Indian boy with this novel syndrome with previously unreported feature of bilateral undescended testes. We also provide a brief overview of all published cases.

List symptoms of 4H leukodystrophy.

550320cbe9bde6963400002d_038