Dataset Information

GJB1 Gene Analysis in Two Extended Families with X-Linked Charcot-Marie-Tooth Disease.

ABSTRACT: X-linked Charcot-Marie-Tooth (CMT) disease type I (CMTX1) is the second most frequent type of CMT disease caused by pathogenic variants in the GJB1 gene. We described 2 extended cases (families) with CMTX1 with identified pathogenic variants - p.Val139Met and p.Arg215Trp. In both the families, neurological symptoms started earlier in male than in female patients. In some family members, molecular diagnostics was performed prior to neurological investigation due to family cascade screening. There was variable neurological phenotype representing CMT. Conclusions: There is a large clinical heterogeneity in CMTX, even amongst the family members.

SUBMITTER: Kovale S

PROVIDER: S-EPMC8299378 | biostudies-literature | 2021 May-Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

<i>GJB1</i> Gene Analysis in Two Extended Families with X-Linked Charcot-Marie-Tooth Disease.

Kovale Sabine S Terauda Ruta R Millere Elina E Taurina Gita G Murmane Daiga D Isakova Jekaterina J Kenina Viktorija V Gailite Linda L

Case reports in neurology 20210501 2

X-linked Charcot-Marie-Tooth (CMT) disease type I (CMTX1) is the second most frequent type of CMT disease caused by pathogenic variants in the <i>GJB1</i> gene. We described 2 extended cases (families) with CMTX1 with identified pathogenic variants - p.Val139Met and p.Arg215Trp. In both the families, neurological symptoms started earlier in male than in female patients. In some family members, molecular diagnostics was performed prior to neurological investigation due to family cascade screening ...[more]

PMID: 34326750

Similar Datasets

Project description:Charcot-Marie-Tooth disease (CMT) due to GJB1 variants (CMTX1) is the second most common form of CMT. It is an X-linked disorder characterized by progressive sensory and motor neuropathy with males affected more severely than females. Many reported GJB1 variants remain classified as variants of uncertain significance (VUS). In this large, international, multicentre study we prospectively collected demographic, clinical and genetic data on patients with CMT associated with GJB1 variants. Pathogenicity for each variant was defined using adapted American College of Medical Genetics criteria. Baseline and longitudinal analyses were conducted to study genotype-phenotype correlations, to calculate longitudinal change using the CMT Examination Score (CMTES), to compare males versus females, and pathogenic/likely pathogenic (P/LP) variants versus VUS. We present 387 patients from 295 families harbouring 154 variants in GJB1. Of these, 319 patients (82.4%) were deemed to have P/LP variants, 65 had VUS (16.8%) and three benign variants (0.8%; excluded from analysis); an increased proportion of patients with P/LP variants compared with using ClinVar's classification (74.6%). Male patients (166/319, 52.0%, P/LP only) were more severely affected at baseline. Baseline measures in patients with P/LP variants and VUS showed no significant differences, and regression analysis suggested the disease groups were near identical at baseline. Genotype-phenotype analysis suggested c.-17G>A produces the most severe phenotype of the five most common variants, and missense variants in the intracellular domain are less severe than other domains. Progression of disease was seen with increasing CMTES over time up to 8 years follow-up. Standard response mean (SRM), a measure of outcome responsiveness, peaked at 3 years with moderate responsiveness [change in CMTES (ΔCMTES) = 1.3 ± 2.6, P = 0.00016, SRM = 0.50]. Males and females progressed similarly up to 8 years, but baseline regression analysis suggested that over a longer period, females progress more slowly. Progression was most pronounced for mild phenotypes (CMTES = 0-7; 3-year ΔCMTES = 2.3 ± 2.5, P = 0.001, SRM = 0.90). Enhanced variant interpretation has yielded an increased proportion of GJB1 variants classified as P/LP and will aid future variant interpretation in this gene. Baseline and longitudinal analysis of this large cohort of CMTX1 patients describes the natural history of the disease including the rate of progression; CMTES showed moderate responsiveness for the whole group at 3 years and higher responsiveness for the mild group at 3, 4 and 5 years. These results have implications for patient selection for upcoming clinical trials.

Dataset Information

GJB1 Gene Analysis in Two Extended Families with X-Linked Charcot-Marie-Tooth Disease.

Publications

<i>GJB1</i> Gene Analysis in Two Extended Families with X-Linked Charcot-Marie-Tooth Disease.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets