A novel GJB1 mutation associated with X-linked Charcot-Marie-Tooth disease in a large Chinese family pedigree

Abstract

Background: Charcot-Marie-Tooth (CMT) disease is a group of hereditary neuropathies with high phenotypic and genetic heterogeneity. In this study, we report a large family with X-linked CMT (CMTX) caused by a novel GJB1 mutation.

Methods: A family with the clinical diagnosis of CMTX was investigated. For mutation analysis, the coding region of GJB1 was sequenced using DNA from 15 family members. The identified GJB1 mutation was investigated by DHPLC in 120 normal controls. Mutation reanalysis was performed based on whole-exome sequencing (WES). Cell transfection studies were performed to characterize the function of the novel mutation.

Results: A missense mutation (c.605T>A) in GJB1 was detected in five patients and eight female carriers but not in two unaffected members of the family. The mutation was not found in 120 healthy controls and has not been previously reported. WES excluded other pathogenic mutations in the family. The pathogenicity of the mutation was confirmed by disrupting the membrane localization of the encoded proteins.

Conclusion: Our findings demonstrate that a novel mutation (c.605T>A) in GJB1 is associated with CMTX and adds to the repertoire of GJB1 mutations related to CMTX.

Keywords: GJB1; Charcot-Marie-Tooth disease; novel mutation; phenotypic heterogeneity.