Mutation in connexin 32 causes charcot–marie–tooth disease in a large Chinese family

Abstract

The purpose was to study the clinical features and genetics of a large Chinese family with Charcot-Marie-Tooth (CMT) disease. A genome-wide linkage scan using Applied Biosystems v. 2.5 411 short tandem repeat (STR) markers was performed in this family. Mutation screening was conducted on connexin 32 (Cx32). Prediction of impact of the mutation and sequence alignments of Cx32 in 10 vertebrates were performed using Polyphen and Clustal W, respectively. Twelve family members were diagnosed as CMT type 1. An X-chromosome locus (DXS991) was linked to the phenotype of this family by the genome-wide linkage analysis. An H100Y mutation found in Cx32 was predicted to be possibly damaging to the function of Cx32, with a PSIC score difference of 1.758. The H100 of Cx32 is highly conserved among the 10 vertebrates. A large Chinese family had CMTX1 linked to Xq13.1 caused by an H100Y mutation in the Cx32 gene.