A novel deletion mutation in GJB1 causes X-linked CMT in a Han Chinese family

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Muscle Nerve. 2010 Dec;42(6):922-6.

A novel deletion mutation in GJB1 causes X-linked Charcot-Marie-Tooth disease in

a Han Chinese family.

Lin P, Mao F, Liu Q, Yang W, Shao C, Yan C, Gong Y.

Key Laboratory for Experimental Teratology, Ministry of Education and Institute

of Medical Genetics, Shandong University School of Medicine, Jinan, Shandong

250012, China.

Abstract

X-linked Charcot-Marie-Tooth disease CMT (CMTX) is predominantly caused by

mutations in the GJB1 gene that encode connexin32. We describe the clinical

findings and the identification of a novel mutation in GJB1 in a large Han

Chinese family with CMTX.

Linkage to GJB1 was determined by genotyping five polymorphic markers flanking

GJB1. Sequence alterations were determined by directly sequencing the coding

region of the GJB1 gene. The affected members have variable clinical

manifestations. Linkage analysis confirmed the cosegregation of the disease with

the GJB1 locus.

Sequencing of the GJB1 gene revealed a 1-basepair deletion (c.110delT) in the

coding region. The frameshift begins at amino acid 37 and generates a premature

stop codon at position 83. The shortened peptide is unlikely to be functional,

as it lacks most of the functional domains. The CMTX in this family is caused by

a novel loss of function mutation. Muscle Nerve 42: 922-926, 2010.