Genetic analysis of GJB2 in a Chinese family with nonsyndromic hearing impairment

Abstract

Nonsyndromic neurosensory hearing impairment (NSHI) is the most common human sensory disorder. Approximately one in a thousand children is born with prelingual hearing loss. Mutations of the GJB2 gene, which encodes Connexin 26, are the most common cause of hereditary NSHI in many ethnic populations, and are responsible for 50% of cases of autosomal recessive NSHI. In this study, we recruited a complex NSHI pedigree from Jiangsu province of China. Linkage analysis of microsatellite markers flanking all known arNSHI genes linked the causative gene in the family to the polymorphic macrosatellite marker D13S175. Direct DNA sequencing of the whole coding region of GJB2 revealed that a common homozygous mutation 235delC was responsible for most of the affected members in the NSHI family.