Molecular genetic studies on the GJB2 gene in the Korean population

Gap junction beta 2 (GJB2) gene, encoding the connexin26 (Cx26) protein, is one of the main causative genes of nonsyndromic hearing loss (HL) in many populations, and a number of different mutations in the GJB2 gene has been reported from diverse ethnic groups. The GJB2 gene has been analyzed for the spectrum and prevalence of the mutations from 324 subjects with nonsyndromic HL in the Korean population. A total of nine different mutations were found in 28 unrelated patients (8.6%). In addition, four previously reported as polymorphisms, p.V27I, p.E114G, p.T123N, and p.I203T, were found in patients and controls. The c.235delC was the most prevalent mutation which accounts for 61.5% of all pathogenic mutant alleles in the Korean NSHI population with a total of 24 alleles. This study further supports the view that mutations in the GJB2 gene are a less common cause of hearing loss in East Asian populations when compared to Caucasian populations.