The Frequency of M34T, 167delT, 235delC and 35delG Mutations in GJB2 Gene in Autosomal Recessive Non-Syndromic Hearing Loss Patients in West Azarbaijan

Mutations in GJB2 gene is the most common cause of autosomal recessive non-syndromic hearing loss in many populations. The aim of this study was to determine the frequency of 35delG, 167delT, M34T, 235delC mutations in West Azarbaijan population. 129 patients from 96 families were studied. Mutations were detected using ASO-PCR and PCR-RFLP methods. Totally, 65.89% of cases were sporadic and the remaining (34.11%) were familial. Six out of 8 cases with 35delG mutation and one case with 235delC mutation were offspring of consanguineous union. Mutations of 35delG were detected in 8 families. 167delT and M34T mutations were not found but 235delC was detected only in one family. On the other hand, 13 out of 258 chromosomes had 35delG mutations. Five patients were homozygous and 3 were heterozygous for 35delG mutation. It means that, in 5.04% of the patients the major reason for hearing loss was 35delG mutation. One out of 258 (0.39%) chromosomes had heterozygous 235delC mutation. It can be concluded that the other genes or mutations could result in autosomal recessive non-syndromic hearing loss in West Azerbaijani population.