[Analysis of GJB2 gene and mitochondrial DNA A1555G mutations in 16 families with non-syndromic hearing loss].

To screen for genetic mutations in families featuring non-syndromic hearing loss.Sixteen families with non-syndromic hearing loss were interviewed to identify medical histories by a questionnaire. Audiological and neurological examinations were conducted for all families. Coding regions of GJB2 and 12S rRNA genes were amplified and sequenced.Of the 17 patients with sensorineural hearing loss, 3 were homozygous mutation for GJB2 235 delC, 1 was 235 delC heterozygous mutation, 1 was 235 delC+299_300 delAT compound heterozygous mutation, and 6 were 79G>A+341G>A heterozygosis in cis mutation. No 1555A>G mutation of mitochondrial DNA (mtDNA) was found in the 16 families.The incidence of mtDNA 12S rRNA 1555A>G mutation in Jiangsu province may be lower than the average across China. Mutations of GJB2 genes may account for as much as 64.7% of non-syndromic hearing loss in this study. Screening for such mutations and genetic counseling may play an important role in the prevention of hereditary hearing loss.