Connexin 26 gene (GJB2) mutation modulates the severity of hearing loss associated with the 1555A -> G mitochondrial mutation

We report a high prevalence of GJB2 heterozygous mutations in patients bear ing the 1555A-->G mitochondrial mutation, and describe a family in which po tential interaction between GJB2 and a mitochondrial gene appears to be the cause of hearing impairment. Patients who are heterozygotes for the GJB2 m utant allele show hearing loss more severe than that seen in sibs lacking a mutant GJB2 allele, suggesting that heterozygous GJB2 mutations may synerg istically cause hearing loss when in the presence of a 1555A-->G mutation. The present findings indicate that GJB2 mutations may sometimes be an aggra vating factor, in addition to aminoglycoside antibiotics, in the phenotypic expression of the non-syndromic hearing loss associated with the 1555A-->G mitochondrial mutation. (C) 2001 Wiley-Liss, Inc.