GJB6 and hearing loss disorder: One point mutation, c.14C>A (p.T5M), in the GJB6 (CX30) is known to be involved nonsyndromic deafness by dominant inhibition of the activity of wild-type GJB6 in normal channels, underlining the critical function of GJB6 in normal hearing [21].Although none of the above mutations were observed in our previous study, we identified a missense heterozygous mutation, c.119C>T (p.A40V) of GJB6, in the patients with nonsyndromic hearing loss [22].