In the present study, definite genetic diagnoses could be achieved in 18 (9.6%) of the 188 families, comprising 13 (6.9%) with bi-allelic GJB2 mutations, three (1.6%) with bi-allelic SLC26A4 mutations, and two (1.1%) with homoplasmic m.1555A>G mutations, by screening the three common deafness genes. The gene discussed is GJB2; the disease is deafness.