In Chinese Hans, for example, bi-allelic GJB2 mutations were reported in 19.1% of patients with non-syndromic deafness, followed by bi-allelic SLC26A4 mutations in 12.1% and the mitochondrial A1555G mutation of MT-RNR in 1.6% [4-6]. The gene discussed is GJB2; the disease is deafness.