GJB2 and hearing loss disorder: To further characterize the molecular etiology of hearing loss in the Chinese population, we recruited a total of 135 unrelated patients with nonsyndromic sensorineural hearing loss (NSHL) for mutational screening of GJB2, GJB3, GJB6, SLC26A4, SLC26A5 IVS2-2A>G and mitochondrial 12SrRNA, tRNASer(UCN) by PCR amplification and direct DNA sequencing.