GJB2 and hearing loss disorder: Although mutations in the GJB3 and GJB6 genes were subsequently discovered, GJB2 remains the most commonly known cause of hereditary hearing loss in many population.[9,10,13]GJB2, located on human chromosome 13q11,[6,14] encodes the connexin 26 (CX26) protein, a member of the connexin family of highly related gap junction proteins.