GJB2 and hearing loss disorder: Despite the high prevalence of GJB2 and GJB6 mutations in some Western populations, for example, two large deletions of the GJB6 (one of 309 kb,⊿GJB6-D13S1830 and another of 232 kb,⊿GJB6-D13S1854) upstream the GJB2 are frequently found among individuals who are deaf in Spain[22], these mutations seem to account for a smaller percentage of hereditary hearing loss in Turkey[23], Greek Cyprus[24] and Austria[20], and few data have been reported on the presence of these mutations in the Chinese population[8].