Forty-eight (26.2%) were found to have confirmative mutations in the common deafness genes (hereafter called "the mutation group," see Tables 2 and 3), including 25 cases with 2 mutated alleles in GJB2 (52.1% of the 48 implantees), 23 with 2 mutated alleles in SLC26A4 (47.9%), and 0 with mutations in the mitochondrial 12S rRNA gene (see Table 4). Here, GJB2 is linked to deafness.