Moreover, no pathogenic mutations in GJB2 were found in a cohort of 44 probands from Nigeria with non-syndromic deafness [28], and only 7% of a cohort of 127 American probands of Hispanic or African descent with bilateral non-syndromic hearing impairment presented a disease causing mutation in GJB2 [29]. This evidence concerns the gene GJB2 and deafness.