GJB2 and hearing loss disorder: The occurrence of ARNSHL has been related to the DFNB1 locus (deafness, autosomal recessive 1) (OMIM 220290) at chromosome 13q11-q12, which contains two genes associated with hearing loss: GJB2 (gap junction protein, beta-2) (OMIM 121011) and GJB6 (gap junction protein, beta-6) (OMIM 604418), which codify the proteins encoding connexins 26 (Cx26) [4] and 30 (Cx30) [5], respectively.