Different alterations of the GJB2 sequence can produce a variety of clinical outcomes, including the most common non-syndromic autosomal recessive deafness, type 1A (DFNB1A, OMIM #220290), autosomal dominant deafness, type 3A (DFNA3A, OMIM #601544), as well as syndromic forms combining hearing loss and skin disorders (OMIM #149200, #602540, #148210, #148350, and #124500). This evidence concerns the gene GJB2 and hearing loss disorder.