Hereditary mutations in the GJB2 gene of connexin 26 are a basis of mutilation syndromes of sensorineural deafness, hearing loss and hyperkeratosis with autosomal recessive (DFNB1) and autosomal dominant (DFNA3) types of inheritance [104, 105]. This evidence concerns the gene GJB2 and autosomal dominant nonsyndromic hearing loss 3A.