Deafness is a monogenic disease, meaning that disruption of the function of a single gene can lead to the development of deafness symptoms. According to statistics, 70% of hereditary deafness is non-syndromic deafness, where deafness is the only manifestation, and 30% is syndromic deafness, where other systemic diseases are present in addition to deafness. Non-syndromic deafness can be subdivided into: autosomal recessive (about 77%), autosomal dominant (about 22%), X-linked (about 1%), Y-linked and mitochondrial (<1%).