The Genetic Basis of Hearing Loss: Recent Advances and Future Prospects

Hearing loss (HL) is a common and complex condition that can occur at any age, be inherited or acquired, and is associated with a wide number of etiologies. HL is the most common sensory deficit in newborn children. In developed countries, genetic causes are considered the most frequent etiology of HL, and are estimated to account for 75% of the causes of HL. Current estimates suggest 1% of human genes (200–250 genes) are associated with genetic HL, and to date, more than 80 genes with over 1000 mutations and 140 loci have been identified associated with non-syndromic HL. The Online Mendelian Inheritance in Man reports more than 400 syndromes with HL. Syndromic and non-syndromic HL can be caused by different mutations within the same gene. Establishing the genetic cause of HL in prelingual children facilitates the medical course of action, rehabilitation choices and long term care in children. Patients with HL of undiagnosed etiology should be evaluated by a clinical geneticist and consider genetic testing as a part of their multidisciplinary evaluation.