Non-syndromic dominant sensorineural hearing loss: from a few phenotypes to many genotypes

Sensorineural hearing loss affects approximately 1 in 2 persons at about 80 years of age and 1 in 750 in childhood. The best known forms of hearing loss with an autosomal dominant pattern of inheritance are the syndromic-mediated ones. At present, the non-syndromic autosomal dominant inherited forms can only be distinguished by the shape of the tone-audiogram. Based on gene linkage studies twelve different genotypes for autosomal dominant hereditary non-syndromic forms of sensorineural hearing loss have been recognized in a period of almost 2 years. In view of the great diversity of types that have been recognized in such a short period, it can be expected that over the next 10 years, several dozens genetically-mediated forms of autosomal dominant inherited sensorineural hearing loss will be detected. Similar developments are taking place in the non-syndromic autosomal recessive hereditary forms of sensorineural hearing loss and deafness. The above indicates clearly that before too long, new genetic investigation techniques will enable us to distinguish between forms of sensorineural hearing loss that could not be distinguished in the past.