Nonsyndromic deafness, autosomal dominant
Late onset progressive deafness is the most common neurological disability of the elderly. Although hearing loss of greater than 25 decibels is present in only 1% of young adults between the ages of 18-24 years of age, this increases to 10% in persons between 55-64 years of age and approximately 50% in octogenarians.
The relative contribution of heredity to age –related hearing impairment is not known, however the majority of inherited late-onset deafness is autosomal dominant and non-syndromic (Van Camp et al., 1997). Over forty genes associated with autosomal dominant non-snydromic hearing loss have been localized and of these fifteen have been cloned.