Syndromic
Deafness
Deafness may occur by itself or as a part of a syndrome in which the deafness is associated with distinctive facial features, heart or other organ involvement, and/or other medical conditions. Recognition of these associated findings has allowed the definition of more than 100 different forms of syndromic deafness.
Familiar examples of dominant syndromes that may involve hearing loss are Waardenburg, Treacher Collins, Apert, Stickler, and Branchio-oto-renal (BOR) syndromes.
Recessive syndromes include those originally described by Usher, Pendred, Jervelle and Lange-Nielsen, Refsum, Fraser, Cockayne as well as biotinidase deficincy, onychodystrophy, and renal tubular acidosis with deafness.
X-linked deafness syndromes include those of Alport, Nance, Hunter, Norrie, and Ziprkowski .
Finally, deafness syndromes showing mitochondrial inheritance include aminoglycoside ototoxicity and a form of diabetes associated with deafness. An extensive list including information about these and other forms of syndromic deafness can be accessed through Online Mendelian Inheritance in Man, OMIM . More information about syndromic and non-syndromic hearing loss can be found on the Hereditary Hearing Loss Homepage .
Some forms of genetic deafness lead to characteristic audiologic findings.
For example, genes have been identified that lead to dominantly inherited
low frequency hearing loss and that lead to only high frequency hearing
loss. Similarly, some forms of genetic hearing loss are progressive
while others are relatively stationary. In about 10-20% of individuals
with genetic deafness, there may be associated difficulties with balance,
resulting from vestibular probems.
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page—Genetic Heterogeneity