Syndromic etiology in children at schools for the deaf in Turkey.
OBJECTIVE
The aim of this study was to determine the syndromic etiology of bilateral severe sensorineural hearing disorders in children and current etiological causes to reduce the cases in the unknown group.


METHODS
This study was conducted on 550 students of five schools for the deaf in Istanbul and Zonguldak, Turkey. Otologic, audiologic, dysmorphologic, ophthalmologic and dental examinations were performed in all children. Familial and medical histories were obtained.


RESULTS
The etiology of hearing loss was genetic in 346 (62.90%), acquired in 107 (19.45%) and unknown in 97 (%17.63) cases. A total of 619 malformations were defined in 550 children and 99 of them belonged to a syndrome. We identified 33 different syndromes for these 99 syndromic children. Syndromic etiology was found in 18.0% of the total and 28.61% of the subjects with genetic etiology. Most common syndrome was Waardenburg syndrome which occurred in 33 children.


CONCLUSIONS
The incidence of hereditary hearing impairment is very high in developing countries compared to developed countries. Prevention is essential to reduce the incidence, multidisciplinary approach and genetic counselling are necessary in this regard.
Medical Biology and Genetic Department, Duzce Medical School, University of Abant Izzet Baysal, Duzce, Turkey. fsilan@yahoo.com
Fatma
F
Silan
Levent
L
Demirci
Ayten
A
Egeli
Erol
E
Egeli
Halil Ibrahim
HI
Onder
Ozcan
O
Ozturk
Zehra Seda
ZS
Unal
D000015:Abnormalities, Multiple / Q000453:epidemiology; D000293:Adolescent; D000328:Adult; D001299:Audiometry; D002648:Child; D003241:Consanguinity; D019988:Children with Disabilities / Q000193:education; D060345:Education of Persons with Hearing Disabilities; D005260:Female; D006312:Hearing Loss, Bilateral / Q000453:epidemiology / Q000209:etiology*; D006319:Hearing Loss, Sensorineural / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D008297:Male; D012574:Schools; D013577:Syndrome; D014421:Turkey / Q000453:epidemiology