title: Etiology of deafness at the Yeditepe School for the deaf in Istanbul.
abstract: OBJECTIVE
  The etiology of deafness can be classified as genetic, acquired and unknown. An unknown etiology was a high incidence in previous reports. The aim of this study is to explore the etiology of deafness and to reduce the cases in the unknown group.
  
  
  METHODS
  This study was conducted on 162 students at the Yeditepe School for the deaf. Otologic, physical and psychological examinations were performed by a team of doctors including four otologists, a geneticist, a dentist, an ophthalmologist and an audiologist.
  
  
  RESULTS
  A genetic cause was identified in 41.35%, acquired 37.65% and unknown 20.98%. Genetic etiologies were stratified as familial and syndromic subgroups. A familial cause was found in 60 of 162 children and in 22 of those 60 cases, the parents had a consanguineous marriage. There was 11 cases associated with a syndrome. Ninety four minor abnormalities have been established in some deaf children. Febrile convulsion (36%) was identified as the most common etiology in acquired cases.
  
  
  CONCLUSIONS
  In contrast with other studies the consanguineous marriage was present in 36.6% of the familial cases and 38.8% in total of the school. An unknown etiology was reported in high rates in previous reports. These unknown cases could be described as a part of a syndrome by a crowded team of consultants. Evaluation of early diagnostic criterias and minor abnormalities can help us to provide early rehabilitation of deafness in childhood.
authors.affiliation: Department of Otorhinolaryngology and Head Neck Surgery, Düzce Faculty of Medicine, University of Abant Izzet Baysal, Konuralp, Turkey. gunferi@yahoo.com
authors.forename: Erol
authors.initials: E
authors.lastname: Egeli
authors.forename: Günferi
authors.initials: G
authors.lastname: Ciçekci
authors.forename: Fatma
authors.initials: F
authors.lastname: Silan
authors.forename: Ozcan
authors.initials: O
authors.lastname: Oztürk
authors.forename: Uğur
authors.initials: U
authors.lastname: Harputluoğlu
authors.forename: Aşkin
authors.initials: A
authors.lastname: Onur
authors.forename: Ayten
authors.initials: A
authors.lastname: Egeli
authors.forename: Aysel
authors.initials: A
authors.lastname: Yildiz
mesh_terms: D000158:Acoustic Impedance Tests; D000293:Adolescent; D000328:Adult; D001299:Audiometry; D001720:Birth Injuries / Q000150:complications; D002648:Child; D000013:Congenital Abnormalities / Q000453:epidemiology; D003638:Deafness / Q000175:diagnosis / Q000209:etiology* / Q000235:genetics; D005260:Female; D005334:Fever / Q000150:complications; D006801:Humans; D006932:Hyperbilirubinemia / Q000150:complications; D008297:Male; D008581:Meningitis / Q000150:complications; D003294:Seizures, Febrile / Q000150:complications; D014421:Turkey / Q000453:epidemiology