title: Causes of hearing impairment in deaf pupils with a mental handicap.
abstract: An aetiological study was performed on 122 deaf pupils (57 aged < 20 years, 65 aged > 20 years) at the Institute for the Deaf in Sint-Michielsgestel, The Netherlands. Besides hearing impairment with thresholds of > 60 dB HL, all the participants had a mental handicap with a non-verbal IQ of 40-80. Sixteen per cent of them were of non-Dutch origin. The cause of hearing impairment was acquired in 48%, inherited in 17%, chromosomal in 4% and unknown in 30%. In comparison with other studies on the aetiology of childhood deafness, acquired causes predominated over inherited causes, which may be typical of deafness combined with a mental handicap. We found a significant predominance of non-Dutch pupils among the rubella aetiology cases and male predominance among the hearing impaired pupils in general.
authors.affiliation: Department of Otolaryngology, University Hospital Nijmegen, The Netherlands. r.admiraal@kno.azn.nl
authors.forename: R J
authors.initials: RJ
authors.lastname: Admiraal
authors.forename: P L
authors.initials: PL
authors.lastname: Huygen
mesh_terms: D000293:Adolescent; D000328:Adult; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D002869:Chromosome Aberrations / Q000235:genetics; D025063:Chromosome Disorders; D003638:Deafness / Q000145:classification / Q000209:etiology* / Q000235:genetics; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D005260:Female; D005799:Genes, Dominant; D005808:Genes, Recessive; D006309:Hearing / Q000502:physiology; D006314:Hearing Loss, Conductive / Q000209:etiology / Q000235:genetics; D006319:Hearing Loss, Sensorineural / Q000209:etiology / Q000235:genetics; D006801:Humans; D008607:Intellectual Disability; D007360:Intelligence; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D012189:Retrospective Studies; D012409:Rubella / Q000150:complications; D012737:Sex Factors; D013577:Syndrome