title: Cross-sectional analysis of hearing threshold in relation to age in a large family with cochleovestibular impairment thoroughly genotyped for DFNA9/COCH.
abstract: Hearing threshold was analyzed for each frequency in relation to age in 88 members of a large Dutch family with cochleovestibular impairment caused by a P51S mutation in the COCH gene within the DFNA9 locus (chromosome 14q12-13). The participants in this study were 34 mutation carriers and 54 relatives without the mutation (control subjects). A sigmoidal dose-response curve with a variable slope was used to fit the mutation carriers' threshold-on-age data. Progression started at about 40 years of age and only lasted for some 20 to 25 years; the associated average progression was 2.9 dB/y for all frequencies. However, some hearing impairment was already present before, predominantly at the high frequencies. The mean thresholds in the young mutation carriers (< 33 years of age) were significantly higher (by 4 to 13 dB) than those in age-matched controls at 2 to 8 kHz. Presumably, mutation carriers have a congenital, stable offset threshold (10 to 29 dB) at these frequencies, and develop progression later in life.
authors.affiliation: Department of Otorhinolaryngology, University Medical Centre St Radboud, Nijmegen, The Netherlands.
authors.forename: Steven J H
authors.initials: SJ
authors.lastname: Bom
authors.forename: Martijn H
authors.initials: MH
authors.lastname: Kemperman
authors.forename: Patrick L M
authors.initials: PL
authors.lastname: Huygen
authors.forename: Mirjam W J
authors.initials: MW
authors.lastname: Luijendijk
authors.forename: Cor W R J
authors.initials: CW
authors.lastname: Cremers
mesh_terms: D000328:Adult; D000367:Age Factors; D001299:Audiometry; D001309:Auditory Threshold; D002883:Chromosomes, Human, Pair 14; D015834:Cochlear Diseases / Q000175:diagnosis / Q000235:genetics; D003638:Deafness / Q000175:diagnosis / Q000235:genetics*; D016326:Extracellular Matrix Proteins; D005260:Female; D006579:Heterozygote; D006801:Humans; D008297:Male; D009154:Mutation; D010375:Pedigree; D011506:Proteins / Q000235:genetics*; D012044:Regression Analysis; D015837:Vestibular Diseases / Q000175:diagnosis / Q000235:genetics
chemical_list: C110668:COCH protein, human; D016326:Extracellular Matrix Proteins; D011506:Proteins