title: Speech recognition scores related to age and degree of hearing impairment in DFNA2/KCNQ4 and DFNA9/COCH.
abstract: OBJECTIVE
  To analyze the relationship between pure-tone hearing threshold and speech recognition performance in DFNA2/KCNQ4 and DFNA9/COCH, 2 types of high-frequency nonsyndromic hearing impairment.
  
  
  METHODS
  Case series with cross-sectional analysis of phoneme recognition scores related to age and hearing level.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  Forty-five members of 4 separate families, all carrying 1 of 3 different mutations in the KCNQ4 gene at the DFNA2 locus (1p34); 42 members of 7 separate families, all carrying the same Pro51Ser mutation in the COCH gene at the DFNA9 locus (14q12-q13).
  
  
  RESULTS
  The deterioration of speech recognition dropped to a 90% score at a higher level of hearing impairment (pure-tone-average at 1, 2, and 4 kHz) in DFNA2-affected patients (65 dB) than in DFNA9-affected patients (46 dB).
  
  
  CONCLUSIONS
  At similar levels of hearing impairment, DFNA2/KCNQ4-affected patients showed better speech recognition performance than DFNA9/COCH-affected patients.
authors.affiliation: Department of Otorhinolaryngology, University Medical Centre St Radboud, Nijmegen, the Netherlands. S.Bom@kno.azn.nl
authors.forename: S J
authors.initials: SJ
authors.lastname: Bom
authors.forename: E M
authors.initials: EM
authors.lastname: De Leenheer
authors.forename: F X
authors.initials: FX
authors.lastname: Lemaire
authors.forename: M H
authors.initials: MH
authors.lastname: Kemperman
authors.forename: W I
authors.initials: WI
authors.lastname: Verhagen
authors.forename: H A
authors.initials: HA
authors.lastname: Marres
authors.forename: H P
authors.initials: HP
authors.lastname: Kunst
authors.forename: R J
authors.initials: RJ
authors.lastname: Ensink
authors.forename: A J
authors.initials: AJ
authors.lastname: Bosman
authors.forename: G
authors.initials: G
authors.lastname: Van Camp
authors.forename: F P
authors.initials: FP
authors.lastname: Cremers
authors.forename: P L
authors.initials: PL
authors.lastname: Huygen
authors.forename: C W
authors.initials: CW
authors.lastname: Cremers
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D003430:Cross-Sectional Studies; D006316:Hearing Loss, High-Frequency / Q000235:genetics* / Q000503:physiopathology*; D006801:Humans; D051656:KCNQ Potassium Channels; D008875:Middle Aged; D015221:Potassium Channels / Q000235:genetics*; D024642:Potassium Channels, Voltage-Gated; D012720:Severity of Illness Index; D013067:Speech Perception
chemical_list: D051656:KCNQ Potassium Channels; C117367:KCNQ4 protein, human; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated