title: Connexin 26 (GJB2) gene-related deafness and speech intelligibility after cochlear implantation.
abstract: OBJECTIVE
  Speech intelligibility in children after cochlear implantation may depend on their deafness cause, including connexin 26 (GJB2) gene-related deafness.
  
  
  BACKGROUND
  There is significant variability in the degree of intelligibility, or clarity, of children's speech after cochlear implantation. GJB2 gene-related deafness may be a factor, as preliminary data suggest that pathologic changes do not affect the spiral ganglion cells, which are the neural elements stimulated by the implant, thus favoring better results.
  
  
  METHODS
  In an observational retrospective cohort study of pediatric cochlear implantees, 38 patients with nonsyndromic deafness of unknown cause and 1 with keratitisichthyosis-deafness syndrome underwent GJB2 mutation analysis using polymerase chain reaction amplification and direct sequencing. The primary outcome measure assessed was Speech Intelligibility Rating score from postoperative Year 1 (n = 39) to Year 5 (n = 17). Educational setting was considered as a secondary outcome measure. Statistical analysis was double-blinded, with patients and assessors of outcome unaware of GJB2 status.
  
  
  RESULTS
  Fourteen patients had GJB2-related deafness and 25 had GJB2-unrelated deafness. Comparisons at Year 3 (n = 31) revealed intelligible speech achieved by 9 of 11 with GJB2-related deafness, compared with only 6 of 20 with GJB2-unrelated deafness (p = 0.017). Ordinal logistic regression analysis on Speech Intelligibility Rating scores found statistically significantly better scores in children with GJB2-related deafness (p < 0.05) both before and after adjustment for confounding variables. A larger proportion with GJB2-related deafness also attended mainstream school (p = 0.01).
  
  
  CONCLUSIONS
  In pediatric cochlear implantees, GJB2-related deafness is a predictor of good speech intelligibility.
authors.affiliation: Northern Ireland Regional Cochlear Implant Center, Belfast City Hospital, Belfast, UK. rajsinn@aol.com
authors.forename: Arasa Raj
authors.initials: AR
authors.lastname: Sinnathuray
authors.forename: Joseph G
authors.initials: JG
authors.lastname: Toner
authors.forename: Joanne
authors.initials: J
authors.lastname: Clarke-Lyttle
authors.forename: Andrea
authors.initials: A
authors.lastname: Geddis
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Patterson
authors.forename: Anne E
authors.initials: AE
authors.lastname: Hughes
mesh_terms: D002648:Child; D002675:Child, Preschool; D019929:Cochlear Implantation; D015331:Cohort Studies; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D003638:Deafness / Q000235:genetics* / Q000503:physiopathology / Q000628:therapy; D060345:Education of Persons with Hearing Disabilities; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D009154:Mutation / Q000235:genetics; D015588:Observer Variation; D012189:Retrospective Studies; D013065:Speech Intelligibility; D013067:Speech Perception; D016896:Treatment Outcome; D014743:Videotape Recording
chemical_list: D017630:Connexins; C000607042:GJB2 protein, human; D000072259:Connexin 26