title: Auditory outcome after cochlear implantation in patients with congenital nonsyndromic hearing loss: influence of the GJB2 status.
abstract: OBJECTIVE
  To compare the audiologic outcome after cochlear implantation between 2 groups of patients with congenital nonsyndromic sensorineural hearing loss.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Department of Otorhinolaryngology, University hospital (tertiary referral center).
  
  
  METHODS
  From a bigger pool of implanted patients, 2 groups, each numbering 30 were enrolled. The patients from the first group were diagnosed with a Connexin 26 mutation (GJB2), whereas all of the patients from the second cohort were with a wild type genotype. Both groups were age matched, 1 to 7 years old at the age of implantation, with diagnosed congenital nonsyndromic sensorineural hearing loss.
  
  
  METHODS
  Both groups were evaluated with the help evaluation of auditory responses to speech/EARS/test battery - LiP test (Listening Progress Profile), MTP tests 3,6,12 (Monosyllabic-Trochee-Polysyllabic Test), GASP test (Glendonald Auditory Screening Procedure), and others. Follow-up period was at least 36 months.
  
  
  RESULTS
  Mean test scores were compared at the 1st, 6th, 12th, 24th, and 36th month. LiP outcome was significantly better (p < 0.05) for the GJB2-related cohort for the whole follow-up period except at the first month. MTP3, 6, and 12 tests displayed the same statistically significant outcome in favor of the first group. In the open-set test GASP, the difference was apparent: 1.22, 2.40, 5.59, and 7.40 mean scores at the 6th, 12th, 24, and 36th months for the first cohort versus 0.00, 0.07, 0.81, and 1.74 for the GJB2-unrelated patients.
  
  
  CONCLUSIONS
  The results from our study suggest that children with GJB2-related deafness show better auditory performance after cochlear implantation than age-matched children with GJB2-nonrelated sensorineural hearing loss.
authors.affiliation: *Department of ENT, Medical University of Sofia, Sofia; and †Department of Medical Chemistry and Biochemistry and Molecular Medicine Center, Medical University of Sofia, Sofia, Bulgaria.
authors.forename: Todor Miroslavov
authors.initials: TM
authors.lastname: Popov
authors.forename: Iglika
authors.initials: I
authors.lastname: Stancheva
authors.forename: Darina L
authors.initials: DL
authors.lastname: Kachakova
authors.forename: Julian
authors.initials: J
authors.lastname: Rangachev
authors.forename: Dimitar
authors.initials: D
authors.lastname: Konov
authors.forename: Sonya
authors.initials: S
authors.lastname: Varbanova
authors.forename: Vanio Ivanov
authors.initials: VI
authors.lastname: Mitev
authors.forename: Radka P
authors.initials: RP
authors.lastname: Kaneva
authors.forename: Diana Petrova
authors.initials: DP
authors.lastname: Popova
mesh_terms: D002648:Child; D002675:Child, Preschool; D019929:Cochlear Implantation; D015331:Cohort Studies; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D003638:Deafness / Q000235:genetics / Q000601:surgery; D005260:Female; D005838:Genotype; D006319:Hearing Loss, Sensorineural / Q000235:genetics / Q000601:surgery*; D006801:Humans; D007223:Infant; D008297:Male; D009154:Mutation; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D017630:Connexins; C000607042:GJB2 protein, human; D000072259:Connexin 26