title: Association between phenotype, performance with hearing aids, and genotype of childhood hearing loss in children with and without genetic alteration.
abstract: OBJECTIVE
  To establish the frequency of genetic mutations related to sensorineural hearing loss (SNHL); to verify if there is association between the degree of SNHL and the presence of genetic alteration; and to verify if the Minimal Response Levels (MRL) with hearing aids vary according to the genetic alteration.
  
  
  METHODS
  Thirty hearing aids users with ages between 8 and 111 months were evaluated. The evaluation procedures used were: pure-tone audiometry; the auditory steady state response (ASSR) on sound field, with and without hearing aids; and genetic study of the hearing loss.
  
  
  RESULTS
  Three genetic mutations were diagnosed: 35delG, A1555G and A827G, and the children with these mutations showed higher degree of SNHL. There was no difference between the genetic patterns regarding the degree of SNHL, except for patients with A827G mitochondrial mutation, because all subjects with this mutation had profound SNHL. The difference between the MRL obtained with and without amplification, considering the presence of mutation and the degree of SNHL, was higher in children with moderate SNHL without genetic alterations, both in behavioral and electrophysiological evaluations.
  
  
  CONCLUSIONS
  Genetic mutations were found in 36.7% of the sample, justifying the importance of genetic tracking in the hearing habilitation process. Children with genetic mutations showed higher degrees of hearing loss. The different mutation patterns do not directly determine the degree of hearing loss. The best thresholds with amplification were found in children with moderate hearing loss without genetic alterations.
authors.affiliation: Department of Speech-Language Pathology and Audiology, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil. eliarapv@yahoo.com.br
authors.forename: Eliara Pinto Vieira
authors.initials: EP
authors.lastname: Biaggio
authors.forename: Marisa Frasson de
authors.initials: MF
authors.lastname: Azevedo
authors.forename: Maria Cecilia Martinelli
authors.initials: MC
authors.lastname: Iório
authors.forename: Maria Carolina Costa Melo
authors.initials: MC
authors.lastname: Svidnicki
authors.forename: Edi Lúcia
authors.initials: EL
authors.lastname: Satorato
mesh_terms: D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D005838:Genotype; D006310:Hearing Aids; D006319:Hearing Loss, Sensorineural / Q000235:genetics* / Q000534:rehabilitation; D006801:Humans; D007223:Infant; D008297:Male; D009154:Mutation / Q000235:genetics*; D010641:Phenotype; D012720:Severity of Illness Index