title: Screening of the mitochondrial A1555G mutation in patients with sensorineural hearing loss.
abstract: The A1555G mitochondrial mutation is the main alteration associated with aminoglycoside-induced deafness.
  
  
  OBJECTIVE
  to investigate the prevalence of the A1555G mutation in patients sensorineural hearing loss patients with and without aminoglycosides antibiotic use.
  
  
  METHODS
  a study of 27 cases with deafness as the sample, and 100 neonates with normal hearing as the control group. DNA was extracted from blood leukocyte samples, and specific oligonucleotide primers were designed to amplify the cytochrome b gene and the region which encloses the A1555G mutation of the mitocondrial DNA using the polymerase chain reaction and restriction fragment length polymorphism.
  
  
  METHODS
  a cross-sectional case study.
  
  
  RESULTS
  a region of the cytochrome b gene was amplified and the presence of the mtDNA was confirmed in all of the 127 cases. The A1555G mutation was not found in any of the 27 patients with hearing loss or the control group with 100 neonates.
  
  
  CONCLUSIONS
  the results agree with studies stating that the A1555G mutation is not prevalent in the Americas. There is interest in establishing the real prevalence of this mutation and to investigate other mutations that may cause hearing loss, associated or not with the use of aminoglycosides, in the Brazilian population.
authors.affiliation: Master's degree student, faculty member of the Otorhinolaryngology and Head & Neck Surgery Department, Medical School, S. J. Rio Preto, SP, FAMERP. Electronic address: vbpiatto@gmail.com.
authors.forename: Luciano Pereira
authors.initials: LP
authors.lastname: Maniglia
authors.affiliation: Medical student, Medical School, São José do Rio Preto, SP, FAMERP.
authors.forename: Bruna Carolina Lemos
authors.initials: BCL
authors.lastname: Moreira
authors.affiliation: Master's degree; head of the Speech Therapy Unit, Otorhinolaryngology and Head & Neck Surgery Department, Medical School, S. J. Rio Preto, SP, FAMERP.
authors.forename: Magali Aparecida Orate Menezes
authors.initials: MAOM
authors.lastname: da Silva
authors.affiliation: Doctor, Adjunct professor.
authors.forename: Vânia Belintani
authors.initials: VB
authors.lastname: Piatto
authors.affiliation: Livre-docente (habilitation) professor, head of the Otorhinolaryngology and Head & Neck Surgery Department, Medical School, S. J. Rio Preto, SP, FAMERP. Medical School, São José do Rio Preto, SP, FAMERP.
authors.forename: José Victor
authors.initials: JV
authors.lastname: Maniglia
mesh_terms: D000328:Adult; D000617:Aminoglycosides / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004272:DNA, Mitochondrial / Q000235:genetics*; D005260:Female; D005820:Genetic Testing / Q000379:methods*; D006319:Hearing Loss, Sensorineural / Q000139:chemically induced / Q000235:genetics*; D006801:Humans; D008297:Male; D009154:Mutation; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length
chemical_list: D000617:Aminoglycosides; D004272:DNA, Mitochondrial