title: Carrier frequency of the 35delG and A1555G deafness mutations in the Argentinean population. Impact on the newborn hearing screening.
abstract: OBJECTIVE
  Hearing loss is a complex multifactorial disorder caused by genetic and environmental factors. The 35delG mutation in the GJB2 gene is the most prevalent mutation in Caucasian patients with genetic sensorineural deafness. The A1555G mutation in the mitochondrial 12S rRNA is the main genetic alteration associated with aminoglycoside-induced deafness. The aim of this study was to evaluate the prevalence of both mutations in general population of Argentina.
  
  
  METHODS
  A total of 712 samples of unrelated healthy blood donors and 330 newborn dried blood spots were studied by PCR-RFLP.
  
  
  RESULTS
  The 35delG mutation was detected in 11/ 712 unrelated blood donors. The carrier frequency found in this sample (1/65) proved to be lower than that found in Southern European countries, mainly Spain and Italy, from where Argentina originally received its major immigration waves. When the populations of Southern Europe were considered altogether, this difference reached statistical significance. The A1555G mutation was not found in any of the 1042 samples tested.
  
  
  CONCLUSIONS
  Taking into account the 35delG carrier frequency found in this study, it could be estimated that 130-160 children with congenital deafness due to mutations in the connexin genes would be born per year in Argentina. In contrast, the mitochondrial mutation A1555G appears to be infrequent in general Argentinean population.
authors.affiliation: Laboratorio de Biología Molecular-Genética, Argentina.
authors.forename: Luis Pablo
authors.initials: LP
authors.lastname: Gravina
authors.forename: María Eugenia
authors.initials: ME
authors.lastname: Foncuberta
authors.forename: Rosaura Caron
authors.initials: RC
authors.lastname: Estrada
authors.forename: Cristina
authors.initials: C
authors.lastname: Barreiro
authors.forename: Lilien
authors.initials: L
authors.lastname: Chertkoff
mesh_terms: D001118:Argentina / Q000453:epidemiology; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D034381:Hearing Loss / Q000151:congenital / Q000453:epidemiology / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D007231:Infant, Newborn; D009154:Mutation / Q000235:genetics*; D020380:Needs Assessment; D015997:Neonatal Screening; D012313:RNA / Q000235:genetics*; D000077278:RNA, Mitochondrial; D012335:RNA, Ribosomal / Q000235:genetics*
chemical_list: D017630:Connexins; C000607042:GJB2 protein, human; D000077278:RNA, Mitochondrial; D012335:RNA, Ribosomal; C075526:RNA, ribosomal, 12S; D000072259:Connexin 26; D012313:RNA