title: Mutational analysis for GJB2, GJB6, and GJB3 genes in Campania within a universal neonatal hearing screening programme.
abstract: OBJECTIVE
  To determine the incidence of GJB2 and GJB3 mutations and of two deletions upstream of the GJB6 gene in infants of the Campania region of southern Italy.
  
  
  METHODS
  DNA samples from non-syndromic hearing-impaired infants enrolled in a neonatal screening programme for sensorineural hearing loss were analysed by PCR and by direct sequencing. The audiological features of infants with biallelic GJB2 mutations were also examined to identify genotype-phenotype correlations.
  
  
  METHODS
  Molecular analyses were carried out in 129 affected and five unaffected infants.
  
  
  RESULTS
  A genetic etiology of hearing loss was identified in 28% of infants, including several at environmental risk of hearing loss. Neither GJB6 nor GJB3 (a gene not previously investigated in the Campania population) mutations were found.
  
  
  CONCLUSIONS
  This study confirms the importance of universal neonatal hearing screening. The identification of a genetic cause in infants at environmental risk indicates that such infants should be included when investigating etiology. We confirm that also in our geographical area, c.35delG homozygotes tend to have severe symmetrical hearing loss, whereas hearing impairment is milder in compound heterozygotes.
authors.affiliation: CEINGE-Biotecnologie Avanzate, Naples, Italy.
authors.forename: Viviana
authors.initials: V
authors.lastname: Chinetti
authors.forename: Sandra
authors.initials: S
authors.lastname: Iossa
authors.forename: Gennaro
authors.initials: G
authors.lastname: Auletta
authors.forename: Virginia
authors.initials: V
authors.lastname: Corvino
authors.forename: Maria
authors.initials: M
authors.lastname: De Luca
authors.forename: Francesca
authors.initials: F
authors.lastname: De Falco
authors.forename: Pasquale
authors.initials: P
authors.lastname: Giannini
authors.forename: Giorgio
authors.initials: G
authors.lastname: Lilli
authors.forename: Rita
authors.initials: R
authors.lastname: Malesci
authors.forename: Pasquale
authors.initials: P
authors.lastname: Riccardi
authors.forename: Elio
authors.initials: E
authors.lastname: Marciano
authors.forename: Annamaria
authors.initials: A
authors.lastname: Franzè
mesh_terms: D000072259:Connexin 26; D000075302:Connexin 30; D017630:Connexins / Q000235:genetics*; D004252:DNA Mutational Analysis; D056726:Genetic Association Studies; D006319:Hearing Loss, Sensorineural / Q000453:epidemiology / Q000235:genetics*; D006801:Humans; D015994:Incidence; D007223:Infant; D007558:Italy / Q000453:epidemiology; D008403:Mass Screening; D017384:Sequence Deletion
chemical_list: D000075302:Connexin 30; D017630:Connexins; C000607042:GJB2 protein, human; C491020:GJB6 protein, human; D000072259:Connexin 26; C068044:GJB3 protein, human