title: Evaluation of newborn screening bloodspot-based genetic testing as second tier screen for bedside newborn hearing screening.
abstract: OBJECTIVE
  : Bedside newborn hearing screening is highly successful in identifying deaf or hard-of-hearing infants. However, newborn hearing screening protocols have high loss to follow-up rates. We propose that bloodspot-based genetic testing for GJB2 alleles can provide a means for rapid confirmation in a subset of infants who fail bedside newborn hearing screening.
  
  
  METHODS
  : We performed a case-control study comparing the prevalence of common GJB2 mutations from deidentified bloodspots designated as "refer" by newborn hearing screening and contemporaneously selected randomly chosen controls designated as "pass." Between March 2006 and December 2007, 2354 spots were analyzed for common alleles, c.35delG, c.167delT, c.235delC, and p.V37I in GJB2 with a subset reanalyzed by conventional Sanger sequencing to search for additional alleles.
  
  
  RESULTS
  : The prevalence of biallelic GJB2 mutations in bloodspots from infants who referred by newborn hearing screening is approximately 1 in 50 (23/1177). In contrast, one bloodspot from an infant who passed newborn hearing screening was identified to harbor biallelic GJB2 mutations.
  
  
  CONCLUSIONS
  : These findings show that when a newborn refers by newborn hearing screening, there is a significant chance that GJB2-related hearing loss is present. Bloodspot-based genetic testing for common GJB2 alleles should be considered as second tier testing for bedside newborn hearing screening.
authors.affiliation: Departments of Pediatrics University of Minnesota, Minneapolis, USA. las@umn.edu
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Schimmenti
authors.forename: Berta
authors.initials: B
authors.lastname: Warman
authors.forename: Mark R
authors.initials: MR
authors.lastname: Schleiss
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Daly
authors.forename: Julie A
authors.initials: JA
authors.lastname: Ross
authors.forename: Mark
authors.initials: M
authors.lastname: McCann
authors.forename: Anne M
authors.initials: AM
authors.lastname: Jurek
authors.forename: Susan A
authors.initials: SA
authors.lastname: Berry
mesh_terms: D000483:Alleles; D014408:Biomarkers, Tumor / Q000097:blood / Q000235:genetics*; D016022:Case-Control Studies; D000072259:Connexin 26; D017630:Connexins / Q000097:blood / Q000235:genetics*; D004252:DNA Mutational Analysis; D005500:Follow-Up Studies; D005820:Genetic Testing / Q000379:methods*; D005838:Genotype; D006309:Hearing / Q000502:physiology*; D034381:Hearing Loss / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics; D006801:Humans; D007231:Infant, Newborn; D009154:Mutation; D015997:Neonatal Screening / Q000379:methods*; D015995:Prevalence; D014481:United States / Q000453:epidemiology
chemical_list: D014408:Biomarkers, Tumor; D017630:Connexins; C000607042:GJB2 protein, human; D000072259:Connexin 26