title: Cystic fibrosis carrier screening effects on birth prevalence and newborn screening.
abstract: OBJECTIVE
  We evaluated the effects of cystic fibrosis (CF) carrier screening on birth prevalence trends and newborn screening (NBS) efficiency by comparing two Italian regions; carrier screening was performed in one region (eastern region (ER)) and not in the other (western region (WR)).
  
  
  METHODS
  Annual births of infants with CF, NBS false-positive results, NBS uncertain diagnoses (borderline sweat chloride (BSC)), carrier tests performed, and carriers detected were monitored during the 1993-2013 period.
  
  
  RESULTS
  A total of 259 newborns with CF were detected. In the ER, 150 carrier couples were found. Mean annual percentage of birth prevalence decrease was 9% per 10,000 (P = 0.002) and was greater in the ER (15%, P = 0.0008; WR 1%, P = ns). The WR estimated birth prevalence was 1/3,589 in 1993 and 1/3,870 in 2013; in the ER it was 1/2,730 in 1993 and 1/14,200 in 2013. The ER birth prevalence correlated inversely with the number of carrier couples (P = 0.0032). The ratio between CF cases and NBS-positive results significantly decreased in the ER (1.6%, P = 0.0001) but not in the WR. The ratio between prevalence of BSC and of CF cases increased in the ER (P = 0.008) but not in the WR (P = 0.1).
  
  
  CONCLUSIONS
  Carrier screening was connected with a decrease in birth prevalence of CF. Poorer NBS performance was observed in the carrier screening area.
authors.affiliation: Cystic Fibrosis Center, Azienda Ospedaliera Universitaria Integrata, Verona, Italy.
authors.forename: Carlo
authors.identifier: http://orcid.org/0000-0003-1916-0963
authors.initials: C
authors.lastname: Castellani
authors.affiliation: Department of Pediatrics, University of Padua, Padua, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Picci
authors.affiliation: Cystic Fibrosis Center, Azienda Ospedaliera Universitaria Integrata, Verona, Italy.
authors.forename: Gloria
authors.initials: G
authors.lastname: Tridello
authors.affiliation: Cystic Fibrosis Center, Azienda Ospedaliera Universitaria Integrata, Verona, Italy.
authors.forename: Elia
authors.initials: E
authors.lastname: Casati
authors.affiliation: Clinical Chemistry and Hematology Laboratory, Azienda Ospedaliera Universitaria Integrata, Verona, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Tamanini
authors.affiliation: ULSS 12 "Veneziana"-Ospedale SS.Giovanni e Paolo-Venezia, Venezia, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Bartoloni
authors.affiliation: Department of Pediatrics, University of Padua, Padua, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Scarpa
authors.affiliation: Cystic Fibrosis Center, Azienda Ospedaliera Universitaria Integrata, Verona, Italy.
authors.forename: Baroukh M
authors.initials: BM
authors.lastname: Assael
mesh_terms: D003550:Cystic Fibrosis / Q000175:diagnosis / Q000453:epidemiology* / Q000235:genetics*; D005820:Genetic Testing; D006579:Heterozygote; D006801:Humans; D007231:Infant, Newborn; D007558:Italy / Q000453:epidemiology; D015997:Neonatal Screening; D015995:Prevalence