Newborn screening strategy for cystic fibrosis: a field study in an area with high allelic heterogeneity

Acta Paediatr. 1997 May;86(5):497-502. doi: 10.1111/j.1651-2227.1997.tb08920.x.


To verify to what extent mutation analysis on blood spot could improve cystic fibrosis neonatal screening in an area with high allelic heterogeneity, we designed a special protocol. Spot trypsin estimation at birth, trypsin re-testing after 1 month, meconium lactase testing and mutation analysis of delta F508, R1162X and N1303K, were retrospectively clustered according to different patterns (trypsin/lactase/mutation; trypsin/lactase/re-testing; trypsin/mutation) and compared. The programme, which lasted 2 years (1993-94) and covered most of North-eastern Italy, included 95,553 screened newborns. Thirty-four affected babies were detected by screening and one by meconium ileus (incidence 1/2730). The combined use of trypsin, lactase and mutation analysis in cystic fibrosis neonatal screening permits a better sensitivity compared to the two other combinations (34 diagnoses vs 32 in both cases). Moreover, the higher specificity of the former method (false positives 42 vs 148) allows a reduction of recalls, which cause considerable anxiety. We confirm in trypsin-positive newborns an increased frequency of cystic fibrosis heterozygotes (1/17).

MeSH terms

  • Clinical Protocols
  • Cystic Fibrosis / genetics*
  • Cystic Fibrosis / metabolism
  • Cystic Fibrosis / prevention & control*
  • DNA Mutational Analysis / methods
  • Genetic Heterogeneity*
  • Genetic Testing / methods*
  • Humans
  • Infant, Newborn
  • Italy
  • Lactase
  • Meconium / chemistry
  • Neonatal Screening / methods*
  • Reproducibility of Results
  • Retrospective Studies
  • Trypsin / blood
  • beta-Galactosidase / analysis


  • Lactase
  • beta-Galactosidase
  • Trypsin