[Newborn screening for cystic fibrosis, a clinical geneticist perspective]

Newborn screening for cystic fibrosis was initiated 35 years ago but the test has been much less established than phenylketonuria or congenital hypothyreosis screening. Among several reasons for continuous discussion on newborn screening for cystic fibrosis, there are evolving methodology and concurrent use of sequential immunoreactive trypsinogen blood assays or their combination with targeted mutation detection. False positive rate is substantial, depending on the method 3 to 24 children have to be re-screened or undergo chloride sweat test for one diagnosis of cystic fibrosis. Early diagnosis of cystic fibrosis saves the patient malnutrition but more evidences are needed to document an impact on pulmonary symptoms progression. Economical balance of newborn screening for cystic fibrosis may be advantageous but no evaluation of this screening on a psychological reception by the society is available. Some effects of the newborn screening on the procreation have been recently recognized suggesting its eugenics interpretation.