Newborn screening for cystic fibrosis.

Newborn screening for cystic fibrosis (CF NBS) has been introduced in almost all of the Western countries, and most of the children with CF are now being identified via CF NBS before disease-related symptoms develop. This review summarizes the evidence that has been generated to date to support the benefit of CF NBS and the various screening algorithms that are used in different jurisdictions. A special focus is directed towards the challenges arising from false-negative and -positive screening results. Finally, we review the emerging data reporting on positively-screened newborns, in whom confirmatory sweat testing resulted in an inconclusive diagnosis for CF.