Newborn screening: complexities in universal genetic testing.

Newborn screening (NBS)--in which each newborn infant is screened for up to 50 specific metabolic disorders for early detection and intervention--is the first program of populationwide genetic testing. As a public health intervention, NBS has greatly improved the lives of thousands of affected children. New technologies and new economic and social forces pose significant ethical and clinical challenges to NBS. Two primary challenges concern (1) accommodating clinical and ethical standards to rapid technological developments in NBS and (2) preparing public health systems to respond to the medical advances and social forces driving expansion of NBS programs. We describe and analyze these challenges through consideration of 3 disorders: phenylketonuria, medium-chain acyl-CoA dehydrogenase deficiency, and cystic fibrosis.