Newborn screening for metabolic disorders

Our lives are often directed by chance occurrences. For Robert Guthrie, a lifelong interest in the cause of mental retardation came from a retarded son and a dedication to preventing mental retardation in phenylketonuria (PKU) came from the diagnosis of PKU in his wife's mentally retarded niece. 1,2 From these roots came Guthrie's introduction of newborn screening for PKU 3 and, subsequently, to the much more inclusive newborn screening for metabolic disorders of today. In this review, we endeavor to describe current newborn screening, the interrelationship between the public and private sectors, the range of metabolic disorders that can be covered by screening, with emphasis on recent expansion using tandem mass spectrometry (MS/MS), the reported outcomes of identified infants, and a number of issues that confront newborn screening.