Neonatal Screening for Phenylketonuria

Abstract

Programs for the detection of phenylketonuria (PKU) were evaluated by surveys of health departments and PKU clinics. Effectiveness was measured by determining (1) the proportion of live births screened, (2) the occurrence of PKU infants missed by screening (false-negatives), (3) the proportion of presumptive positives in whom a diagnosis of PKU was confirmed by follow-up studies, and (4) the interval between screening test and follow-up. More than 10% of infants with PKU are either not being screened or are not being detected by screening. Infants with PKU who are screened on the first 3 days of life are more likely to be missed than those screened later. The infants in whom a diagnosis of PKU was confirmed constituted only 5.1% of all infants with presumptive positive screening tests. Programs differ greatly in the incidence of presumptive positive tests and in the time necessary to follow up positive tests. (JAMA229:667-670, 1974)