Congenital and neurological abnormalities in infants with phenylketonuria.

We reported the occurrence of congenital and neurological abnormalities in 150 children with phenylketonuria (PKU) age 1 year or older, who have been treated with a restricted phenylalanine diet, according to the protocol used in a nation-wide longitudinal collaborative study of children treated for PKU. The overall occurrence (9.3%) of congenital anomalies was not significantly different from that of a general population, except for an apparent increased incidence of pyloric stenosis. None of the subjects had a persistent major neurological defect.