Blood–brain phenylalanine relationships in persons with phenylketonuria

R Koch, R Moats, F Guttler, P Guldberg… - Pediatrics, 2000 - publications.aap.org
Objectives. Clinicians caring for persons with phenylketonuria (PKU) have been perplexed
by the occasional normal individual with the classical biochemical profile consistent with the
diagnosis of PKU. Usually untreated subjects with the biochemical profile of blood
phenylalanine (Phe) levels> 1200 μmol/L are severely mentally retarded and may have
neurological findings. Preliminary reports have recently appeared suggesting that low brain
Phe levels, in comparison with elevated blood Phe levels, account for the occurrence of …