Walsh & Hoyt: Disorders of Amino Acid Metabolism

Neonatal screening detects most children with phenylalaninemia but may miss children with causes of hyperphenylalaninemia that produce lower blood levels of phenylalanine. These diseases appear to be caused by alleles of the phenylketonuria mutation and generally do not have the same pathologic significance. Phenylalanine hydroxylase deficiency (PKU1, phenylketonuria). Dihydropteridine reductase deficiency (PKU2, malignant phenylalaninemia). Tyrosinemia. Maple syrup urine disease. Lowe syndrome (oculocerebrorenal syndrome).