hyperphenylalaninemia

Etiology

 phenylketonuria (MIM.261600)
 hyperphenylalaninemia with primapterinuria (MIM.264070)

NB: Phenylketonuria (PKU) is an autosomal recessive inborn error of metabolism resulting from a deficiency of phenylalanine hydroxylase (EC 1.14.16.1), an enzyme that catalyzes the hydroxylation of phenylalanine to tyrosine, the rate-limiting step in phenylalanine catabolism. The reaction is dependent on tetrahydrobiopterin (BH4), as a cofactor, molecular oxygen, and iron.

NB: Hyperphenylalaninemia with primapterinuria (MIM.264070) is caused by mutation in the PCBD gene (MIM.126090), which encodes the bifunctional protein pterin-4-alpha-carbinolamine dehydratase/dimerization cofactor of hepatocyte nuclear factor-1-alpha.