A group of autosomal recessive disorders marked by a deficiency of the hepatic enzyme PHENYLALANINE HYDROXYLASE or less frequently by reduced activity of DIHYDROPTERIDINE REDUCTASE (i.e., atypical phenylketonuria). Classical phenylketonuria is caused by a severe deficiency of phenylalanine hydroxylase and presents in infancy with developmental delay; SEIZURES; skin HYPOPIGMENTATION; ECZEMA; and demyelination in the central nervous system. (From Adams et al., Principles of Neurology, 6th ed, p952).
Also Known As:
Phenylketonuria; Classical Phenylketonuria; Deficiency Disease, Phenylalanine Hydroxylase; Folling Disease; Hyperphenylalaninaemia; Non Phenylketonuric Hyperphenylalaninemia; Phenylalanine Hydroxylase Deficiency Disease; BH4 Deficiency; DHPR Deficiency; Deficiency Disease, Dihydropteridine Reductase; Deficiency Disease, Phenylalanine Hydroxylase, Severe; Dihydropteridine Reductase Deficiency; Folling's Disease; HPABH4C; Hyperphenylalaninemia Caused by a Defect in Biopterin Metabolism; Hyperphenylalaninemia, BH4-Deficient, C; Hyperphenylalaninemia, Tetrahydrobiopterin-Deficient, Due To DHPR Deficiency; Non-Phenylketonuric Hyperphenylalaninemia; Oligophrenia Phenylpyruvica; PAH Deficiency; PKU, Atypical; Phenylalanine Hydroxylase Deficiency; Phenylalanine Hydroxylase Deficiency Disease, Severe; Phenylketonuria I; Phenylketonuria II; Phenylketonuria Type 2; Phenylketonuria, Atypical; Phenylketonuria, Classical; QDPR Deficiency; Quinoid Dihydropteridine Reductase Deficiency; Tetrahydrobiopterin Deficiency; Atypical PKU; Atypical Phenylketonuria; Biopterin Deficiencies; Deficiency, BH4; Deficiency, Biopterin; Deficiency, DHPR; Deficiency, Dihydropteridine Reductase; Deficiency, PAH; Deficiency, Phenylalanine Hydroxylase; Deficiency, QDPR; Deficiency, Tetrahydrobiopterin; Disease, Folling; Disease, Folling's; Hyperphenylalaninemia, Non Phenylketonuric; Non-Phenylketonuric Hyperphenylalaninemias; Biopterin Deficiency; Dihydropteridine Reductase Deficiency Disease; Hyperphenylalaninemia, Non-Phenylketonuric