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; Hyperphenylalaninaemias; Phenylalanine Hydroxylase Deficiency Disease; Deficiency Disease, Dihydropteridine Reductase; Deficiency Disease, Phenylalanine Hydroxylase, Severe; Folling's Disease; Oligophrenia Phenylpyruvica; Phenylalanine Hydroxylase Deficiency; Phenylalanine Hydroxylase Deficiency Disease, Severe; Phenylketonuria I; Phenylketonuria II; Phenylketonuria Type 2; Phenylketonuria, Atypical; Phenylketonuria, Classical; Atypical Phenylketonuria; Atypical Phenylketonurias; Classical Phenylketonurias; Deficiencies, Phenylalanine Hydroxylase; Deficiency, Phenylalanine Hydroxylase; Disease, Folling; Disease, Folling's; Diseases, Folling; Folling Diseases; Hydroxylase Deficiencies, Phenylalanine; Hydroxylase Deficiency, Phenylalanine; Hyperphenylalaninemia, Non Phenylketonuric; Hyperphenylalaninemias, Non-Phenylketonuric; Non-Phenylketonuric Hyperphenylalaninemia; Non-Phenylketonuric Hyperphenylalaninemias; Oligophrenia Phenylpyruvicas; Phenylalanine Hydroxylase Deficiencies; Phenylketonuria IIs; Phenylketonuria Is; Phenylketonuria Type 2s; Phenylketonurias, Atypical; Phenylketonurias, Classical; Phenylpyruvica, Oligophrenia; Phenylpyruvicas, Oligophrenia; Dihydropteridine Reductase Deficiency Disease; Hyperphenylalaninemia, Non-Phenylketonuric