|
Medical Definition of Malignant hyperphenylalaninaemia
1. DHPR-deficient form; an inherited disorder in which there is an absence or deficiency of dihydropteridine reductase (DHPR); this results in impaired regeneration of tetrahydrobiopterin, causing an elevation in phenylalanine levels, GTP-CH form; an inherited disorder in which there is a deficiency of guanosine triphosphate cyclohydrolase, an enzyme used in the biosynthesis of tetrahydrobiopterin, 6-PTS form; an inherited disorder in which there is a deficiency of 6-pyruvoyl tetrahydropterin synthase, an enzyme that participates in the biosynthesis of tetrahydrobiopterin. Synonym: nonclassical phenylketonuria. (05 Mar 2000)