title: 6-pyruvoyl tetrahydropterin synthase deficiency: a case report.
abstract: A 5 day old girl screened positive for hyperphenylalaninemia on routine newborn screening. Initial diagnostic work-up showed elevated blood phenylalanine of 1100 mmol/L and low tyrosine. Limited protein diet and phenylalanine-free formula were prescribed. Further investigation revealed a defect in biopterin metabolism. Urine had no detectable biopterin (BH4) and an elevated level of neopterin at 24.31 mmol/mole Cr. Enzymatic assay showed zero level of 6-pyruvoyl tetrahydropterin synthase. The activity in the mother was 3.5 or 19.9% of controls consistent with heterozygosity. The concentrations of 5-hydroxyindoleacetic acid and homovanillic acid in the cerebrospinal fluid were below the reference ranges. A treatment regimen of BH4 tablets, 5 hydroxytryptophan and DOPA was initiated. The diagnostic evaluation, management and follow-up of patients with this disorder will be outlined. This is the first reported case of a Filipino with a defect in biopterin metabolism.
authors.affiliation: Department of Pediatrics, Section of Endocrinology and Metabolic Disorders, University of the Philippines-Philippine General Hospital, Manila.
authors.forename: Sylvia B
authors.initials: SB
authors.lastname: Capistrano-Estrada
authors.forename: William L
authors.initials: WL
authors.lastname: Nyhan
mesh_terms: D006916:5-Hydroxytryptophan / Q000008:administration & dosage; D001708:Biopterins / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000172:deficiency / Q000652:urine; D004295:Dihydroxyphenylalanine / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D015997:Neonatal Screening; D019798:Neopterin / Q000652:urine; D010661:Phenylketonurias / Q000175:diagnosis* / Q000188:drug therapy / Q000201:enzymology; D019761:Phosphorus-Oxygen Lyases / Q000172:deficiency* / Q000378:metabolism
chemical_list: D001708:Biopterins; D004295:Dihydroxyphenylalanine; D019798:Neopterin; D006916:5-Hydroxytryptophan; D019761:Phosphorus-Oxygen Lyases; C043497:6-pyruvoyltetrahydropterin synthase; C003402:sapropterin