title: Tetrahydropterin therapy for hyperphenylalaninemia caused by defective synthesis of tetrahydrobiopterin.
abstract: A patient with hyperphenylalaninemia caused by a defect in the synthesis of tetrahydrobiopterin was treated with 6-methyltetrahydropterin. This synthetic analog of the naturally occurring hydroxylation cofactor tetrahydrobiopterin, when given orally at a daily dose of 20 mg per kilogram of body weight increased depressed plasma and cerebrospinal fluid levels of norepinephrine. At a daily dose of 8 mg/kg, this pterin increased depressed cerebrospinal fluid levels of the biogenic amine metabolites dihydroxyphenylacetic acid, homovanillic acid, and 5-hydroxyindoleacetic acid. At these doses of 6-methyltetrahydropterin, there was an improvement of the patient's neurological symptoms, including a pronounced decrease in eye rolling and drooling and a marked increase in muscle strength, coordination, and physical activity.
mesh_terms: D001708:Biopterins / Q000031:analogs & derivatives / Q000378:metabolism / Q000627:therapeutic use*; D001786:Blood Glucose / Q000378:metabolism; D002648:Child; D004305:Dose-Response Relationship, Drug; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D008297:Male; D018377:Neurotransmitter Agents / Q000134:cerebrospinal fluid; D010649:Phenylalanine / Q000097:blood*; D010661:Phenylketonurias / Q000188:drug therapy* / Q000201:enzymology; D011388:Prolactin / Q000097:blood; D011621:Pteridines / Q000627:therapeutic use*; D011622:Pterins / Q000627:therapeutic use
chemical_list: D001786:Blood Glucose; D018377:Neurotransmitter Agents; D011621:Pteridines; D011622:Pterins; D001708:Biopterins; D010649:Phenylalanine; D011388:Prolactin; D013006:Growth Hormone; C017523:6-methyltetrahydropterin; C003402:sapropterin