Tetrahydrobiopterin therapy of atypical phenylketonuria due to defective dihydrobiopterin biosynthesis.

Abstract

A patient with atypical phenylketonuria (defective BH2 synthesis), detected at age 6 months because of severe muscle hypotonia and serum phenylalanine of 20 mg/100 ml, had normal activities of phenylalanine-4-hydroxylase and DHPR in liver biopsy, but only 2% activity in the phenylalanine-4-hyroxylase in vivo test using deuterated phenylalanine. After IV administration of 2.5 mg/kg chemically pure tetrahydrobiopterin bishydrochloride (BH4 . 2HCl), serum phenylalanine decreased from 20.4 to 2.1 mg/100 ml within 3 hours. Administration of 25 mg BH4 . HCl and 100 mg ascorbic acid through a gastric tube decrease; serum phenylalanine from 13.7 to less than 1.6 mg/100 ml within 3 hours and it remained less than 2 mg/100 ml for 2 days.

• Authors: J Schaub, S Däumling, H C Curtius, A Niederwieser, K Bartholomé, M Viscontini, B Schircks, J H Bieri
• Journal: Archives of disease in childhood (Arch Dis Child) Vol. 53 Issue 8 Pg. 674-6 (Aug 1978) ISSN: 1468-2044 [Electronic] England
• PMID: 708106 (Publication Type: Case Reports, Journal Article)

Chemical References

• Pteridines
• Biopterin
• Phenylalanine
• 7,8-dihydrobiopterin
• sapropterin

Topics

• Biopterin (analogs & derivatives, deficiency, therapeutic use)
• Female
• Humans
• Infant
• Phenylalanine (blood)
• Phenylketonurias (drug therapy, etiology)
• Pteridines (therapeutic use)