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.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bartholomé K., Byrd D. J., Kaufman S., Milstien S. Atypical phenylketonuria with normal phenylalanine hydroxylase and dihydropteridine reductase activity in vitro. Pediatrics. 1977 May;59(5):757–761. [PubMed] [Google Scholar]
- Bartholomé K., Lutz P., Bickel H. Determination of phenylalanine hydroxylase activity in patients with phenylketonuria and hyperphenylalaninemia. Pediatr Res. 1975 Dec;9(12):899–903. doi: 10.1203/00006450-197512000-00006. [DOI] [PubMed] [Google Scholar]
- Curtius H. C., Völlmin J. A., Baerlocher K. The use of deuterated phenylalanine for the elucidation of the phenylalanine-tyrosine metabolism. Clin Chim Acta. 1972 Mar;37:277–285. doi: 10.1016/0009-8981(72)90442-1. [DOI] [PubMed] [Google Scholar]
- Curtius H. C., Zagalak M. J., Baerlocher K., Schaub J., Leimbacher W., Redweik U. In vivo studies of the phenylalanine-4-hydroxylase system in hyperphenylalaninemics and phenylketonurics. Helv Paediatr Acta. 1978 Feb;32(6):461–469. [PubMed] [Google Scholar]
- Danks D. M., Cotton R. G., Schlesinger P. Letter: Tetrahydrobiopterin treatment of variant form of phenylketonuria. Lancet. 1975 Nov 22;2(7943):1043–1043. doi: 10.1016/s0140-6736(75)90335-9. [DOI] [PubMed] [Google Scholar]
- Kaufman S., Holtzman N. A., Milstien S., Butler L. J., Krumholz A. Phenylketonuria due to a deficiency of dihydropteridine reductase. N Engl J Med. 1975 Oct 16;293(16):785–790. doi: 10.1056/NEJM197510162931601. [DOI] [PubMed] [Google Scholar]
- Kettler R., Bartholini G., Pletscher A. In vivo enhancement of tyrosine hydroxylation in rat striatum by tetrahydrobiopterin. Nature. 1974 May 31;249(456):476–478. doi: 10.1038/249476a0. [DOI] [PubMed] [Google Scholar]