Health Dictionary
Reliable, easy-to-read patient information on common medical conditions — written in plain language, free of jargon, and grounded in current evidence. Browse the most frequent diagnoses, understand what they mean for everyday life, and learn which steps and questions help you have a focused conversation with your doctor.
Tetrahydrobiopterin
Introduction
Synonyms and keywords: 5,6,7,8-tetrahydrobiopterin, BH4
Overview
Overview
Tetrahydrobiopterin is a cofactor in the synthesis of nitric oxide. It is also essential in the conversion of phenylalanine to tyrosine by the enzyme phenylalanine-4-hydroxylase; the conversion of tyrosine to L-dopa by the enzyme tyrosine hydroxylase; and conversion of tryptophan to 5-hydroxytryptophan via tryptophan hydroxylase.
Clinical significance
Clinical significance
A defect in BH4 production and/or a defect in the enzyme dihydropteridine reductase (DHPR) causes phenylketonuria type IV, as well as dopa-responsive dystonias.
References
References
Thony B, Auerbach G, Blau N (2000). “Tetrahydrobiopterin biosynthesis, regeneration and functions”. Biochem J. 347 Pt 1: 1–16. PMID 10727395.
See also
See also
- Tetrahydrobiopterin deficiency This can also cause mental retardation as seen in patients with Phenylketonuria (PKU).
External links
External links
Editor-In-Chief: Template:Chembox new C. Michael Gibson, M.S., M.D. [1]