Niederwieser A Curtius HC 1987 It has been proven that the most common defect in the tetrahydrobiopterin biosynthesis is caused by 6-pyruvoyl tetrahydropterin synthase deficiency. The enzyme 6-pyruvoyl tetrahydropterin synthase consists of four identical subunits which convert dihydroneopterin triphosphate to 6-pyruvoyl tetrahydropterin in the presence of magnesium. UV, NMR, and MS data prove that the enzyme catalyzes the elimination of triphosphate as well as the intramolecular rearrangement. The 6-pyruvoyl tetrahydropterin synthase activity was measured in fetal erythrocytes and together with the neopterin and biopterin measurements in amniotic fluid this enabled performing prenatal diagnosis of 6-pyruvoyl tetrahydropterin synthase deficiency. Peripheral tetrahydrobiopterin deficiency was shown to be due to an incomplete 6-pyruvoyl tetrahydropterin synthase deficiency or heterozygosity. https://sonar.ch/global/documents/118455 eng info:eu-repo/semantics/altIdentifier/doi/10.1159/000469220 info:eu-repo/semantics/altIdentifier/pmid/3326735 Enzyme. - 1987 Alcohol Oxidoreductases Biopterin Female Humans Phenylalanine Phenylketonurias Phosphorus-Oxygen Lyases Pregnancy Prenatal Diagnosis Tetrahydrobiopterin biosynthetic pathway and deficiency. http://purl.org/coar/resource_type/c_6501