title: Dihydropyrimidine dehydrogenase deficiency leading to thymine-uraciluria. An inborn error of pyrimidine metabolism.
abstract: Three unrelated patients with excessive thymine-uraciluria due to dihydropyrimidine dehydrogenase deficiency are described. Excretory values (mmol/g creatinine) were: uracil 2.0-10.5, thymine 2.3-7.5, 5-hydroxymethyluracil 0.2-0.9. Orally administered (index patient) uracil and thymine were excreted for the greater part whilst dihydrouracil and S-dihydrothymine were mainly metabolised. Dihydropyrimidine dehydrogenase activities (nmol X h-1 X mg-1 protein) in leucocytes were 0.04, 0.01 and less than 0.01 in the patients, 0.31-1.66 in their parents, and 1.01-4.46 in controls (n = 4). The patients presented with a non-specific clinical picture of cerebral dysfunction.
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002855:Chromatography, Thin Layer; D042943:Dihydrouracil Dehydrogenase (NADP); D005260:Female; D006801:Humans; D007962:Leukocytes / Q000201:enzymology; D008297:Male; D013058:Mass Spectrometry; D010088:Oxidoreductases / Q000172:deficiency*; D010432:Pentoxyl / Q000031:analogs & derivatives / Q000652:urine; D011686:Purine-Pyrimidine Metabolism, Inborn Errors / Q000201:enzymology* / Q000652:urine; D013941:Thymine / Q000652:urine*; D014498:Uracil / Q000652:urine*
chemical_list: C008055:5-hydroxymethyluracil; D014498:Uracil; D010432:Pentoxyl; D010088:Oxidoreductases; D042943:Dihydrouracil Dehydrogenase (NADP); D013941:Thymine