New Defects of Pyrimidine Metabolism
The number of inherited defects of the pyrimidine metabolism described so far is small, compared to that of the purine metabolism. Combined deficiency of orotate phosphoribosyltransferase (OPRT) (EC 22.214.171.124) and orotidine 5′-monophosphate decarboxylase (ODC) (EC 126.96.36.199), designated as type I hereditary orotic aciduria, presents with characteristic clinical features such as hypo-chromic anemia with a megaloblastic bone marrow and crystalluria. Only six patients have been described and, as far as we know, new cases have not been discovered recently. ODC deficiency with similar clinical phenomena and leading to increased urinary excretion of orotate and orotidine has been detected in only one patient (1). A third defect, a deficiency of pyrimidine 5′-nucleotidase (Py-5N). (EC 188.8.131.52.) in erythrocytes, is associated with chronic hemolytic anemia and prominent basophylic stippling of the erythrocytes due to accumulated pyrimidine nucleotides. An increasing number of patients have been reported, their detection being facilitated by the typical phenomena. We do not know whether the urinary pyrimidine profile in this condition is abnormal.
KeywordsHigh Performance Liquid Chromatography Orotic Acid Isobutyric Acid Pyrimidine Metabolism Organic Acid Analysis
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- 1.W.N. Kelley and L.H. Smith Jr., Hereditary orotic aciduria, in ‘The Metabolic Basis of Inherited Disease’, eds. J.B. Stanbury, J.B. Wijngaarden, D.S. Frederickson, McGraw-Hill Book Co., New York (1978), pp 1045–1071.Google Scholar
- 2.J.P. Kamerling, M. Brouwer, D. Ketting and S.K. Wadman, Gas chromatography of urinary N-phenylacetylglutam;ne, J. Chromatogr. 64: 217–221 (1979).Google Scholar
- 3.S.K. Wadman, P.K. de Bree, A.H. van Gennip, J.W. Stoop, B.J.M. Zegers and G.E.J. Staal, Urinary purines in a patient with a severely defective T cell immunity and a purine nucleoside phosphorylase deficiency, in “Purine Metabolism in Man-II: regulation of pathways and enzyme defects”, M.M. Müller, E. Kaiser and J.E. Seegmiller, Plenum Publishing Corporation, New York (1977) pp 471–477.Google Scholar
- 5.A.H. van Gennip, E.J. van Bree-Blom, S.K. Wadman, M. Duran and F.A. Beemer, HPLC of urinary pyrimidines for the evaluation of primary and secondary abnormalities of pyrimidine metabolism, in “Biological/biomedical Applications of Liquid Chromatography III, ed. G.L. Hawk, Marcel Dekker, Inc. New York and Basel (1982), pp 285–296.Google Scholar
- 8.A.H. van Gennip, Screening for disorders of purine and pyrimidine metabolism. A chromatographic approach. Thesis., Utrecht (1982).Google Scholar