Inborn Errors of Purine and Pyrimidine Metabolism

Defects in the metabolism of purines and pyrimidines, building blocks for nucleic acid synthesis and intermediates in the transfer of metabolic energy, represent some of the most challenging diagnostic problems in medicine. At least 27 disorders that arise as a result of dysfunction in purine and pyrimidine metabolism have already been documented. These defects are not easily recognised because of their low prevalence rates and also extremely variable signs and symptoms.

For monitoring in vitro activity of purine metabolism enzymes NOVOCIB has developed a range of homogenous microplate assays that allow:
• Accurate estimation of enzyme activity directly expressed in nmol/h;
• Through continuous monitoring at 340nm in a convenient 96-well plate;
• By simultaneous analysis of up to 24 samples per plate in 1h;
• Without sample preparation.

Several inherited disorders of purine metabolism have been described. Most of them are associated with severe clinical manifestations, such as neurological abnormalities of complete deficiency of hypoxanthine-guanine phosphoribosyltransferase (Lesch-Nyhan syndrome); a fatal immunodeficiency syndrome in adenosine deaminase and purine nucleoside phosphorylase. Inherited nerve deafness and severe muscular hypotonia may accompany PP-ribose-P synthetase superactivity, a unique urolithiasis - in adenine phosphoribosyltransferase. Other disorders, such as ITP pyrophosphohydrolase deficiency, myoadenylate deaminase deficiency or XOR deficiency alone may neither have no evident clinical consequences or be relatively bening (1).