Pyrimidine and purine metabolites in ornithine carbamoyl transferase deficiency

Detailed biochemical studies have been carried out in a female heterozygote for ornithine carbamoyl-transferase (OCT) deficiency. Increased levels of the pyrimidines, orotic acid, uridine and uracil, were observed in plasma as well as urine by utilizing an adaptation of high performance liquid chromatography (HPLC). Urinary clearances of these compounds were high, that of orotic acid indicating net secretion. Urinary uric acid clearance was also elevated, a finding attributed to the uricosuric effect of the orotic acid excreted concomitantly. The results in this child and her family are typical of OCT deficiency. They confirm considerable genetic heterogeneity in the biochemical as well as clinical expression in this defect.