The urinary excretion of aminoimidazolecarboxamide in the Lesch-Nyhan syndrome

The urinary excretion of aminoimidazolecarboxamide (AIC), an intermediate in purine synthesis, was studied in five patients with the Lesch-Nyhan syndrome. The mean urinary AIC level for these subjects was 12.03 ± 6.9 mg AIC/mg creatinine as compared to a mean urinary excretion in normal subjects of 1.2 ± 0.6 mg AIC/mg creatinine. None of the patients had clinical evidence of megaloblastic anemia at the time of the study, and their serum folate levels were within the normal range. The increased urinary AIC excretion probably represents a reflection of the deranged purine metabolism in this syndrome and its measurement can be used as a screen for the Lesch-Nyhan syndrome and other disorders of purine and/or folate metabolism.