Congenital Hyperuricemia

RESENT reports have established the existence of a sex-linked, recessive inborn error of purine metabolism in which hyperuricemia and hyperuricosuria are associated with a distinctive clinical syndrome.1-6Stunting of growth, retardation of mental and motor development, choreoathetosis, generalized spasticity, and compulsive selfmutilation characterize the clinical defect.3-6The metabolic abnormalities have been attributed to a deficiency of the enzyme inosinate phosphoribosy pyrophosphate transferase (IMP:PRPP transferase).7This enzyme mediates the conversion of hypoxanthine to inosinate (hypoxanthine ribosylphosphate), a reaction that permits the reutilization of hypoxanthine for nucleotide synthesis. Since hypoxanthine cannot be reutilized in patients with the disease, whatever hypoxan-thine is formed is either excreted or further catabolized to xanthine and uric acid. The hyperuricemia and hyperuricosuria in these patients also reflect a marked increase in de novo purine synthesis associated with an exceedingly rapid turnover of purine nucleotides.3 In the present report, the results of