A case of gouty arthritis associated with Down's syndrome.

Gouty arthritis developed in a twenty-one-year-old male whose karyotyping showed Trisomy 21. His serum urate level was 13.1 mg per 100 ml and his twenty-four-hour urinary uric acid excretion was 431 mg on a low purine diet. Uric acid clearance was decreased to 3.9 ml per minute. The cumulative incorporation of N15-glycine into urinary uric acid during successive seven days was 0.144 per cent, which was within the normal range. Diminished uric acid clearance may be attributed to this hyperuricaemia. The cause of gouty arthritis and Down's syndrome in the patient is discussed.