Familial hypouricaemia due to renal tubular defect of urate transport.

A 28-year-old man was found to have hypouricaemia (plasma uric acid, 0.40 to 1.25 mg/100 ml). The 24-hour urinary urate excretion on a low purine diet was 690 mg, a value higher than the mean value of 419 mg for gouty Japanese patients. Urate clearance was 88.5 ml/min--approximately the same as the endogeneous creatinine clearance. The ratio of urate clearance to creatinine clearance was scarcely altered by pyrazinamide, but diminished by probenecid (from 69.2% to 52.4%). No other renal tubular abnormalities were detected. The findings in this subject may be accounted for by a nearly complete tubular defect in reabsorptive transport mechanisms of urate. A survey of his family revealed at least three similarly affected persons, who were all from consanguineous marriages. The hypouricaemia was transmitted as an autosomal trait.