Familial renal hypouricaemia: two additional cases with uric acid lithiasis.

Two families are reported affected with hereditary renal hypouricaemia associated with uric acid lithiasis. The propositi of both families were found also to have hyperabsorptive hypercalciuria. Based on the study of the effect of pyrazinamide and probenecid on uric acid excretion in both propositi, it is suggested that the defect in uric acid reabsorption is most probably at the pre-secretory site.