[Xanthinuria (author's transl)].

Xanthinuria, described in 1954 by Dent and Philpot, is a rare metabolic disorder, characterised by a deficiency in xanthine-oxidase, a key enzyme in the synthesis of uric acid. It results in hypouricaemia and hypouricuria, the urinary excretion of products of purine synthesis taking place in the form of uric acid precursors: hypoxanthine and xanthine. By virtue of the very slight solubility of xanthine, this xanthinuria may cause urinary lithiasis, in general occurring early. More often, however, the disease is asymptomatic and diagnosed following the chance discovery of hypouricaemia. We report 6 recent cases.