This result was different from previous reports that showed urinary stones was one of the complications of hypouricemia.[10, 26] While it is well-recognized that hereditary renal hypouricemia due to the mutation of urate transporters frequently associated with urinary stones and renal failure, in our study hypouricemia per se did not increase urinary stones both in men and women, indicating the big gap of the rates of complications between hypouricemia per se and hereditary renal hypouricemia. This evidence concerns the gene SLC2A9 and urolithiasis.