pediatrics
Purine Catabolism Disorders
Xanthine oxidase deficiency
Xanthine oxidase is the enzyme that catalyzes uric acid production from xanthine and hypoxanthine. Deficiency causes buildup of xanthine, which may precipitate in the urine, causing symptomatic stones with hematuria, urinary colic, and urinary tract infections. Diagnosis of xanthine oxidase deficiency is by DNA analysis. Enzyme determination requires liver or intestinal mucosal biopsy and is rarely indicated. Treatment of xanthine oxidase deficiency is high fluid intake to minimize likelihood of stone formation andallopurinolin some patients. 