MECHANISM OF HYPOURICEMIA IN A CHILD WITH THE NORMOTENSIVE FORM OF GORDONS-SYNDROME

The mechanism of renal tubular urate transport disorder was studied by the pyrazinamide and probenecid tests in a 12-year-old hypouricemic b oy suffering from the normotensive form of Gordon's syndrome, with inc reased distal tubular reabsorption of NaCl (confirmed by the hypotonic saline diuresis test). The aim of the study was to determine the impa ct of oral hydration during the tests on the phases of renal tubular u rate transport: before (I), and during long-term hydrochlorothiazide t herapy (0.5 mg/kg BW/day) (II), In both periods (I, II), presecretory reabsorption of urate was within normal limits, Hypouricemia in our pa tient was caused by decreased postsecretory reabsorption, with or with out simultaneous increase of tubular urate secretion. The degree of ov erhydration determines which of these mechanisms is responsible for in creased renal urate clearance.