Poor renal uptake of99mtechnetium-dimercaptosuccinic acid and near-normal99mtechnetium-mercaptoacetyltriglycine renogram in nephronophthisis

Four patients with the clinical diagnosis of nephronophthisis are presented, all having a very poor renal uptake of^99mtechnetium-dimercaptosuccinic acid (^99mTc-DMSA) but clearly visualized kidneys on early images with^99mtechnetium-mercaptoacetyltriglycine and a normal or almost normal renogram. There was no difference between a young patient in an early stage of the disease and the other three patients with more advanced renal disease. In contrast, a patient with tubulointerstitial nephritis with uveitis had considerably better renal uptake of^99mTc-DMSA despite impaired renal function. We suggest that the specific tubular function defect in nephronophthisis might be the cause of the poor uptake of^99mTc-DMSA. We also recommend the method to support the clinical suspicion of nephronophthisis, even in the early stages of the disease.