Transient Fanconi syndrome in two preterm infants with hydronephrosis and urinary tract infection.

Type IV renal tubular acidosis is known to occur in obstructive uropathy with urinary tract infection. Fanconi syndrome, however, has not been described in these settings. We report two preterm infants who developed Fanconi syndrome associated with hydronephrosis and urinary tract infection. Patient 1 is a boy with 21 trisomy, bilateral renal hypoplasia and bilateral vesicoureteral reflux delivered at 35 weeks' gestation. At postnatal day 42, he developed Fanconi syndrome after urinary tract infection, which persisted until the surgical correction of vesicoureteral reflux. Patient 2 was delivered at 35 weeks' gestation. At postnatal day 9, he was admitted for severe dehydration. He had phimosis and ultrasonography showed left pelviectasis. Laboratory data were compatible with Fanconi syndrome, which resolved spontaneously after fluid therapy. Subsequently urine culture grew bacteria and treatment for infection and topical corticosteroid for phimosis were performed. DMSA scintigraphy performed later showed left renal scar. Tubular cell stretch, due to vesicoureteral reflux in Patient 1 and phimosis in Patient 2, and urinary tract infection in association with immaturity of tubules are thought to have caused Fanconi syndrome.