ABSTRACT
Overall, boys are twice as often affected as girls and tend to present at a younger age, with an average age at presentation of 36 months for boys and 48 months for girls. Presenting features are macroscopic hematuria, urinary tract infection, or abdominal pain; some children (17 percent) appear to be asymptomatic. Obstruction related to calculi may result in pyonephrosis, perinephric abscess, or progressive pyelonephritis, and renal loss.
