Polyuria due to a vasopressin-resistant renal concentrating defect is often the earliest symptom. Unexplained uremia is an early clue in some patients. Retarded growth and evidence of bone disease are common in children. In many patients, these problems develop slowly over years and are so well compensated that they are not recognized as abnormal until significant uremic symptoms appear. Serum chemistries show chronic renal failure.
Proteinuria is minimal or absent, and the urinary sediment is unremarkable.
Ultrasonography or IVU shows a smooth renal outline and normal-sized or small kidneys and, often, multiple small and occasionally larger cysts at the corticomedullary junction. Thin-section CT is even more sensitive, detecting cysts as small as 5 mm in diameter. Because cysts may be few and small, they can be missed by any or all of these imaging studies. Disease progression varies depending on the degree of renal dysfunction at presentation. Usually, progression is slow but inexorable.