Screening for polycystic kidney disease: importance of clinical presentation in the newborn.

Fifty per cent of the offspring of adults with the adult (dominant) form of polycystic kidney disease are carriers of the abnormal gene. Clinical symptoms and signs before adolescence are rare, but renal ultrasonography may detect evidence of cyst formation. Twenty two children, all offspring of parents with known adult polycystic kidney disease, have undergone renal ultrasonography. In six cases evidence of disease was detected without clinical manifestations at the ages of 1, 2, 5, 8, 13, and 14 years. There were no renal masses, hypertension, haematuria, or evidence of renal insufficiency. In four children from three sibships, whose families had no previous history of renal disease, bilateral renal masses were noted to be present at birth. In each case one parent was subsequently found to have adult polycystic kidney disease. At the ages of 1, 4, 6, and 20 years, while renal masses were still palpable, there was no evidence of renal insufficiency or hypertension in the younger children, while the oldest had mild renal failure. An analysis of the reported cases in childhood is suggestive of a bimodal distribution of enlarged kidneys, with a number of cases diagnosed at birth or soon after, followed by an increasing incidence during later childhood. Adult polycystic kidney disease presenting at birth may be qualitatively different from the disease detected by screening programmes of children at risk.