Nearly 6000 patients enrolled in four clinical trials of the National Wilms
' Tumor Study Group during 1969-1995 were followed until death or for a med
ian of 11.0 years of survival for the onset of renal failure (RF). Thirteen
of 22 patients with Denys-Drash syndrome and 10 of 46 patients with the Wi
lms' tumor aniridia syndrome developed RF. The cumulative risks of RF at 20
years from Wilms' tumor diagnosis were 62% and 38%, respectively. Only 21
cases of RP were observed among 5358 patients with unilateral disease who d
id not have characteristic congenital genitourinary anomalies, and their ri
sk was <1%. Although other explanations cannot be completely excluded, the
high rate of RF in patients with the aniridia syndrome challenges the view
that nephropathy is associated uniquely with missense mutations in the WT1
gene. It suggests the possibility of a further gradation in the spectrum of
phenotypes associated with different WT1 mutations. Patients with Wilms' t
umor and aniridia or genitourinary abnormalities should be followed closely
throughout life for signs of nephropathy or RF.