Biomarkers in Blood and Tumor Tissue Samples From Patients With Wilms Tumor

OBJECTIVES: * To determine whether Wilms Tumor (WT) patients without WT1-associated congenital anomalies or syndromes, but with end-stage renal disease (ESRD) unrelated to progressive bilateral tumors, carry germline WT1 mutations. * To determine whether non-syndromic WT1 germline mutation carriers have a substantially higher incidence of ESRD than do WT patients who do not harbor WT1 mutations. OUTLINE: Archived blood and tumor tissue specimens (or DNA isolated from these samples) are analyzed for WT1 mutations by gene sequencing and PCR.