- Patients with unilateral Wilms tumor and aniridia, Beckwith-Wiedemann Syndrome, idiopathic hemihypertrophy, Simpson-Golabi-Behmel-Syndrome, Denys-Drash Syndrome or other associated genitourinary anomalies; or multicentric or unilateral Wilms tumor with contralateral nephrogenic rest(s) (any size) in a child under 1 year of age who undergo a nephrectomy at diagnosis are not eligible for this study and should be directed to a unilateral Wilms tumor study