Wilms’ tumor is the most common primary malignant renal tumor of childhood, accounting for 6% of all childhood tumors and an estimated 500 new cases per year in the United States.1

Among North American children less than 15 years of age, the incidence of Wilms’ tumor is eight cases per 1 million.1 Wilms’ tumor accounts for more than 90% of all renal cancers in patients under the age of 20 years, with a mean age at diagnosis of approximately 40 months for patients with unilateral disease and 30 months for those with bilateral disease.

A variety of syndromes and congenital abnormalities are associated with the development of Wilms’ tumor, including WAGR syndrome (Wilms’ tumor-aniridia-genitourinary anomalies and mental retardation), Denys-Drash syndrome, and Frasier syndrome.46,47 All of these syndromes involve mutations in the WT1 gene at the 11p13 locus. A second Wilms’ tumor gene, WT2, located at 11p15, has been linked to increased incidence of Wilms’ tumor in Beckwith-Wiedemann syndrome, an overgrowth syndrome associated with increased risk of other malignancies such as hepatoblastoma and adrenocortical carcinoma.46–48 Overexpression, loss of imprinting, hypermethylation, and silencing of one or more genes contained within the WT2 locus such as IGF2, H19, p57, and LIT1 have been documented.46,47,49 Other syndromes associated with an increased susceptibility for the development of Wilms’ tumor include Simpson-Golabi-Behmel syndrome, Sotos syndrome, and Perlman syndrome. Familial predisposition accounts for 1% to 2% of ...