Deletion of the sho arm of chromosome 11 is seen in

Ref Robbins 8/e p479-480, 9/e pPathogenesis and Genetics. The risk of Wilms tumor is increased with at least three recognizable groups of congenital malformations associated with distinct chromosomal loci. Although Wilms tumors arising in this setting account for no more than 10% of cases, these syndromic tumors have provided impoant insight into the biology of this neoplasm. * The first group of patients has the WAGR syndrome, characterized by Wilms tumor, aniridia, genital anoma-lies, and mental retardation. Their lifetime risk of developing Wilms tumor is approximately 33%. Individuals with WAGR syndrome carry constitutional (germline) deletions of 11p13. Studies on these patients led to the identification of the first Wilms tumor-associated gene, WT1, and a contiguously deleted autosomal dominant gene for aniridia, PAX6, both located on chromosome 11p13. Patients with deletions restricted to PAX6, with normal WT1 function, develop sporadic aniridia, but they are not at increased risk for Wilms tumors.9 479-480