Deletions including the PAX6 gene and other neighboring genes do not change the clinical expression of the disease in relation to mutation limited only to PAX6. However, for larger deletions encompassing PAX6 and WT1 genes, separated by 700 kb, patients with aniridia represent a more severe phenotype — WAGR syndrome with intellectual disability and high risk of Wilm’s tumor development. The gene discussed is PAX6; the disease is Nephroblastoma.