PAX6 and isolated aniridia: Congenital aniridia can also occur in the WAGR syndrome (Wilms’ tumor, aniridia, genitourinary abnormalities, and mental retardation), a syndrome due to a contiguous gene deletion encompassing both PAX6 and WT1. Individuals, particularly children under 6 years old, with WT1 deletion may predispose to Wilms’ tumor, a kidney tumor with childhood onset [13].