WT1 and isolated aniridia: While not all (syndromic or non-syndromic) WTs develop from a premalignant lesion such as DHPLN, genetic syndromes that typically feature WT also predispose to nephroblastomatosis: WAGR (WT, aniridia, genitourinary malformations and mental retardation) and Denys–Drash syndrome are characterized by a deletion or an exonic mutation affecting the WT1 gene, respectively, while Beckwith–Wiedemann (methylation changes at 11p15) and Perlman syndrome do not involve WT1 but still increase predisposition [11].