Haploinsufficiency of WT1 is linked with the WAGR syndrome (Wilms’ tumor, aniridia, genitourinary anomalies and retardation; MIM 194072), whereas specific pathogenic variants cause two rare autosomal dominant diseases; Frasier syndrome (MIM 136680; splice site variants) and Denys–Drash syndrome (MIM 194080; variants in exon 8 or 9, encoding zinc fingers 2 and 3 [ZF2 and ZF3]). This evidence concerns the gene WT1 and isolated aniridia.