18). Although the penetrance of WT in children with constitutional WT1 mutation is likely much lower, around 74% children with the classical DDS triad develop WT, often with associated ILNRs (Ref. 18) (using the original narrow phenotypic definition of DDS and not including the more recently broadened phenotype with milder renal dysfunction/genitourinary abnormalities with WT1 mutation). The gene discussed is WT1; the disease is Abnormal renal physiology.