Drash syndrome is usually sporadic and is associated with mutations in the Wilm's tumour predisposing gene, WT1 located on chromosome 11 (11p13). This is a tumour suppressor gene.
Diffuse mesangial sclerosis is a constant finding in Drash syndrome. It may present with a Wilm's tumour. Another feature is male pseudohermaphroditism with ambiguous genitalia or a female phenotype in 46XY subjects. 46XX patients have a normal female phenotype.