Background: Wilms tumor, aniridia, genitourinary anomalies, and mental retardation (WAGR) syndrome is a genetic disorder caused by a deletion of band 11p13, which results in the loss of 1 allele of the Wilms tumor suppressor gene (WT1). It is not classically associated with nephropathies, but increased rates of renal failure are reported. Denys-Drash syndrome (DDS), caused by mutations in the WT1 gene affecting the third or second zinc finger, is characterized by a triad of glomerulopathy progressing rapidly to end-stage renal disease, male hermaphroditism, and Wilms tumor. In patients with DDS, small glomeruli were observed.

Methods: We reviewed histological findings of nontumoral kidney samples of 7 patients with WAGR syndrome at the time of tumor surgery.

Results: Median glomerular diameter was 110 +/- 37 microm in patients with WAGR syndrome versus 125 +/- 18.5 microm in controls (P < 0.0001).

Conclusions: The presence of small glomeruli in patients with WAGR syndrome, as in those with DDS, suggests a specific defect of WT1 function in development and a specific role of WT1 allele loss in the development of renal failure in these patients.