Small Glomeruli in WAGR (Wilms Tumor, Aniridia, Genitourinary Anomalies and Mental Retardation) Syndrome

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 μm in patients with WAGR syndrome versus 125 ± 18.5 μm in controls (P < 0.0001).

Conclusion

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.

Index Words: WAGR syndrome, kidney failure, Wilms tumor, WT1