EXCLUSION OF THE WILMS-TUMOR GENE (WT1) PROMOTER AS A SITE OF FREQUENT MUTATION IN WILMS-TUMOR

WT1 is a tumour suppressor gene expressed in a specific temporal and s patial pattern in the developing kidney. Up to 15% of Wilms tumours ha ve point mutations in the WT1 gene coding sequence. We have now invest igated whether mutations in the WT1 promoter could be associated with loss of control WT1 expression and subsequent Wilms tumour formation. Using single-strand conformational polymorphism (SSCP) analysis we ana lysed 39 sporadic Wilms tumours for WT1 promoter mutations. We found s ix linked common sequence polymorphisms and two unlinked less frequent polymorphisms which allowed us to identify four tumours with loss of heterozygosity but none with point mutations, small deletions, inserti ons or rearrangements. We therefore conclude that WT1 promoter mutatio ns are unlikely to play an important role in Wilms tumorigenesis.