Loss of heterozygosity of WT1 gene in the prognosis of sporadic Wilms' tumour in children

The aim of this report was to evaluate the prognostic value of allele loss of the WT1 gene in children with sporadic Wilms' tumour. Allele loss of the WT1 gene was evaluated using microsatellite polymorphisms in the 3' untran slated region of WT1 in a radioactive PCR assay. The study comprised 66 chi ldren (30 girls and 36 boys), aged from 2 days to 13 years, treated for Wil ms' tumour according to the SIOP-09 and PGGL scheme. We have used DNA isola ted from the neoplastic versus normal kidney tissue from the paraffin embed ded sections using microdissection procedure. Loss of heterozygosity (LOH) of the WT1 gene was found in 12 children (19.6%), 5 cases were noninformati ve. No significant correlation could be found between the LOH of WT1 gene a nd sex and age. Significantly more frequent occurrence of LOH in tumor in l ow stage of advancement and low degree of malignancy was found. However; no significant effect of LOH of WT1 gene was observed on frequency of recurre nces, metastasis and deaths. Study of allele loss of the WT1 gene may be re commended in difficult cases as an additional factor useful for the diagnos is and in the assignment of the tumour to the appropriate risk group.