Preferential loss of maternal alleles in sporadic Wilms' tumour.

Loss of heterozygosity at loci on the short arm of chromosome 11 has been reported in 31% (11/38) of Wilms' tumours in our series. Lymphoblastoid cell lines were prepared from the parents of 10/11 of the patients showing allele loss in their tumours. In 9 of the cases, where the parental origin of the alleles could be followed, it was the paternal alleles which were retained in the tumour. This preferential loss of the maternal alleles implies a role for genomic imprinting in the pathogenesis of Wilms' tumour.