Wilms' tumour: association with cellular sensitivity to mitomycin C in patients and first-degree relatives.

To investigate whether predisposition to Wilms' tumour is associated with a particular defect in the handling of DNA damage, cell-lines from families in which the tumour had occurred were tested for sensitivity to a variety of DNA-damaging agents. Lymphoblastoid lines from both Wilms' tumour patients and their first-degree relatives showed increased sensitivity to the cross-linking agent, mitomycin C, but normal sensitivity to ultraviolet (UV) and gamma irradiation. Thus sensitivity to mitomycin C damage can be associated with the Wilms'-tumour-susceptible genotype and could be a genetic factor responsible for the modification of expression of this genotype.