Objective: To compare chromosomal damage in lymphocytes of individuals who did or did not report first-degree relatives with cancer.
Materials and methods: Cases and controls (68 each) were matched for sex, age and radon exposure. Chromosomal damage was quantified as frequency of micronucleus-containing cells and proportion of centromere-free micronuclei.
Results: Individuals not reporting cancer in their families showed lower values of both the frequency of micronucleus-containing cells (n.s.) and the proportion of centromere-free micronuclei (p < 0.05) in some subgroups, but not in all.
Conclusion: The chromosomal damage observed may be due to inheritable genomic instability, but environmental influences cannot be excluded.
Keywords: Micronucleus centromere test; cancer predisposition; chromosomal damage; inheritable trait; radon.