Mechanisms of Micronuclei induction due to reduced repair capacity

1. Background: An increased micronucleus (MN) frequency has been observed in irradiated peripheral lymphocytes of BRCA mutation carriers, sporadic breast cancer patients and patients with ovarial cancer by the micronucleus assay. To assess the mechanism leading to higher MN frequencies in cancer patients, we performed FISH analysis on chromosomes 1,7 and 17 and terminal nick end labelling to detect MN with highly fragmented DNA. 2. Methods Unselected sporadic breast cancer patients (n=140) and controls (n=149) were analysed by the G0 micronucleus test (MNT). On two probands with high MN frequency and on two prob…