MSH2 and breast cancer: As observed in our pedigree,PMS2deficiency is also associated with increased risk of breast cancer and cumulative risk at the age of 60 years is 37.7%.4Sheehan et al26reported an increased prevalence of breast cancer among women carrying LS due to mutations inPSM2as compared with those carrying mutations inMLH1,MSH2, andMSH6genes.