MSH2 and breast cancer: When the comparison was restricted to genes with variants of higher penetrance (BRCA1, BRCA2, MSH2, MLH1, MSH6, PMS2), the prevalence of BRCA1 and BRCA2 variants was about twofold increased in BC patients compared to EC patients (p = .16, 2 df) but the presence of 4 BRCA2 and 3 BRCA1 pathogenic variants in the EC series still appeared high (2.0%).