MLH1 and colorectal cancer: Mismatch repair (MMR), genes had the highest frequency of PVs in the sub-group of patients presenting with colorectal cancer, (MLH1; 3%), MSH2; 1.8%, MSH6; 3%, PMS2; 1.1%) or uterine cancer (MLH1; 2.6%) and MSH2, MSH6, PMS2 with1.3% each).