MLH1 and Lynch syndrome: It is an autosomal dominant condition that is caused by pathogenic variants (PVs) in DNA mismatch repair (MMR) genes (MLH1, MSH2, PMS2, MSH6) or the EPCAM gene, which causes upstream promoter hypermethylation of MSH2. The lifetime risk of developing cancer among those with Lynch syndrome is highly variable, ranging from 10-90%, and is now understood to be related to the specific pathogenic variant (PV) causing the disorder in an individual or family (3–5).