The index person (no. #165;10), who carries the MSH2 c.2168C>T variant, have had two primary cancers: Colon cancer (IHC: lack of MSH2 expression, microsatellite instability (MSI) status unknown) and an adenocarcinoma at the major duodenal papilla (IHC: lack of MLH1/PMS2, and methylation of the MLH1 promoter). This evidence concerns the gene MLH1 and malignant colon neoplasm.