MMR IHC from colorectal adenocarcinoma showed a loss of MSH2 and MSH6 expression, and the NGS TruSight Cancer panel discovered a disease-causing (Class 5) variant in MSH2 NM_000251.2: c.1283_1284del p.(His428Profs*14), which had not been described in the databases at the time the analysis was performed (in 2018). This evidence concerns the gene MSH2 and colorectal adenocarcinoma.