The father of patient #9 with high-grade glioma and two heterozygous MLH1 variants died of colorectal carcinoma, while the grandfather of patient #11 with high-grade glioma and MSH2 variant had a positive history on the mother’s side of the family, with a grandfather who died from stomach cancer and a grandmother from a brain tumor. This evidence concerns the gene MSH2 and colorectal carcinoma.