MSH2 and colorectal cancer: The patient was referred for genetic counseling, and molecular genetic testing was performed using Illumina Miseq next-generation sequencing technology with targeted sequencing of colorectal-cancer-related genes (MLH1, MSH2, MSH6, PMS2, EPCAM, APC, MUTYH, STK11, SMAD4, BMPR1A TP53, NTHL1, POLE, POLD1, MSH3) included in the TruSight Cancer panel, complemented by bioinformatic analysis.