Inclusion Criteria:  Age ≥18 years with a proven pathogenic germline variant in one of the MMR genes (MLH1, MSH2, MSH6) or Epcam deletion who are under surveillance colonoscopy.  Exclusion Criteria:  Previous history of total colectomy, Concomitant inflammatory bowel disease, Inability or refuse to sign the informed consent, Previous colonoscopy < 12 months. Inadequate bowel preparation. Incomplete procedure. PMS2 mutation carriers