Lynch syndrome (hereditary nonpolyposis colorectal cancer), is an autosomal dominant inherited disorder caused by mutations in mismatch repair genes; MLH1, MSH2, MSH6, PMS2, or EPCAM which lead to high risk of colorectal cancer (80% lifetime risk) among others, including cancer of the ovaries (10–15% lifetime risk) and endometrium (71% lifetime risk)[22]. The gene discussed is PMS2; the disease is Lynch syndrome.