Lynch syndrome is an autosomal dominantly inherited cancer syndrome including colorectal (CRC), endometrial (EC), and ovarian cancer (OC).1 It is caused by pathogenic variants of the DNA mismatch repair (MMR) system genes MLH1, MSH2, MSH6, and PMS2, which prevent the correction of acquired errors during DNA synthesis. The gene discussed is MSH6; the disease is colorectal carcinoma.