Familial Lynch syndrome with early age of onset and confirmed splice site mutation in MSH2: A case report.

Lynch syndrome (LS) is an autosomal dominant cancer syndrome. It can be caused by mutations of several genes, including MLH1, MSH2, MSH6, PMS2, MLH3 and MSH3, which are responsible for DNA mismatch repair, and LS affects 3-5% of patients with colorectal cancer (CRC). LS is associated with a high risk of cancer in several different locations, although the most commonly affected regions are the colon (20-70% risk), endometrium (15-70% risk), stomach (6-13% risk) and ovaries (4-12% risk).