Lynch syndrome, or hereditary nonpolyposis colon cancer, is the most common form
of hereditary colorectal cancer and causes roughly 3-5% of all colon cancers.3 Lynch
syndrome is caused by autosomal dominant mutations to the major mismatch repair
genes MLH1, MSH2, MSH6 or PMS2 as well as the EPCAM gene that inactivates MSH2.
In addition to colorectal cancer, Lynch syndrome is associated with several other
cancers including endometrial, ovarian and stomach cancer.
Familial Adenomatous Polyposis
Familial Adenomatous Polyposis (FAP) results from autosomal dominant mutations in the tumor suppressor gene, APC, and causes approximately 1% of all colon cancers. Most people develop multiple colon polyps by the age 39. If not detected and treated, these polyps will almost always develop into cancer. Typically FAP is diagnosed when your doctor finds a large number (>100) of colorectal polyps. Blood tests can be used to confirm the presence of mutations associated with FAP.5