CausesBy Mayo Clinic Staff
Lynch syndrome runs in families in an autosomal dominant inheritance pattern. This means that if one parent carries a gene mutation for Lynch syndrome, there's a 50 percent chance that mutation will be passed on to each child. The risk of Lynch syndrome is the same whether the gene mutation carrier is the mother or father or the child is a son or daughter.
How gene mutations cause cancer
The genes inherited in Lynch syndrome are normally responsible for correcting mistakes in the genetic code (mismatch repair genes).
Your genes contain DNA, which carries instructions for every chemical process in your body. As your cells grow and divide, they make copies of their DNA and it's not uncommon for some minor mistakes to occur.
Normal cells have mechanisms to recognize mistakes and repair them. But people who inherit one of the abnormal genes associated with Lynch syndrome lack the ability to repair these minor mistakes. An accumulation of these mistakes leads to increasing genetic damage within cells and eventually can lead to the cells becoming cancerous.
March 13, 2015
- Genetics of colorectal cancer (PDQ). National Cancer Institute. http://www.cancer.gov/cancertopics/pdq/genetics/colorectal/healthprofessional. Accessed Feb. 17, 2015.
- Lindor NM, et al. Concise handbook of familial cancer susceptibility syndromes. Journal of the National Cancer Institute Monographs. 2008;38:1.
- Genetic/familial high-risk assessment: Colorectal. Fort Washington, Pa.: National Comprehensive Cancer Network. http://www.nccn.org/professionals/physician_gls/f_guidelines.asp. Accessed Feb. 17, 2015.
- Lindor NM, et al. Recommendations for the care of individuals with an inherited predisposition to Lynch syndrome: A systematic review. Journal of the American Medical Association. 2006;296:1507.
- Giardiello FM, et al. Guidelines on genetic evaluation and management of Lynch syndrome: A consensus statement by the U.S. Multi-Society Task Force on Colorectal Cancer. Gastroenterology. 2014;147:502.
- Syngal S, et al. ACG clinical guideline: Genetic testing and management of hereditary gastrointestinal cancer syndromes. American Journal of Gastroenterology. 2015;110:223.
- AskMayoExpert. Lynch syndrome. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2014.
- Making sense of your genes: A guide to genetic counseling. Genetic Alliance. http://www.geneticalliance.org/publications/guidetogeneticcounseling. Accessed Feb. 17, 2015.
- Lynch HT, et al. Milestones of Lynch syndrome: 1895-2015. Nature Reviews Cancer. http://www.nature.com/nrc/journal/vaop/ncurrent/abs/nrc3878.html. Accessed Feb. 17, 2015.
- Thibodeau SN, et al. Microsatellite instability in cancer of the proximal colon. Science. 1993;260:816.
- Vasen HF, et al. Revised guidelines for the clinical management of Lynch syndrome (HNPCC): Recommendations by a group of European experts. Gut. 2013; 62:812.
- Burn J, et al. Long-term effect of aspirin on cancer risk in carriers of hereditary colorectal cancer: An analysis from the CAPP2 randomised controlled trial. The Lancet. 2011;378:2081.
- Lindor NM. Lynch syndrome 101 (years, that is). American Society of Clinical Oncology. http://meetinglibrary.asco.org/content/114000027-144. Accessed Feb. 20, 2015.
- Lindor NM (expert opinion). Mayo Clinic, Phoenix/Scottsdale, Ariz. Feb. 19, 2015.