Email Share this article
People with Lynch syndrome are at a much higher risk for developing certain types of cancer. The two most common cancers they may develop are colon cancer and uterine cancer.
Both men* and women* with Lynch syndrome may have up to a 49% chance of developing colon cancer in their lifetime. This is compared to the typical risk of around 4%. Women with Lynch syndrome may also have up to a 57% chance of developing uterine cancer. People with Lynch syndrome may develop these cancers earlier in life too.
On average, around 1 in 280 Americans has Lynch syndrome. This translates to more than one million people in the U.S. People of all ethnicities can have Lynch syndrome.
Why is it important to know about Lynch syndrome?
Lynch syndrome genetic testing is important for the estimated one million people in the U.S. with the condition, because this knowledge can save their lives. The most important action people with Lynch syndrome can take is speaking with their physician and scheduling regular cancer screenings. Catching cancer early can significantly increase the chances of beating it. For colon cancer, for instance, the five-year survival rate is 90% when it’s caught early.
Most people start colon cancer screening with colonoscopies after age 45. But current medical guidelines recommend people with Lynch syndrome start colonoscopies between ages 20 to 25, or even earlier depending on family history.
How is Lynch syndrome passed down?
Each child of someone with Lynch syndrome has a 50% chance of having Lynch syndrome as well, as do any full brothers or sisters. This means that at least one parent of someone with Lynch syndrome likely has it too.
Here is how the inheritance works in most cases: A person has two copies of most of their genes, one from each parent. To have Lynch syndrome, they would only need to inherit a Lynch syndrome DNA difference from one of their parents. This type of inheritance is called autosomal dominant inheritance.
What does the test offered through AncestryHealth® look at?
The genes linked to Lynch syndrome play a big part in how cells fix their DNA. Cancer happens when mistakes build up in one’s DNA over time. Because cells have ways to fix mistakes, there is usually a slow buildup of damage over time. This is why cancer usually happens later in life.
The test offered through AncestryHealth® looks for specific DNA changes in four genes (MLH1, MSH2, MSH6, and PMS2) that may result in the body’s DNA repair system not working as well. The end result is a faster buildup of mistakes, which means a higher risk of developing cancer earlier in life. AncestryHealth®, powered by next-generation sequencing technology, can detect up to 80% of the DNA differences linked to Lynch syndrome, the most common form of inherited colon cancer.
*Assigned sex at birth
AncestryHealth® includes laboratory tests developed and performed by an independent CLIA-certified laboratory partner, and with oversight from an independent clinician network of board-certified physicians and genetic counselors. The test results are not diagnostic and do not determine your overall chance of developing a disease or health condition. The tests are not cleared or approved by the U.S. Food and Drug Administration. You should consult a healthcare provider before taking any action based on AncestryHealth® reports, including before making any treatment, dietary, or lifestyle changes. AncestryHealth® is not currently available in New York, New Jersey, or Rhode Island.
- National Cancer Institute.Cancer Stat Facts:Colorectal Cancer. Accessed September, 2019
- National Comprehensive Cancer Network. Genetic/Familial High-Risk Assessment: Colorectal (Version 1.2019). NCCN Guidelines. www.nccn.org/professionals/physician_gls/pdf/genetics_colon.pdf
- Win AK, Jenkins MA, Dowty JG, et al. Prevalence and Penetrance of Major Genes and Polygenes for Colorectal Cancer. 2017; 26(3):404-412. www.ncbi.nlm.nih.gov/pubmed/27799157