How do I know if I have Lynch Syndrome?

Lynch syndrome is a hereditary condition that significantly increases the lifetime risk of developing colorectal, endometrial, and several other cancers. You identify potential risk through a detailed review of your family health history, specifically looking for patterns of early-onset cancers, which then warrants genetic counseling and diagnostic testing.

What are the primary indicators of Lynch syndrome?

Lynch syndrome is typically identified not by physical symptoms, but by a strong personal or family history of cancer. Because the condition is often asymptomatic until a malignancy develops, the primary "symptom" is a pattern of cancer occurrences that seem to cluster in families. Lynch syndrome is caused by a germline mutation in one of the DNA mismatch repair (MMR) genes, specifically MLH1, MSH2, MSH6, PMS2, or EPCAM.

How can I self-assess my risk for Lynch syndrome?

To determine if you should investigate Lynch syndrome, look for these specific red flags in your family tree:

• Colorectal or endometrial cancer diagnosed before age 50.


• Multiple family members with related cancers (colon, uterine, ovarian, stomach, small bowel, or pancreas) across multiple generations.


• A family member who has been diagnosed with two or more Lynch-related cancers.


• A known genetic mutation for Lynch syndrome in a first-degree relative.

When should I consult a doctor about Lynch syndrome?

If you notice these patterns, schedule an appointment with your primary care physician or a genetic counselor. Clearly state: "I am concerned about a family history of early-onset cancers and would like to be evaluated for Lynch syndrome." If your concerns are dismissed, request a referral to a certified genetic counselor or a gastroenterologist specializing in hereditary cancer syndromes. You have the right to advocate for a formal risk assessment based on your family pedigree.

What diagnostic tests are used for Lynch syndrome?

Testing for Lynch syndrome usually begins with immunohistochemistry (IHC) or microsatellite instability (MSI) testing on tumor tissue if a family member has already had cancer. If those results suggest a deficiency, or if testing a tumor is not possible, a blood or saliva test is used to perform germline genetic sequencing to confirm the diagnosis.

Next steps

• Gather detailed medical records from relatives regarding their cancer types and age of diagnosis.


• Consult a board-certified genetic counselor to map your family history.


• Join our community of 79 members at DiseaseMaps.org to connect with others navigating this condition.

Medical disclaimer: This information is for educational purposes only and does not replace professional medical advice, diagnosis, or treatment.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Lynch Syndrome


• Orphanet: Hereditary Non-Polyposis Colorectal Cancer (HNPCC)


• OMIM: Lynch Syndrome (Entry #120435)


• Lynch Syndrome International (LSI)