Reference summary — not medical advice or a personal risk estimate.
Lynch syndrome (hereditary mismatch repair gene mutations)
Quick answer
Not IARC-classified — this is not a chemical or physical agent IARC rates. Recognized as a cancer risk factor based on sufficient evidence in humans. Inherited. Passed down from a parent; identified through genetic testing, typically pursued after genetic counseling for people with relevant personal or family history.
Summary
Lynch syndrome is an inherited condition caused by mutations in DNA mismatch repair genes that substantially raises lifetime risk of colorectal, endometrial, and several other cancers.
What's not established
Lynch syndrome substantially raises risk but does not make cancer certain, and the exact lifetime risk varies by which gene is affected and other individual factors. This entry does not establish your personal risk and is not a substitute for genetic counseling.
Evidence sources
Every claim on this page traces back to one of these. Click through to read the primary document yourself.
Primary sources
NCI
NCI — The Genetics of Cancer
Last reviewed: October 2026
Official reference list
A government list some readers use alongside the primary evidence. Meyron is not affiliated with it. A chemical being listed does not by itself describe a risk from any particular product.
- California Prop 65 list
State of California's list of chemicals known to cause cancer or reproductive harm.