What should you know about genes involved in Lynch syndrome?

These genes help correct copying errors in DNA. When mismatch repair does not work properly, errors can build up as cells divide, increasing the chance of certain cancers. The gene result is interpreted alongside personal and family history.

Lynch syndrome can be associated with bowel cancer, womb cancer, and ovarian cancer, among other cancers. Having a gene change raises risk; it does not mean that a person definitely has cancer or will develop every associated cancer.

A genetic counsellor can explain whether a result is positive, negative, or uncertain and discuss who in the family may benefit from testing. Screening plans are individualised and may include colonoscopy at an age and interval chosen by the specialist.

Keep copies of genetic reports and tell relevant clinicians about the result. If a relative has had a related cancer at a young age or several relatives are affected, share that history with the genetics team rather than relying on memory alone.

Arrange medical review for blood in the stool, a persistent change in bowel habit, unexplained weight loss, ongoing abdominal or pelvic pain, unusual womb bleeding, or a new persistent ovarian or pelvic symptom. These symptoms have many possible causes, but prompt assessment is appropriate.

Which gene or variant was found? What does the result mean for my cancer screening? Should relatives consider testing? When should colonoscopy be arranged? Would a hereditary cancer panel test add useful information?