Family Health History and Lynch Syndrome

Having a family health history of Lynch syndrome makes you more likely to have Lynch syndrome yourself. Lynch syndrome is an inherited genetic condition that makes you more likely to get colorectal (colon) and other types of cancer.

If someone in your family has been diagnosed with Lynch syndrome, share this information with your doctor. Your doctor may refer you for genetic counseling or genetic testing. If you have Lynch syndrome, let your family members know. Note that not all inherited colorectal cancers are due to Lynch syndrome, and not everyone with Lynch syndrome will get colorectal cancer.

Lynch syndrome is hereditary, meaning that it is caused by an inherited genetic change, or mutation, that can be passed from parent to child. If you have Lynch syndrome, your parents, children, sisters, and brothers have a 50% chance of having Lynch syndrome. Once a mutation that causes Lynch syndrome is found in one person in a family, other members can then be tested for that mutation to find out if they have Lynch syndrome.

Tell your doctor if you have

  • A first-degree relative (parents, sisters, brothers, and children) with Lynch syndrome
  • A first-degree relative with colorectal or endometrial cancer diagnosed before age 50
  • A first-degree relative with colorectal or endometrial cancer and another Lynch syndrome related cancer either occurring at the same time, or at a different time.
  • Two or more first- or second-degree relatives (grandparents, aunts, uncles, and half-siblings) with Lynch syndrome related cancers, and at least one that was diagnosed before age 50
  • Three or more first- or second-degree relatives with Lynch syndrome-related cancers at any age

If you need help getting started, visit the Surgeon General’s Family Health History tool.

If you have a family history of Lynch syndrome, your doctor may recommend genetic counseling.