Lynch Syndrome

Frequently Asked Questions (FAQs)

Q: Who is the best person in the family to undergo genetic testing?
A: Genetic testing is recommended foremostly for the family member whose cancer diagnosis is most suggestive of a hereditary cause (e.g., young or unusual cancer). Those with a history of cancer are more likely to have inherited a faulty gene(s) over those without such history.

If a hereditary cause is identified, testing can be subsequently offered to at-risk relatives who do not have cancer or are asymptomatic. In some cases, testing an affected family member is not possible and genetic testing can be offered to asymptomatic individuals.

The genetic test results of an asymptomatic individual may have limitations:

• If they were to receive a negative result, it may not mean that there is no hereditary cause of cancer in the family. The individual being tested may not have inherited it, but others in the family may have, or the faulty gene(s) may not have been identified yet.
• The result is only useful to the asymptomatic person being tested and their children, but not to their parents, siblings and other seconddegree family members.

Q: Is testing recommended in children?
A: Genetic testing for adult-onset conditions like Lynch syndrome is not recommended in individuals under the age of 21.

Genetic testing in children is only offered when they have a personal history of certain cancers, or if the faulty gene(s) identified in the family is known to increase the risk of cancer during childhood.

Common Myths & Misconceptions

1. If my genetic test result is positive, it means that I have or will have cancer, or my cancer will recur.

   FALSE. Your genetic test result cannot determine the likelihood of cancer recurrence or the presence of cancer. A positive result only indicates an increased risk of getting cancer or of a new cancer developing.
   
   

2. If I test positive, it means that my children will also have Lynch syndrome.

   FALSE. If you have a positive genetic test result where a faulty gene(s) is identified, it means each of your children has a 50% (1 in 2) chance of inheriting the faulty gene(s). It affects both males and females.
   
   

3. My daughter looks a lot like me, so she must have inherited the faulty gene(s) since I have it.

   FALSE. Genes that govern your appearance are different from Lynch syndrome (MMR) genes like MLH1, MSH2, MSH6, PMS2 and EPCAM. All first-degree relatives (siblings, children, parents) have a 50% (1 in 2) chance of inheriting the faulty MMR gene(s).
   
   

4. I have two brothers, so one will inherit the faulty gene(s) and one will not, because there is a 50% chance.

   FALSE. Each first-degree relative (parents, siblings and children) has a 50% (1 in 2) chance of inheriting the faulty gene(s). The genetic test result of one sibling does not impact the chances of the other sibling.

Download the Lynch syndrome brochure.