Multiple Endocrine Neoplasia Type 2 (MEN2)

Frequently Asked Questions (FAQs)

Q: Who is the best person in the family to undergo genetic testing?
A: In order to determine if a hereditary cause exists in the family, genetic testing is usually initially offered to the family member whose personal history is most suggestive of MEN2 (e.g., someone with a personal history of medullary thyroid cancer at a young age or clinical presentations suggestive of MEN2).

It is usually not advisable to test someone without a history of cancer / tumours / clinical features unless a hereditary cause has already been identified in the family.

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

• If they were to receive a negative result, it may not mean that there is no hereditary cause of cancer/tumours in the family. The individual being tested may not have inherited it, but others in the family may have, or the faulty gene 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.

Once the faulty gene in the family is identified, genetic testing can be offered to other family members including those who do not have a tumour/cancer. This will help them understand if they have inherited the faulty gene change and if so, tailor their management to manage or reduce their risks.

Common Myths & Misconceptions

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

   FALSE. The genetic test result cannot determine the likelihood of tumour/cancer recurrence or the presence of a tumour/cancer. A positive result only indicates that you have been diagnosed with MEN2 and are at an increased risk of developing tumours/cancer.
   
   

2. If I or my child tests positive, it means that my children/grandchildren will develop tumours/cancer.

   FALSE. If you or your child has a positive genetic test result where a faulty RET gene is identified, it means that each of your children/grandchildren has a 50% (1 in 2) chance of inheriting the faulty RET gene.
   
   

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

   FALSE. Genes that govern your appearance are different from the RET gene that causes MEN2. All firstdegree relatives (siblings, children and parents) have a 50% (1 in 2) chance of inheriting the faulty RET gene, regardless of whether they look like you or not.
   
   

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 Multiple Endocrine Neoplasia Type 2 brochure.