Is Multiple Endocrine Neoplasia hereditary?

Multiple Endocrine Neoplasia (MEN) is a group of hereditary disorders characterized by the development of tumors in two or more endocrine glands. Because these conditions are caused by germline mutations in specific genes, they are inherited in an autosomal dominant pattern, meaning each child of an affected parent has a 50% chance of inheriting the mutation.

Is Multiple Endocrine Neoplasia hereditary?

Yes, Multiple Endocrine Neoplasia is a hereditary condition. In clinical genetics, we distinguish between "genetic" (caused by a change in DNA) and "hereditary" (passed from parent to child). Multiple Endocrine Neoplasia is both. It is caused by specific pathogenic variants in genes—most commonly the MEN1 gene for MEN1 and the RET proto-oncogene for MEN2A and MEN2B. Because these mutations are present in the germline, they are passed down through families, establishing a clear hereditary link.

What is the inheritance pattern and risk for children?

All types of Multiple Endocrine Neoplasia follow an autosomal dominant inheritance pattern. This means that only one copy of the mutated gene is required to potentially cause the disease. If a parent carries the mutation, there is a 50% statistical probability that any child will inherit the mutation, regardless of gender. It is important to note that while the inheritance of the gene is 50%, the clinical expression—the actual development of tumors—can vary in severity and age of onset among family members, a concept known as variable expressivity.

Are de novo mutations common in Multiple Endocrine Neoplasia?

While Multiple Endocrine Neoplasia is typically inherited from an affected parent, de novo (spontaneous) mutations do occur. This is especially true for MEN2B, where a significant percentage of cases—estimated at approximately 50%—arise from a new mutation in the RET gene in the affected individual, meaning neither parent carries the mutation. In such cases, the individual is the first in their family to be affected, but they can still pass the mutation on to their own children.

How does genetic testing and counseling work?

Genetic testing is the gold standard for confirming a diagnosis of Multiple Endocrine Neoplasia and for identifying at-risk relatives. We recommend genetic counseling for any family with a history of endocrine tumors to navigate the complexities of testing and surveillance. The following steps are typically involved in the genetic management of the condition:

• Diagnostic Testing: Confirms the presence of a pathogenic variant in an individual showing symptoms.


• Cascade Screening: Once a mutation is identified in a family, we test asymptomatic relatives to determine who is at risk and requires early endocrine screening.


• Reproductive Options: Families planning pregnancies may explore Preimplantation Genetic Testing (PGT) during IVF to select embryos that do not carry the familial mutation.


• Psychosocial Support: Genetic counselors help families process the implications of a positive test result, which often requires lifelong medical surveillance.

Currently, 137 people with Multiple Endocrine Neoplasia have joined the DiseaseMaps community, sharing their experiences with genetic testing and the diagnostic journey. Connecting with this community can provide invaluable peer support as you navigate these clinical decisions.

Next steps

• Consult with a board-certified clinical geneticist to discuss whether testing is appropriate for you or your family members.


• Schedule an appointment with an endocrinologist who specializes in Multiple Endocrine Neoplasia to establish a surveillance plan.


• Join the DiseaseMaps community to connect with other patients and families navigating the complexities of this rare condition.


• Request a referral to a genetic counselor to discuss family planning and prenatal testing options if you are considering starting a family.

Medical disclaimer: This information is for educational purposes only and does not replace professional medical advice, diagnosis, or treatment; always seek the advice of your physician or other qualified health provider with any questions regarding a medical condition.

References

• National Institutes of Health (NIH) Genetic and Rare Diseases Information Center (GARD): Multiple Endocrine Neoplasia.


• Orphanet: Rare Disease Database - Multiple Endocrine Neoplasia.


• Online Mendelian Inheritance in Man (OMIM): Entry #131100 (MEN1) and #171400 (MEN2).


• American Association of Clinical Endocrinology (AACE) Clinical Practice Guidelines for the Management of MEN Syndromes.