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Multiple Endocrine Neoplasia Type 1

Also called: MEN1, MEN1 syndrome, Wermer Syndrome 

Multiple endocrine neoplasia type 1 (MEN1) is a rare genetic disorder that can be passed down from parents to their children (inherited). People with MEN1 have a higher risk of developing certain kinds of tumors. These tumors are usually non-cancerous (benign) but may sometimes be cancerous (malignant).

A person with MEN1 may have tumors in the endocrine glands. The endocrine glands make high levels of chemicals called hormones. Hormones send messages throughout the body. These messages control the activities of cells and organs.

People with MEN1 may also have tumors in other parts of their bodies, which are not in the endocrine system. These are known as non-endocrine tumors.

Cancer risk with multiple endocrine neoplasia type 1

People with MEN1 have an increased risk of developing endocrine and non-endocrine tumors. Nearly all people with MEN1 develop some type of endocrine tumor during their lifetime.

Endocrine tumors from MEN1 Lifetime risk
Parathyroid gland tumors: tumors in the small parathyroid glands located next to the thyroid gland in the neck 100%
Pituitary gland tumors: tumors in the pea-size pituitary gland located near the base of the brain 10–60%
Stomach, intestine, or pancreas tumors (GEP tract tumors): known as tumors of the “gastro-entero-pancreatic” or GEP tract 34–55%

Adrenal gland tumor: tumors in the glands that are on top of each kidney

Carcinoid tumors: tumors of the cells that line the digestive system, lungs, or the thymus gland, which is in the chest 10%
Non-endocrine tumors from MEN1 Lifetime risk
Multiple facial angiofibromas: acne-like bumps that form near the nose and mouth 88%
Collagenomas:  skin-colored bumps on the trunk, neck, and limbs 72%

Lipomas: tumors made of fatty tissue that grow just under the skin

Meningiomas: tumors of the membranes that surround the brain and spinal cord 8%
Ependymomas: tumors of the fluid-producing cells in the brain or spinal cord 1%
Leiomyomas: smooth muscle tumors Rare; exact risk unknown

Symptoms of multiple endocrine neoplasia type 1

MEN1 can affect many areas of the body, so people with this condition may have a variety of symptoms. Their symptoms will vary, depending on where tumors are located and the amount of hormones their tumor makes.

Not all people with MEN1 will have all these symptoms. Some people may have no symptoms. Others may have many symptoms.

Parathyroid gland tumor symptoms

  • Change in mental status (tired, depressed, less alert, confused)
  • Weight loss
  • Constipation
  • Nausea and vomiting
  • Urinating more than normal
  • Dehydration (not drinking enough fluids)
  • Weak bones
  • High blood pressure
  • Heart rhythm problems
  • Kidney stones

Pituitary and adrenal gland tumors symptoms

  • For women: a lack of periods (amenorrhea) or abnormal production of milk in the breasts (galactorrhea)
  • For men: a loss of sex drive
  • Cushing syndrome: obesity, diabetes, hypertension, bone loss, and depression
  • For pituitary gland tumors: taller than normal (gigantism); overgrowth of the hands, feet, and face (acromegaly)

Stomach, intestine, and pancreas tumors symptoms

  • Pain in the abdomen (belly)
  • Nausea and vomiting
  • Loss of appetite
  • Diarrhea
  • Heartburn (esophageal reflux)
  • Peptic ulcers

Causes of multiple endocrine neoplasia type 1

Multiple endocrine neoplasia type 1 is caused by changes in gene known as MEN1. This gene carries important information that controls cell growth and function. A change that causes the gene to not work correctly is called a mutation.

How multiple endocrine neoplasia type 1 is inherited

Everyone has 2 copies of the MEN1 gene. Children without this disorder carry 2 normal copies of the MEN1 gene in their cells. One copy of MEN1 is inherited from the child’s mother, and the other comes from the child’s father.

Children who have multiple endocrine neoplasia type 1 inherit 1 normal copy of the MEN1 gene and 1 copy that is changed (mutated). This change makes the gene not work correctly. It is called a MEN1 mutation.

About 90% (9 out of 10) of children with MEN1 inherit the MEN1 gene mutation from a parent who also has this disorder. The other 10% (1 in 10) of children with this disorder have a new MEN1 mutation that did not come from a parent. These children have no history of this disorder in their family. In such cases, an MEN1 gene mutation happened either in:

  • An ovum (egg) or sperm that formed the child
  • 1 of the child’s cells before they were born

These children are the first in their families to have multiple endocrine neoplasia type 1.

No matter how they acquired the MEN1 mutation, people with multiple endocrine neoplasia type 1 have a 50% (1 in 2) chance of passing it on to their children.

Diagnosis of multiple endocrine neoplasia type 1

Health history

A health care provider may suspect that your child has MEN1 after studying their medical and family cancer history.

This information helps the health care provider and the genetic counselor know if:

  • There are more tumors than normal in your family
  • These tumors happened at a younger age than expected
  • The types of tumors match up with what might be seen in those with MEN1
  • There are family members who have clinical signs of MEN1

Your provider or genetics counselor may recommend genetic testing if they suspect MEN1.\

Learn more about types of genetic tests

Genetic testing for multiple endocrine neoplasia type 1

A blood sample is sent to a genetic testing lab. The lab runs genetic tests that look for changes in the MEN1 gene.

If your child has an MEN1 mutation, a genetic counselor will work with your family to:

  • Find out if other family members should consider testing for an MEN1 mutation
  • Help your family understand their increased cancer risk
  • Give you information to help with your decisions about prenatal genetic testing

Even if genetic testing does not find a mutation in the MEN1 gene, a person can still have this condition. There may be other types of mutations that cause multiple endocrine neoplasia type 1 that doctors do not yet know about.

Genetic testing before or during pregnancy

Parents can get prenatal testing to find out if the pregnancy is affected by a known MEN1 mutation.

Testing may take place either before pregnancy occurs or during pregnancy.

You should work with a genetic counselor to review the pros and cons of the test. The genetic counselor can also help you prepare for the test results.

Testing before pregnancy is called preimplantation genetic testing (PGT). This special type of genetic testing is done along with in vitro fertilization (IVF). PGT tests embryos for a known MEN1 mutation before a provider places an embryo into the uterus.

Testing during pregnancy can help providers see if a pregnancy has a known MEN1 mutation. A doctor gathers cells from the pregnancy in 1 of 2 ways:

  • Chorionic villus sampling (CVS) is done during the first 3 months of pregnancy (1st trimester).
  • Amniocentesis is done after the first 3 months of pregnancy (2nd trimester or later).

After tissue collection, the lab checks the sample for the MEN1 mutation. Both tests carry minor risks. You should talk about these risks with an experienced health care provider or a genetic counselor.

Special concerns for genetic testing

Take time to think carefully about the benefits and risks of genetic testing. Speak with a genetic counselor before testing. If you decide to get tested, talk with your health care provider or a genetic counselor about your results so you can understand what they mean.

Sometimes, children or adults with MEN1 feel sad, anxious, or angry after getting their test results. Parents may feel guilty if they pass the MEN1 gene mutation to 1 or more of their children. People with the MEN1 gene mutation may also have trouble getting disability or life insurance.

Read more about genetic discrimination

Diagnosis of MEN1 without genetic testing

It is possible to have a clinical diagnosis of MEN1 without genetic testing. A person with any 2 of these kinds of endocrine tumors can be diagnosed with MEN1:

  • Parathyroid gland tumors
  • Pituitary gland tumors
  • Stomach, intestine, or pancreas tumors (GEP tract tumors)

A person who develops only 1 of the tumors listed above may be diagnosed with MEN1 if they have other family members diagnosed with the disorder.

Monitoring and follow-up care for multiple endocrine neoplasia type 1

Monitoring and follow-up care for MEN1 depends on how severe the disease is, the location of any tumors that may arise, and a person’s overall health. Care may involve managing symptoms with medications or hormones. Patients may also have surgery to remove their tumors if the tumor presses on nearby organs or produces very high levels of hormones in their bodies.

Some tumors, like carcinoid tumors, may require treatments such as chemotherapy.

Because MEN1 is a complex condition, parents should discuss screening options for their child with an experienced health care provider who knows this condition well. The goal of screening is to find and treat tumors early. Doing so allows the best outcome for patients. There are clinics throughout the country that specialize in taking care of people with MEN.

It is also important that parents work with a genetic counselor to find experienced health care providers for their child. To find a genetics counselor in your area, visit Personalized Care for Your Genetic Health.

Cancer screening for those with MEN1

Although most of the tumors related to MEN are not cancerous, people with MEN1 should be monitored for the development of these tumors throughout their lives. Some non-cancerous tumors cause problems.

The following lifelong screenings are recommended for people with MEN1:

  • Yearly physical exams by a health care provider who is familiar with multiple endocrine neoplasia type 1
  • Blood tests to screen for abnormally high levels of various hormones and calcium in the blood. These should be started at age 5 and repeated yearly.
  • MRI of the head starting at age 5 and repeated every 3–5 years
  • MRI or CT scan of the abdomen beginning at age 10

These recommendations may change over time as doctors learn more about MEN1. Some physicians may order extra tests and/or scans besides these.

Living with multiple endocrine neoplasia type 1

People of any age with MEN1 have a higher risk of tumors than people without MEN1. They should monitor their health and adopt healthy habits throughout life. It is important to continue to have regular physical checkups and screenings. That way, any tumor can be found early at the most treatable stage.

Maintain a healthy lifestyle

Habits that will help you maintain a healthy lifestyle include:

  • Eat a healthy diet with lots of fruit and vegetables.
  • Get regular exercise.
  • Avoid excess sun exposure. Always wear a hat, protective clothing, and sunscreen (at least SPF 30 or higher) when out in the sun.
  • Avoid unnecessary radiation exposure.
  • Avoid smoking or the use of tobacco products.
  • Avoid being around secondhand smoke.
  • Avoid excessive alcohol use.

Multiple endocrine neoplasia type 1 care at            St. Jude

The St. Jude Cancer Predisposition Program is dedicated to diagnosing and screening children with a genetic predisposition for cancer. Our program offers the best clinical care possible. We engage in cutting-edge research to gain more information about genetic disorders and cancer, and to improve the care and treatment for patients who are affected by these conditions. Learn more about the Division of Cancer Predisposition at St. Jude.

Our genetic counselors, clinicians, genetics nurse practitioners, and research assistants work together to provide patients with:

  • A complete health history
  • A record of cancer that happened over the past 3 generations (family tree or pedigree) to see how diseases were passed down
  • Physical exams to check for physical signs of a genetic disorder or disease
  • Confidential genetic counseling and testing
  • Cancer screenings for those with genetic disease to detect and treat cancer as soon as it occurs
  • Recommended cancer treatments and ways to reduce cancer risk
  • Genetic testing for immediate (1st degree) relatives (including siblings and parents)

MEN1 increases your child’s risk for tumors and, less commonly, certain cancers. 

Related clinical trials  

St . Jude offers clinical trials and cancer research studies for children, teens, and young adults who have cancers associated with MEN1.

Learn more about clinical research at St. Jude

GENETX: Assessing Gene Therapy Communication Needs

Study goal:

To learn more about participants beliefs, attitudes, and questions about gene therapy to help make web-based resources to share information. This could help patients make treatment decisions.


18 to 35 years old with rare genetic diseases

Published results
G4K: Genomes for Kids

Study goal:

The main goal of this study is to learn more about the reasons childhood tumors form and how to treat them better.

TBANK: Collecting, Banking, and Distributing Human Tissue Samples in St. Jude Biorepository

Study goal:

To provide a high-quality repository of tumor and normal samples to facilitate translational research performed by St Jude faculty and their collaborators

PG4KDS: Clinical Implementation of Pharmacogenetics

Study goal:

1) Test each patient for hundreds of gene variations that might be important for drug use. All of the gene test results will be in the research laboratory, but as time goes on, the study will evaluate scientific evidence and selectively move test results for a few genes into the medical record if the evidence strongly shows that the result can help in better prescribing of drugs for patients; 2) Estimate how often pharmacogenetic test results are moved from research tests into a patient’s medical record; 3) Use methods to choose which of these tests should be put in the medical record; 4) Use computer-based tools in the electronic medical record to help doctors use gene test results when prescribing drugs; 5) Share feelings and concerns of patients and their families about gene test information being put in their medical record.

SJFAMILY: Study of Cancer in Families

Study goal:

The main purpose of this trial is to learn about the genetic causes of cancer. 


Younger than 50 years old

A statue of children running and holding hands

Seeking treatment at St. Jude

Patients accepted to St. Jude must have a disease we treat and must be referred by a physician or other qualified medical professional. We accept most patients based on their ability to enroll in an open clinical trial.

How to seek treatment

Contact the Physician / Patient Referral Office

Call: 1-888-226-4343 (toll-free) or 901-595-4055 (local)  | Fax: 901-595-4011 | Email: | 24-hour pager: 1-800-349-4334


Learn more

If you have questions about the Genetic Predisposition Clinic and care for MEN1, email our team at

Resources outside St. Jude