Multiple endocrine neoplasia, type 1 (MEN 1), sometimes called Wermer's syndrome, is a rare disorder that causes tumors in the endocrine glands and parts of the small intestine and stomach. In MEN 1, the endocrine glands — usually the parathyroids, pancreas and pituitary — grow tumors and release excessive amounts of hormones that can lead to disease. However, the tumors are usually noncancerous (benign).

The excess hormones can cause a wide variety of signs and symptoms. These can include tiredness, bone pain, broken bones, kidney stones, and ulcers in the stomach or intestines. MEN 1 can't be cured. But regular testing can detect problems, and doctors can provide treatment as needed.

MEN 1 is an inherited disorder. This means people who have the gene mutation can pass it on to their children. Each child has a 50% chance of inheriting the disorder.


Signs and symptoms of MEN 1 include the following:

  • Tiredness
  • Bone pain
  • Broken bones
  • Kidney stones
  • Ulcers in the stomach or intestines

Symptoms are caused by the release of too many hormones in the body.

Multiple endocrine neoplasia, type 1 (MEN 1) care at Mayo Clinic

Aug. 31, 2022
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