Skip to Main Content
  • Become an Access Reviewer
  • Clinical Phenotypes
  • OMMBID Advisory banner
  • Ommbid banner
  • Ommbid latest banner



  1. Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder with endocrine tumors of the parathyroids, the enteropancreatic neuroendocrine tissues, the anterior pituitary, and foregut carcinoid. Associated nonendocrine tumors include facial angiofibromas, skin collagenomas, and lipomas.

  2. Most of the tumors are benign and produce symptoms and signs by oversecreting hormones (parathyroid hormone, gastrin, prolactin, etc.). Associated gastrinomas and foregut carcinoid tumors have a substantial malignant potential.

  3. The most common endocrinopathy is primary hyperparathyroidism with several features different from features in sporadic parathyroid adenoma. Hyperparathyroidism in MEN1 is expressed earlier than in sporadic adenoma; 50 percent of gene carriers express it by ages 18 to 30. Most MEN1 patients have multiple parathyroid tumors and, after successful subtotal parathyroidectomy, have a high likelihood of late recurrence. Hyperparathyroidism can exacerbate the simultaneous Zollinger-Ellison syndrome in MEN1.

  4. The MEN1 gene was identified by positional cloning in 1997. Its sequence predicted a novel protein termed menin.

  5. MEN1 germ-line mutations have been found in over 80 percent of MEN1 families and in a similar fraction of patients with sporadic MEN1. Clinical use of germ-line MEN1 mutation testing can give valuable information. It does not have the urgency of germ-line RET mutation testing for MEN2a or MEN2b.

  6. Certain sporadic endocrine and nonendocrine tumors often show somatic MEN1 mutation. In fact, MEN1 is the known gene most commonly mutated in sporadic parathyroid adenoma, gastrinoma, insulinoma, and bronchial carcinoid tumor.

  7. MEN1 is likely a tumor-suppressor gene, since most MEN1 tumors and many sporadic endocrine tumors with MEN1 mutation show inactivation (recognized as loss of heterozygosity) of the normal allele at 11q13, the MEN1 locus.

  8. The MEN1-encoded protein, menin, is mainly located in the nucleus. It binds to and inhibits junD, an AP1 transcription factor. It shows no protein homologies. Most germ-line or somatic MEN1 mutations predict truncation of the menin protein and are thus likely to cause inactivation of menin function. Inactivation-type mutation further supports menin's predicted role as a tumor suppressor.

Want remote access to your institution's subscription?

Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.


About MyAccess

If your institution subscribes to this resource, and you don't have a MyAccess profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.

Subscription Options

OMMBID Full Site: One-Year Subscription

Connect to the full suite of OMMBID content including new and revised chapters that reflect the latest research, image galleries, clinical phenotypes, and more.

$295 USD
Buy Now

Pay Per View: Timed Access to all of OMMBID

24 Hour Subscription $34.95

Buy Now

48 Hour Subscription $54.95

Buy Now

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.