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The official name of this gene is “multiple endocrine neoplasia I.”
MEN1 is the gene's official symbol. The MEN1 gene is also known by other names, listed below.
The MEN1 gene provides instructions for making a protein called menin. This protein acts as a tumor suppressor, which means that it keeps cells from growing and dividing too fast or in an uncontrolled way. Although the exact function of menin is uncertain, it is likely involved in several important cell functions. For example, it may play a role in copying and repairing DNA and regulating controlled cell death (apoptosis). The menin protein is present in the nucleus of many different types of cells and appears to be active in all stages of development.
Menin interacts with many other proteins, including several transcription factors. Transcription factors bind to specific areas of DNA and help control whether particular genes are turned on or off. Some of these genes likely play a role in cell growth and division. Researchers are working to identify the proteins that interact with menin and determine its specific role as a tumor suppressor.
Mutations in the MEN1 gene have been found in some cases of familial isolated hyperparathyroidism, a condition characterized by overactivity of the parathyroid glands (primary hyperparathyroidism). These glands help control the normal balance of calcium in the blood. This balance is disrupted in familial isolated hyperparathyroidism, which can lead to high blood calcium levels (hypercalcemia), kidney stones, thinning of bones, nausea and vomiting, high blood pressure (hypertension), weakness, and fatigue. Primary hyperparathyroidism is the most common sign of another condition called multiple endocrine neoplasia type 1 (described below); however, familial isolated hyperparathyroidism is diagnosed in people with hyperparathyroidism but not the other features of multiple endocrine neoplasia type 1.
Many of the mutations in the MEN1 gene that are associated with familial isolated hyperparathyroidism change single protein building blocks (amino acids) in the menin protein. It is thought that these amino acid changes impair menin's ability to interact with other proteins. Without normal menin function, cells likely divide too frequently, leading to the formation of tumors involving the parathyroid glands. Researchers speculate that the mutations that cause familial isolated hyperparathyroidism have a milder effect on the function of menin than the mutations that cause multiple endocrine neoplasia type 1. Occasionally, individuals with familial isolated hyperparathyroidism later develop features of multiple endocrine neoplasia type 1, although some never do. Familial isolated hyperparathyroidism caused by MEN1 gene mutations may be an early or mild form of multiple endocrine neoplasia type 1.
More than 400 mutations in the MEN1 gene can cause multiple endocrine neoplasia type 1. Most of these mutations lead to the production of an abnormally short, inactive version of menin or an unstable protein that rapidly breaks down. As a result of these mutations, one copy of the MEN1 gene in each cell makes no functional protein. If the second copy of the MEN1 gene is also altered in certain cells, those cells have no working copies of the gene and do not produce any menin. Without this protein, cells in endocrine glands (the glands that produce hormones) and other tissues can divide too frequently and form tumors. In multiple endocrine neoplasia type 1, tumors often occur in the parathyroid glands, the pituitary gland, and the pancreas. Although menin appears to be necessary for preventing tumor formation, researchers have not determined how a lack of this protein leads to the particular tumors characteristic of multiple endocrine neoplasia type 1.
Some gene mutations are acquired during a person's lifetime and are present only in certain cells. These changes, which are called somatic mutations, are not inherited. Somatic mutations in the MEN1 gene have been identified in several types of nonhereditary (sporadic) tumors. Specifically, MEN1 gene mutations have been found in a significant percentage of noncancerous tumors of the parathyroid gland (parathyroid adenomas), pancreatic tumors called gastrinomas and insulinomas, and cancerous tumors of the major airways in the lungs (bronchi) called bronchial carcinoids. Many of these tumor types are also found in people who have multiple endocrine neoplasia type 1 (described above). Like hereditary MEN1 gene mutations, somatic mutations in the MEN1 gene allow the formation of tumors when both copies of the MEN1 gene are inactivated in select cells.
Cytogenetic Location: 11q13
Molecular Location on chromosome 11: base pairs 64,570,985 to 64,578,765
The MEN1 gene is located on the long (q) arm of chromosome 11 at position 13.
More precisely, the MEN1 gene is located from base pair 64,570,985 to base pair 64,578,765 on chromosome 11.
See How do geneticists indicate the location of a gene? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation) in the Handbook.
You and your healthcare professional may find the following resources about MEN1 helpful.
You may also be interested in these resources, which are designed for genetics professionals and researchers.
See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.
acids ; amino acid ; apoptosis ; bronchi ; calcium ; cell ; DNA ; familial ; gene ; genome ; hypercalcemia ; hyperparathyroidism ; hypertension ; kidney ; kidney stones ; neoplasia ; nucleus ; pancreas ; pancreatic ; parathyroid ; parathyroid gland ; pituitary gland ; protein ; sign ; sporadic ; transcription ; tumor
You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).
The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.