MEN1 gene
The MEN1 gene provides instructions for making the protein menin, which acts as a tumor suppressor to prevent cells from growing and dividing too rapidly.
Normal Function
The MEN1 gene provides instructions for making a protein called menin. This protein acts as a tumor suppressor, keeping cells from growing and dividing (proliferating) too fast or in an uncontrolled way. Menin is present in the nucleus of many cell types and is involved in several important functions, including:
- Copying and repairing DNA
- Regulating the controlled self-destruction of cells (apoptosis)
- Interacting with transcription factors to turn specific genes on or off
Health Conditions Related to Genetic Changes
Familial isolated hyperparathyroidism
Variants in the MEN1 gene have been found in some people with familial isolated hyperparathyroidism. This condition is characterized by overactive parathyroid glands, which disrupts blood calcium regulation. Symptoms include:
- High blood calcium levels (hypercalcemia)
- Kidney stones
- Thinning of the bones (osteoporosis)
- Nausea, vomiting, and fatigue
- High blood pressure (hypertension)
These variants often produce an abnormal or shorter form of menin, impairing its ability to interact with other proteins. Without functional menin, cells divide too frequently, leading to enlarged parathyroid glands or benign tumors that overproduce parathyroid hormone.
Multiple endocrine neoplasia
Over a thousand variants in the MEN1 gene have been found to cause multiple endocrine neoplasia type 1 (MEN1). This condition involves the development of tumors in two or more endocrine glands, most commonly the parathyroid glands, the pituitary gland, and the pancreas. These tumors can be benign or cancerous. In these cases, cells produce an inactive or unstable version of menin, and if the second copy of the gene is also altered, the cell loses all functional menin, leading to uncontrolled cell division.
Primary macronodular adrenal hyperplasia
MedlinePlus Genetics provides information about Primary macronodular adrenal hyperplasia.
Other tumors
Somatic variants in the MEN1 gene—those acquired during a person's lifetime—have been identified in several types of nonhereditary (sporadic) tumors, including:
- Benign tumors of the parathyroid glands (parathyroid adenomas)
- Pancreatic tumors (nonfunctioning neuroendocrine tumors, gastrinomas, and insulinomas)
- Cancerous tumors of the major airways in the lungs (bronchial carcinoids)
As with hereditary cases, these tumors occur only when both copies of the MEN1 gene are inactivated in specific cells.