Multiple Endrocine Neoplasia type 1, abbreviated as MEN1, is a hereditary condition that causes tumors in the glands of the endocrine system. A rare disorder, around one in 30,000 people has developed MEN1. About 10% of those cases are patients with a new mutation of the gene responsible for causing it. Also called Wermer syndrome, growths typically develop within the pituitary gland, pancreatic islet cells, and parathyroid gland. MEN1 can also produce carcinoid tumors, cortical tumors, and (rarely) masses in the adrenal glands. In some cases, tumors may be found in other areas of the digestive tract.
MEN1 masses form when there is enlargement and over-activity in the affected gland. Most tumors associated with this disorder are noncancerous. However, around one-third of carcinoid and islet cell growths are malignant and spread to other areas of the body, usually the liver, lungs, and lymph nodes. Benign tumors can still create problems when they cause glands to produce too much hormone.
Symptoms associated with the condition vary depending on the location of the tumors. Most of the time, they stem from the overproduction of some type of hormone. Patients with a mass in the parathyroid gland might experience:
Pancreatic tumors are often due to the overproduction of insulin and may produce symptoms such as:
Pituitary tumors sometimes put pressure on the optic nerve, causing symptoms related to changes in vision and headaches. Carcinoid tumors are more likely to show up in the lungs, stomach, thymus or pancreas, and they produce symptoms like flushing, wheezing, and diarrhea.
Multiple Endocrine Neoplasia occurs in three forms, Types I, IIA and IIB. All forms of the condition are caused by genetic mutations. In Type I, the MEN1 gene is altered in some way. MEN1 controls the production of a protein called menin. It is thought that menin helps control the rate at which cells divide and multiply, and thus performs the function of tumor suppression. When the gene mutates, the mutation inactivates the gene and cells divide and multiply too quickly, forming tumors. These tumors target the endocrine system and tumors tend to form on the parathyroid, the pituitary glands, the pancreas, and less frequently, the thyroid and adrenal glands. Multiple Endocrine Neoplasia Type I is an inherited disease and occurs in roughly 1 out of every 30,000 people. Children of an affected parent have an estimated 50% chance of inheriting and developing the condition.
MEN1 treatment plans are developed around symptoms and the location of the tumor. Usually, therapies involve various medications to regulate hormone production or surgery to remove the tumor. The condition will be monitored regularly to help medical professionals adjust treatment as needed.
Because it is a genetic, inherited disease, Multiple Endocrine Neoplasia Type I cannot be prevented through control of environmental factors or behavioral choices. For patients likely to develop the condition, regular medical monitoring is essential to control tumor growth and management of symptoms. For parents at risk of having children with the condition, the only way to completely prevent the passing on of MEN1 would be to use alternate fertility methods. Using a donor egg or sperm that does not carry the gene mutation would be an option. Use of a surrogate to carry the fetus would be preventative as well. Currently, there is no way to repair the affected gene mutation, so the prevention has to center on avoidance of transmission from parent to child.