MEN1

Multiple Endocrine Neoplasia Type 1 (MEN1) is a rare hereditary condition characterized by the development of tumors in endocrine glands and other tissues. The condition is also known as Wermer's syndrome, named after the physician who first described it. MEN1 is an autosomal dominant disorder, meaning that it can be passed from an affected parent to their child with a 50% chance of inheritance.

Etiology and Genetics

MEN1 is caused by mutations in the MEN1 gene, which is located on chromosome 11q13. This gene encodes a protein called menin, which is involved in regulating cell growth and preventing tumor formation. Mutations in the MEN1 gene lead to a loss of function of menin, resulting in the development of tumors in various endocrine glands.

Clinical Features

The primary endocrine glands affected in MEN1 are the parathyroid glands, the pancreatic islets, and the pituitary gland. Patients with MEN1 typically develop:

• Parathyroid adenomas, leading to hyperparathyroidism and associated symptoms such as kidney stones, bone pain, and abdominal pain.
• Pancreatic neuroendocrine tumors (PNETs), which can be non-functioning or produce hormones leading to conditions such as Zollinger-Ellison syndrome or hypoglycemia.
• Pituitary adenomas, which can result in overproduction of pituitary hormones, leading to conditions such as acromegaly or Cushing's disease.

Other tumors and abnormalities can also occur in MEN1, including adrenal cortical tumors, thyroid tumors, and non-endocrine tumors such as facial angiofibromas and collagenomas.

Diagnosis

Diagnosis of MEN1 is based on clinical criteria, family history, and genetic testing. The presence of two or more primary MEN1-associated tumors (parathyroid, pancreatic, pituitary) is suggestive of the syndrome. Genetic testing for mutations in the MEN1 gene can confirm the diagnosis.

Management

Management of MEN1 involves surveillance and treatment of the various endocrine and non-endocrine tumors. This includes regular biochemical screening, imaging studies, and surgical intervention when necessary. Due to the complexity of the condition, management is best coordinated by a multidisciplinary team with expertise in hereditary endocrine disorders.

Prognosis

The prognosis for individuals with MEN1 varies depending on the types and severity of tumors that develop. While surgery and medical management can control many of the endocrine abnormalities, the risk of malignant transformation in some of the tumors (e.g., pancreatic neuroendocrine tumors) can affect long-term survival.

See Also

• Multiple Endocrine Neoplasia Type 2
• Neuroendocrine tumors
• Genetic testing
• Endocrine system