Multiple endocrine neoplasia syndromes (MEN) are a group of inheritable syndromes that causes tumors in multiple endocrine organs.
MEN gene mutations
MEN1
Results from a mutation (change) in the menin gene. The affected endocrine organs are the parathyroid, pancreas, and pituitary glands. There often is a family history. Genetic testing is available.
MEN2A
Results from a mutation in the ret gene. Individuals with this mutation will almost always develop medullary thyroid cancer; some will also have pheochromocytoma and parathyroid hyperplasia. Genetic counseling and testing is recommended, so that preventive thyroidectomy may be performed.
MEN2B
Results from a mutation in the ret gene. Individuals with the mutation may have a marfanoid habitus (tall and gangly), have abnormal corneal nerves, and have noticeable small bumps in their lips and mouth. They will almost always develop medullary thyroid cancer, usually at a young age. Some will also have pheochromocytoma. Genetic counseling and testing is recommended, so that preventative thyroidectomy may be performed.