Multiple endocrine neoplasia type 1

Multiple endocrine neoplasia type 1, also known as MEN-1 or Wermer syndrome, is an inherited disorder in which people develop tumors in the pituitary gland, parathyroid glands, pancreas and other endocrine tissue. It is caused by mutations in the MEN1 tumor-suppressor gene, inherited in an autosomal dominant pattern; a person inherits one faulty copy, and uncontrolled growth follows once a second copy is mutated in a given cell, an example of Knudson's two-hit hypothesis. The condition affects about 1 in 30,000 people, and hyperparathyroidism is its most common feature, appearing in 90 percent or more of patients, while pancreatic islet cell tumors occur in 60 to 80 percent of cases and are the leading cause of death, and pituitary tumors, mostly prolactinomas, occur in 15 to 42 percent. It was first described by Paul Wermer in 1954.