GTR Home > Conditions/Phenotypes > Multiple endocrine neoplasia, type 1

Disease characteristics

Excerpted from the GeneReview: Multiple Endocrine Neoplasia Type 1
Multiple endocrine neoplasia type 1 (MEN1) syndrome includes varying combinations of more than 20 endocrine and non-endocrine tumors. Endocrine tumors become evident by overproduction of hormones by the tumor or by growth of the tumor itself. Parathyroid tumors are the main MEN1-associated endocrinopathy; onset in 90% of individuals is between ages 20 and 25 years with hypercalcemia evident by age 50 years; hypercalcemia causes lethargy, depression, confusion, anorexia, constipation, nausea, vomiting, diuresis, dehydration, hypercalciuria, kidney stones, increased bone resorption/fracture risk, hypertension, and shortened QT interval. Pituitary tumors include prolactinoma (the most common) which manifests as oligomenorrhea/amenorrhea and galactorrhea in females and sexual dysfunction in males. Well-differentiated endocrine tumors of the gastro-entero-pancreatic (GEP) tract can manifest as Zollinger-Ellison syndrome (gastrinoma); hypoglycemia (insulinoma); hyperglycemia, anorexia, glossitis, anemia, diarrhea, venous thrombosis, and skin rash (glucagonoma); and watery diarrhea, hypokalemia, and achlorhydria syndrome (vasoactive intestinal peptide [VIP]-secreting tumor). Carcinoid tumors are non-hormone-secreting and can manifest as a large mass after age 50 years. Adrenocortical tumors can be associated with primary hypercortisolism or hyperaldosteronism. Non-endocrine tumors include facial angiofibromas, collagenomas, lipomas, meningiomas, ependymomas, and leiomyomas.

Associated genes

Clinical features

  • Hypercalcemia
  • Cafe-au-lait spot
  • Confetti-like hypopigmented macules
  • Diarrhea
  • Esophagitis
  • Abnormality of the thyroid gland
  • Hyperparathyroidism
  • Growth hormone excess
  • Multiple lipomas
  • Subcutaneous lipoma
  • Hypercortisolism
  • Exocrine pancreatic insufficiency
  • Hypoglycemia
  • Zollinger-Ellison syndrome
  • Pituitary adenoma
  • Parathyroid adenoma
  • Abnormality of the gastric mucosa
  • Peptic ulcer
  • Pituitary prolactin cell adenoma
  • Adrenocortical adenoma
  • Adenoma sebaceum
  • Carcinoid
  • Insulinoma
Show all (23)
Go to complete MedGen record for Multiple endocrine neoplasia, type 1

Clinical resources

Practice guidelines

  • ACMG, 2013
    ACMG recommendations for reporting of incidental findings in clinical exome and genome sequencing.
  • ASCO, 2010
    American Society of Clinical Oncology policy statement update: genetic and genomic testing for cancer susceptibility.
  • NSGC, 2004
    Genetic cancer risk assessment and counseling: recommendations of the national society of genetic counselors.
  • Intl, 2001
    Guidelines for diagnosis and therapy of MEN type 1 and type 2.

IMPORTANT NOTE: NIH does not independently verify information submitted to the GTR; it relies on submitters to provide information that is accurate and not misleading. NIH makes no endorsements of tests or laboratories listed in the GTR. GTR is not a substitute for medical advice. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

Write to the Help Desk