Pathogenic variants (disease-causing) in the gene MEN1 causes Multiple Endocrine Neoplasia type 1 (MEN1), a syndrome in which people commonly develop tumors of the parathyroid glands, the pancreas/duodenum (neuroendocrine tumors), and the pituitary gland. Tumors associated with MEN1 are frequent, with 91-100% of individuals developing related tumors, often appearing at younger ages. Many MEN1 tumors are benign (non-cancerous), but can become malignant (cancerous) or cause serious hormone-related symptoms. Because MEN1 affects hormone-producing glands, it influences how the body regulates calcium, blood sugar, and other hormones. Management of MEN1–related tumor risk includes regular surveillance tailored to guidelines for typically involving periodic biochemical testing, imaging, and clinical evaluation to detect tumors early. MEN1 variants are not known to be more common in the Ashkenazi Jewish population.
Pathogenic variants in MEN1 exhibit autosomal dominant inheritance. This means there is a 50% chance the condition can be passed from generation-to-generation. First degree relatives (parents, siblings, children) have a 50% chance to have the same pathogenic variant whereas second degree relatives (grandparents, aunts/uncles, nieces/nephews, half-siblings) have a 25% chance. More distant relatives have lower chances of having the same pathogenic variant when one is identified in the family.
Resources:
Association for Multiple Endocrine Neoplasia Disorders
International Neuroendocrine Cancer Alliance
Written December 2025
