At a Glance McCune-Albright syndrome is characterized by multiple fibrous bone lesions (fibrous dysplasia), cafe au lait spots, and a variety of endocrine disorders, including gonadotropin-independent precocious puberty. Although the syndrome is rare, the underlying defect is an activating mutation in the GNAS gene, which leads to constitutive activation of cAMP-based intracellular signaling. Such mutations…
At a Glance Multiple endocrine neoplasia type I (MEN1) is a syndrome of inherited predisposition to tumors of the parathyroid, pancreatic islets, and anterior pituitary gland. This syndrome, which is typically caused by germline mutations in the MEN1 gene, is diagnosed when a patient manifests at least two of these tumor types. Family members of…
At a Glance Multiple Endocrine Neoplasia Type 2A (MEN2A) is a syndrome composed of medullary thyroid carcinoma (MTC), pheochromocytoma, and primary hyperparathyroidism. Predisposition to this syndrome is caused by germline mutations in the RET proto-oncogene. Two of the clinical features of MEN2A are sufficient to diagnose MEN2, and one clinical feature, along with either a…
At a Glance Multiple Endocrine Neoplasia Type 2B (MEN2B) is a syndrome composed of medullary thyroid carcinoma (MTC), pheochromocytoma, mucosal neuromas, and marfanoid features. Predisposition to this syndrome is caused by germline mutations in the RET proto-oncogene. Unlike MEN2A, primary hyperparathyroidism is not a feature of MEN2B, and the two syndromes arise from different mutations…
At a Glance Polyglandular autoimmune (PGA) syndrome (also abbreviated APS) is a disease in which the functions of multiple endocrine organs (i.e., thyroid, parathyroid, pancreatic islets, and adrenal gland) are affected by endogenous autoantibodies. Common manifestations of autoantibody activity are hyper- or hypothyroidism, Addison disease, hypoparathyroidism, and type I diabetes mellitus (DM). PGA syndrome is…
