Causes of Endocrine Dysfunction

Type of Endocrine Disorder Examples A) Hyperfunction    1. Neoplastic           Benign Pituitary adenomas, hyperparathyroidism, autonomous thyroid or adrenal nodules, pheochromocytoma         Malignant Adrenal cancer, medullary thyroid cancer, carcinoid         Ectopic Ectopic ACTH, SIADH secretion         Multiple endocrine neoplasia MEN 1, MEN 2 2. Autoimmune Graves' disease 3. Iatrogenic Cushing's syndrome, hypoglycemia   4.Infectious/inflammatory Subacute thyroiditis 5. Activating receptor mutations LH, TSH, Ca2+ and PTH receptors, Gs-alpha B) Hypofunction      Autoimmune Hashimoto's thyroiditis, Type 1 diabetes mellitus, Addison's disease, polyglandular failure   Iatrogenic Radiation-induced hypopituitarism, hypothyroidism, surgical   Infectious/inflammatory Adrenal insufficiency, hypothalamic sarcoidosis   Hormone mutations GH, LH, FSH, vasopressin   Enzyme defects 21-Hydroxylase deficiency   Developmental defects Kallmann syndrome, Turner syndrome, transcription factors   Nutritional/vitamin deficiency Vitamin D deficiency, iodine deficiency   Hemorrhage/infarction Sheehan's syndrome, adrenal insufficiency C) Hormone resistance      Receptor mutations       Membrane GH, vasopressin, LH, FSH, ACTH, GnRH, GHRH, PTH, leptin, Ca2+       Nuclear AR, TR, VDR, ER, GR, PPAR-alpha   Signaling pathway mutations Albright's hereditary osteodystrophy   Postreceptor Type 2 diabetes mellitus, leptin resistance