How does MEN1 affect the endocrine glands and the duodenum?
The parathyroids are the endocrine glands earliest and most often affected by MEN1. The body normally has four parathyroid glands, which are located close to the thyroid gland in the front of the neck. The parathyroids release into the bloodstream a chemical called parathyroid hormone (PTH), which helps maintain a normal supply of calcium in the blood, bones, and urine. Hyperparathyroidism In MEN1, all four parathyroid glands tend to be overactive, causing hyperparathyroidism. The parathyroid glands form tumors that release too much PTH, leading to excess calcium in the blood. High blood calcium, known as hypercalcemia, can exist for many years before it is found by accident or through screening for MEN1. Unrecognized hypercalcemia can cause excess calcium to spill into the urine, leading to kidney stones or kidney damage. Also, the bones may lose calcium and weaken. Nearly everyone who inherits a susceptibility to MEN1 will develop hyperparathyroidism by age 50, but the disorder can o
