How does congenital adrenal hyperplasia arise?
An enzyme deficiency may result in a failure of the adrenal glands to make normal amounts of cortisol. The decrease in cortisol level stimulates the pituitary gland to release adrenal corticotrophic hormone (ACTH). ACTH makes the adrenal gland enlarge and produce more cortisol, mineralocorticoids and androgens. • Cortisol is a glucocorticoid. Glucocortocoids have multiple actions on many organ systems. They increase liver glucose output, cause atrophy of type II muscle fibres, inhibit bone formation, reduce calcium absorption in the gut, increase cardiac output, increase blood pressure and increase lung maturation. They also cause insulin resistance, modulate the thyroid axis and reduce the number of circulating lymphocyte cells. • The major minerolocorticoid is aldosterone. This acts on the kidneys to reabsorb sodium and water into the blood stream, and to secrete potassium into the urine. • The adrenal androgens are dehydroepiandrosterone (DHEA), androstenedione and 11-hydroxyandrost
