Congenital adrenal hyperplasia epidemiology and demographics


 * Associate Editor-In-Chief:

Epidemiology and Demographics

 * The disorder in the most classical form is thought to affect approximately 1 in 15-30,000 patients. Milder forms of the disease are estimated to occur in as many as 1 in 100-1000 patients.  90% of CAH is due to a complete or partial deficiency in 21-hyroxylase.  5-8% of CAH is due to deficiency in 11-hydroxylase.  In rare instances, 17-alpha-hydroxylase and 3-beta-hydroxysteroid dehydrogenase deficiency can lead to CAH.  Certain ethnic groups are thought to be at increased risk such as Yupik Eskimos and Jews of Moroccan ancestry.
 * 21-Hydroxylase
 * Defective conversion of 17-hydroxyprogesterone to 11-deoxycortisol leads to decreased cortisol synthesis and increased ACTH secretion. The resulting adrenal stimulation leads to increased production of androgens.  Aldosterone secretion is also impaired in some patients.  There are several clinical syndromes based on the degree of enzyme deficiency.  These include the simple virilizing form, salt-wasting form and nonclassical form.
 * 11-Hydroxylase
 * Deficiency of this enzyme leads to excessive production of androgens and mineralocorticoids. There is excessive production of 11-deoxycorticosterone, which has mineralocorticoid effect, and adrenal androgens.