Congenital adrenal hyperplasia.

Congenital adrenal hyperplasia (CAH) is a family of autosomal recessive disorders in which there is a deficiency of one of the enzymes necessary for cortisol synthesis (1) (see Fig. 1). An abnormality in each of the enzymatic activities required for cortisol synthesis has been described. As a result of the disordered enzymatic step, there is decreased cortisol synthesis, increased ACTH via the negative feedback system, overproduction of the hormones prior to the enzymatic step or not requiring the deficient enzyme, and deficiency of the hormones distal to the disordered enzymatic step. Since certain of the enzymatic steps are required for sex hormone synthesis by the gonad, a disordered enzymatic step in the gonad, resulting in gonadal steroid hormone deficiency, may also be present (2).