Congenital Adrenal Hyperplasia: Impaired Steroid Synthesis in the Adrenal Gland In congenital adrenal hyperplasia (CAH), the synthesis of cortisol by the adrenal gland is impaired as a result of an enzyme deficiency. Consequently, the secretion of adrenocorticotropin hormone (ACTH) by the pituitary gland is increased, resulting in hyperplasia of the adrenal cortex and excess production of steroids that do not require the specific deficient enzyme for their synthesis (1). Figure 1 depicts the pathway for normal adrenal steroid synthesis. Mutations in the genes encoding for the enzymes 21-hydroxylase, 17-hydroxylase/17,20-lyase, 11-hydroxylase, 30-hydroxysteroid dehydrogenase, or the protein StAR (intracellular cholesterol transport protein) lead to CAH. The most frequent cause of CAH (more than 90% of all cases) is 21-hydroxylase deficiency. This deficiency results in cortisol and aldos-terone deficiency and an overproduction of 17-hydroxyprogesterone and androstene-dione, leading to androgen excess.
From: Male Hypogonadism: Basic, Clinical, and Therapeutic Principles Edited by: S. J. Winters © Humana Press Inc., Totowa, NJ
StAR protein/SCC Pregnenolone 17-hydroxylase Sß-HSD
Progesterone 17-hydroxylase i7.20-ivase> Dehydroepiandrosterone
2 ¡-hydroxylase ^21-hydroxylase
11-hydroxylase 1 ¡-hydroxylase
Fig. 1. Adrenal steroid synthesis. StAR, steroidogenic acute response protein; SCC, (cholesterol) side chain cleavage enzyme; 3ß-HSD, 3ß-hydroxysteroid dehydrogenase.
Was this article helpful?
It seems like you hear it all the time from nearly every one you know I'm SO stressed out!? Pressures abound in this world today. Those pressures cause stress and anxiety, and often we are ill-equipped to deal with those stressors that trigger anxiety and other feelings that can make us sick. Literally, sick.