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

17,20-iyase Androstenedione


^3ß-HSD 17-OH-Progesterone

2 ¡-hydroxylase ^21-hydroxylase

Deoxycorticosterone 11-Deoxycortisol

11-hydroxylase 1 ¡-hydroxylase

Corticosterone Cortisol


18-OH-Corticosterone dehydrogenase


Fig. 1. Adrenal steroid synthesis. StAR, steroidogenic acute response protein; SCC, (cholesterol) side chain cleavage enzyme; 3ß-HSD, 3ß-hydroxysteroid dehydrogenase.

100 Pregnancy Tips

100 Pregnancy Tips

Prior to planning pregnancy, you should learn more about the things involved in getting pregnant. It involves carrying a baby inside you for nine months, caring for a child for a number of years, and many more. Consider these things, so that you can properly assess if you are ready for pregnancy. Get all these very important tips about pregnancy that you need to know.

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