In congenital adrenal hyperplasia, what hormonal pattern is typically observed?

• A. Low aldosterone, low cortisol, high sex steroids
• B. High aldosterone, high cortisol, low sex steroids
• C. Normal
• D. All high

Answer: (A)

In congenital adrenal hyperplasia caused by 21-hydroxylase deficiency, the block stops the synthesis of cortisol and aldosterone. Because 21-hydroxylase is needed to make cortisol precursors and the mineralocorticoid (aldosterone) precursors, both cortisol and aldosterone fall. The drop in cortisol removes the negative feedback on the pituitary, so ACTH rises and drives adrenal hyperplasia. The excess ACTH pushes precursors into androgen pathways, causing high levels of sex steroids (androgens). So the typical hormonal pattern is low cortisol, low aldosterone, and high androgens. The other patterns don’t fit because they would require intact cortisol and/or aldosterone synthesis or increased all hormones, which isn’t the case with this enzymatic block.