Congenital adrenal hyperplasia comprises three distinct enzymatic deficiencies (21-hydroxylase, 11-beta-hydroxylase, 17-alpha-hydroxylase) in cortisol biosynthesis, all sharing the common mechanism of low cortisol driving compensatory ACTH hypersecretion via the hypothalamic-pituitary-adrenal axis, with elevated POMC (the ACTH precursor) also raising MSH and causing hyperpigmentation and adrenal hyperplasia. The subtypes are differentiated by divergent effects on mineralocorticoid and androgen synthesis in the other adrenal cortical zones, producing distinct clinical syndromes of electrolyte and virilization abnormalities. This is a topic within endocrinology/adrenal pathophysiology, encompassing HPA-axis feedback regulation, steroidogenesis pathway biochemistry, and the resulting clinical and diagnostic reasoning.
Congenital adrenal hyperplasia comprises three distinct enzymatic deficiencies (21-hydroxylase, 11-beta-hydroxylase, 17-alpha-hydroxylase) in cortisol biosynthesis, all sharing the common mechanism o…