The origin of congenital adrenal hyperplasia occurs when circulating cortisol levels are low.
Congenital adrenal hyperplasia (CAH) is an autosomal recessive disease which results from mutations of genes for enzymes involved in the biochemical steps of production of mineralocorticoids, glucocorticoids or sex steroids from cholesterol by the adrenal glands (steroidogenesis). Low cortisol production results in rising levels of ACTH (adrenocorticotropic hormone) because cortisol usually inhibits ACTH production. This increased ACTH production induces overgrowth (hyperplasia) and overactivity of the steroid-producing cells of the adrenal cortex.