3-beta-HSD

3-beta-HSD (or 3-beta-hydroxysteroid dehydrogenase-isomerase) is an enzyme which catalyses the synthesis of progesterone from pregnenolone, 17-hydroxyprogesterone from 17-hydroxypregnenolone, and androstenedione from dehydroepiandrosterone in the adrenal gland. It is the only enzyme in the adrenal steroidogenic pathway that is not a member of the Cytochrome P450 family.

Clinical significance
It is associated with congenital adrenal hyperplasia due to 3 beta-hydroxysteroid dehydrogenase deficiency.