Molecular genetics of androgenic 17 beta-hydroxysteroid dehydrogenases.

17 beta-Hydroxysteroid dehydrogenase (17 beta-HSD) type 2 catalyzes the NAD(+)-dependent oxidation of androgens, estrogens and progestins, predominantly in the secretory endometrium, placenta, liver and small intestine. 17 beta-HSD type 3 catalyzes the NADPH-dependent conversion of androstenedione to testosterone in the testis, and the genetic disease 17 beta-HSD deficiency is caused by mutations in the 17 beta-HSD3 gene.