17β-Hydroxysteroid dehydrogenase type 3 (HSD17B3)

17β-Hydroxysteroid dehydrogenase type 3 (HSD17B3) is a short-chain dehydrogenase/reductase enzyme predominantly expressed in the testes, where it catalyzes the final step in testosterone biosynthesis by converting androstenedione to testosterone. It is essential for normal male sexual development and fertility. Deficiency leads to disorders of sexual development, and while no selective clinical inhibitors currently exist, the enzyme represents a potential therapeutic target for androgen-related conditions. The broader testosterone biosynthesis pathway includes cytochrome P450 and hydroxysteroid dehydrogenase enzymes, but HSD17B3 is central for testosterone production in the testes.

Other names

Hydroxysteroid 17-beta dehydrogenase 3Testicular 17-beta-hydroxysteroid dehydrogenase17-beta-hydroxysteroid dehydrogenase type 3Testosterone 17-beta-dehydrogenase 3SDR12C2Estradiol 17-beta-dehydrogenase 2

Inhibitors block the conversion of androstenedione to testosterone, reducing androgen effect. Testosterone replacement acts as substrate/product replacement in deficiency.