3-beta-HSD is a bifunctional enzyme, that catalyzes the oxidative conversion of Delta(5)-ene-3-beta-hydroxy steroid, and the oxidative conversion of ketosteroids. The 3-beta-HSD enzymatic system plays a crucial role in the biosynthesis of all classes of hormonal steroids. a 3beta-hydroxy-Delta(5)-steroid + NAD(+) = a 3-oxo-Delta(5)-steroid + H(+) + NADH a 3-oxo-Delta(5)-steroid = a 3-oxo-Delta(4)-steroid NAD(+) + pregnenolone = H(+) + NADH + pregn-5-ene-3,20-dione pregn-5-ene-3,20-dione = progesterone 3beta-hydroxyandrost-5-en-17-one + NAD(+) = androst-5-ene-3,17-dione + H(+) + NADH androst-5-ene-3,17-dione = androst-4-ene-3,17-dione Lipid metabolism; steroid biosynthesis. Expressed in adrenal gland, testis and ovary. The disease is caused by variants affecting the gene represented in this entry. Mild HSD3B2 deficiency in hyperandrogenic females is associated with characteristic traits of polycystic ovary syndrome, such as insulin resistance and luteinizing hormone hypersecretion. Belongs to the 3-beta-HSD family. The frameshift is caused by a single nucleotide insertion which is found in AH2.