17-Beta-Hydroxysteroid Dehydrogenase Type 3 (HSD17b3)

HSD17b3 is expressed predominantly in the testis and catalyzes the conversion of androstenedione to testosterone. It preferentially uses NADP as cofactor. Deficiency can result in male pseudohermaphroditism with gynecomastia.

Geissler et al. (1994) used expression cloning to isolate cDNAs encoding a microsomal 17-beta-HSD type 3 isozyme that shares 23% sequence identity with other 17-beta-HSD enzymes, uses NADPH as a cofactor, and is expressed predominantly in the testes.Geissler et al. (1994) determined that the HSD17B3 gene spans at least 60 kb and consists of 11 exons, ranging in size from more than 264 bp to as small as 35 bp.