17β-hydroxysteroid dehydrogenase

17β-hy·droxy·ste·roid de·hy·dro·gen·ase (hi-drok″se-sterґoid de-hiґdro-jən-ās) a large family of enzymes that modulate the potency of androgens and estrogens by catalyzing the interconversion of active 17-hydroxysteroids and inactive 17-ketosteroids. Members of this family are encoded by nonhomologous genes, have different substrate and cofactor specificities, subcellular locations, and tissue-specific patterns of expression. Deficiencies of types 3, 4 (D-bifunctional protein, q.v.), and 10 cause disease.