<unk><unk>  type<unk>  <unk> R2) is an enzyme, encoded by the SRD5A2 gene, that is expressed in specific tissues in the male body from fetal development to adulthood. The enzyme catalyzes the transformation of testosterone (T) to<unk> -dihydrotestosterone (DHT) intracellularly. DHT is the most potent ligand to the androgen receptor (AR). Upon binding, the DHT-AR complex translocates from cytoplasm to the nucleus and activates the androgen receptor-regulated genes involved in processes that include male sexual differentiation. Some mutations in<unk> R2 impair the synthesis of DHT resulting in<unk> R2D. In the male fetus, T mediates Wolffian ductal differentiation while DHT mediates external genital and prostate differentiation. The fact that women with the same<unk> R2 mutations as affected male siblings have normal female phenotypes and normal reproductive function supports the notion that<unk> R2 does not play an important role in female biology. Most aspects of virilization in male puberty are driven by testosterone, which is why most affected males undergo virilization at that time. Though<unk> R2D only affects a small number of people, study of this disorder revealed fundamental aspects of<unk><unk> s (including cloning of the underlying genes), androgen action, the process of sexual differentiation, and the factors that influence normal sexual behavior. Biochemical effects of 5-ARD in testosterone biosynthesis. Levels of testosterone are elevated, while levels of DHT are significantly decreased, leading to male undervirilization.
5α-Reductase 2 deficiency
Isolated 17,20-lyase deficiency
17β-Hydroxysteroid dehydrogenase III deficiency
Aromatase deficiency
Cortisone reductase deficiency
Androgen-induced hermaphroditism
Multiple sulfatase deficiency
Gonadotropin-releasing hormone insensitivity