5-α-reductase enzyme 5α- 5-alpha reductase 5-alpha-reductase 5-alpha reductase 5α-reductase 5α還原酶 5-alpha reductase 5-alpha reductase enzyme 5 alpha reductase 5-alpha reductase 5-alpha reductase 5-alpha reductase gene 5 alpha reductase 5α-reductase 5-alpha-reductase 5-alpha reductase 5 alpha reductase 5alpha-reductase 5-alpha reductase 5α-réductase