Steroid 17-alpha-Hydroxylase

**Definition:** A microsomal cytochrome P450 enzyme that catalyzes the 17-alpha-hydroxylation of progesterone or pregnenolone and subsequent cleavage of the residual two carbons at C17 in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP17 gene, generates precursors for glucocorticoid, androgen, and estrogen synthesis. Defects in CYP17 gene cause congenital adrenal hyperplasia (ADRENAL HYPERPLASIA, CONGENITAL) and abnormal sexual differentiation.

**Tree numbers:** - D08.244.453.487.500 - D08.244.453.915.748 - D08.811.682.690.708.170.444.500 - D08.811.682.690.708.170.915.748 - D12.776.422.220.453.487.500 - D12.776.422.220.453.915.748

**Synonyms:** - Cytochrome P-450(17 alpha) - Steroid 17 alpha-Hydroxylase - Steroid-17-Hydroxylase - Steroid 17-Hydroxylase - Steroid 17-Monooxygenase - 17,20-Desmolase - 17 alpha-Hydroxylase Cytochrome P-450 - Cytochrome P450(17 alpha) - Steroid 17 alpha-Monooxygenase - CYP17 - 17 alpha-Hydroxylase - P450(c17) - Cytochrome P-450(17-alpha) - 17,20-Lyase