17ɑ-hydroxylase/17,20-lyase deficiency (17OHD) was caused by mutations in the CYP17A1 gene. It was a rare form of congenital adrenal hyperplasia with an estimated incidence of about 1:50,000. The clinical manifestation of 17OHD includes hypertension and hypokalemia due to excessive synthesis of mineralocorticoid precursors, undermasculinized external genitalia in 46, XY males, and primary amenorrhea in 46, XX females.