Steroid 17 alpha-hydroxylase deficiency: First Australian case report

17 alpha-hydroxylase deficiency is a rare form of congenital adrenal hyperplasia (CAH) that affects both glucocorticoid and sex hormone biosynthesis. We report a case of an unambiguous female with testes and hypertension. She was found to have deficient 17 alpha-hydroxylase activity. The diagnosis was not made easily, the condition being unexpected due to its rarity. The discriminating feature of this form of sex-reversal is the presence of hypertension due to the elevated serum deoxycorticosterone levels. A failure to detect this will inappropriately focus attention on other, more common causes of sex reversal such as androgen insensitivity and gonadal dysgenesis, and expose the patient to the long-term sequelae of uncontrolled arterial hypertension.