Abstract
Introduction: 17 alpha-hydroxylase deficiency (17-OHD) is an infrequent autosomal recessive disorder in adrenal and gonadal steroidogenesis due to the CYP17A1 defect. Affected girls are characterized by delayed puberty, absence of secondary sex characteristics at puberty, and primary amenorrhea. Affected boys show female or ambiguous genitalia. Hormone imbalances result in varying degrees of hypertension and hypokalemia. The increase in corticosterone levels prevents the development of typical adrenal insufficiency symptoms. Glucocorticoid and sex steroid supplementation is the preferred treatment. Case Presentation: We reported two phenotypically female siblings, aged 14 and 25 years, with the 17-OHD from Ankara, the capital city of Turkey. The younger child had a 46,XX karyotype and the older had a 46,XY chromosome pattern. Another feature of the second patient (aged 25 years), was the presence of a large myelolipoma in her right adrenal gland. Conclusions: 17 alpha-hydroxylase patients are usually diagnosed late, and unlike patients with other forms of congenital adrenal hyperplasia, hypertension is the major finding, and 10% - 15% of patients have normal blood pressure at diagnosis. The delay in diagnosis causes hypertension and renovascular changes, psychological problems, osteoporosis, and irreversible damage to breast tissue.