Objective: To describe a patient with aldosterone synthase deficiency, who presented with failure to thrive, hypovolemic hyponatremia, and the unexpected finding of hypertension.
Methods: We present a case report, review the related literature, and outline a possible mechanism for the concomitant occurrence of high blood pressure and hyponatremia in this patient.
Results: A 5-month-old infant with unambiguous female genitalia was admitted to our hospital with failure to thrive and hyponatremia. Her blood pressure was 115/88 mm Hg (>95% for age). The serum sodium concentration was 123 mEq/L (normal for age, >130), and the potassium level was 5.3 mEq/L (normal, 3.5 to 5.3). A direct renin measurement by immunochemiluminescence assay was 11,400 microU/mL (normal, <5), and the aldosterone level was 4 ng/dL (normal, 2 to 70). These findings indicated a diagnosis of aldosterone synthase deficiency. Treatment with fludrocortisone and sodium chloride was begun, but the hypertension worsened. Therapy with an angiotensin-converting enzyme inhibitor was transiently required.
Conclusion: Angiotensin II, a potent vasoconstrictor, is an intermediate in the renin-angiotensin system. We believe that this protein was the cause of the hypertension in the setting of aldosterone deficiency in our patient.