Familial hyperaldosteronism type 1 in pregnancy

Familial hyperaldosteronism type 1 (FH-1) is a rare condition, accounting for less than 1% of cases of primary hyperaldosteronism. There are few published data regarding outcomes and management of FH-1 in pregnancy. Herein, we report a case of a young woman with FH-1 and clinical and biochemical changes associatedwith pregnancy. A 28-year-old woman had been investigated for secondary causes of hypertension after presenting with a blood pressure of 160/90 mmHg. Verapamil was commenced when her blood pressure increased to 200/ 100 mmHg. Her father also had a history of hypertension since his twenties and had a stroke when aged 65 years. Initial testing suggested primary hyperaldosteronism, with aldosterone of 1120 pmol/L (110–860) and plasma renin activity (PRA) <0.10 lg/L per hour (1.3–4.0) and a saline suppression test showed incomplete suppression of aldosterone.Given the family history and anormal finecut computed tomography of the adrenals, FH-1 was suspected. 48 h of dexamethasone completely suppressed aldosterone to <50 pmol/L and genetic testing confirmed the diagnosis of FH-1 (Fig. 1). Her father was also diagnosed with FH-1 on genetic testing. Shortly after her diagnosis of FH-1 was made, she became pregnant and verapamilwas ceased.During the course of her pregnancy, her blood pressure was monitored closely and remained normal without medication. PRA progressively rose to 2.7 lg/L per hour at 18 weeks and 7.0 lg/L per hour at 24 weeks gestation with repeatedly normal aldosterone levels (260 pmol/L; 685 pmol/L). At 1-monthpost-partum, her hypertension recurred andwent up to 160/120 mmHg, with an associated decrease in PRA to 0.29 lg/L per hour with aldosterone of 605 pmol/L. Prednisolone was commenced at 2.5 mg daily.