APPARENT MINERALOCORTICOID EXCESS IN THREE SIBLINGS

Three siblings (1 boy, 2 girls) with hypertension and hypokalemia are presented, two with low plasma aldosterone and suppressed renin activity and the eldest with a high renin and aldosterone level due to secondary changes in her kidneys. Urinary tetrahydrocortisol (THF) was increased relative to tetrahydrocortisone (THE). Cortisol ring A reduction constant was also lower than normal. These findings are suggestive of decreased cortisol-II β-hydroxysteroid dehydrogenase activity and ring A reduction defect which has previously been described in type 1 apparent mineralocorticoid excess.1 The existence of this disease in three siblings from healthy parents with consanguinous marriage reveals the genetic (autosomal recessive) nature of the disease. Spironolactone normalized serum potassium in all three patients and hypertension in two of them. Furosemide and captopril were required for lowering blood pressure in the eldest one. Treatment caused growth catch up in all three patients