Snapshot A 1-year-old girl is brought to the pediatrician’s office for failure to thrive and muscle weakness. Her parents deny any problems with feeding. On physical exam, her blood pressure is elevated for her age. Laboratory tests reveal hypokalemia, metabolic alkalosis, and low serum aldosterone and renin. Introduction Clinical definition Syndrome of Apparent Mineralocorticoid Excess (SAME) is a hereditary defect in 11β-hydroxysteroid dehydrogenase causing hypertension hypokalemia metabolic alkalosis these findings are similar to those in primary aldosteronism Epidemiology demographics early childhood onset risk factors family history Etiology hereditary deficiency acquired disorder ingestion of glycyrrhetinic acid (licorice) Pathogenesis genetic loss-of-function mutation in 11β-hydroxysteroid dehydrogenase (kidney isoform) 11β-hydroxysteroid dehydrogenase usually converts cortisOL to cortisONE login to view 2 more bullets deficiency results in excess cortisol login to view 1 more bullet glycyrrhetinic acid inhibits 11β-hydroxysteroid dehydrogenase and reduces gene expression Genetics inheritance pattern autosomal recessive mutations chromosome 16 11β-HSD2 gene Presentation Symptoms infants low birth weight failure to thrive Physical exam muscle weakness due to hypokalemia hypertension Studies Labs hypokalemia metabolic alkalosis ↓ aldolsterone level ↓ renin activity may have ↑ creatinine Urine hypercalciuria free cortisol to free cortisone ratio on 24-hour urine collection Differential Liddle syndrome urine cortisol to cortisone ratio is normal Primary aldosteronism elevated aldosterone Treatment Conservative remove licorice from diet indications login to view 1 more bullet Medical mineralocorticoid receptor blockade indications login to view 1 more bullet drugs login to view 4 more bullets corticosteroids indications login to view 1 more bullet thiazides indications login to view 1 more bullet Complications Cardiac arrhythmia from hypokalemia Nephrocalcinosis