Abstract: FR-PO0901
Familial Apparent Mineralocorticoid Excess Syndrome: A Three-Case Series
Session Information
- Fluid, Electrolyte, and Acid-Base Disorders: Case Reports - 1
October 23, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Fluid, Electrolytes, and Acid-Base Disorders
- 1102 Fluid, Electrolyte, and Acid-Base Disorders: Clinical
Authors
- Elhassan, Afra Ahmed Mohamed, Hamad Medical Corporation, Doha, Qatar
- Abuhelaiqa, Essa, Hamad Medical Corporation, Doha, Qatar
- Nauman, Awais, Hamad Medical Corporation, Doha, Qatar
Introduction
Apparent mineralocorticoid excess (AME) is a rare autosomal disorder causing severe low-renin, low-aldosterone hypertension due to HSD11B2 variants. It can mimic Liddle syndrome and cause renal/cardiovascular injury if diagnosis is delayed.
Case Description
We report 3 male patients with familial, genetically confirmed AME. Case 1 is a 28-year-old male born to first-cousin parents who presented neonatally with heart failure, congenital cardiomyopathy, severe hypertension, and hypokalemia. Initial evaluation showed suppressed renin and aldosterone levels, and he was initially diagnosed with Liddle syndrome. Whole exome sequencing in adulthood identified a homozygous likely pathogenic HSD11B2 variant consistent with autosomal recessive AME. Family screening showed heterozygous carrier status in both parents and one sibling. Case 2 was a 22-year-old male presenting at 14 months with severe hypertension and persistent hypokalemia. Imaging demonstrated bilateral medullary nephrocalcinosis, nephrolithiasis, and left ventricular hypertrophy. Genetic testing identified a homozygous exon 2 HSD11B2 variant. Despite multidrug therapy, disease control remained suboptimal because of poor adherence. Case 3, the younger brother of Case 2, presented at 7 months with hypertension, vomiting, metabolic alkalosis, and hypokalemia. Genetic testing confirmed the same homozygous exon 2 HSD11B2 variant. Similar complications including nephrocalcinosis and LVH were identified. All 3 patients received amiloride and calcium channel blockers; one also received an ACE inhibitor.
Discussion
These cases show the broad phenotype of familial AME, including cardiomyopathy, nephrocalcinosis, nephrolithiasis, growth impairment, and resistant hypokalemic hypertension. Overlap with Liddle syndrome delayed diagnosis, emphasizing genetic testing in early-onset low-renin hypertension. Intrafamilial variability and adherence influenced outcomes.
AME should be suspected in children with severe hypokalemic hypertension and suppressed renin/aldosterone, especially in consanguineous families. Early diagnosis, family screening, and adherence help prevent complications.