CASE REPORT
ALDOSTERONE SYNTHASE DEFICIENCY FROM HOMOZYGOUS CYP11B2 MU-TATION PRESENTING WITH SALT-WASTING CRISIS AND FAILURE TO THRIVE IN AN INFANT

UDK: 616-056.7-053.31

Nikchevska N¹, Palchevska-Kocevska S¹,³, Choneska-Jovanova B1,3, Demerdzieva A1,,3 Spasevska S¹, Gjorgjievska K²

 

¹Department of Pediatrics, Acibadem Sistina Clinical Hospital, Skopje, North Macedonia
²Faculty of Medicine, Ss. Cyril and Methodius University in Skopje, North Macedonia
³Faculty of Medical Sciences, Goce Delchev University of Štip, North Macedonia

 

Abstract

Introduction:
Aldosterone synthase deficiency (ASD) is a rare autosomal recessive disorder caused by pathogenic variants in the CYP11B2 gene, leading to impaired aldosterone synthesis and life-threatening salt-wasting. We present a case of an infant with failure to thrive, dehydration, and electrolyte imbalance, diagnosed through next-generation sequencing.

Material and Methods:

A 9-month-old male infant was admitted with persistent vomiting, constipation, and a10% weight loss. Laboratory evaluation showed severe hyponatremia (116 mmol/L), hyperkalemia (6.5 mmol/L), hypochloremia (87 mmol/L), and metabolic alkalosis. Differential diagnosis included gastrointestinal loss, renal salt-wasting, cystic fibrosis, celiac disease, and congenital adrenal hyperplasia. Normal 17-hydroxyprogesterone excluded classical CAH. Next-generation sequencing was performed.

Results:
A homozygous pathogenic variant c.554C>T (p.Thr185Ile) in CYP11B2 confirmed ASD. Treatment with fludrocortisone and sodium supplementation resulted in rapid correction of electrolytes and improved growth. Follow-up at 3.5 years showed normal growth (14.5 kg, 103 cm), stable electrolytes, and normal development, with only mild transient hyponatremia during illness.

Conclusion:
ASD should be considered in infants with vomiting, dehydration, and combined hyponatremia–hyperkalemia when CAH is excluded. Early diagnosis and mineralocorticoid therapy prevent complications and support normal development.

 

Key words: aldosterone synthase deficiency; CYP11B2; infant; hyperkalemia; hyponatremia; fludrocortisone.

 

 

 

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