Primary hypoaldosteronism is a rare autosomal recessive disorder that causes defects in aldosterone synthase enzyme activity due to an inactivating mutation in the CYP11B2 gene. Patients with primary hypoaldosteronism exhibit symptoms such as vomiting, dehydration, feeding problems, and failure to thrive. This disease is characterized by hyponatremia, hyperkalemia, metabolic acidosis, high renin, and low aldosterone levels. It also causes salt loss syndrome in the newborn period. In this article, we described a newborn with primary hypoaldosteronism who showed feeding problems and weight loss. Laboratory findings revealed hyponatremia, hyperkalemia, high plasma renin, and low aldosterone levels, while genetic analysis showed homozygous c.788T>A (p.Ile263Asn) variant in the CYP11B2 gene (NM_000498.3). Our patient responded well to oral salt and fludrocortisone treatments. Early diagnosis and treatment are particularly important because primary hypoaldosteronism causes life-threatening electrolyte disorders and salt loss syndrome.

Keywords: CYP11B2, Newborn, Primary hypoaldosteronism, Salt-wasting