A Rare Cause of Neonatal Salt Wasting Syndrome: Clinical Management of a Case Diagnosed with Pseudohypoaldosteronism Due to a Novel Homozygous Variant in the SCNN1B Gene.

Pseudohypoaldosteronism (PHA) is a rare disorder that, if not promptly recognized and treated, can lead to life-threatening hyperkalemia resulting in cardiac arrest and death. Systemic PHA is caused by variants that deactivate the epithelial sodium channel (ENaC) subunits. Management is challenging due to high-dose oral replacement therapy, and patients with systemic PHA require lifelong treatment. Here, we present the clinical course of a newborn diagnosed with PHA at 7 days of age due to severe dehydration, inadequate feeding, vomiting, and lethargy. The patient was found to be homozygous for the variant c.1234dup (p.Glu412Glyfs*39) in exon 8 of the SCNN1B gene. The patient had multiple hospitalizations during follow-up and died at the age of 10 months due to pneumonia. Maintaining a high clinical suspicion for PHA is crucial for initiating treatment and preventing potential cardiac arrest and death in these patients. Further research is needed to determine the significance of such novel mutations in this disease.