Pseudohypoaldosteronism presenting with thrombocytosis and bilateral pneumothoraces in an infant

Pseudohypoaldosteronism type 1 (PHA-1) is a rare salt-wasting syndrome caused by a peripheral resis tance to aldosterone. Here, we describe an unusual presentation of the autosomal dominant PHA-1 featuring bilateral pneumothoraces at birth, thrombocytosis in infancy, and hypercalcemia in addition to the well-described findings of hyponatremia, hyperkalemia, and failure to thrive. These findings contribute to the limited case descriptions of PHA-1 and may suggest additional diagnostic considerations in a neonate presenting with hyperkalemia, hyponatremia, and failure to thrive.