This pattern, alongside laboratory findings of low cortisol levels and an inadequate adrenocorticotropic hormone (ACTH) stimulation test response, strongly suggests that eosinophilia served as an early clinical clue to underlying adrenal insufficiency. The coexistence of hyponatremia further supports this diagnosis, as cortisol deficiency impairs free water excretion, leading to dilutional hyponatremia - a well-recognized feature of adrenal insufficiency. The gene discussed is POMC; the disease is Adrenal insufficiency.