Because of the radiographic esophageal abnormalities, an adrenocorticotropic hormone (ACTH) stimulation test was performed on the suspicion of Addison's disease and was within normal limits (baseline cortisol 129.7 nmol/L; reference interval (RI) 27.6–138.0 nmol/L, one-hour post-ACTH stimulation cortisol 380.7 nmol/L using an unknown amount of cosyntropin; RI 220.7–469.0 nmol/L). The gene discussed is POMC; the disease is primary adrenal insufficiency.