POMC and X-linked adrenoleukodystrophy: His higher serum ACTH level, lower corticosteroid level, and hyperpigmentation in the gingiva, tongue, areolae, creases of the hand, and elbow joint indicated that he had the “Addison‐only” phenotype of X‐ALD (van Geel, Assies, Wanders, & Barth, 1997).