Phosphomannomutase 2-congenital disorder of glycosylation (PMM2-CDG) is a hereditary defect causing hypoglycosylation of N-linked glycoproteins. It was recently suggested that patients with PMM2-CDG may have central adrenal insufficiency. We present an 18-year-old male with PMM2-CDG, whose initial screening suggested adrenal insufficiency.