[Primary adrenal insufficiency as the form of onset of adrenoleukodystrophy in a 4-year-old boy].

X-linked adrenoleukodystrophy is an inherited metabolic disease caused by the accumulation of saturated very long chain fatty acids (VLCFA). Given that the form of presentation can be primary adrenal insufficiency, diagnosis in affected males is important. Patient was a 4-year-old boy with attention deficit hyperactivity disorder, cutaneous-mucosal hyperpigmentation, and dehydration with hyponatremia and hyperpotassemia was diagnosed with adrenoleukodystrophy presenting as primary adrenal insufficiency. Antiadrenal antibodies: negative. Plasma VLCFA: C(26:0)=1.25mg/ml (0.18-0.48), C(24:0)/C(22:0) =1.53 (< 1), and C(26:0)/ C(22:0)=0.04 (< 0.02). Abdominal computed tomography: small adrenal glands. Cranial magnetic resonance imaging and evoked potentials: normal at diagnosis and with signs of white matter demyelination after 2 years of follow-up. Testing for an autoimmune etiology and adrenoleukodystrophy is important in boys with primary adrenal insufficiency before Addison's disease is diagnosed.