Novel ABCD1 Gene Mutation in a Korean Patient with X-Linked Adrenoleukodystrophy Presenting with Addison's Disease

X-linked adrenoleukodystrophy (X-ALD) occurs due to mutations in the ABCD1 gene that encodes the peroxisomal membrane protein peroxisomal transporter ATP-binding cassette sub-family D member 1 (ABCD1). Degradation of very long-chain fatty acids in peroxisomes is impaired owing to ABCD dysfunction, subsequently leading to adrenomyeloneuropathy, cerebral adrenoleukodystrophy, and adrenal insufficiency. X-ALD frequently induces idiopathic Addison's disease in young male patients. Here, we confirmed the diagnosis of X-ALD in a young male patient with primary adrenal insufficiency, and identified a novel ABCD1 gene mutation (p.Trp664*, c.1991 G>A).