X‐linked adrenoleukodystrophy (ALD) (OMIM # 300100) is the most common peroxisomal disorder caused by pathogenic variants in ABCD1,1, 2 which encodes a peroxisomal membrane transporter and affects the brain, spinal cord, adrenal glands, and testes.3, 4. The gene discussed is ABCD1; the disease is adrenoleukodystrophy.