X-linked adrenoleukodystrophy (X-ALD) is a peroxisomal disorder resulting in cerebral demyelination, axonal dysfunction in the spinal cord leading to spastic paraplegia, adrenal insufficiency and in some cases testicular insufficiency. The disease is X-linked adrenoleukodystrophy (Orphanet_43, an Orphanet rare-disease nomenclature identifier). Also known as: ALD, X-ALD, X-linked ALD.