X-linked adrenoleukodystrophy (X-ALD) is caused by mutations in the ABCD1 gene that results in elevated very long-chain fatty acids (VLCFA) levels in tissues. X-ALD can manifest as a rapidly progressive and fatal cerebral inflammatory demyelinating disease (cerebral ALD) or as a slowly progressive noninflammatory distal axonopathy (AMN). Biochemical analysis suggests that VLCFA play an important role in the onset of cerebral ALD: myelin from cerebral ALD patients contains more VLCFA compared to myelin from AMN patients. Unfortunately, this cannot be proven in the X-ALD knockout (Abcd1-/-) mouse develop AMN at 20 months of age. Experimental evidence indicates …