Figure 1. The pathogenesis of X-ALD: The mutated ABCD1 gene encodes a defective  Adrenoleukodystrophy Protein (ALDP) that impedes Very Long Chain Fatty Acids (VLCFAs) from entering the peroxisome to undergo degradation. This leads to accumulation of VLCFAs in the cytosol, which is further aggravated by the elongation of LCFAs carried out by specific VLCFA elongase (ELOVL1), The accumulation of VLCFA has been shown to be toxic by causing the breakdown of cell membranes and by evoking mitochondrial dysfunction as a result of oxidative stress