The degree of demyelination in adrenoleukodystrophy is related to the Pentacosanoic to Docosanoic acid ratios (C25:0/C22:0 and C26:0/C22:0). Mainly saturated fatty acids of the middle class components (C24:0, C25:0 and C26:0) are found in severely affected areas where the active process is complete. Because a region of high long chain fatty acid content, lacking histopathological change, is detected[1].
The area with myelin destruction with axonal preservation is generally most prominent in the frontal edge of the lesion. A bell-shaped distribution of very long chain fatty acids, esterified to cholesterol, are detectable, with the mid-point being formed by Pentacosanoic (C25 : 0) and Hexacosanoic (C26 : 0) acids[1].