Plasma phospholipid fatty acids in X-linked adrenoleukodystrophy.

Blood cell and plasma lipid classes and their fatty acids were analyzed in a child with X-linked adrenoleukodystrophy. The increase in saturated fatty acids with very long chains typical of this disease occurred almost exclusively in sphingomyelin. In this lipid, the proportion of lignoceric (24:0) and hexacosanoic (26:0) acids increased while that of 18:0, 20:0, and 24:1 decreased. In the rest of the lipid classes, but especially in cholesteryl esters and triacylglycerols, the proportion of linoleate (18:2) decreased while that of oleate (18:1) increased. In glycerophospholipids, polyunsaturated fatty acids such as 20:4n-6, 22:5n-6, and 22:6n-3 were reduced while their immediate precursors, 20:3n-6, 22:4n-6, and 22:5n-3, respectively, were relatively increased, suggesting a defect in fatty acid desaturation mechanisms. Although less pronounced, a similar trend of changes was seen in the patient's mother; in both, all alterations were more marked in serum than in blood cells.