Polyunsaturated fatty acid lipidosis: a new nosological entity.

Lipid analyses in the terminal stage of the disease polyunsaturated fatty acid lipidosis (PFAL), showed a brain very poor in lipids. The concentration of sphingolipids was particularly low: gangliosides of cerebral cortex was only 10% of the control value, and cerebrosides of white matter only 2%. Of the gangliosides, GM1 and GD1 a were reduced more than any other ganglioside fraction. The fatty acid compositions of the phosphoglycerides were the same in cerebral cortex and white matter. Compared with what was found in the controls, ethanolamine phosphoglycerides had much higher proportions of 18:1 and 20:4 (n-6) and much lower proportions of 22:4 (n-6) and 22:6 (n-6) and 22:6 (n-3) in the cerebral cortex. Similar changes in the fatty acid patterns were found in the other phosphoglycerides. It is assumed that in PFAL there is a primary disturbance in the metabolism of arachidonic acid, which leads to a series of secondary changes. The results suggested that the gangliosides GM1 and GD1a, sialidase and phosphoglycerides with dokosahexaenoic acid are confined to the nerve endings.