Lipid analyses were performed on cerebral tissue from three children who had died of a progressive
encephalopathy and from one living child in an early stage of the disease. In the terminal stage of the disease, the cortex and white matter content of all
lipid classes, particularly the
sphingolipids, were very low. The concentration of
gangliosides of the cerebral cortex was 10%, and of
cerebrosides in white matter, 2-3% of the normal values for the age. The porportion of the minor
gangliosides with short
carbohydrate chains was increased because the reduction affected mainly the four major brain
gangliosides GM1, GD1a, GD1b and GT1. In the child from whom the biopsy specimen was obtained in an early phase of the disease the cerebral
lipid pattern appeared to be normal. A patient who had died of
neuronal ceroid-lipofuscinosis (Janský-Bielschowsky) did not show any major
lipid changes. The
fatty acid patterns of the
phosphoglycerides showed such changes as have never been observed in any other disease. In the three advanced cases the
fatty acid compositions in cerebral cortex and white matter were identical. In
ethanolamine phosphoglycerides the proportions of 18: 1 and 20: 4 (n-6) were increased, while those of 22: 4 (n-6) and 22: 6 (n-3) were markedly diminished. Similar changes in the
fatty acid patterns were found in the other
phosphoglycerides. In the early phase of the disease 22: 4 (n-6) was decreased and 18: 1 increased. We propose that this new disease be termed
polyunsaturated fatty acid lipidosis (PFAL).