Further study on cerebral sphingolipids including gangliosides in two cases of juvenile amaurotic family idiocy (Spielmeyer-Vogt type) using a new analytical procedure of sphingolipids.

Sphingolipids isolated from cerebral grey and white matter of two patients with Juvenile Amaurotic Idiocy (Spielmeyer-Vogt Type) were studied. A new analytical procedure was attempted for the determination of sphingolipids, i.e., cerebroside, sulfatide, sphingomyelin and gangliosides were subjected to ozonolysis and reduced with NaBH4. Fatty alcohols thus derived from the double bond-containing long chain bases of the sphingolipids were analyzed by GLC as their TMS-derivatives using an internal standard. The new procedure was suitable for the analysis of small amounts of sphingolipids and could determine the amounts of C18 and C20 sphingosines. It was found that all individual gangliosides in both cases gave lower proportions of C20 sphingosine to the total long chain bases. Sphingomyelin in normal human grey matter contained a small but significant amount of C20 sphingosine, while the sphingomyelin of the two patient brains indicated a much lower proportion of C20 sphingosine in comparison with those of age-matched controls. Thus, this disease seemed to be related to a genetical defect in the metabolic regulation of the long chain bases of gangliosides and grey matter sphingomyelin. On the other hand, it was noted that the ganglioside pattern of grey matter in case-1 was entirely different from that of case-2. The grey matter gangliosides in case-1 were composed of 1.78% of GM2, 81.19% of GM1 and 17.02% of GD1b by the amounts of long chain bases, while the grey matter gangliosides in case-2 seemed to be similar to those of normal human brains. Also, unusual fatty acid compositions of galactosphingolipids (cerebrosides and sulfatides) were observed to a somewhat extent in the grey matter of case-1.