The lipid composition of liver, spleen, and brain in Niemann-Pick disease was examined. Sphingomyelin, phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, and phosphatidylinositol were determined quantitatively. In liver and spleen, a marked increase in sphingomyelin concentration was found, and cholesterol accumulation in all the tissues. The fatty acid pattern of these sphingomyelins differed significantly from other phospholipids, and further showed special feature in brain compared with those in liver and spleen. However, as regards other phospholipid components, the fatty acid pattern in liver was distinguished from other tissues
