A FAMILIAL METABOLIC DISORDER WITH STORAGE OF AN UNUSUAL POLYSACCHARIDE COMPLEX

A metabolic disease, characterized by the accumulation of a mixture of complex polysaccharides in liver, spleen, lung, kidney and reticuloendothelial system, is described in three patients. Its familial nature is indicated by the fact that two of the cases were siblings. The salient clinical features included hepatosplenomegaly, anemia, failure in physical development and susceptibility to respiratory infection. The disease simulates glycogen storage disease in the response in the epinephrine tolerance test, and in an inability to call on glycogen stores. Histochemical tests on the tissue containing the storage cells indicated that the material was not glycogen, even though polysaccharide in nature. The storage material was isolated from the liver of one of the cases. This isolated material proved to be a complex consisting of two major moieties. The first appeared to possess a high molecular weight, was insoluble in organic solvents, and contained glucose, galactose, glucosamine and hexuronic acids as constituents. A small amount of peptides were associated with this fraction. The second major moiety of the storage material was soluble in ethanol and contained glucose, galactose, glucosamine, fatty acids, hexuronic acids and neuraminic acid as main constituents (hence a lipopolysaccharide). Attention is drawn to the fact that the storage material would have been considered an "abnormal glycogen" if the customary procedures for the isolation of glycogen had been applied to the tissue. It is suggested that caution be exercised in future studies involving storage diseases where storage of an "abnormal glycogen" with an abnormality in side-chains is suspected.