The liver in GM1 gangliosidosis types 1 and 2. A light and electron microscopical study

The livers from two cases of GM1 gangliosidosis types 1 and 2 were examined by histochemistry, light and electron microscopy. Type 1 GM1 gangliosidosis is characterized by large amounts of a water soluble substance in the hepatocytes, presumed to be keratan sulfate-like mucopolysaccharide, with similar material and probably a ganglioside in the Kupffer cells. In type 2 GM1 gangliosidosis, there is minimal storage of water soluble material and abundant presumed ganglioside in the Kupffer cells. The histochemical and ultrastructural features support the chemical findings and indicate a quantitative and morphologic difference in storage between the two types. These morphologic differences may provide an additional diagnostic parameter in the delineation of the two clinical variants.