Three cases of GM1-gangliosidosis.

A biochemical analysis was carried out on three cases of GM1-gangliosidosis which showed different clinical manifestations. These cases were classified in a previous study as Type 1, Type 2 (2B) and Type 2 (2A), an intermediate type between classical Type 1 and Type 2 (2B), by the determination of the chromatographic profile of the liver beta-galactosidase activities. Gangliosides, neutral glycolipids; phospholipids and glycopeptides were analyzed in the brain and the liver of these cases. The concentration of total ganglioside was increased in the brain in all cases. The elevation was due to an increase of GM1-ganglioside, which accounted for 63% or more of the total ganglioside, while in the control brain about 20% of the total ganglioside was GM1-ganglioside. In type 2A, increases of GM1-ganglioside and and asialo-GM1 in the liver were more prominent than those in the liver of Type 2B. The non-dialyzable glycopeptides were analyzed only in Type 2A. In the liver of Type 2A, the hexosamine and hexose contents of the non-dialyzable glycopeptides were about 10 times and 5 times higher than those of the control. These biochemical analyses revealed that Type 2A had intermediate characteristics between two Types. In this classification of the three Types, biochemical data were well correlated with clinical features.