GM2-ganglioside accumulation Gangliosides are the main glycolipids of neuronal cell plasma membranes which ensure normal cellular activities. GM2-gangliosidosis can be caused by mutations in three genes: HEXA, HEXB, and GM2A. In patients with HexA deficiency GM2 ganglioside accumulates inside lysosomes, which form characteristic inclusions within the cells, so called membranous cytoplasmic bodies, which are enlarged lysosomes filled with gangliosides. The highest concentration of GM2 ganglioside is found in neuronal cells, therefore, the HexA deficiency primarily affects the nervous system, causing mental and motor developmental delay in patients. Later, progressive destruction of neurons, proliferation of microglia and accumulation of complex lipids in macrophages are observed in the brain tissue. Cellular accumulation of GM2 gangliosides. UMLS:C1848920 HP:0003495 Ganglioside accumulation