Ganglioside GM2 is a glycosphingolipid component of cellular membranes, primarily the plasma membrane. Levels of ganglioside GM2 are elevated in the brain of patients with Sandhoff disease, as well as feline and mouse models of the disease. Ganglioside GM2 accumulates in the lysosomes of individuals with Tay-Sachs disease and GM2-activator deficiency, as well as in the CNS of patients with and animal models of mucopolysaccharide storage disorders and Niemann-Pick disease types A, C1, and C2. Ganglioside GM2 mixture contains ganglioside GM2 molecular species with C18:1 and C20:1 sphingoid backbones.