Gangliosidosis is any of a group of inherited disorders that gradually destroys nerve cells (neurons) in the brain and spinal cord. The destruction of the cells is caused by the storage of non-catalysed macromolecules in the lysosomes of the cells, in this case lipids called gangliosides. The cause of this buildup of molecules may be due to either non-production of the needed enzyme to catalyze the molecules or the enzyme produced is of a sufficiently different structure so that it cannot perform its function. There are two types of gangliosidosis, GM1 and GM2 gangliosidosis.
In GM1 gangliosidosis, the buildup of gangliosides happen in the cells of the central and peripheral nervous systems and is caused by a deficiency of the enzyme beta-galactosidase. GM1 gangliosidosis has three forms based on diagnosis in either early infancy, late infancy or adulthood.
In GM2 gangliosidosis, the buildup occurs in the neurons of the brain it is caused by a deficiency of the enzyme β-hexosamidase. There are three disorders or variants under this group; Tay–Sachs disease, AB variant, and Sandhoff disease. These three are indistinguishable from each other in terms of clinical observation but they differ as to the point of failure in the enzymatic catalytic process.