The substance which accumulates in Tay Sach's disease is?

Tay sach's disease is caused due to deficiency of the enzyme hexosaminidase A. During this disease there is an accumulation of gangliosides and the symptoms include mental retardation, blindness and muscular weakness. Also Know: In Tay sach's disease gangliosides are found in highest concentration in cells of the nervous system and are normally broken down inside lysosomes by orderly removal of the sugar residues, paly by the action of the enzyme -N-acetylhexosaminidase. When this enzyme is missing or deficient, ganglioside GM2 cannot be broken down and Tay-Sachs disease results. Symptoms of weakness and delayed development of muscle skills are usually evident before the age of 1 year with subsequent blindness and death, usually by the age of 3 years. Neurons of affected patients are literally swollen with lysosomes filled with GM2. Ref: Hopkin R., Grabowski G.A. (2012). Chapter 361. Lysosomal Storage Diseases. In D.L. Longo, A.S. Fauci, D.L. Kasper, S.L. Hauser, J.L. Jameson, J. Loscalzo (Eds), Harrison's Principles of Internal Medicine, 18e.