A GM2 gangliosidosis that is characterized onset in infancy of developmental retardation, followed by paralysis, dementia and blindness, with death in the second or third year of life and has_material_basis_in homozygous or compound heterozygous mutation in the alpha subunit of the hexosaminidase A gene (HEXA) on chromosome 15q23.

Reference
DiseaseOntology: Tay-sachs disease