The GM1 gangliosidoses are caused by a deficiency of the enzyme beta-galactosidase, resulting in abnormal storage of acidic lipid materials particularly in the nerve cells in teh central and peripheral nervous systems. GM1 gangliosidosis has three clinical presentations: early infantile, late infantile, and adult. Signs of early infantile GM1 (the most severe subtype, with onset shortly after birth) may include neurodegeneration, seizures, liver and spleen enlargement, coarsening of facial features, skeletal irregularities, joint stiffness, distended abdomen, muscle weakness, exaggerated startle response, and problems with gait