GLB1 and Ataxia: The clinical phenotype of the Glb1−/− mouse most closely resembles that of infantile GM1 gangliosidosis, with motor abnormalities appearing by 4 months of age and severe ataxia or paralysis necessitating euthanasia presenting by 10 months of age.20,21 The Glb1−/− mouse model does not exhibit any peripheral organ involvement, unlike infantile GM1 patients who often develop bone deformities and hepatosplenomegaly.20,21 The Glb1−/− mouse is, therefore, a representative model of the neurological features of infantile GM1 gangliosidosis, but not the systemic disease manifestations.