GLB1 and GM1 gangliosidosis: β-Galactosidase (GLB1), a lysosomal hydrolytic enzyme, catalyzes the degradation of galactosylceramide to galactose and ceramide within the lysosome and GLB1 mutation causes a deficiency in β-galactosidase-1 resulting in abnormal lysosomal accumulation of GM1 (GM1 gangliosidosis).