GM1 gangliosidosis (OMIM 230500) is an LSD caused by genetic defects in the GLB1 gene, which encodes a lysosomal enzyme, β-galactosidase (β-gal), that hydrolyzes the nonreducing terminal β-galactosyl residues of GM1 ganglioside (GM1), glycoproteins, and glycosaminoglycans (2). This evidence concerns the gene GLB1 and GM1 gangliosidosis.