GLB1 and sphingolipidosis: GS, currently classified as a sphingolipidosis or a glicoproteinosis, in its features of sphingolipidosis is biochemically characterized by the storage of GM1 ganglioside, due to a deficiency of GLB1, which cleaves the beta-linked galactose of lactosylceramide, asialofetuin, oligosaccharides and, above all, GM1 ganglioside4.