The GLB1 gene encodes for acidic beta-galactosidase-1 enzyme, a lysosomal hydrolase which catalyzes the removal of terminal beta linked galactose from ganglioside GM1. It has also a catalytic effect on other glycoconjugates such as oligosaccharides, and the mucopolysaccharide keratan sulfate. Therefore, the absence or reduction of the enzyme activity causes the accumulation of the glycoconjugates and their derivatives, including GM1 ganglioside, its derivative, asialo- and lyso-GM1 ganglioside, and keratan sulfate in all body tissues, especially in the central and peripheral nervous system and are also excreted in high amounts through the urine. All these effects are seen in patients affected with GM1 gangliosidosis disease. Also, the deficiency of this enzyme causes Morquio disease type B. The main substrate that accumulates in GM1 gangliosidosis patients is the sphingolipid ganglioside GM1, whereas the glycosaminoglycan keratin sulfate is the main substrate that accumulates in Morquio B patients.