Contributor: Gordon K. Klintworth
The GM1-gangliosidoses are a collection of autosomal recessive  lysosomal storage diseases that result from mutations in the GLB1 gene that encodes for the lysosomal enzyme acid-beta-galactosidase. Three subgroups of GM1-gangliosidosis are recognized (GM1-gangliosidosis type I,  GM1-gangliosidosis type II, GM1-gangliosidosis type III. There is an intracytoplasmic storage of GM1-gangliosides and glycosaminoglycans within lysosomes in the brain and viscera because of  their incomplete degradation.The GM1-gangliosidoses need to be differentiated from the GM2-gangliosidoses.