A rare biochemical disorder involving a deficiency of an enzyme (beta-galactosidase A) which results in the accumulation of harmful chemicals (GM1 gangliosides) in the central nervous system and other body tissues. Type 1 is a severe infantile form of the disorder and involves a greater degree of accumulation than type II or III. Mutations in the GLB1 gene cause GM1 gangliosidosis. The GLB1 gene provides instructions for making an enzyme called beta-galactosidase (β-galactosidase), which plays a critical role in the brain. This enzyme is located in lysosomes, which are compartments within cells that break down and recycle different types of molecules. This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations.
Individuals with GM1 gangliosidosis type I usually do not survive past early childhood.