This gene encodes a member of the glycosyl hydrolase 20 family of proteins. The encoded preproprotein is proteolytically processed to generate the alpha subunit of the lysosomal enzyme beta-hexosaminidase. This enzyme, together with the cofactor GM2 activator protein, catalyzes the degradation of the ganglioside GM2, and other molecules containing terminal N-acetyl hexosamines. Mice lacking the encoded protein exhibit accumulation of gangliosides in the brain and membranous cytoplasmic bodies in neurons. Certain mutations in the human ortholog of this gene cause Tay-Sachs disease. [provided by RefSeq, Aug 2016]