A ganglioside storage disorder caused by beta-galactosidase (EC 3.2.1.23) deficiency with resulting accumulation of excessive amounts of ganglioside GM1 in the brain tissue with less severe abnormalities than those seen in other gangliosidoses and inconsistent phenotype. Onset takes place in late teens or early adult life with cerebellar dysfunction, visual problems, and coarsening of facial features. Intellectual impairment is mild at first but intelligence tends to deteriorate in time.
