GM1 Type 3 Gangliosidosis

GM1 gangliosidosis is a rare disease due to β-galactosidase deficiency. The late-onset form, type 3, is characterized by early-onset progressive generalized dystonia, often associated with akinetic-rigid parkinsonism. Mild skeletal dysplasia and short stature are good diagnostic clues. The diagnosis is confirmed by measuring β-galactosidase activity and by identifying two mutated alleles of the GLB1 gene.