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Genetic and Rare Diseases Information Center (GARD)

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GM1 gangliosidosis

Other Names for this Disease
  • Beta galactosidase 1 deficiency
  • Beta-galactosidosis
  • GLB 1 deficiency
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What causes GM1 gangliosidosis?

All three types of GM1 gangliosidosis are caused by mutations (changes) in the GLB1 gene. This gene provides instructions for making an enzyme called beta-galactosidase (β-galactosidase), which plays an important role in the brain. The enzyme is located in compartments within cells called lysosomes, where it helps break down certain molecules, including a substance called GM1 ganglioside. GM1 ganglioside is important for nerve cell function in the brain.

Mutations in the GLB1 gene may decrease or eliminate the activity of the β-galactosidase enzyme, which means that the GM1 ganglioside cannot be broken down. As a result, it accumulates to toxic levels in tissues and organs, particularly in the brain. This accumulation then leads to the destruction of nerve cells in the brain, which causes the features of the condition.

In general, individuals with higher enzyme activity levels usually have milder signs and symptoms than those with lower activity levels because they have less accumulation of GM1 ganglioside within the body.[1]
Last updated: 8/6/2012

  1. GM1 gangliosidosis. Genetics Home Reference. July 2010; Accessed 4/3/2012.
  2. NINDS Gangliosidoses Information Page. National Institute of Neurological Disorders and Stroke (NINDS). October 2011; Accessed 4/3/2012.
  3. Tegay D. GM1 Gangliosidosis. eMedicine. March 29, 2012; Accessed 4/3/2012.
  4. About Gangliosidosis-1 (GM-1). National Tay-Sahs and Allied Diseases Association, Inc.. Accessed 4/3/2012.