GM1 gangliosidosis, or Landing disease, is a rare inherited neurodegenerative lysosomal storage disorder affecting 1 in 100,000 – 200,000 newborns. There are approximately 2,000 patients with GM1 gangliosidosis worldwide.

GM1 gangliosidosis is caused by mutations in the GLB1 gene that encodes the beta-galactosidase enzyme. This enzyme is present in lysosomes, compartments within cells that function as the body’s recycling centers. The beta-galactosidase enzyme is responsible for breaking down a substance called GM1-ganglioside. While indispensable for regular function of nerve cells in the brain, an overabundance of GM1-ganglioside leads to neurodegeneration, resulting in severe neurological symptoms.


GM1 gangliosidosis FAQ
The content provided here is for informational purposes only and is not intended as medical advice, or as a substitute for the medical advice of a physician.
What is GM1 gangliosidosis?
GM1 gangliosidosis, also known as Landing disease, is a rare inherited neurodegenerative lysosomal storage disease that progressively destroys nerve cells in the brain and spinal cord. GM1 gangliosidosis is characterized by severe cognitive and motor developmental delays and can be categorized into subtypes: Early Infantile (Type I), Late Infantile (Type IIa), Juvenile (Type IIb), and Adult (Type III).
What is GM1 gangliosidosis Type I?
Early infantile GM1 gangliosidosis (Type I) is the most severe type and usually appears in the first six months of life. Infants with this subtype present with hypotonia, or decreased muscle tone. They display developmental delays by 12 months of age as well as rapidly progressive neurodegeneration.
What is GM1 gangliosidosis Type II?
Late Infantile (Type IIa) and Juvenile (Type IIb) GM1 gangliosidosis onset usually occurs between ages 1 and 2 for Late Infantile and between ages 2 and 10 for Juvenile. This subtype is considered to be an intermediate form of the disease. Characterized by a plateauing of milestones acquisition followed by progressive decline in motor and cognitive skills, both subtypes display motor and cognitive regression, ataxia, and seizures.
What is GM1 gangliosidosis Type III?
Adult GM1 gangliosidosis (Type III) can appear between the ages of 10 and 20. It is usually less severe and slower to progress than Type I or Type II. Symptoms include progressive intellectual impairment and gait disturbance.
How common is GM1 gangliosidosis?
The exact number of people with GM1 gangliosidosis is unknown but it is estimated to affect approximately 1 in 100,000 – 200,000 newborns
What causes GM1 gangliosidosis?
GM1 gangliosidosis is caused by a genetic mutation in the GLB1 gene that triggers a deficiency in an enzyme called beta-galactosidase necessary for the breakdown of certain molecules within cells. This results in a toxic buildup that causes disease, which is characterized by severe cognitive and motor developmental delays.
How is GM1 gangliosidosis inherited?
GM1 gangliosidosis is inherited in an autosomal recessive manner, meaning that both parents must pass on an altered gene to their child in order for the disorder to develop.
Is GM1 gangliosidosis fatal?
The life expectancy of people with GM1 gangliosidosis varies from early childhood to adulthood depending on which type of the disease they have.
How is GM1 gangliosidosis diagnosed?
GM1 gangliosidosis can be diagnosed using a blood test and enzyme analysis of the beta-galactosidase enzyme, and/or by molecular genetic testing. During pregnancy, prenatal testing can detect GM1 gangliosidosis.
Are there any treatments for GM1 gangliosidosis?
No effective medical treatment for GM1 gangliosidosis is currently available—a key reason that we are committed to advancing research and development of our gene therapy candidate and bringing it to market.