Mark Forman, MD, PhD, Chief Medical Officer at Passage Bio, provides an overview of GM1 gangliosidosis.

As Dr. Forman explains, GM1 gangliosidosis is an inherited lysosomal storage disorder caused by mutations in the GLB1 gene, which encodes the lysosomal enzyme beta-galactosidase (β-gal). Reduced β-gal activity results in the accumulation of GM1 gangliosides in neurons, causing rapidly progressive neurodegeneration. Progressive damage is also seen in the heart, liver, and bones. The condition may be classified into three major types: classic infantile (type 1); juvenile (type 2); and adult onset or chronic (type 3). 

Common signs and symptoms among all three subtypes include hypotonia, progressive neural dysfunction, seizures, and developmental regression. Currently, there is no targeted treatment approved for GM1 gangliosidosis and management is primarily supportive in nature.

To learn more about GM1 gangliosidosis and other rare lysosomal storage disorders, visit