Tay-Sachs disease

Tay-Sachs disease (also known as GM2 gangliosidosis type 1 or hexosaminidase A deficiency) is a rare, inherited lysosomal storage disorder caused by mutations in the HEXA gene on chromosome 15q23-q24. This gene encodes the alpha subunit of the enzyme beta-hexosaminidase A, which is essential for breaking down GM2 ganglioside, a fatty substance found in nerve cells. When this enzyme is deficient or absent, GM2 ganglioside accumulates progressively in neurons of the brain and spinal cord, leading to devastating neurological deterioration. The most common and severe form is the infantile (classic) variant, which typically presents between 3 and 6 months of age. Affected infants appear normal at birth but progressively develop an exaggerated startle response, loss of previously acquired motor skills, hypotonia (decreased muscle tone), progressive neurological decline, seizures, vision loss, and a characteristic cherry-red spot on the macula of the eye. As the disease progresses, children develop macrocephaly, spasticity, dysphagia, and profound intellectual disability. The infantile form is uniformly fatal, with most children dying by age 4 to 5 years. Later-onset forms also exist, including juvenile and late-onset (chronic) variants, which present with milder symptoms such as muscle weakness, ataxia, speech difficulties, and psychiatric manifestations, with a more variable and slower disease course. Tay-Sachs disease is particularly prevalent among individuals of Ashkenazi Jewish descent, as well as certain French-Canadian, Cajun, and Old Order Amish populations, though it can occur in any ethnic group. There is currently no cure or disease-modifying treatment for Tay-Sachs disease. Management is supportive and palliative, focusing on seizure control, nutritional support, respiratory care, and physical therapy. Research into potential therapies including gene therapy, substrate reduction therapy, and enzyme replacement therapy is ongoing. Carrier screening programs, particularly in the Ashkenazi Jewish community, have significantly reduced the incidence of the disease since the 1970s.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

Common questions about Tay-Sachs disease