Tay-Sachs disease is a severe genetic disease of the nervous system that is nearly always fatal, usually by three to four years of age. It is caused by mutations in the HEXA gene, which codes for a component of the enzyme β-hexosaminidase A or "Hex A." The resulting accumulation of a brain lipid called G_M2 ganglioside produces brain and spinal cord degeneration. It is a rare disease that is found in all populations, but it is particularly prevalent in Ashkenazi Jews of Eastern European origin. There is no treatment, but research aimed at treating the disease by blocking synthesis of the affected molecules has been ongoing since the late 1990s. Carriers can be identified by DNA or enzyme tests and prenatal diagnosis is available to at-risk families.

History and Disease Description

In 1881 Warren Tay, a British ophthalmologist, observed a "cherry red spot" in the retina...