Tay-Sachs disease is a hereditary disorder of the nervous system. It occurs chiefly among Jewish children of eastern European ancestry. Tay-Sachs disease causes severe brain damage, enlargement of the head, convulsions, blindness, deafness, lack of energy, and eventually death. Victims develop a reddish spot on the retina of the eye. They begin to have symptoms when they are about 6 months old. There is no treatment for Tay-Sachs disease. Most victims live for only three or four years.
Tay-Sachs disease occurs in children who have too little of the enzyme hexosaminidase A. This enzyme controls the amount of ganglioside that accumulates in nerve cells. Ganglioside is a fat produced by normal cell growth. Nerve cells that store too much ganglioside become swollen and eventually die. A large number of damaged or dead nerve cells causes brain damage.
Tay-Sachs symptoms were first reported during the 1880’s by two physicians, Waren Tay of Britain and Bernard Sachs of the United States. In 1969, researchers discovered that the lack of hexosaminidase A caused the disease. Today, scientists use a variety of tests to determine the activity of hexosaminidase A in samples of blood and various tissues. These tests can reveal whether unborn babies have the disease. They also show whether adults are carriers. Carriers do not have the disease themselves. However, if two carriers marry, their children may inherit the disease from them.