What is Tay-Sachs Disease

Tay-Sachs disease is a progressive neurological genetic disorder that appears in three forms:
Classic Infantile, Juvenile and Late Onset or Chronic Tay-Sachs.

History:

The disease is named for Warren Tay (1843-1927), a British ophthalmologist who in 1881 described a patient with a cherry-red spot on the retina of the eye. It is also named for Bernard Sachs (1858-1944), a New York neurologist whose work several years later provided the first description of the cellular changes in Tay-Sachs disease. Sachs also recognized the familial nature of the disorder, and, by observing numerous cases, he noted that most babies with Tay-Sachs disease at that time were of Eastern European Jewish origin. Today, Tay-Sachs occurs among people of all backgrounds.

Cause:

Tay-Sachs disease is caused by the absence or insufficient level of a vital enzyme called Hexosaminidase A (Hex-A). Without Hex-A, a fatty substance or lipid called GM2 ganglioside accumulates abnormally in cells, especially in the nerve cells of the brain. This ongoing accumulation, also called “substrate,” causes progressive damage to the cells. In Classic Infantile the destructive process begins in the fetus early in pregnancy, although the disease is not clinically apparent (symptoms do not start) until the child is several months old. By the time a child with Tay-Sachs disease is three or four-years old, the nervous system is so badly affected that life itself cannot be supported. Even with the best of care, all children with classic Tay-Sachs disease die early in childhood, usually by the age of 5, although some do live longer.

Treatment:

To date, there is no cure or effective treatment for Tay-Sachs disease. However, there is active research being done in many investigative laboratories in the U.S. and around the world exploring a range of therapeutic approaches. For the first time in the history of the disease there currently are clinical trials testing the potential of a substrate reduction drug (miglustat) in all three forms of Tay-Sachs, with the Late Onset trial having started in 2002. The uses of enzyme replacement therapy to provide the Hex-A that is missing in babies with classic infantile or significantly reduced in children and adults with Tay-Sachs disease has been explored but presents serious obstacles. Because the disease affects brain cells that are protected by the blood-brain barrier, enzymes such as Hex-A are blocked from entering the brain by the blood. Stem cell transplantation using umbilical cord blood is an investigational procedure attempted with a small number of very young children, but to date there is not enough information for specific results about reversing or slowing damage to the central nervous system in this group with Tay-Sachs disease. Gene therapy, molecular or pharmacological chaperone therapy and neural stem cell therapy are among those potential treatments being researched.

Testing:

Tay-Sachs carrier testing is vital for individuals in high-risk populations: Ashkenazi Jews, French Canadians, Louisiana Cajun, Pennsylvania Dutch and preliminary data suggests persons of British Isle and Italian decent have an increased carrier rate over the general population. Carrier testing is best completed before conception. Even if your childbearing years are over, your carrier status can be an extremely important piece of information. If you are a carrier, your close relatives (children, brothers, sisters, cousins, aunts, uncles) should be alerted so that they can be tested as well. Tay-Sachs carrier testing is also vital for the close relatives of families with an affected child, regardless of ethnic background, since all parents of children with Tay-Sachs are, by definition, carriers.

Support:

Although a cure for Tay-Sachs disease does not exist at the present time, specific support, programs and services for affected individuals and their families are available through organizations such as National Tay-Sachs & Allied Diseases Association, Inc. (NTSAD).