Tay Sachs is an incurable genetic disease that affects the central nervous system. It is a rare disease that occurs primarily in infants and children, especially those of Jewish descent. It is characterized by a red spot on the retina, paralysis, progressive blindness and loss of muscle movement. Tay Sachs can only be hereditary, meaning it is passed down only from parent to child. The process begins in the fetus, very early in pregnancy. However, the disease does not appear physically until the child is several months old. Tay Sachs is caused by the absence of a vital enzyme, called the Hex A gene, which is found on chromosome 15. This gene plays an important role in the nervous system. It breaks down the fatty substance called ganglioside GM2 in nerve cells. If this enzyme is not able to do its job, the compound will gradually build up until it reaches toxic levels in the brain and spinal cord. The accumulation of GM2 leads to the destruction of nerve cells, which causes the signs and symptoms of Tay-Sachs. The only way for a child to develop Tay Sachs is to inherit it. This genetic trait is relatively common in certain ethnic groups, such as Ashkenazi Jews. There is a 1 in 27 chance that a Jew in the United States is a Tay Sachs carrier, and a 1 in 250 chance that someone in the general U.S. population is a carrier. Tay Sachs carriers have a 50 percent chance of passing the defective gene to their children. A child who inherits a single bad gene is a Tay Sachs carrier, just like their parent. If both parents are carriers and pass on the Tay Sachs gene to their child, the child will have a 50% chance of being a carrier; a 25 percent chance of not being a carrier and not having the disease;...... middle of paper ......d symptoms are generally milder than those seen in infants with the disease disease. Symptoms of Tay Sachs in adulthood include: muscle weakness, loss of muscle coordination (ataxia), other movement problems, speech problems, and mental illness. Adults with Tay Sachs as adults can usually live their lives to the fullest, although they will most likely be in a wheelchair. There is currently no cure for any form of Tay Sachs disease. Therefore, treatment focuses on controlling the symptoms of Tay Sachs. Doctors are able to help a child manage the symptoms of Tay Sachs disease by prescribing medications to relieve pain, manage seizures, and control muscle spasticity. Researchers are developing ways to study and improve treatment options for Tay Sachs disease. However, even with the best possible care, children with Tay Sachs disease usually die before the age of 4 or 5.