Tay-Sachs disease is a disease that affects children. This disease is caused by a deficiency of a crucial enzyme referred to as hexosaminidase- A or hex – A  for short. With the absence of hex – A a lipid called GM2 ganglioside compiles abnormally in nerve cells. If this persists serious cell damage can be the outcome. This disease can be passed down to the child by the parent. Carriers appear normal all their lives but run the risk of passing it down to their child. This disease comes from a defect in chromosome 15.  Each person has two of these if both are active than their body is producing enough enzyme to prevent a compile of GM2 ganglioside.  If one is active and one is inactive than they are carriers and do not have the disease but could give it to their children. Carriers have a 50% chance of passing it down to their children. When both parents are carriers each child has a 25% chance of having Tay-Sachs and a 50% chance of being a carrier. So if a child gets only one defective Gene, then it just a carrier like their parents, but if it gets a defective Gene from one of each parent then the child will have Tay-Sachs.  The devastation of Tay-Sachs starts early in the fetus during pregnancy.  However, the disease is not noticed until the baby is about 6 months old when the maturation slows down.  By the time the baby reaches the age of 2 they start having seizures in depletion of mental Behavior. It eventually gets where the child cannot crawl, sit, reach or turn over. The child will become blind cognitively impaired, paralyzed and non-responsive. When the child approaches the age of three or four, the child’s nervous system is so bad off that it results in death by the age of 5. You can get a simple blood test to determine whether you are a carrier. Samples then can be analyzed by either enzyme assay or DNA studies. Enzyme assay is a biochemical test to determine the levels of hex – A in a person’s blood. If you are a carrier than you have less hex – A in body fluids and cells than those of noncarriers. To this day studies show that there is still no cure for this disease.Even though anyone can get this disease, Eastern European Jews are at greater risk. About 1 in every 27 Jews in the USA end up being carriers of this disease. Even non-Jewish French Canadians living around the Saint Lawrence River have a high chance of having Tay-Sachs. Even Though there is no cure for Tay-Sachs scientist are looking for ways to slow the process down or get rid of it. They have tried enzyme replacement and bone marrow transplants but nothing successful has been recorded to date. They have started to pursue gene therapy, which is taking the defective gene and replacing it with a normal one. This gives hope to future patients with Tay-Sachs.  This disease was discovered by Warren Tay in 1881 along with Bernard Sachs in 1896.