TAY-SACHS DISEASE
Tay-Sachs Disease (TSD) is caused by the absense 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 causes progressive damage to the cells resulting in a deterioration of mental and physical abilities.
Infants with Tay-Sachs appear normal at birth and seem to develop normally until about six months of age. Initially, development slows, there is a loss of periphial vision, and the child exhibits an abnormal startle response. By about two years of age, most children experience recurrent seizures and diminishing mental function. The infant gradually regresses, losing skills one by one, and is eventually unable to crawl, turn over, sit or reach out. Other symptoms include increasing loss of coordination, progressive inability to swallow and breathing difficulties. Eventually the child becomes blind, mentally retarded, paralyzed and nonresponsive to his or her environment.
There is no treatment for TSD and even with the best of care most children die by age 5.
Patients and carriers of Tay-Sachs Disease can be identified by a simple blood test. Both parents must be carriers in order to have an affected child. When both parents are found to be carriers, there is a 25% chance, with each pregnancy, that the infant will be affected with TSD. Children with TSD are most often born to parents with no family history of the disease. Carriers themselves do not have the disease, and carrier status does not affect the mother or father physically, mentaly or in any other way; the only consequence of being a carrier is the possibility of transmitting the disease to a child.
Prenatal monitoring of pregnancies is available and is highly recommended.
TSD frequently occurs in descendants of Central and Eastern European (Ashkenazi) Jews, French-Canadiens from the St. Lawrence River Valley in Quebec and the Cajun community of Louisiana. Of these groups, approximately one in every 30 people is a carrier. Outside these groups approximately one in every 250 people is a carrier.
For additional resources on Tay-Sachs Disease please visit the following sites:
Tay-Sachs Family Links:
Our journey with TSD has introduced us to many wonderful people. We encourage you to visit their web sites as well. Thank you.
