Tay-Sachs disease is caused by the absence 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. The destructive process begins in the fetus early in pregnancy, although the disease is not clinically apparent until the child is several months old. By the time a child with TSD 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 classical TSD die early in childhood, usually by the age of five.
A baby with Tay-Sachs disease appears normal at birth and seems to develop normally until about six months of age. The first signs of TSD can vary and are evident at different ages in affected children. Initially, development slows, there is a loss of peripheral 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 non-responsive to his or her environment.
Currently, there is no treatment or cure for Tay-Sachs. However, since its inception in 2001, the Lord Foundation has provided critical funding to advance medical research towards an understanding of and treatment for Tay-Sachs and other lysosomal storage disorders . . . and now HOPE IS ON THE HORIZON. Partnering with National Tay-Sachs and Allied Disease and its Scientific Advisory Committee, the Foundation provided cornerstone funding that resulted in the creation of the Tay-Sachs Gene Therapy Consortium, an international collaboration of scientists who are working to deliver critical (missing) genes to the brain via vectors. The Consortium received $3.5 million from the NIH in 2010 to further the investigations. In the years that have followed, research has moved from mice to cat to sheep to primate models.
While the Foundation will continue to nimbly support exciting research as it accelerates towards clinical trials, it also continues to fund other research and approaches. It will take many breakthroughs across a broad front to treat these complex diseases.