Studies of Tay–Sachs mutations using new molecular techniques such as linkage disequilibrium and coalescence analysis have brought an emerging consensus among researchers supporting the founder effect theory. History
Waren Tay and Bernard Sachs were two physicians. They described the diseases progression and provided differential diagnostic criteria to distinguish it from other neurological disorders with similar symptoms.Both Tay and Sachs reported their first cases among Ashkenazi Jewish families. Tay reported his observations in 1881 in the first volume of the proceedings of the British Ophthalmological Society, of which he was a founding member. By 1884, he had seen three cases in a single family. Years later, Bernard Sachs, an American neurologist, reported similar findings when he reported a case of "arrested cerebral development" to other New York Neurological Society members.Sachs, who recognized that the disease had a familial basis, proposed that the disease should be called amaurotic familial idiocy. However, its genetic basis was still poorly understood. Although Gregor Mendel had published his article on the genetics of peas in 1865, Mendels paper was largely forgotten for more than a generation – not rediscovered by other scientists until 1899. Thus, the Mendelian model for explaining Tay–Sachs was unavailable to scientists and doctors of the time. The first edition of the Jewish Encyclopedia, published in 12 volumes between 1901 and 1906, described what was then known about the disease:
It is a curious fact that amaurotic family idiocy, a rare and fatal disease of children, occurs mostly among Jews.
Chorionic villus sampling (CVS), the most common form of prenatal diagnosis, can be performed between 10 and 14 weeks of gestation. Amniocentesis is usually performed at 15–18 weeks. These procedures have risks of miscarriage of 1% or less. Preimplantation genetic diagnosis. By retrieving the mothers eggs for in vitro fertilization, it is possible to test the embryo for the disorder prior to implantation. Healthy embryos are then selected and transferred into the mothers womb, while unhealthy embryos are discarded. In addition to Tay–Sachs disease, preimplantation genetic diagnosis has been used to prevent cystic fibrosis and sickle cell anemia among other genetic disorders. Mate selection. In Orthodox Jewish circles, the organization Dor Yeshorim carries out an anonymous screening program so that carriers for Tay–Sachs and other genetic disorders can avoid marrying each other. Management
As of 2010 there was no treatment that addressed the cause of Tay–Sachs disease or could slow its progression; people receive supportive care to ease the symptoms and extend life by reducing the chance of contracting infections. Infants are given feeding tubes when they can no longer swallow. In late-onset Tay–Sachs, medication (e.g., lithium for depression) can sometimes control psychiatric symptoms and seizures, although some medications (e.g., tricyclic antidepressants, phenothiazines, haloperidol, and risperidone) are associated with significant adverse effects. Outcomes
As of 2010, even with the best care, children with infantile Tay–Sachs disease usually die by the age of 4.