What is Tay-Sachs disease?

Causes and Symptoms

Tay-Sachs disease is a genetic disorder of lipid (fat) metabolism

resulting from a missing enzyme. This enzyme normally breaks down special nerve lipids known as gangliosides, which are present in the brain and spinal cord. These substances accumulate and destroy the cells, often killing the child by age three or four years.

Several features at birth may raise the possibility of early detection, particularly cherry-red spots on the retina of the eye. Most newborns with Tay-Sachs disease, however, appear normal at birth. Between the ages of three months and six months, the progressive neurologic damage becomes apparent: deafness, blindness, muscle paralysis, and developmental disorders. By eighteen months, the infant is usually already in a vegetative state, requiring complete care. The child may survive until three or four years of age, dying from complications associated with comatose and bedridden patients, usually infections.

Treatment and Therapy

Tay-Sachs disease has no cure, and only supportive measures can be used. Feeding tubes for nutrition and fluids, suctioning of throat secretions, meticulous skin care for bed sores, and oxygen to assist breathing are among the types of support needed. Full-time skilled nursing care at home or at a facility is often necessary.

Perspectives and Prospects

While Tay-Sachs disease is the most common lipid (or lysosomal) storage disease, it is rare in the general population—about one in 250 people carry the genetic mutation that causes Tay-Sachs. It is much more common, however, in people of Ashkenazi (Eastern European) Jewish ancestry, as well as those of French Canadian and Cajun ancestry. Among these populations, approximately one person in twenty-seven is a carrier of the genetic defect. If two such carriers have children, they have a 25 percent chance of having a child with Tay-Sachs disease. Prenatal testing using amniocentesis or chorionic villus sampling can detect affected fetuses. More important is genetic counseling and screening of couples with a family history. A blood test can identify carriers.

Ongoing research is attempting to correct the disease in the developing fetus through the insertion of the missing gene.

Bibliography

Bartoshesky, Louis E. "Tay-Sachs Disease." KidsHealth.org. Nemours Foundation, May 2011.

Behrman, Richard E., Robert M. Kliegman, and Hal B. Jenson, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia: Saunders/Elsevier, 2011.

Bellenir, Karen, ed. Genetic Disorders Sourcebook: Basic Consumer Information About Hereditary Diseases and Disorders. 3d ed. Detroit, Mich.: Omnigraphics, 2004.

Gormley, Myra Vanderpool. Family Diseases: Are You at Risk? Baltimore: Genealogical Publishing, 2002.

Harper, Peter S. Practical Genetic Counselling. 7th ed. New York: Oxford University Press, 2010.

Hollenstein, Jenna, and Kari-Kassir. "Tay-Sachs Disease." Health Library, Nov. 26, 2012.

McCance, Kathryn L., and Sue M. Huether. Pathophysiology: The Biologic Basis for Disease in Adults and Children. 6th ed. St. Louis, Mo.: Mosby/Elsevier, 2010.

Milunsky, Aubrey, ed. Genetic Disorders of the Fetus: Diagnosis, Prevention, and Treatment. 6th ed. Hoboken, N.J.: Wiley-Blackwell, 2009.

"NINDS Tay-Sachs Disease Information Page." National Institute of Neurological Disorders and Stroke, Oct. 6, 2011.

Parker, James N., and Philip M. Parker, eds. The Official Parent’s Sourcebook on Tay-Sachs Disease. San Diego, Calif.: Icon Health, 2002.

"Tay-Sachs Disease." MedlinePlus, May 9, 2013.

"Tay-Sachs Disease." National Tay-Sachs and Allied Diseases Association, 2012.