Tay Sachs

Abstract

Tay-Sachs disease is a fatal inherited disease of the central nervous system. The most common form of the disease affects babies. Affected babies appear healthy at birth and seem to develop normally for the first few months of life. After this time, development slows and symptoms begin. Sadly, there is no effective treatment for these babies. Babies with Tay-Sachs lack an enzyme (protein) called hexosaminidase A (hex A) necessary for breaking down certain fatty substances in brain and nerve cells. These substances build up and gradually destroy brain and nerve cells, until the entire central nervous system stops working. Symptoms of classical Tay-Sachs disease first appear at 4 to 6 months of age when an apparently healthy baby gradually stops smiling, crawling or turning over, loses its ability to grasp or reach out and, eventually, becomes blind, paralyzed and unaware of its surroundings. Death occurs by age 5.

Who Is at Risk of Tay-Sachs Disease?

Tay-Sachs disease occurs most frequently in descendants of Central and Eastern European (Ashkenazi) Jews. About one out of every 30 American Jews carries the Tay-Sachs gene. Some non-Jewish individuals of French-Canadian ancestry (from the East St. Lawrence River Valley of Quebec), and members of the Cajun population in Louisiana, are at similarly increased risk. These groups have about 100 times the rate of occurrence of other ethnic groups. The juvenile form of Tay-Sachs, however, may not be increased in these groups.
How Is the Disease Transmitted?

Only through heredity. A Tay-Sachs carrier has one normal gene for hex A and one Tay-Sachs gene. The carrier does not have the illness and leads a normal, healthy and full life. However, when two carriers become parents: There is a one-in-four chance that any child they have will inherit a Tay-Sachs gene from each parent and have the disease. There is a one-in-four chance that the child will inherit the normal gene from each parent and be completely... [continues]

Read full essay