Tay-Sachs Disease

By: Stephanie Bielawa

Overview

Tay-Sachs disease is a fatal genetic disorder that is commonly found in infants. You don't see any symptons until the age of 6 months old. The outcome is terrible. Tay-Sachs is the progressive destruction if the nervous system. The child will appear normal until about six months when the development slows. By the age of 2 most children experience seizures and diminishing brain function. The infant regresses being unable crawl, sit-up or reach.

Heredity

It is a disease inherited from one of the parents who does not display any symptoms. The parents have a defective gene but don't express the mutation and symptoms. The child has a chance of inheriting the bad gene from the mom and dad and will be born with it. Some people effected with the disease don't show symptoms until later in life. Hexosaminidase A is on chromosome 15 when the mutation takes place. Hex A is important in biochemical reactions. The GM2 ganglioside is the fatty substance needed for your nerves. But with too mush it starts to deteriorate the nerve endings. Carriers have a 50% chance of giving Tay-Sachs to their child. A child who inherits an inactive gene become a carrier. If each parent is a carrier, each child has a 25% of having Tay-Sachs and 50% are the carriers. Anyone can be a carrier, but the disease was most commonly found in Ashkenazi Jewish population. 1 in every 27 Jews in the united States carry Tay-Sachs.

Symptoms

A baby with Tay-Sachs disease seems normal until 6 months old when the development slows down in the child. By about two years old, most children experience seizures and diminishing brain function. The infant regresses and eventually will be unable to sit-up, reach, and crawl. Eventually the child will become blind, mentally impaired, paralyzed and unresponsive. When the child reaches the ages 3-4 the nervous system is so badly damaged and at the age of 5 the result is usually death. A much rarer form of Tay-Sachs is found in adults. They become intellectually and mentally impaired. A child born with Tay-Sachs will have a cherry red spot on macula. Raising a child with Tay-Sachs by yourself is hard to manage. The child usually ends with a care taker or in a hospital for the rest of its life.

Test and Treatments

There is no treatment for Tay-Sachs. The parents however can have a simple blood test to determine if you have the mutation. They can go through a genetic test and carriers will have less Hex A in their blood than non-carriers. They can do a procedure around the 11th week of pregnancy and test the placenta.

Research

Current tests have shown about 95% of carriers are Ashkenazi Jewish background and about 60% of carriers in the population. The mutation is found in every 1 out of 27 Jews in the United States are carriers. About 1 in 3,600 Jewish infants are born with the disease. Among non-Jews 1 in 300 people are carriers. They have tried different things to see if they can change the Tay-Sachs disease. Scientists are exploring enzyme replacement and bone marrow transplants but to date none have been successful. Another way is gene therapy with replacing the abnormal gene with a good healthy gene. These approaches have led people to believe they are going to be successful in their research.

Fair Use Statement

This presentation contains copyrighted material under the educational fair use exemption to the U.S. copyright law. It has been prepared according to the multimedia fair use guidelines and is restricted from further use.

Citations

"Learning about Tay-Sachs Disease." Genome. NIH, 17 Mar. 2011. Web. 4 Apr. 2016.
<https://www.genome.gov/10001220>.
"Tay-Sachs." Rosen Publishing. N.p.: n.p., n.d. N. pag. Teen Health and
Wellness: Real Life, Real Answers. Web. 5 Apr. 2016.

"Tay-Sachs disease." The Gale Encyclopedia of Science. N.p.: n.p., n.d. N. pag.
Science in Context. Web. 5 Apr. 2016. <http://ic.galegroup.com/ic/
scic/ReferenceDetailsPage/
ReferenceDetailsWindow?failOverType=&query=&prodId=SCIC&windowstate=normal&conten
tModules=&display-query=&mode=view&displayGroupName=Reference&limiter=&currPage=&
disableHighlighting=false&displayGroups=&sortBy=&search_within_results=&p=SCIC&ac
tion=e&catId=&activityType=&scanId=&documentId=GALE%7CCV2644032211&source=Bookmar
k&u=down87562&jsid=e5ce3d9d19c9f668ee164ed9d6afd363>.