Tay - Sachs Disease[]
Tay Sachs Disease is when the victim lacks the enzyme, Hexosaminidase A (Hex A), that breaks down fatty substances, gangliosides, in brain cells. The disease is named after Warren Tay an opthalmologist (specialist of the anatomy and functions of the eye) who was the first to observe the evident red spot in the eyes of his patient; Bernard Sachs was a neurologist who discovered abnormalities in the brains of Ashkenazi Jews.
Creation of Lysosomes lacking Hex A
Buildup of Gangliosides
Symptoms[]
- the loss of sight, hearing and movement
- appearence of a red spot in the victim's eye
The tell tale "Red Spot"
- lack of standard child-like behavior ( no crawling or smiling)
- at age two, seizures and disability become more apparant
- by age five, death occurs
Classic Infantile Tay-Sachs is the most common form of this rare disease and is characterized by very little to no enzyme activity, the victim has the Hex A enzyme, but not enough to fully function normally, symptoms are still present, but appear later on, and death occurs around age 15. Another form of Tay - Sachs Disease is Juvenile Tay sachs which ocurs later on in teens and adults; symptoms are the same but occur later on in life. Late-onset Tay-Sachs (LOTS) disease is a rare form of Tay-Sachs disease, a lysosomal storage disorder caused by the absence of the enzyme causes muscle fatigue and impaired speech but victim's senses are still functional. Some symptoms include swallowing and speech difficulties.
Detection[]
Couples who are expecting can have a blood test done in order to see if they have the Tay Sachs gene. There are two other methods of detection which can be performed during the pregnancy. In the 10th week a CVS, chorionic villus sampling, is a test in which a needle draws tissue from the placenta. Also during the 15th week an amniocentesis is a procedure where the amniotic fluid is drawn from the stomach through the use of a needle. Both of these samples are then tested to see if the baby has inherited the gene.
Process of Amniocentesis
Treatment[]
There is no known treatment for this disease yet but some medication is available to lessen the pain of the symptoms, such as medicine that would reduce the seizures and pain. Although there was an enzyme replacement therapy in which a functional Hex- A would be placed into the patient but the enzyme ended up being to large and could not pass from blood to brain.
thumb|300px|rightLife Expectancy/ Quality of life[]
The nervous systems of children with Tay Sach's disease are so badly affected that the children die at the early age of five. Also until this age, they experience all the different functions of their body beginning to fall apart. For example, they will start losing their eyesight even before they have really had a chance to see the world.
How is Disorder Inherited?[]
Tay-Sachs is a recessively inherited disease that only occurs when both parents carry a Tay-Sachs gene and each parent transmits the defective gene to their child. A child who inherits two Tay-Sachs genes (one from each parent) produces no functional Hex-A enzyme and is certain to develop Tay-Sachs disease. The Tay-Sachs genes are located on chromosome 15.
Inheritance of Tay - Sachs Disease
Who is at risk?[]
Tay-Sachs carriers are found most frequently among families of eastern European Jewish descent (Ashkenazi Jews). Also, French Canadians, Louisiana Cajun, Pennsylvania Dutch and people of the British Isle and Italian decent have an increased carrier rate over the general population. In the United States today, approximately 1 in every 27 Jews is a Tay-Sachs carrier. Current research indicates that among Irish Americans, the carrier rate is about one in 50.