Tay-Sachs disease By Marco Rabello July/2005 NS 215 Dr.Williams

The disease is named for Warren Tay( ) and for Bernard Sachs( ). The disease is named for Warren Tay( ) and for Bernard Sachs( ). They made the first description of the cellular changes in Tay-Sachs. They made the first description of the cellular changes in Tay-Sachs.

Tay-Sachs disease is a fatal genetic disorder in children that causes progressive destruction of the central nervous system. Tay-Sachs disease is a fatal genetic disorder in children that causes progressive destruction of the central nervous system. They usually die by age 5. They usually die by age 5.

Transmission TSD is controlled by a pair of genes on chromosome 15. TSD is controlled by a pair of genes on chromosome 15. They are the genes that code for the enzyme Hex-A. They are the genes that code for the enzyme Hex-A.

Causes It is caused by the absence and insufficient activity of a vital enzyme called hexosaminidase A (Hex-A). It is caused by the absence and insufficient activity of a vital enzyme called hexosaminidase A (Hex-A).

Causes Without Hex-A, a fatty lipid called GM2 ganglioside accumulates in cells, especially in the nerve cells of the brain. Without Hex-A, a fatty lipid called GM2 ganglioside accumulates in cells, especially in the nerve cells of the brain.

Symptoms The initial symptoms may include: an exaggerated loss of ability to hold the head up or to sit. The initial symptoms may include: an exaggerated loss of ability to hold the head up or to sit. Muscles begin to atrophy and paralysis sets in. Muscles begin to atrophy and paralysis sets in.

Symptoms The child becomes blind, deaf, and unable to swallow. The child becomes blind, deaf, and unable to swallow. Patients with Tay-Sachs have a “cherry-red” spot in the back of their eyes (retina). Patients with Tay-Sachs have a “cherry-red” spot in the back of their eyes (retina).

Detection A simple blood test can determine a person’s Hex-A level. A simple blood test can determine a person’s Hex-A level. Carriers have less Hex-A in their body fluid and cells than non- carriers do. Carriers have less Hex-A in their body fluid and cells than non- carriers do.

At-risk couples, in which both male and female are carriers, have a 25% chance with each pregnancy of producing a child with Tay - Sachs disease. At-risk couples, in which both male and female are carriers, have a 25% chance with each pregnancy of producing a child with Tay - Sachs disease.

Carriers of TSD Autosomal recessive. Autosomal recessive. People who have one copy of the inactive gene. People who have one copy of the inactive gene. Pregnancy: both parents carries (25%). Pregnancy: both parents carries (25%).

Treatment There is no cure for TSD. There is no cure for TSD. However, several methods of treatment are being investigating. However, several methods of treatment are being investigating.

Treatment Enzyme replacement therapy. Enzyme replacement therapy. Gene therapy. Gene therapy.

Conclusion Although a cure for Tay-sachs does not exist at the present time, there is active research being done in the U.S and around the world. Although a cure for Tay-sachs does not exist at the present time, there is active research being done in the U.S and around the world.