Tay-Sachs

Sarit S. Wild Card #8 1/11/11 8th:

Sarit S. Wild Card #8 1/11/11 8th

Tay-Sachs Disease:

Tay -Sachs Disease Tay -Sachs disease (TSD) is caused by mutations in the HEXA gene, located on chromosome 15. It is a fatal genetic disorder in children that causes the slow destruction of the central nervous system. It is caused by the absence of an important enzyme called hexosaminidase A (hex-A). Without hex-A, a fatty substance called GM2 ganglioside builds up abnormally in the cells, particularly the brain's nerve cells.

Tay-Sachs continued:

Tay -Sachs continued Eventually, these cells degenerate and die. This destructive process begins early in the development of a fetus, but the disease is not usually diagnosed until the baby is several months old. By the time a child with TSD is four or five years old, the nervous system is so badly damaged that the child most likely will die.

What does Tay-Sachs do?:

What does Tay -Sachs do? Muscles used for movement weaken. Affected infants lose motor skills such as turning over, sitting, and crawling. They also startle easy to loud noises. As the disease progresses, children with Tay -Sachs disease experience seizures, vision and hearing loss, intellectual disability, and paralysis.

Who discovered it?:

Who discovered it? In 1881 Warren Tay , a British ophthalmologist, observed a "cherry red spot" in the retina of a one-year-old child with mental and physical disabilities. Later, in 1896 Bernard Sachs, an American neurologist, observed extreme swelling of neurons in autopsy tissue from affected children. Both physicians were describing the same disease. But not until the 1930s that the material causing the cherry-red spot and neuronal swelling was identified as a ganglioside lipid and the disease.

Picture of Cherry Red-Eye:

Picture of Cherry Red-Eye

Who is at Risk?:

Who is at Risk? Each year, about 16 cases of Tay -Sachs are diagnosed in the United States. Although Ashkenazi Jews (Jews of central and eastern European descent) are at the highest risk, it is now also prevalent in non-Jewish populations, including people of French-Canadian/Cajun heritage.

What genes are related to Tay-Sachs disease?:

What genes are related to Tay -Sachs disease? Tay -Sachs is an autosomal (a chromosome that is not a sex chromosome) recessive genetic disorder caused by mutations in both alleles of the HEXA gene on chromosome 15. Both sweet mama and the sweet daddy must be carriers of the defective Tay -Sachs gene in order to produce a child with the disease. People who carry the gene for TSD are entirely unaffected and usually unaware that they have the potential to pass this disease to their offspring. A blood test distinguishes Tay -Sachs carriers from noncarriers . Blood samples may be analyzed by enzyme test or DNA studies. Enzyme test measures the level of hex-A in blood. Carriers have less hex-A than noncarriers

Continued…:

Continued… When only one parent is a carrier, the couple will not have a child with TSD. When both parents carry the recessive TSD gene, they have a one in four chance in every pregnancy of having a child with the disease. They also have a 50% chance of bearing a child who is also a carrier.

Overall Facts:

Overall Facts Some people carry the genetic mutation that causes Tay -Sachs, but do not develop the full-blown disease. Among Ashkenazi Jews, 1 in 27 people are carriers; in the general population 1 in 250 are carriers. A child can only have Tay -Sachs disease if both parents are carriers of the gene. When two carriers have a child together, there's a: 50% chance that their child will be a carrier, but not have the disease. 25% chance that their child will not be a carrier and not have the disease. 25% chance that their child will have the disease.

Are you a carrier?:

Are you a carrier? Smart thing to do… get tested before having any children make sure that you and your partner are both not carriers of Tay -Sachs.

Picture of child with Tay-Sachs:

Picture of child with Tay -Sachs

Thanks for Listening!:

Thanks for Listening!