Tay-Sachs Disease

By: Bella Pelaia

What is Tay-Sachs Disease?

Tay-Sachs is a single gene mutation that occurs when a certain enzyme produces insufficient activity. When this enzyme, beta-hexosaminidase or HEXA, does not work, nerve cells cannot be made. These enzymes, located in lysosomes, can create a fatty substance called ganglioside to build up in the tissues and nerve cells in the brain and spine.

The child in the photo above has been diagnosed with Tay-Sachs.

Tay-Sachs inheritence

Big image
This recessive trait mutation occurs on chromosome 15. This rare disorder results in less then 20,000 cases per year. To inherit this disorder, both parents must be carriers of Tay-Sachs. If you get both of the parent's dominant traits, you will not carry the disorder. You too will be a carrier if you receive one dominant and on recessive trait. Finally, there is a 25% chance that you can inherit Tay-Sachs if you inherit both of your parents recessive traits. (This is shown in the diagram above). This disorder is most commonly found in Ashkenazi Jew descendants. Tay-Sachs is also commonly found in Irish, British, French-Canadian, and Louisiana Cajan descendants.

Does this disorder have an impact on life expectancy?

This disorder does have an impact on the life expectancy of an individual. If diagnosed as an infant, symptoms aren't usually detectable until a few months of age. The life expectancy is usually before the age of 4 or 5 in this case.

What are the symptoms of this disease?

Symptoms vary on how bad the disease is or when in your life you get it. When you develop Tay-Sachs you're prone to becoming blind, deaf, unable to swallow, speech impediments, and lack of muscle control. Also, you may develop dementia, have seizures, startle reflex to noises, intellectual disability, and mental illness. Finally. when Tay-Sachs is developed you may have cherry-red spots. Cherry-red spots are small, red, circular findings in the macula of the eye. (Example shown in photo to the right).

If I develop Tay-Sachs Disease how would I know? What tests are performed?

If you develop this disease, you would know due to symptoms. With Tay-Sachs, if someone develops this disorder, symptoms don't usually occur until a few months later if you are a baby. Therefore, its good to perform certain tests. To see if you are a carrier of Tay-Sachs blood tests are available. Also, Amniocentesis and Chronic villus sampling are available to test if your child is to have the disorder. Amniocentesis is where amniotic fluid is tested from a fetus. Chronic Villus sampling is also to test for genetic disorders in a baby. Finally, you could get an eye examination performed to see if you have cherry-red spots.

Is Tay-Sachs Disease preventable? Can it be treated?

Sadly, Tay-Sachs is not preventable and can not be treated. Many scientists are working on treatments and have actually cured mice carrying this disorder. Scientists are working with Pyrimethamine, a medication that increases enzyme activity, to treat this disorder.

History and Discovery of Tay-Sachs

What organizations are in existence to help with this genetic disorder?

Big image
Big image