Tay-Sachs Disease

What is Tay-Sachs Disease?

Tay-Sachs is a fatal disease that is the result of a fatty substance that accumulates in the brain because of the absence of a specific enzyme. As the fatty substance collects in the brain it kills nerve cells and causes complications in the body, both physically and mentally.

This is an inherited disease and infants who are born with this condition will thrive normally until they are around three to six months of age and then the symptoms will begin to appear. A baby will be born with this disease only if both parents are carriers of the flawed gene. If only one parent has the gene malfunction, the baby will be born a carrier of the disease.

What are the Symptoms of Tay-Sachs Disease?

Once the symptoms appear, Tay-Sachs disease will quickly advance and it most often becomes fatal when the child is four to five years of age. The symptoms include continued vision problems that result in blindness, seizures, deafness, stiff muscles and paralysis.

An infant’s physical, social and mental growth will stall. Adults who have a mild type of this disease may also experience symptoms, such as speech difficulties, weakened muscles, problems with their memory, instability while walking and body tremors.

Tay-Sachs Causes

Tay-Sachs disease is caused by a genetic defect on chromosome 15, HEX-A (also called the Tay-Sachs genes). This genetic defect on the two Tay-Sachs genes prevents our bodies’ ability to create a protein called hexosaminidase A. This protein is essential in inhibiting chemicals called gangliosides from building up in our brain’s nerve cells. Tay-Sachs disease is caused when the brain’s nerve cells are destroyed by these chemicals.

Tay-Sachs is an autosomal recessive character, which means it is a hereditary condition passed down to a child through defective genes in both parents, giving the child a 25% chance of developing Tay-Sachs disease. If just one of the parents passes down the defective gene to a child, the child will not be affected by the Tay-Sachs genes. However, they will be a carrier and may pass the defective gene down to their children in turn.

People hailing from Ashkenazi Jewish communities in Central and Eastern Europe are most likely to be carriers of these defective genes.

How is Tay-Sachs Disease Treated?

The diagnosis of this disease can be determined when the mother is ten to twelve weeks into her pregnancy with a chorionic villus sampling test. An amniocentesis procedure is often performed by collecting placenta cells by inserting a needle into the mother’s abdomen.

The treatment for infants or children with Tay-Sachs disease centers on making sure they are comfortable and by easing the symptoms. Those who have seizures will be prescribed anti-epileptic drugs. Physical therapy sessions can help those who have issues with weakened or stiff muscles. Many children will be required to have feeding tubes so they can get adequate nutrition.

Tay-Sachs Disease Prevention

There is no way to prevent Tay-Sachs disease other than getting screened for the HEXA mutation that causes Tay-Sachs prior to starting a family.

The two highest-risk groups are those with a family history of Tay-Sachs disease and those of Ashkenazi Jewish descent (many Jewish peoples of England are Ashkenazi). The Tay-Sachs gene is carried in approximately 1 in 30 of the Ashkenazi Jewish population, while the prevalence of this gene is approximately 1 in 300 for the rest of the population.

The best way to prevent Tay-Sachs disease is to know family history and for those at risk to get screened, particularly if they are planning to start a family. If both partners test positive for the gene, there is a 25% chance their child will develop Tay-Sachs disease. Adoption is an alternative method for couples to that do not wish to take such a risk.

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Last Reviewed:
October 11, 2016
Last Updated:
March 30, 2018
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