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Tay-Sachs is a rare disease. A person with Tay-Sachs has changed (mutated) genes that don't make any or enough of an enzyme called hexosaminidase A (hex A). Hex A breaks down fatty compounds (called GM2 gangliosides). Without it, fatty compounds build up in the nerve cells of the brain and cause damage.
There are three forms of Tay-Sachs:
Tay-Sachs occurs due to very low levels of hex A. Low levels of hex A happen when parents pass on a changed gene to their child.
In late-onset Tay-Sachs (LOTS), the body makes a small amount of hex A. People with LOTS inherit the late-onset hex A gene change from both parents.
The changed gene that causes Tay-Sachs disease is more commonly found in people of Ashkenazi Jewish descent. About 1 out of 30 people in this population is a carrier of the disease. People who have family from the Quebec Bas-St-Laurent or Gaspésie regions or New Brunswick territories, or have a family history of the disease are also more likely to carry the changed gene.footnote 1
Each form of Tay-Sachs disease has different symptoms.
With infantile Tay-Sachs, a baby looks healthy at birth. A doctor may see a red spot on the child's retina. But symptoms increase over time. By 6 months of age, babies start losing the ability to see, hear, and move. By 2 years of age, a child may have seizures and no longer respond to their surroundings.
Juvenile Tay-Sachs occurs in children 2 years of age or older. Symptoms progress more slowly than they do in infantile Tay-Sachs. A child may have seizures and may lose the ability to walk and communicate.
In late-onset Tay-Sachs (LOTS), early symptoms such as clumsiness or mood changes may be minor or seem "normal" and go unnoticed. Later symptoms may include difficulty walking, slurred speech, or mental health problems. The symptoms depend on how much Hex A the body makes.
If you or your doctor thinks that your child has Tay-Sachs disease, your doctor will do a physical examination and a blood test to check the level of an enzyme called Hex A. A genetic test may be needed to be sure the disease is Tay-Sachs.
The focus of treatment for Tay-Sachs disease is to control symptoms and make your child as comfortable as possible. There is no cure. It may be helpful to seek counselling or find support from others who are going through the same thing you are.
If you have late-onset Tay-Sachs disease (LOTS), treatment also focuses on controlling symptoms. The treatment you receive, such as medicine for depression, depends on the symptoms you have.
It may be overwhelming to learn that your child has Tay-Sachs. It's important that you care for yourself as well as your child. Talk to your doctor about:
As the disease gets worse, your child will need more care. Encourage your child to be as active as possible for as long as possible. Give your child your love and affection.
You may not be able to care for your child without help. Talk with your doctor about groups that can help you.
If you are thinking about having a child, experts recommend that:footnote 1
Carriers of the Tay-Sachs gene changes can pass the changed gene to their children even though the carriers don't have the disease. If both you and your partner are carriers, there is a 1-out-of-4 chance (25%) that any child you have will have Tay-Sachs disease.
CitationsWilson RD, et al. (2016). Joint SOGC–CCMG opinion for reproductive genetic carrier screening: An update for all Canadian providers of maternity and reproductive healthcare in the era of direct-to-consumer testing. Journal of Obstetrics and Gynaecology Canada, 38(8): 742–762.e3. DOI: 10.1016/j.jogc.2016.06.008. Accessed October 6, 2020.
Adaptation Date: 2/24/2022
Adapted By: Alberta Health Services
Adaptation Reviewed By: Alberta Health Services
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