Tay-Sachs disease (TSD) is a genetic disorder. It occurs when a fatty substance builds up in the brain. This causes progressive destruction of the brain. There are 3 forms:
- Infantile-onset—usually fatal before 5 years of age
- Juvenile-onset—usually fatal in late childhood or adolescence
- Adult-onset—may survive up to 60 years of age
TSD is caused by the absence of an enzyme. This enzyme is needed to break down a fatty substance called ganglioside (GM2). As a result, GM2 builds up. The build up in the brain causes damage.
TSD occurs when both parents pass on the faulty genes. A person can have just one copy of the faulty gene. In this case, there are no symptoms. The person is called a carrier.
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Having parents who are carriers of the TSD gene is the most common risk factor.
TSD is found in specific ethnic groups:
- Those of Eastern European (Ashkenazi) Jewish descent
- French Canadians living in eastern Quebec and New England
- Select Cajun populations in Louisiana
- Non-Amish Pennsylvania Dutch
Babies with TSD may seem to develop normally until about 4-5 months of age when symptoms begin to occur. Symptoms may include:
- Floppy body position
- Shrill cry
- Decreased eye contact
- Increased startle reaction
- Loss of motor skills
- Enlarged head
- Vision loss or blindness
- Difficulty swallowing
- Muscular difficulties such as spastic muscles, weakness, or paralysis
In some cases, the symptoms do not begin until age 2-5 years old. The condition progresses slowly. Symptoms may include:
- Loss of the ability to speak
- Developmental delay and intellectual disability
- Loss of bowel control
- Sleep problems
- Movement disorder, such as difficulty walking and muscle weakness
- Slurred speech
- Psychiatric problems
- Loss of vision
- Spasticity and seizures
You will be asked about your child's symptoms and medical history. A physical exam will be done. The doctor may examine your child's eyes to look for a cherry red spot on the retina.
Your child's bodily fluids may be tested. This can be done with blood tests.
There is presently no treatment for TSD. Treatment is aimed at managing symptoms.
There are no known ways to prevent Tay-Sachs disease. If you are a carrier of the gene that causes TSD, you can talk to a genetic counselor before deciding to have children. Prenatal testing during the first trimester is also available.
National Tay-Sachs and Allied Diseases
About Kids Health—The Hospital for Sick Children
Caring for Kids—The Canadian Paediatric Society
Fernandes Filho JA, Shapiro BE. Tay-Sachs disease.
Arch Neurol. 2004;61(9):1466-1468.
Tay-Sachs disease. EBSCO DynaMed Plus website. Available at:
http://www.dynamed.com/topics/dmp~AN~T115899/Tay-Sachs-disease. Updated May 12, 2014. Accessed June 6, 2016.
Tay-Sachs disease information page. National Institute of Neurological Disorders and Stroke website. Available at:
http://www.ninds.nih.gov/disorders/taysachs/taysachs.htm. Updated February 22, 2016. Accessed June 6, 2016.