Cynthia M. Johnson, MA
Tay-Sachs disease (TSD) is a genetic disorder. It is when a fatty substance builds up in the brain. This causes progressive destruction of the brain. There are three 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). GM2 builds up without it. The buildup in the brain causes damage.
It happens 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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Risk Factors TOP
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
- Some Cajun populations in Louisiana
- Non-Amish Pennsylvania Dutch
Babies with TSD may seem to develop normally until about four to five months of age when symptoms begin to start. Babies may have:
- Floppy body position
- Shrill cry
- Decreased eye contact
- Increased startle reaction
- Loss of motor skills
- Enlarged head
- Vision loss or blindness
- Problems swallowing
- Muscular difficulties such as spastic muscles, weakness, or paralysis
- Learning problems
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 learning problems
- Loss of bowel control
- Sleep problems
- Movement disorder, such as difficulty walking and muscle weakness
- Slurred speech
- Mental health problems
- Loss of vision
- Spasticity and seizures
You will be asked about your child's symptoms and health history. A physical exam will be done.
Blood tests will be done.
Imaging tests may be done, such as:
TSD can’t be cured. Treatment is aimed at managing symptoms.
TSD can’t be prevented. If you are a carrier of the gene that causes TSD, you can talk to a genetic counselor before deciding to have children.
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:
. Updated November 14, 2017. Accessed July 6, 2018.
NINDS Tay-Sachs disease information page. National Institute of Neurological Disorders and Stroke website. Available at:
...(Click grey area to select URL)
Accessed July 6, 2018.
Last reviewed May 2018 by Kari Kassir, MD
Last Updated: 7/6/2018