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.
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
- Intellectual disability
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
The doctor will ask 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 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.
- Reviewer: Michael Woods, MD
- Review Date: 06/2015 -
- Update Date: 05/11/2013 -