Definition

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

Causes

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.

Risk Factors

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

Symptoms

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
• Deafness
• Difficulty swallowing
• Muscular difficulties such as spastic muscles, weakness, or paralysis
• Intellectual disability
• Seizures

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
• Tremor
• Slurred speech
• Psychiatric problems
• Loss of vision
• Spasticity and seizures

Diagnosis

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.

Treatment

There is presently no treatment for TSD. Treatment is aimed at managing symptoms.

Prevention

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

Association, Inc. http://www.ntsad.org

Caring for Kids—The Canadian Paediatric Society http://www.caringforkids.cps.ca

Tay-Sachs disease. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed
Updated January 16, 2012. Accessed August 9, 2013.

NINDS 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 October 6, 2011. Accessed August 9, 2013.