What is tay-sachs disease?

Each form of Tay-Sachs disease has different symptoms.

Infantile Tay-Sachs

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

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.

Late-onset Tay-Sachs

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.

The goal of treatment is to control symptoms and maintain a good quality of life. Treatment depends on the symptoms. As the disease gets worse, more care will be needed. Talk with your doctor about support groups and family counseling that can help.

If you or your doctor thinks that your child has Tay-Sachs disease, your doctor will do a physical exam 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.

Work with your doctor to find ways you can help keep your child comfortable. Give any medicines as instructed. Be sure to care for yourself as well as your child. Consider getting counseling or finding support from others who are going through the same thing you are.

Tay-Sachs can occur when parents pass on a changed gene to their child.

• A baby who gets the changed gene from both parents will have the disease.
• A baby who gets the changed gene from only one parent will be a carrier. This means that the child will have one gene that produces Hex A and one that doesn't. The child will have enough Hex A and won't get the disease. But the child can pass the changed gene on to their children.

The juvenile and late-onset forms of Tay-Sachs are also caused by a changed gene from both parents.

The changed gene that causes Tay-Sachs disease is more commonly found in people of Ashkenazi Jewish descent. About 3 out of 100 people in this population are carriers of the disease. People of French-Canadian descent or Cajun descent are also more likely to carry the changed gene.

Tay-Sachs is a rare disease that is passed down through some families. A person with Tay-Sachs has gene changes that prevent the body from making any or enough of an enzyme called hexosaminidase A (Hex A). This enzyme breaks down fatty compounds. Without it, fatty compounds build up in the nerve cells of the brain and cause damage.

There are three forms of Tay-Sachs:

• Infantile Tay-Sachs. This is the most common form. It develops soon after a baby is born and causes death early in childhood.
• Juvenile Tay-Sachs. This affects children ages 2 and older and progresses more slowly than the infantile form. Children don't live beyond their mid-teens.
• Late-onset Tay-Sachs. This is very rare and can start between puberty and the mid-30s. It is a milder form of Tay-Sachs. Some people who have this form may live a normal lifespan.