What Is Tay-Sachs Disease?
Tay-Sachs is a disease of the central nervous system. It is a
neurodegenerative disorder that most commonly affects infants. In infants, it
is a progressive disease that is unfortunately always fatal. Tay-Sachs can also
occur in teens and adults, causing less severe symptoms, although this occurs
What Are the Symptoms of Tay-Sachs?
Symptoms of Infantile Tay-Sachs
Most affected infants have nerve damage starting in utero (before
birth), with symptoms appearing from age 3 to 6 months, in most cases.
Progression is rapid, and the child will typically pass away by 4 or 5 years
Symptoms of Tay-Sachs in infants include:
- progressive blindness
- decreased muscle strength
- increased startle response
- paralysis or loss of muscle function
- muscular stiffness (spasticity)
- delayed mental and social development
- slow growth
- red spot on the macula (an oval-shaped area near
the center of the retina in the eye)
If your child has a seizure or has trouble breathing, go to the
emergency room or call 911 immediately.
Symptoms of Other Forms of Tay-Sachs
There are also late-onset juvenile, chronic, and adult forms of
the disease, which are much more rare, but tend to be milder in severity.
People with the juvenile
form of Tay-Sachs typically display symptoms between the ages of 2
and 10 and usually pass away by age 15.
Those with the chronic
form of Tay-Sachs develop symptoms by the age of 10, but the
disease progresses slowly. Symptoms may include slurred speech, muscle cramps,
and tremors. Life expectancy varies with this form of the disease, and some people
have a normal lifespan.
Adult Tay-Sachs is
the mildest form. Symptoms appear during adolescence or adulthood. People with
the adult form of Tay-Sachs disease usually have these symptoms:
- muscle weakness
- slurred speech
- unsteady gait
- memory problems
The severity of symptoms and life expectancy varies.
What Causes Tay-Sachs?
A defective gene on chromosome 15 (HEX-A) causes Tay-Sachs
disease. This defective gene causes the body to not make a protein called
hexosaminidase A. Without this protein, chemicals called gangliosides build up
in nerve cells in the brain, destroying brain cells.
The disease is hereditary, which means it is passed down through
families. You have to receive two copies of the defective gene — one from each
parent — to become affected. If only one parent passes down the defective gene,
the child becomes a carrier. They will not be affected, but may pass the
disease down to their own children.
What Are the Risk Factors for Tay-Sachs?
The disease is most common among Ashkenazi Jews. These are people
whose families descend from the Jewish communities in Central or Eastern
Europe. According to the Center for Jewish
Genetics, approximately one in 30 people in the American Ashkenazi Jewish
population is a Tay-Sachs carrier.
There is no way to prevent the disease, but you can have genetic
testing done to see if you are a carrier or if your fetus has the disease. If
you or your spouse is a carrier, genetic testing can help you make a decision
about whether or not to have children.
How Is Tay-Sachs Diagnosed?
Prenatal tests, such as chorionic
villus sampling (CVS) and amniocentesis, can diagnose Tay-Sachs disease.
Genetic testing is generally done when one or both members of a couple are
carriers of the disease.
CVS is performed between 10 and 12 weeks of pregnancy and
involves taking a sample of cells from the placenta via the vagina or abdomen. Amniocentesis is done
between 15 and 20 weeks of pregnancy and involves extracting a sample of the
fluid surrounding the fetus using a needle through the mother’s abdomen.
If a child is displaying symptoms of Tay-Sachs, a doctor can
perform a physical examination and collect a family history. Enzyme analysis
can be done on the child’s blood or tissue samples, and an eye exam may reveal
a red spot on their macula (a small area near the center of the retina of their
How Is Tay-Sachs Treated?
There is no cure for Tay-Sachs. Treatment typically consists of
keeping the child comfortable. This is called “palliative care.” Palliative care
may include medication for pain, anti-epileptics to control seizures, physical
therapy, feeding tubes, and respiratory care to reduce mucus buildup in the
Emotional support for the family is also important. Seeking out
support groups can help you cope. Taking care of a sick child is emotionally
challenging and talking with other families combating the same disease can be
Screening to Help Tay-Sachs Disease
Because Tay-Sachs disease is inherited, there is no way to
prevent it except through screening. You can screen for carriers of the
Tay-Sachs disease by doing genetic testing on two parents who are thinking
about starting a family. Screening for carriers of Tay-Sachs was started in the
1970s, and has reduced the number of Ashkenazi Jews born with Tay-Sachs by 90 percent.
Talk to a genetic counselor if you are thinking about starting a
family and you or your partner think you might be carriers for the Tay-Sachs