Prenatal Diagnosis
Pregnant women can have their unborn babies tested for the HEXA deficit that
causes Tay-Sachs disease:
- If the tests do not detect HEXA, the infant will have Tay-Sachs
disease.
- If the tests do detect HEXA, the infant will not have it.
Between the 10th and 12th weeks of pregnancy, an expectant mother can get a chorionic villus sampling (CVS),
in which a small sample of the placenta is drawn into a needle or a small tube for
analysis.
Between the 15th and 18th weeks of pregnancy, a woman can have an amniocentesis
to test for the Tay-Sachs gene. In this test, a needle is inserted into the mother's
belly to draw a sample of the amniotic fluid that surrounds the fetus.
Signs and Symptoms
Kids are usually tested for Tay-Sachs after having hearing, sight, and movement
problems. A doctor can identify the disease with a physical exam and blood tests.
A baby born with Tay-Sachs develops normally in the first 3 to 6 months of life.
During the next months — or even years — the baby will progressively lose
the ability to see, hear, and move. A red spot will develop in the back of the child's
eyes. The child will stop smiling, crawling, turning over, and reaching out for things.
By age 2, the child may have seizures and become completely disabled. Death usually
occurs by the time the child is 5 years old.
In rare forms of the disease, a child may have the HEXA enzyme, but not enough
of it to prevent developmental problems. In one of these forms, called juvenile HEXA
deficiency, those problems may not appear until the child is 2 to 5 years old. The
disease progresses more slowly, but death usually occurs by the time the child is
15 years old.
In another, milder form of Tay-Sachs (called late-onset Tay-Sachs), the disease
causes muscle weakness and slurred speech, but sight, hearing, and mental capabilities
remain intact.
Helping a Child With Tay-Sachs
There is no cure for any form of Tay-Sachs disease. But doctors may be able to
help a child cope with its symptoms by prescribing medicines to relieve pain, manage
seizures, and control muscle spasticity.
Researchers are studying ways to improve treatment of and screening for Tay-Sachs
disease.
If your child has been diagnosed with Tay-Sachs or both you and your partner are
carriers of the gene, talk to your doctor or a genetic counselor about ongoing research.
You also might seek support from a group such as the National Tay-Sachs and Allied
Diseases Foundation or the March of Dimes Foundation.
Date reviewed: October 2014