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Tay-Sachs Disease


But a baby with Tay-Sachs disease is born without one of those important enzymes, hexosaminidase A (HEXA). So, as those fatty proteins build up in the brain, they hurt the baby's sight, hearing, movement, and mental development.

A child can only get Tay-Sachs by inheriting the gene for it from both parents. Tay-Sachs can be detected before birth, so couples who are thinking of having children may want to get a blood test to find out whether their child would be likely to have it.

Who Is at Risk for Tay-Sachs?

Each year, about 16 cases of Tay-Sachs are diagnosed in the United States. Although people of Ashkenazi Jewish heritage (of central and eastern European descent) are at the highest risk, people of French-Canadian/Cajun heritage and Irish heritage have also been found to have the Tay-Sachs gene.



  • 25% chance that their child will have the disease



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



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.


Date reviewed: October 2014