Tay-Sachs disease

Tay-Sachs disease is a genetic disorder that causes permanent brain damage. Tay-Sachs disease is more common in people of Ashkenazi Jewish heritage, a group of people whose heritage is from Central and Eastern Europe. About 1 in 25 members of this community carry the gene for Tay-Sachs disease.

Types of Tay-Sachs disease

There are 3 main types of Tay-Sachs disease:

• infantile (the most common)
• juvenile
• late-onset

Children with Tay-Sachs disease seem healthy when they are born, but start developing symptoms from about 6 months old, including:

• losing skills such as smiling, crawling, rolling over and grasping
• blindness
• paralysis
• low muscle tone
• seizures

Children with Tay-Sachs disease don't usually live past the age of 5 years.

Tay-Sachs disease is caused by a problem with the HEXA gene. This leads to a deficiency in an enzyme that is needed for the brain to function properly.

Tay-Sachs disease is an autosomal recessive disorder. This means that a child must inherit faulty HEXA genes from both parents in order to have Tay-Sachs disease.

If both parents are carriers of faulty HEXA genes, there is a:

• 1 in 4 chance that the child will be healthy and not carrier the gene
• 1 in 4 chance that the child will inherit Tay-Sachs disease
• 1 in 2 chance that the child will be healthy, but carry the Tay-Sachs gene

If one parent is a carrier, there is 1 in 2 chance of the child also becoming a carrier.

If your child has any of the symptoms of Tay-Sachs disease, they should see their doctor.

If you are of Jewish Ashkenazi descent and are planning a family, see your doctor to discuss genetic screening.

In Australia, there are genetic screening programs offered for high school students of Ashkenazi Jewish heritage, who have a 1 in 25 chance of carrying a faulty HEXA gene.

Screening is not perfect — it will pick up only the most common problems with the HEXA gene. However, knowing if you carry the gene for Tay-Sachs disease can help you plan a healthy family.

If your heritage puts you at risk of being a carrier of Tay-Sachs disease, talk to your doctor.

Your doctor may suspect Tay-Sachs disease after asking about your child's symptoms and examining them. The diagnosis can be confirmed with a blood test.

There is currently no cure or effective treatment for Tay-Sachs disease, but your health team can offer palliative care options to ease symptoms. This may include nutritional support and medicines to treat seizures.

It can be challenging to care for a child with a life-limiting illness. Psychological support is recommended for the whole family.

Genetic screening can help prevent you having a child with Tay-Sachs disease.

You and your partner can undergo genetic screening to find out whether you are carriers of the HEXA genes. If you are both carriers, you can prevent having an affected baby by undergoing assisted reproduction (IVF (Opens in new tab)) with preimplantation genetic testing.

In this process the egg and sperm are fertilised in a lab and the resulting embryos are checked. Only embryos that do not carry the Tay Sachs gene are transferred back into your uterus.

If you are already pregnant, you can undergo amniocentesis (Opens in new tab) or chorionic villus sampling (CVS) (Opens in new tab) to check if your pregnancy is affected by Tay-Sachs disease. If your pregnancy is affected, you and your partner can decide whether or not to continue the pregnancy.

It is best to talk to either your doctor or a genetic counsellor (Opens in new tab). To find a genetic counsellor, visit the Australian Society of Genetic Counsellors (Opens in new tab).

Read more about genetic disorders. You might be able to find a support group through Genetic Alliance Australia (Opens in new tab).

Call healthdirect helpline on 1800 022 222 at any time to speak to a registered nurse (known as NURSE-ON-CALL in Victoria) for more information and advice.