Now that you are expecting, the health of you baby may be a source of persistent worry for you and your partner. Many couples worry about the possibility of passing on a genetic disease to their child, especially if there is a family history of the disorder. Tay-Sach's disease is an inherited illness that attacks the nervous system in the brain. If you or your partner is a carrier of the Tay-Sachs gene, it is important to be tested as soon as possible to prevent passing the disorder along to your children.
What is Tay-Sachs Disease?
Tay-Sachs disease is an inherited chromosomal disorder that causes severe physical and mental side effects. Affecting most children in the first months of life, Tay-Sachs disease occurs when fatty buildup in the brain prevents nerve cells from functioning properly. This fatty buildup impedes mobility, expression, communication, and even basic functioning. Unfortunately, there is no cure for Tay-Sachs disease; most children with Tay-Sachs will die within the first five years of life.
What Causes Tay-Sachs Disease?
Tay-Sachs disease is caused by a deficient protein enxyme, called hexosaminidase (hex A). Hex A is an enzyme produced by your body; it helps to break down fatty products in your nerve cells, and kill them, enabling your nerve cells to function properly. However, children with Tay-Sachs disease donï¿½t have any of the hex A enzyme in their bodies. As a result, their bodies arenï¿½t able to attack the fatty substance in their brains, leaving them open to blindness, deafness, and even death.
How is it Inherited?
Tay-Sachs disease is a hereditary disorder. This means that it is passed down from parent to child. When a baby is conceived, it receives half of his chromosomes from his mother and the other half of his chromosomes from his father. If both parents are carriers of the deficient Tay-Sachs enzyme, there is a 1 in 4 chance of receiving news that he does have Tay-Sachs disease. If only one parent is a carrier of the Tay-Sachs enzyme, the baby will not develop Tay-Sachs disease, but will become a carrier of the disorder.
Who Gets Tay-Sachs Disease?
Luckily, Tay-Sachs disease is not very common. However, certain factors do increase you risk for having a child with the disorder. These risk factors include:
- being of Central or European Jewish descent
- being of Cajun descent
- being of French-Canadian descent
Symptoms of Tay-Sachs Disease
Babies born with Tay-Sachs disease are typically healthy until about four months of age. Around this time, symptoms of the disorder will begin to appear. Common symptoms of the disease include:
- decline in eye contact
- exaggerated startle response
- slow physical and mental development
- gradual loss of mobility
- muscular atrophy leading to paralysis
- gradual blindness
- gradual deafness
The symptoms of Tay-Sachs disease are progressive and will become worse as time goes on. As a result, most children born with Tay-Sachs disease will die before the age of five.
If you are pregnant or are thinking about becoming pregnant, it is probably a good idea to find out if either you or your partner is a carrier of the Tay-Sachs gene. This is especially important if you belong to a high-risk group or have a history of Tay-Sachs disease in your family. The carrier screen is a very simple blood test that analyzes the level of hex A in your bloodstream. Carriers of Tay-Sachs have only half of the normal levels of this enzyme in their bodies. A DNA test can also be performed on your blood, during which defects in the hex A gene can be isolated.
It is possible to test your baby for Tay-Sachs disease before she is born. In-utero screening can be performed by your health care provider, through amniocentesis or chorionic villi sampling. Prenatal screening is often helpful, because it can help prepare you for giving birth to a baby with Tay-Sachs disease.
- Amniocentesis: Amniocentesis is typically performed between the 15th and 18th week of pregnancy. A needle is inserted into your abdomen in order to remove a sample of your amniotic fluid. This fluid is then tested for the presence of the hex A enzyme.
- Chorionic Villi Sampling: This test is performed between the 10th and 12th week of pregnancy. A thin tube is inserted into your vagina, through your cervix, and into your placenta. A sample of placental cells are removed and tested for the presence of the hex A enzyme.
Treating Tay-Sachs Disease
Unfortunately, there is no cure for Tay-Sachs disease and there is no way to prevent or slow the progression of the disorder. The disease is fatal, but children can be made to feel more comfortable through the use of certain medications and therapies.