Tearing Down Tay-Sachs Disease

She used to be such an energetic baby. Then at six months old, she just stopped everything. She stopped smiling, crawling, turning over, and losing the ability to grasp. The doctor said she has Tay-Sachs disease.

Tay-Sachs is a recessive or inherited birth defect. Symptoms first appear at 4 to 6 months of age and relentless deterioration of mental and physical abilities occur. A child with the disease becomes blind, deaf, unable to swallow and usually dies by age 4 or 5.

In rare cases, adults can develop the disease. The incidence of Tay-Sachs is particularly high among Ashkenazi Jews as well as French Canadians and the Cajun population.

There are few treatments. Anticonvulsive medicine can help control seizures. Children often need feeding tubes.

Tay-Sachs disease is a fatal genetic disorder that causes buildup of a fatty substance on tissues and nerve cells in the brain. Children with two copies of the Tay-Sachs gene have insufficient activity of the enzyme beta-hexosaminidase A, which breaks down fatty materials known as gangliosides.

These substances build up and gradually destroy brain and nerve cells until the entire central nervous system shuts down.

Both parents must be carriers of Tay-Sachs in order to have an affected child. If two perfectly healthy carriers conceive a child, there is a one in four chance that the child will inherit the disease.

There’s no cure and treatment is aimed at supporting the child and keeping them comfortable.

Genetic testing is available for couples who face a higher risk for having a baby with Tay-Sachs. Genetic testing and counseling help these couples make informed decisions regarding family planning.

According to the Cleveland Clinic, there are several forms of the Tay-Sachs disease. The type that a child has depends on when the symptoms developed. Families usually have one form of the disease. So if one member of the family has infantile Tay-Sachs, it is not likely that older siblings will have juvenile or late onset Tay-Sachs. Some forms of Tay-Sachs include:

§  Classic infantile Tay-Sachs: This is the most common form of Tay-Sachs. Children will have symptoms at around 6 months of age.

§  Juvenile Tay-Sachs: Children develop symptoms between ages 2 and 5. This form of Tay-Sachs is very rare.

§  Chronic Tay-Sachs: Children develop symptoms before age 10.

§  Late-onset Tay-Sachs: Symptoms start to appear during teen years or early adulthood. But it can develop later as well. This type doesn’t affect life expectancy. It is a very rare form of Tay-Sachs.

Symptoms of the most common form of Tay-Sachs start developing when babies are around 3 to 6 months old. The symptoms continue to progress as the child ages. These children don’t meet their developmental milestones.

Symptoms at 3 to 6 months:

§  Increased startle response.

§  Low muscle tone.

§  Muscle weakness.

§  Myoclonic jerks, which are sudden contractions of large muscles when falling asleep.

Symptoms at 6 to 10 months:

§  Decreased eye movement and eye contact.

§  Lack of attentiveness.

§  Losing ability to do tasks they could do before like sitting up.

§  Not meeting motor milestones such as sitting up on their own, pulling up to standing, and picking up objects with all their fingers.

§  Cherry-red spot in the eye, which provider can see easily in an eye exam.

Symptoms at 8 to 10 months:

§  Less movement.

§  Less responsiveness.

§  Loss of vision.

§  Start of seizures.

At 18 months of age, the child’s head size starts to grow. At two years of age, they start to have trouble swallowing. They may enter into a nonresponsive state where they don’t have much brain function. Age of death is usually between 2 and 4 years old where pneumonia is often the cause of death.

Healthcare providers will do a blood test in order to diagnose Tay-Sachs. They measure the amount of hexosaminidase A in the body, which is nonexistent in a child with classic Tay-Sachs. People with other forms of the disease have reduced levels.

Your provider may perform an eye exam to see if your child has a cherry-red spot in the eye.

You can also opt for genetic counseling which is available to you as a parent of a child with Tay-Sachs. You undergo a blood draw. After, your genetic counselor will discuss the results with you and what it means for your family.

You can choose to do a prenatal diagnosis, where tests such as chorionic villus sampling (placenta sampling) and amniocentesis (amniotic fluid sampling) are performed. Then there’s the preimplantation genetic diagnosis where specialists perform tests to see if an embryo carries Tay-Sachs before implanting it in the uterus.

Treatment options aim to address some of the symptoms. For example, your provider may prescribe medicine to control seizures.

There is no cure for Tay-Sachs. Your best option is to seek out genetic testing before you get pregnant.

Treatment for a child with Tay-Sachs means trying to keep them comfortable despite the symptoms. Genetic testing allows you to make sound choices regarding family planning.

You should talk to your healthcare provider if you plan to get pregnant and you belong to one of the high risk groups for Tay-Sachs disease.