Does your child have Tay-Sachs disease? (Tay-Sachs Disease) - Let's talk about this

There is nothing more joyful than watching a newborn baby. But as that baby grows, rolls over like other babies, doesn't sit up, and wakes up at the slightest sound, it is difficult to put into words the fear and anxiety that a mother or father feels. Today we are talking about a rare genetic disease that breaks the hearts of such parents, but we must be aware of. That is Tay-Sachs disease.

Simply put, what is Tay-Sachs disease?

Tay-Sachs is a genetic disease that is passed down from generation to generation, damaging the neurons in our child's brain and spinal cord, eventually destroying those cells. Think of it like a factory in our body. This factory has a special enzyme to remove unnecessary waste (toxic substances). What happens in Tay-Sachs disease is that this enzyme is not produced. Then that waste, that is, a fatty substance, starts to accumulate inside the nerve cells. These toxic substances accumulate and damage the nerve cells.

This is a progressive disease, with symptoms that get worse from child to child. Sadly, children die at a very young age due to this condition. There is no cure yet. However, there are treatments that can help reduce the symptoms and keep the child as comfortable as possible.

What are the main types of Tay-Sachs disease?

This disease is divided into three main types based on the age at which symptoms begin to appear. To make it easier to understand, let's look at it this way.

Importantly, this type of disease is passed down from generation to generation within families in the same way. For example, if one child develops the infantile form, other children in the family are not at risk of developing the late-onset form.

What are the symptoms of Tay-Sachs disease?

Symptoms vary depending on the age of the child and the type of disease. We will focus on the most common type of symptoms seen in infancy (Classic Infantile).

Classic Infantile Symptoms

• Early symptoms (around 6 months):
• Muscle weakness.
• Difficulty rolling over, sitting up, or crawling.
• A sudden loud noise causes a hard jolt.

• During the exacerbation of the disease (before the year):
• Involuntary muscle jerks (myoclonic jerks).
• Seizures.
• Difficulty swallowing food (dysphagia).
• Gradual loss of vision and hearing.
• When the doctor examines the eyes, he sees a cherry-red spot on the retina of the eye. This is a characteristic feature of this disease.
• Frequent respiratory infections (e.g. pneumonia).

By the age of two, the disease has taken full control of the child. The child may enter an unresponsive state. This means that most of the brain function is lost. Sadly, these children usually die between the ages of 2 and 4. The cause of death is often a serious infection such as pneumonia.

Symptoms in childhood and adulthood

These are very rare, so let's take a brief look.

• Juvenile: Symptoms include muscle weakness, difficulty speaking, forgetting things learned, behavioral changes, and seizures.
• Late-onset:Muscle weakness and tremors, difficulty walking (ataxia), difficulty speaking and swallowing, and mental problems (psychosis) may occur.

Why is this happening? What is the reason?

Tay-Sachs disease is caused by a mutation in a gene called HEXA . Simply put, it is a small change in a gene.

These genes give instructions to every cell in our body. The HEXA gene gives instructions to make the enzyme `hexosaminidase A` that we talked about earlier. When the gene is mutated, this enzyme is not produced. Then those toxic fatty substances accumulate in the nerve cells and destroy them.

How can this be inherited by a child?

This is a bit complicated to understand, but it's very important. Tay-Sachs disease is inherited in an autosomal recessive pattern. This means that in order to develop the disease, a child must inherit this mutated HEXA gene from both their mother and father.

Think of it this way. Everyone has two copies of every gene. One from their mother, and one from their father.

• Who is a carrier?: A carrier is someone who has one copy of the HEXA gene that is healthy and the other copy that is mutated. These people do not develop the disease or show symptoms because the healthy copy of the gene makes the necessary enzyme. However, they can pass the mutated gene on to their children.

Now, look at what can happen to a child if both parents are carriers :

• There is a 25% (one in four) chance that a child will inherit only healthy genes from both parents. Then the child will be healthy and not a carrier.
• There is a 50% (one in two) chance that the child will receive the mutant gene from one parent and the healthy gene from the other . The child will then be a carrier, but will not develop the disease.
• There is a 25% (one in four) chance that a child will inherit both mutated genes from both parents . That child will develop Tay-Sachs disease.

How to diagnose the disease?

If a doctor suspects Tay-Sachs disease, they will mainly do a blood test to confirm it.

• Blood test: A sample of the baby's blood is taken and the level of an enzyme called `hexosaminidase A` is measured. A baby with Tay-Sachs disease has very low or no levels of this enzyme.
• Eye exam: The doctor will examine the child's eyes and check for the cherry-red spot we mentioned earlier.

Can this be detected during pregnancy?

Yes. There are two special tests that can detect this disease early during pregnancy. These are usually done for parents who are at high risk of developing the disease.

1. Amniocentesis:A sample of the amniotic fluid surrounding the baby in the womb is taken and tested.

2. Chorionic Villus Sampling (CVS): A very small piece of tissue is taken from the placenta and examined.

Both of these tests look at the level of the enzyme `hexosaminidase A`. If that level is low, it can be diagnosed that the child has the disease.

Treatment and care of the child

I know this must be a big burden for you to hear. There is no cure for Tay-Sachs disease yet. However, there are many things you can do to help your child feel less pain and discomfort and to keep them as comfortable as possible. This is called supportive care .

• Respiratory problems: These children may have difficulty swallowing, which can lead to frequent lung infections. Medications, special devices, and positioning the child correctly can help.
• Nutrition: As swallowing difficulties increase, a feeding tube may be needed.
• Seizures: Medication is given to control seizures.
• Sensory stimulation: Since a child's five senses are limited, things like soft music, scents, and soft toys can provide comfort to the child.

When do you need to see a doctor?

• If you are planning to have a child: It is very important to seek genetic counseling before having a child, especially if you or your partner has a family history of Tay-Sachs disease, or if you suspect that both of you may be carriers. Ask your doctor for advice on this.
• During pregnancy: If you have any doubts or concerns about your baby's health, see your doctor immediately.
• If you notice a problem with your child's development: If you notice that your child is not doing things that they should be doing at their age (like rolling over, sitting up), talk to your pediatrician about it.

Tay-Sachs is a truly heartbreaking diagnosis. But by being aware of it, understanding the risks, and seeking early genetic testing if necessary, we can prevent future heartache.