Tay Sachs Disease: Causes, Symptoms, Risks & Treatment

Tay Sachs disease is a rare but devastating genetic disorder that affects children. It is a neurological condition that targets the brain and spinal cord nerve cells. Newborns with Tay Sach suffer from this deficiency due to a lack of an essential enzyme. That enzyme acts as a catalyst for vital cellular processes.

There are several risk factors for Tay Sachs, including family history. The disease is passed from parents to their children in a recessive genetic pattern.

What is Tay Sachs disease?

Tay Sach is a genetic disorder that occurs mainly in infants. Due to the lack of a particular enzyme, the nerve cells in the brain and spinal cord are gradually destroyed. The name of that enzyme is hexosaminidase A or HEXA. Without this enzyme, a fatty substance called ganglioside builds up in the brain and nerve cells. This buildup causes severe neurological effects and eventually proves fatal.

The Accumulation of fat in the brain is incurable and progressive. This makes it a chronic condition that leads to death due to toxic substances in the brain. Children born with Tay Sachs disease often succumb to pneumonia before their fourth birthday.

What are the forms of Tay Sachs?

Several types of Tay-Sachs have been identified based on their presentation and genetic cause. These types are as follows:

1. Infantile Tay Sachs:

This is the most general form of Tay Sach disease and affects infants. Symptoms appear from birth or in the first year of a child's life and progress rapidly. Lethal outcome occurs within 2-3 years.

2. Juvenile Tay Sachs:

This milder form appears during childhood and progresses slowly. Symptoms include impaired coordination, speech and language issues and vision loss.

3. Chronic Tay Sachs:

This is the rarest form and affects adults. Symptoms include muscle weakness, paralysis, difficulty with movement, loss of mental function and vision loss.

4. Late Onset Tay Sachs:

This form is the most recent to be discovered to affect early-age adults or teens. This is the rarest form and affects adults. Symptoms appear over the age of 30, do not affect life expectancy, but lead to a complete loss of self-care skills.

Tay Sachs disease symptoms

In most affected infants, nerve damage begins in utero (before birth). Tay Sachs disease symptoms appear in most cases between 3 and 6 months of age. Progress is rapid, and the child usually dies by age 4 or 5.

Tay-Sachs symptoms in infants include:

• Deafness

• Progressive blindness

• Decreased muscle strength

• Overreaction to surprise

• Paralysis or loss of muscle function

• Subtraction

• Muscle stiffness (spasticity)

• Delayed mental and social development

• Slow growth

• Red spot on the macula (oval area near the centre of the retina)

Here are the symptoms of other forms of Tay Sachs disease:

There are also juvenile, chronic, and late-onset adult forms of the disease, which are much less common but tend to be milder in severity.

People with mild Tay Sachs disease usually show symptoms between the ages of 2 and 10 and usually die by the age of 15.

Individuals with chronic Tay Sachs syndrome develop symptoms by age 10, but the disease progresses slowly. Symptoms may include muscle cramps, slurred speech, and chills.

People with adult Tay Sachs disorder usually have the following symptoms:

• Muscle weakness

• Slurred speech

• Unsteady walking

• Memory problems

• Temor

The severity of the signs and life expectancy vary according to the disease type.

Causes of Tay Sachs disease

A defective gene on chromosome 15 (HEX-A) causes Tay Sachs disorder. This defective gene causes the body to produce a protein known as hexosaminidase A. Without this protein, chemicals called gangliosides collect in nerve cells in the brain and damage the brain cells.

Risks of Tay Sachs disease

The risks of Tay Sachs disease are very low. The risk is highest in people of Jewish descent, especially those of Ashkenazi Jewish origin. The risk is also higher for certain French Canadians and people of Cajun descent.

Tay-Sachs screening tests are available to determine if a person is a carrier. If both parents are carriers, there is a 25% chance of the child having the condition.

Diagnosis of Tay-Sachs disease

To detect if someone has Tay Sachs, a doctor may recommend a genetic test to identify the HEXA gene that creates this condition.

Additional tests may be done to confirm the diagnosis, such as a urine test, a blood test, an eye exam, or a lumbar puncture (spinal tap).

Treatment of Tay Sachs disease

Sadly, there's no remedy for Tay Sachs disorder. Individuals with the condition eat high-quality food to support their comfort and well-being. This is called "palliative care".

Palliative care may include pain medication and antiepileptic drugs to control seizures. Examples of physical therapy are tube feeding and respiratory care to reduce mucus buildup in the lungs.

The emotional support of the family is also important.

How to prevent Tay Sachs disease

Parents can take steps to reduce their risk of having a child with Tay Sachs disorder.

• If either parent is known to be a carrier of the defective gene (HEXA), they can get genetic counselling before becoming pregnant. This will help to identify their risk and give them the option of prenatal testing.

• Carrier screening tests are also available to determine if a person is a carrier. This can help couples determine their risk of having a child with Tay Sachs.

• Finally, couples at risk can use preimplantation genetic diagnosis (PGD). This is a technique used to identify diseases such as Tay-Sachs during in vitro fertilization (IVF).