Tay-Sachs Genetic Disorder {Guide}

Updated June 26, 2019

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Tay-Sachs genetic disorder destroys the nervous system. Damage continues to the cells until they are too badly destroyed to function. It leads to death in children and severe impairment to adults who develop the disease later in life.

What's in this Guide?

Disclaimer: Before You Read

It is important to know that your genes are not your destiny. There are various environmental and genetic factors working together to shape you. No matter your genetic makeup, maintain ideal blood pressure and glucose levels, avoid harmful alcohol intake, exercise regularly, get regular sleep. And for goodness sake, don't smoke.

Genetics is a quickly changing topic.

Learning about the cause, symptoms, treatment, and long term prognosis of Tay-Sachs disease is vital to understanding how the disease works, who it affects, and how it can be stopped. That's why here at YourDNA.com, we have looked into this disorder and have filtered all the information down into a form you can use.

What Is Tay-Sachs Genetic Disorder?

A rare disorder caused by a deformity in the genes, Tay-Sachs is a progressive disease 1 that does severe damage to the body. The nerve cells within the brain and spinal cord are especially affected.

The HEXA gene is a vital enzyme that people with Tay-Sachs are missing. GM2 ganglioside, a fatty substance, builds up in the cells and causes damage because hexosaminidase is not there to stop it. The enzymes needed are located within the lysosomes.

These structures are essentially recycling centers. They break down toxic substances. Within the lysosomes is where HEXA is supposed to be working. Without them there, this process does not get completed and harmful toxins are left to take over.

There are other names for this condition as well 2. You may hear it referred to as simply HEXA deficiency, or TSD. Some call it B variant GM2 gangliosidosis. GM2 gangliosidosis Type 1, Hexosaminidase A deficiency, Sphingolipidosis, and Hexosaminidase alpha-subunit deficiency (variant B) are other versions. No matter what you call it, the disease is the same.

Different Forms of Tay-Sachs

Three different forms of Tay-Sachs exist. The most common occurs in infants. Babies born with Tay-Sachs do not usually show signs until 6 months of age. They may start to develop seizures by the time they are two. Death tends to occur before the age of five.

Infants with the disease do not usually live to see a full childhood. The damage is too great to their little bodies.

Juvenile Tay-Sachs presents in children between the ages of 2 and 5 on average. Slurred speech and trouble maintaining balance may be starting symptoms.

Over time children start to lose their ability to function normally. They will require assistance with most tasks. Children must develop this disease before the age of 10 in order for it to be considered juvenile.

Late-onset Tay-Sachs is when adults finally show symptoms. The disease has many more symptoms than in infant stages, but it is also slow to progress.

Adults with the disease may continue to live a full life. It is sometimes still fatal due to infections that can develop because of a weakened body and nervous system, but that is not always the case. The younger you develop the disease, the more likely you are to experience a fatal result.

Tay-Sachs Cause

There is only one cause of Tay-Sachs. It is an inherited disease caused by a mutation of the HEXA gene in chromosome 15 at position 24.1. Without this enzyme to prevent a harmful fatty substance from damaging the cells, the brain and spinal cord become too badly destroyed and functioning of the body ceases.

How Is Tay-Sachs Inherited?

Tay-Sachs inheritance is only possible if the person receives 2 mutated copies of the gene. This is known as an autosomal recessive inherited disorder.

Both parents would have to have a mutated gene and be carriers in order for their child to get the disease. That is why there are so few new cases each year.

The answer of how many cases of Tay-Sachs per year is that about 16 cases are diagnosed in the United States in that timeframe. There is a one in four chance that a child of two carriers will develop the disease.

Can Tay-Sachs Be Prevented?

Prevent Tay-Sachs by getting genetic testing done. If you find out that you’re a carrier, choose not to carry a child of your own and opt for adoption or surrogacy instead.

Tay-Sachs Risk Factors

Certain people are more at risk for Tay-Sachs. People of eastern and central European descent with Jewish heritage seem to be one of the largest groups affected. One in every 27 Jews is a carrier of the disease 3. The disease is also commonly seen in Quebec, the Amish communities in Pennsylvania, and in Louisiana. The prevalence of Tay-Sachs in the general population is low. Tay-Sachs disease ethnic connections seem to be important to consider.

Who Is Most Likely to Get Tay-Sachs Disease?

Tay-Sachs is possible in males or females. It does not discriminate based on gender. Only ethnicity seems to impact the likelihood of developing the disease, though anyone can be affected. There are Tay-Sachs support groups you can join if you have the disease or are a caregiver for someone who has it.

Tay-Sachs Symptoms

Living with Tay-Sachs can be debilitating.

Infants who develop symptoms may be startled with any noise. They tend to sleep longer and have no energy. They no longer can crawl and move around well if they once did. There are many severe symptoms that can occur as well, including:

  • Vision loss
  • Hearing loss
  • Inability to move
  • Muscular stiffness
  • Paralysis
  • Seizures
  • Permanent disability

These symptoms are often common in infants starting around 6 months of age and continuing to age 5 when most succumb to their disease.

Juveniles may experience:

  • Behavioral problems
  • Frequent infections
  • Loss of motor control
  • Problems with speech
  • Muscle weakness
  • Seizures

Adults experience:

  • Clumsiness
  • Loss of balance
  • Muscle weakness
  • Difficulty swallowing
  • Trouble speaking
  • Muscle spasms
  • Psychiatric disorders, such as schizophrenia
  • Dementia

The symptoms adults experience start out slowly and may seem minor for a while until they progress. Not all adults experience all symptoms, either. You may only have a couple of struggles while others have most of them.

How Does Tay-Sachs Affect the Body?

Tay-Sachs causes an attack on the nerve cells. The functioning of the brain and muscles will start to weaken. There may be cognitive impairments, trouble with vision, poor coordination, difficulty walking, and more.

The different forms will determine the effects, as children and adults tend to experience some differing symptoms. The results may also vary from person to person, with some affected worse than others.

Tay-Sachs Diagnosis

There are diseases similar to Tay-Sachs as well. It’s important to get a diagnosis to be sure that this is, in fact, the disease you or your child has and it isn’t something similar. Sandhoff disease is one example. It is also a neurodegenerative disorder.

How Is Tay-Sachs Diagnosed?

The diagnosis for Tay-Sachs is performed through a simple blood test. This will tell if the HEXA gene is present or not. A full genetic test may also be warranted depending on symptoms and a physical examination. It is often best to see a genetic counselor during this process as they can explain the results in full detail.

Can Tay-Sachs be Detected Before Birth?

It is possible to get a diagnosis even before birth. During the 10th to 12th week of pregnancy, expectant mothers can choose to have their unborn babies tested. A chorionic villus sampling (CVS) can be used to determine if the baby has the presence of HEXA or not. If they do not, then they will have Tay-Sachs. This test is done using a sample of the placenta.

During the 15th to 18th week, an amniocentesis will need to be performed instead of a CVS. A sample of the amniotic fluid is used for the test. The same rule applies, where the sample gets checked for HEXA to determine if Tay-Sachs is a possibility.

Who Should Be Tested for Tay-Sachs Disease?

Anyone hoping to have children can get tested for the disease to see if they are carriers. People who are more at risk due to their ethnicity, such as those of Jewish descent, should especially be tested.

Your test results can help you determine if you want to continue to try for children, especially with such a low probability of developing the disease or find alternative methods, such as adoption.

Since both parents need to have the gene, only one with it is not a reason to stop trying to start a family. Only when the prospective father and mother both have it do you need to consider the risk and possibly other options.

Genetic Tests Currently Available for Tay-Sachs:

A genetic test can be done through a genetic counselor. Speak with your doctor about where to go for this test in your area. There may be free Tay-Sachs testing available at some locations, so it is important to ask about the Tay-Sachs test cost and options you may have with limited financial means. Look into insurance coverage as well.

Tay-Sachs Treatment Options

Tay-Sachs disease treatment is possible for some of the symptoms caused. These treatment options will not completely cure the disease but can help to prolong life and improve the overall quality of life in some cases.

The Tay-Sachs treatment cost will vary from one procedure option to the next, but insurance may cover some of the costs so it is not so expensive for the family. It is best to speak with your doctor and insurance company about this.

Tay-Sachs Gene Therapy

There are new approaches to treatment using gene therapy 4. Some have been used before while others are in development stages. Introducing new, healthy genes into a body that is lacking them will help prevent symptoms and allow the body to replicate these new cells that have the missing elements it needs.

Basic Treatment

Basic treatment options include medication to control seizures and other symptoms 5. Respiratory care may be necessary for those who struggle with their lung health. Chest physiotherapy may be required to remove mucus from the lungs and help improve breathing.

There is also the option of a feeding tube. Respiratory problems and trouble swallowing can make it difficult to eat and even drink. An assistive feeding device or surgery to insert a tube directly into the stomach would help with this struggle.

Physical therapy is the final basic treatment option. This will help to delay joint stiffness and prevent the pain this causes from starting so soon. The disease can make it difficult to move around, but physical therapy will allow the patient to continue to remain mobile for as long as possible.

Is There a Cure for Tay-Sachs?

There is not yet a cure for Tay-Sachs. Foundations have been created to aid in the research and funding of projects so a cure may be found in the future.

As of 2019, only treatment options used to help manage symptoms are available, but the disease persists. There is hope, however, according to the Cure Tay-Sachs Foundation. Any donations provided go towards finding a cure in the future. Spreading awareness is also beneficial to the cause.

Tay-Sachs Prognosis

A Tay-Sachs prognosis is a better one than many diseases, for adults at least. Adults who develop the disorder tend to have symptoms progress slowly.

The prognosis of late-onset Tay-Sachs is that the person may continue to live a full life, just with some complications. The disease is usually fatal for infants diagnosed, however. The disease progresses very quickly in children and those who have it tend to live for only a few years with quickly progressing symptoms that are debilitating.

How Long Can a Person Live with Tay-Sachs?

People may question why does Tay-Sachs disease persist? There isn’t a cure for the disease and more research is needed to find better treatment options and solutions for stopping the disease.

The Cure Tay-Sachs Foundation is continuing with its fundraising and research initiatives to find an improved treatment plan. They were even awarded a grant for more than $200,000 to fund a research project.

Even with the disease continuing, teens and adults who may develop it can continue to live a long life even while having it. Infants and children may only live for a few years with Tay-Sachs disease, but adults can live for many, many years past diagnosis.

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Referenced Sources

  1. About Tay-Sachs Disease.
    National Human Genome Research Institute. 2019.
  2. Tay-Sachs disease.
    Genetics Home Reference. U.S. National Library of Medicine. 2019.
  3. Tay-sachs Disease.
    National Tay-Sachs & Allied Diseases Association of Delaware Valley. 2019.
  4. New Approaches to Tay-Sachs Disease Therapy.
    Valeriya V. Solovyeva, Alisa A. Shaimardanova, Daria S. Chulpanova, Kristina V Kitaeva, Lisa Chakrabarti, Albert A. Rizvanov, 2018 Nov 20.
  5. Tay-Sachs disease.
    Mayo Foundation for Medical Education and Research (MFMER). 2019.