What is Tay-Sachs Disease (TSD)?
Tay-Sachs disease (TSD) is a rare congenital disorder of the central nervous system – the brain and spinal cord. This is a neurodegenerative disorder that affects mostly infants. The disease is progressively causing damages to the nerve cells which is unfortunately at all times fatal.
Tay-Sachs disease (TSD) is a mutation in the Hex-A gene that causes the body to have very low levels or none at all of the Hex-A enzyme. The Hex-A enzyme helps the cells, particularly the nerve cells in the brain, to break down the fatty waste products. The absence of the Hex-A enzyme will cause the waste products to build-up which will result in the swelling of the cells and eventually will cause it to die.
Infants affected by Tay-Sachs disease lose their motor skills like sitting, crawling, and turning over. Infants usually become overly sensitive to loud noises and they tend to have exaggerated startle reactions.
Generally, infantile cases have no Hex-A present the reason why the disease progresses very fast.
For adolescents and adults, Tay-Sachs disease may rarely manifest and with less severity of symptoms than those in the infantile form.
The Tay-Sachs disease is named after its discoverers. Initially, it was named after Warren Tay, a British ophthalmologist who described the cherry-red spot on the retina of the eye of the patient in 1881. Then, it was also named after Bernard Sachs, an American neurologist from New York in 1896, who did a continuous study and after several years provided the first description of the cellular changes, that is the extreme swelling of neurons in patients with Tay-Sachs disease.
Forms of Tay-Sachs Disease
Generally, there are 3 forms of Tay-Sachs disease, that is dependent on the nature of the symptoms and its on-set, namely:
- Infantile Onset or Classic
The babies with classic Tay-Sachs do not have the Hex-A enzyme, the reason why the progress of the disease is very quick.
- Juvenile Onset
The person with Juvenile forms produces very small amounts of the Hex-A enzyme. The probable reason why their symptoms are milder than the classic form and manifestation of it begin later in life.
- Late-Onset or Chronic Tay-Sachs
Just like with the juvenile form, the individual with late-onset Tay-Sachs disease produces little amount of the Hex-A enzyme. The symptoms are milder than the children with the infantile or juvenile form. The symptoms usually start between adolescence and mid-30s, although it may sometimes start from childhood.
Affected persons usually do not suffer from loss of hearing and vision. The lifespan of the person varies as well and in some cases, it remains unaffected.
Signs and Symptoms
Infants affected with Tay-Sachs disease mostly begin in the fetal stage – before the birth, when the nerve damage started. In most cases, symptoms will start to show from ages 3 to 6 months but typically appear normal prior to the manifestation. There is a rapid progression of the disease and because of this, the child may only live until early childhood that is only about 4 to 5 years old.
Symptoms of Tay-Sachs disease in Infantile or Classic Form include:
- Hearing loss or deafness
- Decreased muscle strength
- Slow growth
- Increased startle response
- Paralysis or loss of muscle function
- Spasticity – muscular stiffness
- Impaired vision or progressive blindness
- Intellectual disability
- Delayed mental and social development
- Eye abnormality called – “cherry-red spot” on the retina in the eye
Symptoms of Tay-Sachs disease in Other Forms include:
The Juvenile form and the Late-onset form or Chronic Tay-Sachs symptoms are rare and the severity of the symptoms tends to be milder as compared to the symptoms of the Infantile or Classic form.
Children with juvenile form manifest symptoms beginning the age of 2 up to 10 years of age. The symptoms appear the same as those of the Classic form but the development of the disease is much slower. The lifespan of the child reaches the age of 15.
Those inflicted with the Late-onset or Chronic form of Tay-Sachs show symptoms by the age of 10. In this form, the disorder develops slowly. The person may manifest the following Late-onset or Chronic symptoms which may include:
- Slurred speech
- Muscle weakness
- Muscle cramps
- Unsteady gait
- Mental abilities like memory problems and comprehension
- Some mental illness
The severity of the symptoms and lifespan of the individual varies. Some people may even have a normal lifespan.
In order to establish the diagnosis, the physician may gather information regarding the child’s symptoms and correlate it to family history tackling the family hereditary disorders and may require a diagnostic blood analysis in order to confirm the presence of Tay-Sachs disease.
With the blood analysis, the levels of the Hex-A enzyme will be checked. The low levels or absence of the Hex-A enzyme will confirm the Tay-Sachs disease.
The physician may also perform eye tests to determine the presence of a cherry-red spot in the back of the eyes, which is indicative of the Tay-Sachs disease.
For the nervous system test, the child may be recommended to undergo a consultation with a pediatric neurologist and for a thorough eye examination, to a pediatric ophthalmologist.
Just like in any congenital hereditary disease, there is no known cure for Tay-Sachs disease, but to manage the symptoms and alleviate the condition of the person, some treatments can be done. The objective of the treatment is to provide comfort and support and this may include the following:
To ease the symptoms, medications may be prescribed like anti-seizure.
- Feeding Tubes
It is recommended that the child uses a feeding tube to avoid the trouble with swallowing or to prevent the child from developing respiratory problems that may be caused by inhaling food or liquid into the lungs while eating. In order to prevent such issues during mealtime of the child, an assistive feeding device is suggested.
- Physical Therapy
It is beneficial for the child to have physical therapy in order to keep the joints flexible and maintain the range of motion.
- Respiratory Care
There is a high risk of lung infections for children with Tay-Sachs disease. And this lung infection will cause breathing problems and accumulation of mucus in the lungs. Chest physiotherapy (CPT) is needed to help in the removal of mucus from the lungs.