What is Tay-Sachs Disease?

Human body is made up of cells. The cells are instructed to carry out their functions by following instructions called chromosomes. These are chemical structures made up of DNA molecules. There are 22 non-sex chromosomes and 1 sex chromosome which form a set.

Chunk of chromosomes form a gene. When there is a change in the chemical structure of any of the 22 non-sex chromosomes in a gene, an autosomal disorder can develop. The genes exist in pairs. When both the copies of the genes are defective, then the disorder is recessive.
Carrying one abnormal gene, makes a person carrier of the disorder.

There is a 25 percent possibility that parents having both the defective genes of a pair can give birth to off-springs with autosomal recessive disorders or traits. One such genetic disorder is known as Tay – Sachs disease. It is known after British eye specialist Warren Tay (first observed the disease in 1881) and American specialist in neurology Bernard Sachs (explained the changes in the cells responsible for the disorder in 1887).

Tay - Sachs Disease

What is Tay – Sachs disease (TSD)?
It mostly affects infants around the age of six months. There is progressive deterioration of the physical and mental abilities. It eventually leads to the death of the child by the age of four.

Research studies have found that the disorder is caused by change in the chemical structure of the chromosome 15 on the HEXA gene. The event is technically known as mutation.

TSD is also one among the 50 rare diseases that is caused owing to the malfunctioning of one of the components inside the human cell known as the lysosome. It is the cells’ recycling center where the unwanted materials are processed into useful substances.

When compared to other autosomal diseases like sickle cell anemia and cystic fibrosis, this disease is rare. 1 in 27 – 1in 30 Ashkenazi Jews in the United States is a recessive carrier of this genetic disorder. There is a 1 in 50 chance of an Irish American to belong to the mentioned category.

Tay – Sachs Disease Symptoms:

In Infants:

  • Blindness
  • Red spot in the retina
  • Deafness
  • Inability to swallow
  • Partial or complete wasting away of muscles
  • Paralysis

In Juveniles: In extremely rare cases, children belonging to the age group of 2-10 years can also develop this disease with the following signs to watch out for:

  • Motor difficulties
  • Speech difficulties
  • Cognitive difficulties
  • Red spot in the retina
  • Unsteadiness while walking
  • Difficulty in swallowing
  • Unusual tightness of muscles
  • Death between 5-15 years of age

In Adults: In rare incidences, the disease develops very late in adults in their 20s or early 30s. It is known as Late Onset Tay–Sachs disease (LOTS). Though not properly diagnosed, the disease is not life-threatening. Its symptoms are:

  • Increase in neurological deterioration
  • Unsteadiness while walking
  • Difficulty in swallowing
  • Red spot in the retina
  • Difficulty in speech
  • Decline in cognitive abilities
  • Tightness in muscles
  • Psychological illness like Schizophrenic Psychosis

Diagnosis of the symptoms is a tough task for physicians as many are aware of the fact that the disease can develop in people other than Jews. Some of the screening techniques of this disease are prenatal testing, carrier testing, enzyme assay technique and mutation analysis technique.

Conclusion: Unfortunately, there is no cure or treatment for it. Children suffering from this disorder are given palliative care which aims at curbing the above mentioned signs of the disease. Advancement in this field has lead to the increase in the survival period up to the age of 5.

Experimental treatment methods to address the complexity of Tay-Sachs disease are being studied. Some of these under-trail research modalities are gene therapy, enzyme replacement therapy and substrate reduction therapy.

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