Tay-Sachs disease is a very rare autosomal recessive genetic disorder. Tay-sachs disease commences around six months of age, causing a deterioration of nerve cells, physical and mental abilities and usually results in death.
The accumulation of harmful amount of cell membrane components known as gangliosides in the brain nerve cell’s causes this disease, which leads to the premature death of the cells. There exists no known treatment or cure.
Tay-sachs disease is mainly classified into three forms, depending on the onset age of neurological symptoms.
- Infantile Tay–Sachs disease: Infants suffering with Tay–Sachs disease develop normally for the first six months from the time of birth. As the neuronsbecome distended with gangliosides, the child becomes deaf, blind, and unable to swallow. Death could occur at the age of four.
- Juvenile Tay–Sachs:This disease is the rarest form of Tay–Sachs, and is seen in children between two to ten years old. Patients with Tay–Sachs disease develop motor skill andcognitive deterioration, dysarthria, ataxia,spasticity, anddysphagia.Death could occur between the ages of five to fifteen years.
- Adult or Late-Onset Tay–Sachs disease: This isanother rare form of the disease, first symptoms could be seen around 30s. Tay–Sachs disease is not as fatal as the other forms and as its effects could stop progressing. It is frequently misdiagnosed. Symptoms includespasticity, speech and swallowing difficulties and psychiatric illness.
For any age of onset, the testing initially involves anassay of enzyme to measure the hexosaminidase activity inleukocytes, serum or fibroblasts. Total activity of hexosaminidase enzyme is reduced in individuals with Tay-Sachs. Once the decreased enzyme activity is confirmed in an individual further molecular analysis could be pursued to confirm it.
Main approaches to prevent tay-Sachs disease are:
- Prenatal diagnosis: When both parents are identified as tay-sachs disease carriers, prenatal diagnosis could be done to determine if the fetus has accidentally inherited a defective gene copy from the parents. Couples may then choose to have an abortion.
- Preimplantation genetic diagnosis: In virtue fertilization the mother’s eggs are retrieved and the embryo is tested for the disorder ahead of the implantation. Only healthy embryos are selected and placed into the mother’s womb, discarding the unhealthy ones.