BTEC 3301 Lecture Notes - Lecture 1: Hexa, Ganglioside, Hexosaminidase
4 May 2018
School
Department
Course
Professor
Tay-Sachs Disease
What is Tay-Sachs Disease?
Tay-Sachs disease is a rare and inherited disorder that progressively destroys nerve cells in the
brain and spinal cord. This disease is very commonly found in infants and appear in 3-6 months
of being born. It becomes more noticeable when there the development and muscle growth
slows down. Genetic testing can help diagnose the disease and the lack of Hexosaminidase A
can be used as a marker to tell if one has the disease.
Why is it a problem?
This is a fatal condition which causes a slow in development. Infants can lose the ability to turn
over, sit, and crawl. An exaggerated reaction to loud noises can develop. Other symptoms
include seizures, vision and healing loss, intellectual disability, and paralysis. Muscle weakness
and loss of muscle coordination can also happen to those with this disease. Whoever has this
disease usually dies in their infant years or early childhood. A characteristic of this disorder is a
cherry-red spot found in the eye.
Symptoms of the late-onset/juvenile form have milder reactions.
What causes Tay-Sachs?
This disease is caused by a mutation in chromosome 15, the HEXA gene. HEXA is used to
degrade gangliosides in the central nervous system. Because there is a mutation, the HEXA
isn’t utilized properly and gangliosides continue to grow and destroy brain cells and there is a
loss of function in the brain and the spine.
Who are at risk?
Tay-Sachs disease has an autosomal recessive inheritance. Those who are just carriers will
have no effect to their lives. One in 320,000 births are diagnosed with the disease, but one in
250 are carriers. Populations with a higher risk include Ashkenazi Jewish, French Canadian,
Irish, Pennsylvania Dutch, and Cajun communities. All populations found with the HEXA
mutation have higher risk. One in 3,900 are found to have the disease in Jewish population.
What is the incidence of the disease?
Tay-Sachs disease is 100 times more common in infants with ancestry in Ashkenazi Jews
compared to non-Jewish infants. In 2000, over 52,000 TSD carriers and 1,400 risk couples have
been identified via the TSD screenings.
How is the disease treated?
There is no way to treat the disease other than alleviate the seizures by administering medicine
and giving them a supportive and pleasurable living experience.
How is the disease prevented?
There is no cure or effective preventive treatment to slow the disease. However, carriers of the
gene can do genetic tests to decide if they want to start a family together. Screenings have help
reduce the occurrence of TSD to 90%.
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Tay-sachs disease is a rare and inherited disorder that progressively destroys nerve cells in the brain and spinal cord. This disease is very commonly found in infants and appear in 3-6 months of being born. It becomes more noticeable when there the development and muscle growth slows down. Genetic testing can help diagnose the disease and the lack of hexosaminidase a can be used as a marker to tell if one has the disease. This is a fatal condition which causes a slow in development. Infants can lose the ability to turn over, sit, and crawl. An exaggerated reaction to loud noises can develop. Other symptoms include seizures, vision and healing loss, intellectual disability, and paralysis. Muscle weakness and loss of muscle coordination can also happen to those with this disease. Whoever has this disease usually dies in their infant years or early childhood. A characteristic of this disorder is a cherry-red spot found in the eye.
