Tay-Sachs Disease

Tay-Sachs Disease

Genetic Research Assignment

What is it?

This is a rare, inherited neurodegenerative disease. Causes a lack of the enzyme called beta-hexosaminidase A.This disease will show up earlier and more severely the less of the enzyme they have. 

3 forms based on age of onset:

Infantile: most common severe form, appears within first few months of their life. 

Juvenile: range of severity, symptoms appearing during childhood.  

Late onset/adult: least severe form, symptoms appear late childhood to adulthood.  

Multiple Choice

most common severe form is_____?

• infantile

• juvenile

• late onset

Symptoms part 1

Infantile: usually appear healthy in the newborn phase. First symptom may be exaggerated startle response to noise. This will progress to them not reaching important milestones like rolling or sitting up. They then develop muscle weakness that leads to paralysis. They slowly lose mental functions and lose awareness to their surroundings. They can develop blindness, seizures and difficulty swallowing. 

Symptoms part 2

Juvenile: frequent infections, behavioral problems, and progressive loss of mental function, speech and movement control. May also develop seizures and loss of vision.  

Late onset: “Neurological impairment is slowly progressive and may lead to clumsiness and loss of coordination, muscle weakness, tremors, difficulty speaking or swallowing, and uncontrollable muscle spasms and movements.[...]In some people with this form, the first obvious symptom is a severe psychiatric disorder such as schizophrenia.” (Tay-Sachs Disease | Genetic And Rare Diseases Information Center (GARD))

Prognosis

For Infantile: most do not survive past the age of four

For Juvenile: most pass away during childhood or adolescence. 

For Late onset: some will have a drastically shortened lifespan while others will not. 

Mode of Inheritance

Autosomal Recessive.

Caused by a mutation in the HEXA gene

Multiple Choice

Caused by mutation in which gene?

• SRF gene

• HEXA gene

• TANK gene

• LAT2 gene

Treatment and Symptom management

There is currently no cure for Tay-sachs disease or any treatments that slow or stop the progression. The only treatment is to manage symptoms and increase quality of life as much as possible. Research for potential treatments is ongoing. 

2 Interesting Things

The amount of enzyme activity directly affects the outcome. 

The diagnosis of Tay-Sachs disease involves a blood test that detects enzyme activity 

Sources

" Tay-Sachs Disease | Genetic And Rare Diseases Information Center (GARD) – An NCATS Program ". Rarediseases.Info.Nih.Gov, 2020,https://rarediseases.info.nih.gov/diseases/7737/tay-sachs-disease . Accessed 12 Dec 2020.

"Human Genetics Problem Set". Biology.Arizona.Edu, 2020, http://www.biology.arizona.edu/human_bio/problem_sets/human_genetics/04t.html. Accessed 26 Dec 2020.