2. Background info on Tay Sachs
• Causes intense mental and physical
deterioration at a young age
• Currently there is no cure
• Mutations in the HEXA gene cause
Tay-Sachs disease
3. Genetic Information
• Autosomal recessive genetic disorder
• It is caused by a genetic defect in a single gene
with one defective copy of that gene inherited
from each parent
• Mutation is on 15th chromosome
5. When each parent has the gene…
• 50% chance that their child will be a
carrier, but not have the disease
• 25% chance that their child will not be a
carrier and not have the disease
• 25% chance that their child will have the
disease
6. What actually happens?
• Harmful quantities of a fatty substance called
ganglioside GM2 build up in tissues and nerve
cells in the brain
• Insufficient activity of an enzyme called beta-
hexosaminidase A that catalyzes the
biodegradation of the gangliosides
7. Affected Body Parts
• Red spot behind eye, forms
– Blindness follows
• Hearing loss
• Complete loss of physical movement
– Seizures
8. Diagnosis
• Complete physical evaluation
• A detailed history of symptoms and family
hereditary disorders
• Eye examination
– Looking for red spot on eye
• Blood test
– A blood test can measure hexosaminidase A (hex A)
activity
– Parents can get blood tests to see if they carry the Tay
Sachs gene
9. Prognosis
• You’re screwed
• Death usually occurs by the time the child is 5
years old
• In cases where kids get Tay Sachs later on in
childhood (rare) they usually die once the
reach their teen years
10. History of Disease
• Named after Warren Tay and Bernard Sachs
• Warren Tay
– First described red spot on retina in 1881
• Bernard Sachs
– Did further research and described the changes in
cells during Tay Sachs
– also noted an increased prevalence of Tay Sachs
disease in the eastern and central European
Jewish population
