Gene Therapy - ADA Deficiency - Unsolved Practice Set
Chapter: Biotechnology and Its Applications | Topic: Gene Therapy ADA Deficiency
GENE THERAPY - ADA DEFICIENCY - UNSOLVED PRACTICE SET
Topic: Gene Therapy ADA Deficiency
Multiple Choice Questions
Q1. Gene therapy is defined as a technique that attempts to correct a genetic defect by:
- Removing all genetic material from a patient's cells
- Inserting a normal, functional gene into an individual's cells to compensate for a defective or missing gene
- Preventing all future reproduction
- Using only chemical medication with no genetic involvement
Q2. The first clinical case of successful gene therapy was carried out to treat a genetic condition known as:
- Down syndrome
- Adenosine Deaminase (ADA) deficiency
- Sickle cell anaemia
- Colour blindness
Q3. ADA deficiency is a genetic disorder that results in:
- Improved immune function
- A severe combined immunodeficiency (SCID) due to a lack of a functional immune-related enzyme
- No noticeable health effects
- Excess red blood cell production
Q4. In early ADA deficiency gene therapy, lymphocytes were extracted from the patient's blood, and a functional ADA gene was introduced into these cells using a:
- Restriction enzyme alone
- Retroviral vector
- Bacterial plasmid only
- Chemical mutagen
Q5. A significant limitation of early ADA deficiency gene therapy was that:
- It provided a permanent cure with a single treatment
- The effect was temporary, since the genetically modified lymphocytes are not permanently self-replicating, requiring periodic repeated treatment
- It had no effect on the patient's immune function
- It could not be performed on humans at all
Short Answer Questions
Q6. Define gene therapy, in your own words.
Q7. What is ADA deficiency, and what health condition does it cause in affected individuals?
Q8. Briefly describe the basic procedure used in the first successful case of gene therapy for ADA deficiency.
Q9. Why was the effect of early ADA deficiency gene therapy considered temporary rather than permanent?
Long Answer Questions
Q10. Describe the process involved in the first successful gene therapy case for treating ADA deficiency, explaining how a functional gene was introduced into the patient's cells.
Q11. Discuss the significance and limitations of early gene therapy approaches for ADA deficiency, and explain why researchers have since explored alternative approaches, such as introducing the gene into bone marrow stem cells.
APPLICATION / ANALYSIS
Q12. A child diagnosed with ADA deficiency undergoes gene therapy involving the reintroduction of genetically modified lymphocytes carrying a functional ADA gene. Explain why this child might need to undergo repeated treatments over time, rather than being permanently cured after a single procedure.
Q13. Researchers propose introducing the functional ADA gene into a patient's bone marrow stem cells instead of mature lymphocytes, hoping to achieve a more lasting therapeutic effect. Explain, using your understanding of stem cells, why targeting bone marrow stem cells might provide a more permanent solution compared to treating mature lymphocytes alone.