In gene therapy of Adenosine Deaminase (ADA) deficiency, the patient requires periodic infusion of genetically engineered lymphocytes because: (NEET 2022)
Answer: (D) Genetically engineered lymphocytes are not immortal cells.. Answer: (D) Genetically engineered lymphocytes are not immortal cells.
- A.Retroviral vector is introduced into these lymphocytes
- B.Gene isolated from marrow cells producing ADA is introduced into cells at embryonic stages
- C.Lymphocytes from patient's blood are grown in culture, outside the body
- D.Genetically engineered lymphocytes are not immortal cells.✓
Correct Answer
(D) Genetically engineered lymphocytes are not immortal cells.
Solution & Explanation
Answer: (D) Genetically engineered lymphocytes are not immortal cells. Solution: In ADA gene therapy, lymphocytes from the patient's blood are cultured, a functional ADA cDNA is introduced using a retroviral vector, and the cells are returned to the patient. Because these mature lymphocytes are not immortal, they die off, so the patient needs periodic re-infusion of fresh genetically engineered lymphocytes. NCERT Reference: Ch 10, p.182, line 36 — "as these cells are not immortal, the patient requires periodic infusion of such genetically engineered lymphocytes"