Arrange the following steps of gene therapy for Adenosine deaminase deficiency in sequence.
(A) Patients lymphocytes are grown in culture outside the body
(B) Functional ADA cDNA is introduced into lymphocytes using retroviral vector
(C) Lymphocytes are taken from the blood of the patient
(D) Genetically engineered lymphocytes introduced back to the patient body
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (C), (A), (B), (D)
Lymphocytes are taken from the patient’s blood (C), grown in culture (A), given a functional ADA cDNA through a retroviral vector (B), and the engineered lymphocytes are returned to the patient (D).
NCERT Extract:
Gene Therapy – “… As a first step towards gene therapy, lymphocytes from the blood of the patient are grown in a culture outside the body. A functional ADA cDNA (using a retroviral vector) is then introduced into these lymphocytes, which are subsequently returned to the patient.”