Which one of the given enzymes is involved in first clinical gene therapy?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Adenosine deaminase
Gene therapy means delivering a normal gene into a person to take over the work of a faulty gene. The first clinical gene therapy was given in 1990 to a four-year-old girl who had ADA deficiency. The enzyme adenosine deaminase is needed for the working of the immune system, and the disorder arises when its gene is deleted.
(1) Adenosine deaminase — Correct. This is the enzyme that was missing in the patient and whose gene was supplied.
(2) DNA polymerase — Incorrect. This enzyme builds new DNA strands in replication and in PCR. Its absence was not the cause of the disorder.
(3) RNA polymerase — Incorrect. This enzyme makes RNA from DNA in transcription. It was not the enzyme concerned.
(4) Restriction endonuclease — Incorrect. This enzyme cuts DNA at specific sequences and is a tool of recombinant DNA technology. It was not the missing enzyme.
NCERT Extract:
Gene Therapy – …
