Question

In the 1990s, gene therapy was seen as a probable cure for many genetic diseases. List three reasons why it has so far been of limited success.

Select the three correct statements.

1) The viral vector itself can also elicit a severe immune reaction in some individuals, which was the case in early gene therapy trials.

2) It is challenging to deliver the gene to the correct tissue to ensure proper wild-type expression.

3) It is challenging to determine the location in a genome to ensure proper wild-type expression of the incorporated gene.

4) Gene therapy may inadvertently result in the activation or deactivation of other genes based on where the DNA incorporates into the genome.

5) If homologous recombination is used, gene therapy may inadvertently result in cancer.

6)The viral vector itself can also elicit a severe viral infection, which was the case in early gene therapy trials.

Answer 1

Answer: Options 1, 2, and 4 are correct
Explanation:
Challenges in Gene therapy:
1. Immune response: Viral vectors are used to transfer desired genes into the host. These disarmed viral vectors can elicit an immune response.
2. The integration of the gene into the host genome is a random process. So, some essential genes may get silenced or mutated during the transgene integration.
3. Gene delivery and activation: It is challenging to deliver the transgene to the desired tissue to enable proper expression.