In gene therapy, what is the typical aim?

• A. To silence all gene expression in a cell.
• B. To replace a defective gene with a healthy one.
• C. To edit the genome in all cells of the body.
• D. To remove all DNA from a cell.

Answer: (B)

Gene therapy aims to fix the genetic defect by providing a healthy version of the gene or correcting the mutation so the normal protein is made again. Replacing a defective gene with a functioning one directly addresses the underlying cause of the disorder and can restore normal cellular function. Silencing all gene expression would disrupt essential cellular processes, editing the genome in every cell is not practical or safe, and removing all DNA would destroy the cell. Therefore, the typical aim is to replace the faulty gene with a healthy copy to restore proper protein production.