Question

Give a reason for the following: Kanika was suffering from SCID and needed periodic infusion of transformed lymphocytes.

Hint:

A permanent cure for ADA deficiency is only possible if the corrective gene is introduced into bone marrow cells at an early embryonic stage.

Answer 1

Step 1: Understanding the Concept:
SCID (Severe Combined Immunodeficiency) can be treated with gene therapy using the patient's own lymphocytes.

Step 2: Detailed Explanation:
In gene therapy, a functional ADA gene is inserted into the patient's lymphocytes.
However, these lymphocytes have a limited lifespan; they naturally die after some time.
Therefore, the patient requires regular infusions of new genetically modified lymphocytes to maintain an active immune system.

Step 3: Final Answer:
Periodic infusion is necessary because lymphocytes are not immortal and have a finite life span.