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: Understand the disease SCID.
SCID stands for Severe Combined Immunodeficiency. It is a genetic disorder in which a person’s immune system is extremely weak or almost absent because the body cannot produce functional T-lymphocytes and B-lymphocytes.

Step 2: Identify the cause of the condition.
In many cases, SCID occurs due to a mutation in the gene responsible for the enzyme adenosine deaminase (ADA). Because of this deficiency, lymphocytes fail to develop or function properly, leaving the patient highly vulnerable to infections.

Step 3: Explain why transformed lymphocytes are infused.
To help the immune system function, genetically transformed lymphocytes containing a normal ADA gene are periodically infused into the patient. These modified lymphocytes temporarily restore the immune function and help the body fight infections.

Step 4: Reason for periodic infusion.
The infused lymphocytes do not survive permanently in the body, so they must be periodically infused to maintain adequate immune protection.

Final Answer:
Kanika required periodic infusion of transformed lymphocytes because she had ADA deficiency causing SCID, and the infused genetically modified lymphocytes temporarily restore immune function.