Question

Given below are two statements
Statement I: Adenosine deaminase is crucial for the immune system to function.
Statement II: Adenosine deaminase deficiency can be cured only by bone marrow transplantation.
In the light of the above statements, choose the correct answer from the options given below.

• A. Both Statement I and Statement II are true
• B. Both Statement I and Statement II are false
• C. Statement I is true, but Statement II is false
• D. Statement I is false, but Statement II is true

Hint:

Watch out for extreme keywords like "only" or "always" in biology statements. ADA deficiency has multiple treatment avenues (Enzyme replacement, BMT, Gene therapy).

Answer 1

The Correct Option is C

Step 1: Understanding the Problem:
Adenosine Deaminase (ADA) deficiency is an autosomal recessive metabolic disorder that leads to Severe Combined Immunodeficiency (SCID).
Step 2: Approach and Formula:
Evaluate the biological role of ADA and carefully analyze the validity of the word "only" regarding its available medical treatments.
Step 3: Detailed Explanation:
- Statement I: The enzyme Adenosine Deaminase is absolutely crucial for the proliferation and maturation of lymphocytes (T-cells and B-cells). Without it, toxic metabolic byproducts accumulate and destroy these immune cells, crippling the immune system. Thus, Statement I is true.
- Statement II: The statement claims it can be cured only by bone marrow transplantation. This is factually incorrect. ADA deficiency can be treated through Enzyme Replacement Therapy (ERT) and Bone Marrow Transplantation, though neither is completely curative. A more permanent cure is achievable via Gene Therapy (introducing functional ADA cDNA using a retroviral vector) especially if administered during early embryonic stages. Since BMT is not the "only" treatment/cure, Statement II is false.
Step 4: Final Answer:
Statement I is true, but Statement II is false.