Question

The first clinical use of gene therapy was done for treatment of

• A. Peptide deaminase deficiency
• B. Adenosine deaminase deficiency
• C. Cytosine decarboxylate deficiency
• D. Adenosine demethylase deficiency

Hint:

• First gene therapy (1990) → ADA-SCID
• Landmark in medical biotechnology

Answer 1

The Correct Option is B

Concept: The first successful clinical gene therapy was performed in 1990 for a genetic disorder affecting the immune system.
• Disease: ADA deficiency (Adenosine deaminase deficiency)
• Leads to Severe Combined Immunodeficiency (SCID)

Step 1: Understanding the disease.

• ADA enzyme deficiency → toxic metabolite accumulation
• Results in impaired immune function

Step 2: Gene therapy approach.

• Functional ADA gene introduced into patient's cells
• Restores immune function

Step 3: Analyzing options.

• Adenosine deaminase deficiency: Correct → first gene therapy case.
• Other options: Not known gene therapy targets → Incorrect.

Step 4: Selecting the correct answer.
Thus, the first gene therapy was for ADA deficiency.