The first clinical gene therapy was given in_________.

Answer

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks for the year when the first clinical gene therapy was administered.

2. **Recall Historical Context**: The first clinical gene therapy is a significant milestone in the field of biotechnology and medicine.

3. **Determine the Year**: The first clinical gene therapy was performed in the year 1990.

4. **Identify the Patient**: The therapy was administered to a 4-year-old girl.

5. **Understand the Condition**: The girl was suffering from Severe Combined Immunodeficiency (SCID), a genetic disorder that severely affects the immune system.

6. **Explain the Cause**: SCID is primarily caused by a deficiency in the enzyme adenosine deaminase (ADA), which is crucial for purine metabolism in the body.

7. **Conclude the Answer**: Therefore, the correct answer to the question is that the first clinical gene therapy was given in **1990**.

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