Which kind of therapy was given in 1990 to a four year old girl with adenosine deaminase (ADA) deficiency?

Options

A. Gene therapy
B. Chemotherapy
C. Immunotherapy
D. Radiation therapy

Answer

**Step-by-Step Solution:**

1. **Identify the Condition**: The question refers to a four-year-old girl with adenosine deaminase (ADA) deficiency. This condition leads to a genetic disorder known as Severe Combined Immunodeficiency (SCID).

2. **Understand the Cause**: ADA deficiency is caused by a mutation in the gene that codes for the enzyme adenosine deaminase. This mutation results in the accumulation of toxic substances, specifically deoxyadenosine, which adversely affects lymphocytes, the key cells of the immune system.

3. **Determine the Treatment**: In 1990, the treatment provided for this condition was gene therapy. This therapy aims to correct the genetic defect by introducing a functional copy of the ADA gene.

4. **Explain the Gene Therapy Process**:
- **Cell Harvesting**: Cells were harvested from the patient (the girl).
- **Gene Modification**: The mutated ADA gene was isolated, and an altered (functional) version of the ADA gene was inserted into a modified virus. This virus was altered so that it could not reproduce.
- **Transduction**: The modified virus was then mixed with the patient’s cells, allowing the altered gene to be incorporated into those cells, making them transgenic.
- **Reintroduction**: These transgenic cells were then injected back into the patient’s body, where they began to produce the functional ADA enzyme.

5. **Conclusion**: The gene therapy successfully corrected the ADA deficiency, allowing the girl to produce the necessary enzyme and alleviating the symptoms of SCID.

**Final Answer**: The kind of therapy given in 1990 to the four-year-old girl with adenosine deaminase (ADA) deficiency was **gene therapy**.

---