Adenosine deaminase deficiency can be permanetly cured by which of the following methods ?

Options

A. Bone marrow transplantation
B. Enzyme replacement therapy
C. Gene therapy at early embryonic stages
D. All of these

Explanation

**Step-by-Step Solution:**

1. **Understanding Adenosine Deaminase Deficiency**:
- Adenosine deaminase (ADA) deficiency is a genetic disorder that affects the immune system, leading to severe combined immunodeficiency (SCID).

2. **Identifying Treatment Options**:
- The question asks for methods that can permanently cure this deficiency. The common treatment options include:
- Bone marrow transplantation
- Enzyme replacement therapy
- Gene therapy

3. **Evaluating Each Treatment Method**:
- **Bone Marrow Transplantation**: This method involves transplanting healthy bone marrow cells from a donor to the patient. While it can provide a functional immune system, it is not a permanent cure for ADA deficiency as it relies on the availability of a suitable donor and may have complications.
- **Enzyme Replacement Therapy**: This involves administering the ADA enzyme to the patient. Although it can alleviate symptoms, it does not provide a permanent solution as the treatment needs to be repeated regularly.
- **Gene Therapy**: This method involves introducing a functional copy of the ADA gene into the patient’s cells, ideally at an early embryonic stage. This approach aims to correct the underlying genetic defect and can potentially provide a permanent cure.

4. **Conclusion**:
- Among the options provided, gene therapy at an early embryonic stage is the only method that can lead to a permanent cure for adenosine deaminase deficiency.

**Final Answer**: Gene therapy at an early embryonic stage is the method that can permanently cure adenosine deaminase deficiency.

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