Which technique would you expect to be completely curative in SCID ?

Options

A. Gene therapy in adult stage
B. Gene theraphy in embryonic stage
C. Bone marrow transptation
D. Enzyme replacement therapy

Answer

To determine which technique would be completely curative for Severe Combined Immunodeficiency (SCID), we need to analyze the options provided:

1. **Understanding SCID**: SCID, or Severe Combined Immunodeficiency, is a genetic disorder characterized by a significant defect in the immune system, particularly affecting T-cells. This condition leaves individuals highly susceptible to infections.

2. **Evaluating the Options**:
- **A. Gene therapy in adult stage**: While gene therapy can be beneficial, it is not guaranteed to be completely curative in adults, especially since the immune system may already be compromised.
- **B. Gene therapy in embryonic stage**: This option has potential, but it is not widely practiced or guaranteed to be completely curative at this stage.
- **C. Bone marrow transplantation**: This technique involves transplanting healthy bone marrow stem cells into the patient. These stem cells can differentiate into various types of blood cells, including T-cells, thereby restoring the immune system's functionality. This method has been shown to provide a complete cure for SCID.
- **D. Enzyme replacement therapy**: This therapy is used for certain metabolic disorders but does not address the underlying genetic defect in SCID and therefore cannot be considered curative.

3. **Conclusion**: Among the options, **C. Bone marrow transplantation** is the technique that is expected to be completely curative for SCID. It effectively replaces the defective immune system with a functional one derived from healthy donor stem cells.

### Final Answer:
C. Bone marrow transplantation