In case of chronic myetogenous lukemia, which one of the following is called "Philadelphia chromosome"?

Options

A. Chromosome 22
B. Chromosome 21
C. Chromosome 9
D. Chromosome 5

Answer

To solve the question regarding which chromosome is referred to as the "Philadelphia chromosome" in the context of chronic myelogenous leukemia (CML), we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Context**: The question is about chronic myelogenous leukemia (CML), a type of cancer that affects the blood and bone marrow.

2. **Identify Key Terms**: The term "Philadelphia chromosome" is crucial. This term is associated with a specific genetic abnormality linked to CML.

3. **Research the Philadelphia Chromosome**: The Philadelphia chromosome is a result of a translocation between chromosome 9 and chromosome 22. This translocation leads to the formation of the BCR-ABL fusion gene, which is implicated in the pathogenesis of CML.

4. **Evaluate the Options**: The options given are:
- Chromosome 22
- Chromosome 21
- Chromosome 9
- Chromosome 5

5. **Determine the Correct Answer**: Since the Philadelphia chromosome is specifically identified as chromosome 22, we conclude that the correct answer is **chromosome 22**.

### Final Answer:
The Philadelphia chromosome is **chromosome 22**.

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