Chromosomes 15, 17 translocation is seen in which leukemia:
## **Core Concept**
The question tests knowledge of specific cytogenetic abnormalities associated with various types of leukemia. Chromosomal translocations are genetic alterations that can lead to the development of leukemia by disrupting normal gene function. The specific translocation mentioned, involving chromosomes 15 and 17, is a well-known abnormality in hematological malignancies.
## **Why the Correct Answer is Right**
The correct answer, , is associated with the t(15;17) translocation. This translocation involves the fusion of the promyelocytic leukemia (PML) gene on chromosome 15 with the retinoic acid receptor-alpha (RARα) gene on chromosome 17. This fusion gene, PML-RARα, disrupts the normal process of myeloid cell differentiation and is characteristic of acute promyelocytic leukemia (APL), a subtype of acute myeloid leukemia (AML). The PML-RARα fusion protein acts as a dominant repressor of retinoic acid receptor function, preventing normal myeloid cell maturation.
## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because it does not correspond with the specific translocation t(15;17).
- **Option B:** This option is incorrect as it is not associated with the t(15;17) translocation.
- **Option D:** This option is incorrect because it does not represent the leukemia associated with the t(15;17) translocation.
## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that the t(15;17) translocation and the resultant PML-RARα fusion protein are specifically targeted by all-trans retinoic acid (ATRA) and arsenic trioxide therapies in the treatment of APL. This targeted therapy has significantly improved the outcomes for patients with APL.
## **Correct Answer:** .