Which leukemia is associated with the Philadelphia chromosome?

Which leukemia is associated with the Philadelphia chromosome?

• A. Acute lymphoblastic leukemia
• B. Chronic myeloid leukemia
• C. Acute myeloid leukemia
• D. Chronic lymphocytic leukemia

Answer: (B)

The Philadelphia chromosome is a specific genetic change: a reciprocal translocation between chromosomes 9 and 22 that creates the BCR-ABL fusion gene. This fusion protein has constitutive tyrosine kinase activity, driving uncontrolled cell growth and accumulation of mature granulocytes. That pattern is the hallmark of chronic myeloid leukemia, making this the classic disease linked to the Philadelphia chromosome. Treatments targeting this abnormal protein, such as BCR-ABL inhibitors, are especially effective in CML, reinforcing the connection. While the chromosome can appear in some cases of acute lymphoblastic leukemia, it is not the defining feature of AML or CLL, so CML is the best answer.

The Philadelphia chromosome is a specific genetic change: a reciprocal translocation between chromosomes 9 and 22 that creates the BCR-ABL fusion gene. This fusion protein has constitutive tyrosine kinase activity, driving uncontrolled cell growth and accumulation of mature granulocytes. That pattern is the hallmark of chronic myeloid leukemia, making this the classic disease linked to the Philadelphia chromosome. Treatments targeting this abnormal protein, such as BCR-ABL inhibitors, are especially effective in CML, reinforcing the connection. While the chromosome can appear in some cases of acute lymphoblastic leukemia, it is not the defining feature of AML or CLL, so CML is the best answer.