Acute Promyelocytic Leukemia (APL) is a distinct subtype of acute myeloid leukemia (AML) characterized by an abnormal accumulation of immature granulocytes called promyelocytes. APL is caused by a specific genetic abnormality, the translocation between chromosomes 15 and 17, which results in the fusion of the PML gene on chromosome 15 with the RARA gene on chromosome 17. This genetic fusion creates the PML-RARA fusion protein, which plays a crucial role in the pathogenesis of APL by blocking the differentiation of myeloid cells.
