Possible Evolution of Paroxysmal Nocturnal Hemoglobinuria into Chronic Myeloid Leukemia: A Rare Transformation

PNH is a rare acquired clonal hematopoietic stem cell disorder characterized by abnormal sensitivity of red blood cells to lysis by complement. It is caused by genetic mutation resulting in deficiency of glycosyl phosphatidylinositol anchor (GPA) for cell membrane proteins including complement regulating proteins CD55 and CD59. PNH tends to be associated with Aplastic Anemia (anemia due to failure of the bone marrow to produce red and white blood cells as well as platelets), Myelodysplastic Syndrome (a group of cancers in which immature blood cells in the bone marrow do not mature or become healthy blood cells) or rarely Acute Myeloid Leukemia (AML) (also known as acute nonlymphocytic leukemia, representing a group of clonal hematopoietic stem cell disorders in which both a block in differentiation and unchecked proliferation result in the accumulation of myeloblasts at the expense of normal hematopoietic precursors). Here we report a case and assume possible evolution of PNH into CML (a myeloproliferative malignant clonal disease characterized by presence of fusion BCR/ABL fusion oncogene).