CML Overview

Chronic myelogenous leukemia (CML) is one of a group of myeloproliferative disorders. These are disorders that affect the bone marrow, in which excess red blood cells, granulocytes, and/or platelets are produced. It is also referred to as chronic myeloid leukemia, chronic granulocytic leukemia, or chronic myelocytic leukemia.

CML accounts for about 15%–20% of all cases of adult leukemia (Faderl et al., 1999).

More than 95% of patients diagnosed with CML have the presence of a cytogenetic anomaly known as the Philadelphia chromosome (Ph1), a translocation of genes on chromosomes 9 and 22, which causes the Abelson (ABL) oncogene on chromosome 9 to transfer to a site on chromosome 22 known as the breakpoint cluster region (BCR). This ABL/BCR fusion causes the abnormal production of tyrosine kinase protein, which causes the abnormal myelopoiesis of CML (Deininger, Goldman, & Melo, 2000). Ph1-negative CML is more difficult to identify and generally has a poorer response to treatment and shorter overall survival than Ph1-positive CML (Onida et al., 2002).