Geographic Heterogeneity of the AML۱-ETO Fusion Gene in Iranian Patients with Acute Myeloid Leukemia

Background: The human AML۱ gene, located on chromosome ۲۱, can be fused to the AML۱- eight-twenty-one (ETO) oncoprotein on chromosome eight, resulting in a t(۸;۲۱)(q۲۲;q۲۲) translocation. Acute myeloid leukemia (AML) associated with this translocation is considered a distinct AML with a favorable prognosis. Due to the various incidences of the translocation, which is associated with geographic diversities, investigation of molecular epidemiology is important to increase the awareness of physicians and hematologists regarding the frequency this chromosomal aberration. Methods: The patients were classified according to the French–American–British classification into eight groups: M۰–M۷. Determination of the prevalence of the AML۱-ETO fusion gene was accomplished by TaqMan real-time PCR. Bone marrow samples from ۱۱۳ patients with newly-diagnosed, untreated AML -M۱, -M۲, and -M۴, and ۲۰ healthy controls admitted to the Ghaem Hospital in Mashhad, Iran were studied. Results: The AML۱-ETO fusion gene was detected up ۵۰% of the M۲ subgroup and absent in the M۱ and M۴ subtypes and healthy controls. Comparison of the prevalence of the t(۸;۲۱) translocation with results of previous studies showed that it varies between countries. This result may be due to geographic or ethnic differences, or both. Conclusions: The relatively high prevalence of the t(۸;۲۱) translocation in Iran was similar to that found in other Asian countries. It was closely associated with female gender, relatively young age, and FAB-M۲ subtype. Its distribution varied considerably with geographic area. Therefore, further studies are needed to provide epidemiological data important for the establishment of optimal therapeutic strategies applicable to patients of each region.