Cytogenetic Analysis of Acute Myeloid Leukemia with t(8;21): Its Clinical Correlation with Loss of X Chromosome and Del (9q)

Abstract

T ranslocation (8;21) is the most frequent chromosomal aberration in adult de novo AML. The t (8;21) involves acute myeloid gene 1 (AML1) of chromosome 21 and myeloid transforming gene 8 (ETO) of chromosome 8 and it gives rise to AML1–ETO positive AML. The promotion effect of the fusion protein AML1-ETO on the growth arrest and apoptosis of hematopoietic cell progenitors suggests that cooperating mutations must overcome this cell death in order for leukemia to develop. The t(8;21) is often detected together with additional cytogenetic and molecular abnormalities. The most common cytogenetic aberrations are loss of sex chromosome followed by deletion of the long arm of chromosome 9 and trisomy 8. However, previous studies showed conflicting data regarding the role of secondary cytogenetic aberrations in addition to t(8;21). This study aimed to investigate the effect of additional aberrations (loss of X chromosome and del (9q)) on the clinicopathological and prognostic behavior of t(8;21) de novo AML patients. This study was conducted on 28 newly diagnosed AML-M2 patients associated with t (8;21). The patients were recruited from hematology & oncology unit at Ain Shams University Hospitals during the years 2014-2016. All patients were subjected to complete history, thorough clinical examination and laboratory investigations including: complete blood count, bone marrow aspiration, examination of Leishman-stained peripheral blood and bone marrow smears, immunophenotyping and FISH analysis using the following probes: LSI RUNX1/RUNX1T1 for detection of t(8;21) (q22;q22), CEP X probe for detection of loss of X chromosome and LSI ABL probe for detection of del (9q).