Frequency of KMT2A abnormalities affecting prognosis in acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML)

Detection of KMT2A gene abnormalities in patients with acute leukemia indicates an unfavorable prognosis. The aim of the study is to determine the frequency of these abnormalities in adult patients with acute leukemia in the Southeastern Anatolia Region. Anomalies were investigated by applying the KMT2A dual FISH probe to bone marrow and blood samples taken from patients with pre-diagnosis of Acute Lymphoblastic Leukemia (ALL) and Acute Myoloid Leukemia (AML) who came to the Hematology clinic of Dicle University hospitals. For FISH cases with anomaly, the panel analysis reports of the samples that were positive in this study among the samples sent to the Dicle University Medical Genetics Department laboratory for routine studies were also examined. Evaluation was made by comparing the KMT2A region with the other gene regions examined in the panel. In patients with acute leukemia, it is possible that anomalies in the KMT2A region are seen together with anomalies in some other regions. In this study, anomaly was also seen in the 7th chromosome in 2 of the cases with KMT2A anomaly, and tetrasomy in 8q24.21 region was seen in 1 case and trisomy in 8q21.3 region in 1 case. In the study conducted with the FISH method, anomaly was detected in the 11q23.3 gene region in 4 of 62 cases. 4 of these cases are male, while 3 of them are ALL, 1 has AML. Tetrasomy in the KMT2A gene region and tetrasomy in MYC, ABL1, BCR regions were detected in 1 of the cases with ALL. Trisomy in the KMT2A gene region was found in 1 patient with ALL, and hyperdiploidy was found in 1 patient. KMT2A deletion was observed in another case with ALL. Monosomy was detected in the KMT2A gene region in a case with AML. Numerical and structural changes in the 11q23.3% gene region were determined in 62 cases in 4.76% of FISH analysis from 21 cases with ALL and 2.43% of cases with AML. In our study; The rates obtained by FISH were found to be equivalent for ALL but lower for AML when compared with the literature.