Frequency of TEL-AML1 Fusion Gene in Patients of Acute Lymphoblastic Leukemia

Abstract

Acute lymphoblastic leukemia (ALL) is the most common malignant tumor in children and forms a major fraction of childhood malignancies in the developed countries. Numerous chromosomal aberrations have been observed in ALL including translocations which result in the production of fusion genes (BCR-ABL, TEL-AML1, and MLL-AF4). These chromosomal rearrangements have great prognostic and therapeutic significance. Amongst these, TEL-AML1 fusion gene represents a subgroup of ALL cases, which are associated with many clinically important parameters of good prognosis. The objective of this study was to detect the frequency of TEL-AML1 fusion oncogene in ALL and its association with already established prognostic factors such as age, WBC count and FAB subtype. Materials and Methods: Sixty-six patients with newly diagnosed ALL were studied and patients on chemotherapy and T-ALL were excluded. The data was analyzed by SPSS20 for prognostically important parameters such as age, sex, hemoglobin level, WBC profile, platelet count, FAB type and immunophenotype. RNA extraction was performed and RT-PCR procedure was conducted to detect TEL-AML1 fusion oncogene. Results: Out of 66 samples, frequency of TEL-AML1 fusion oncogene was detected in 5 subjects (7.6%). Almost all TEL-AML1 positive patients carried FAB ALL-L1, B-Lineage immunophenotype, mean hemoglobin
level of 6g/dl and age from 3 to 5 years. All these features are related to good prognosis. Conclusion: To conclude, we reported 7.6% frequency of TEL-AML1 fusion gene, in our study subjects, which is different from that reported in western literature. If universally accepted, the identification of TELAML1 fusion gene in ALL, will improve risk stratification and will help in selection of appropriate therapeutic regimens.