FLT3 Internal Tandem Duplication and D835 Mutations in Acute Myeloid Leukemia

Bănescu Claudia¹, Dobreanu Minodora², Duicu Carmen³, Benedek I⁴, Macarie I⁵, Köpeczi Judit⁴

1 Department of Genetics, University of Medicine and Pharmacy, Tîrgu Mureş, Romania
2 Department of Clinical Biochemistry, University of Medicine and Pharmacy, Tîrgu Mureş, Romania
3 Pediatric Clinic, University of Medicine and Pharmacy, Tîrgu Mureş, Romania
4 Hematology Clinic 2, University of Medicine and Pharmacy, Tîrgu Mureş, Romania
5 Hematology Clinic 1, University of Medicine and Pharmacy, Tîrgu Mureş, Romania

Introduction: FLT3 is a member of receptor tyrosine kinases expressed in leukemic cells. Internal tandem duplications (ITDs) and D835 mutations in FLT3 tyrosine kinase receptor have been shown to confer a bad prognosis in acute myeloid leukemia (AML). The aim of the present study was to determine the incidence of both ITD and D835 mutations in the FLT3 gene, in patients with AML from Tg-Mures, Romania.
Materials and methods: DNA was obtained from peripheral blood samples. ITDs were investigated by polymerase chain reaction (PCR). D835 mutations were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), with the digestion of restriction endonuclease EcoR V. The amplified and restricted products were finally electrophoresed on agarose gel stained with ethidium bromide.
Results: Alterations in the FLT3 gene were detected in 8 patients out of the 23 cases analyzed. These aberrations included ITD in 4 cases, D835 mutations in 2 cases and both types of alteration (ITD + D835) in 2 patients.
Conclusion: In this study we demonstrated that FLT3 mutations are frequent molecular abnormalities in AML patients with an incidence of 34.8%. Although our data do not support its value as a prognostic factor in AML patients because of the small cohort, further investigation is required.