Lack of FLT3-ITD in Tunisian childhood acute lymphoblastic leukemia

Background: The fms-like tyrosine kinase 3 (FLT3) gene belong to the class III receptor tyrosine kinases witch is predominantly expressed on hematopoietic progenitor cells, and plays an important role in haematopoiesis. Targeting the FMS-like tyrosine kinase receptor-3 (FLT3) in acute leukemia is mainly important. Therefore, activating mutations in FLT3, primarily the FLT3-internal tandem duplication (FLT3-ITD), was used as a prognostic marker especially in myeloid leukemia; however, in ALL, the prognostic relevance of FLT3 mutations is less clear. Objectives: This study was conducted to evaluate the frequency of FLT3-ITD mutation in Tunisian childhood acute lymphoblastic leukemia, and to correlate this mutation with prognostic parameters. Methods: Genomic DNA was extracted from EDTA-anticoagulant blood samples from a total of 25 children suffering from acute lymphoblastic leukemia (ALL). After DNA extraction, the polymerase chain reaction using specific primers was conducted to screen the FLT3-ITD. Results: In acute lymphoblastic leukemia (ALL), 9 cases with LAL-B were detected and the median age is 13 years. Chromosome abnormalities were detected in 5 with ALL and are correlated with worse prognosis (very high risk and relapse). At molecular lever, never FLT3-ITD was detected. Conclusions: Our findings suggest that FLT3 mutations are not common in Tunisian childhood ALL and thus do not affect clinical outcome. Keywords: Fms-like tyrosine kinase 3; internal tandem duplication; acute lymphoblastic leukemia.