FLT3 INTERNAL TANDEM DUPLICATION AND D835 MUTATIONS IN PATIENTS WITH ACUTE LYMPHOBLASTIC LEUKEMIA AND ITS CLINICAL SIGNIFICANCE

The fms-like tyrosine kinase 3 (FLT3) gene is a member of the class III receptor tyrosine kinase family, mutations of FLT3 were first described in 1997 and account for the most frequent molecular mutations in acute myeloid leukemia. No data currently exist regarding FLT3 mutations in Saudi acute lymphoblastic leukemia (ALL) patients as no study has reported for FLT3 mutations in Saudi ALL patients. In this retrospective study, we have examined a cohort of 77 ALL patients, to determine the prevalence of FLT3 mutations and the possible prognostic relevance of these mutations in ALL patients and did correlations to other biologic factors, such as karyotype, molecular mutations, and leukocyte count. FLT3 internal tandem duplication (ITD) mutations and point mutation in tyrosine kinase domain (D835) mutations were analyzed in ALL patients at diagnosis by polymerase chain reaction (PCR). 2 cases (2.6%, 2/77) were positive for FLT3 mutations, one was found to have FLT3/ITD and other was found to have FLT3/D835. Our findings suggest that FLT3 mutations were not common in Saudi ALL and did not affect clinical outcome