Genetic analysis of acute myeloid leukaemia (AML) has identified multiple genetic markers of prognostic significance that can be used for risk stratification of patients at diagnosis. Of these, mutations of the FMS-like tyrosine kinase 3 receptor gene (FLT3) are one of the most important. FLT3 mutations are found in 30% of AML cases overall. They are present in different AML entities and across the cytogenetic subgroups, the most common being in AML patients with a normal karyotype. They are generally considered poor prognostic indicators although the prognostic impact is influenced by the type of FLT3 mutation as well as the co-existence of other mutations and cytogenetic background. FLT3 encodes a tyrosine kinase receptor that can be targeted by tyrosine kinase inhibitors and their introduction into treatment protocols has significantly improved the prognosis of these patients with a prior dismal outcome. Given the poor prognosis, and availability of targeted treatment, FLT3 testing is recommended for all new AML cases at diagnosis with the results available within 72 hours for determination of treatment strategies. This short turnaround time (TAT) is challenging for diagnostic laboratories and affects the method of testing. Herein, we review the current recommendations for FLT3 testing in AML, discuss the different available methods for FLT3 mutation testing, and highlight considerations for AML clinicians when faced with AML patients at diagnosis or at a relapsing stage.

(BELG J HEMATOL 2022;13(2):59–64)