Detection of FLT3 Mutations in Patients from Eastern Slovakia.

BACKGROUND

The study investigated FLT3 gene mutations in patients from eastern Slovakia using a simple molecular method.

PATIENTS AND METHODS

We analyzed 141 patients with primary acute myeloid leukemia (AML) and 8 patients with AML that developed from myelodysplastic syndrome (MDS) who were aged 19-81 years. DNA isolated from peripheral blood and/or bone marrow was analyzed by PCR. FLT3 internal tandem duplication (FLT3-ITD) was detected by amplification of exons 14 and 15. Point mutations in the FLT3 tyrosine kinase domain (FLT3-TKD) were detected by digesting the PCR product of exon 20 with the restriction endonuclease EcoRV. Fragments were separated electrophoretically. PCR products of the positive samples were also analyzed using a microchip device (Bioanalyzer 2100).

RESULTS

LT3-ITD and point mutations in the FLT-TKD were detected in 19 and 8% of patients, resp. Two patients (1%) harbored both types of mutations. Patients with and without FLT3 mutations were called FLT+ and FLT-, resp. Most FLT3+ patients had no chromosomal aberrations (59%) or harbored the t (15; 17) translocation in PML-RARA (15%). The mortality rate was 33% among FLT3+ patients and 10% among FLT3-patients. Among FLT3+ patients, the mortality rates of patients with FLT3-ITD and point mutations of the FLT-TKD were almost the same. A 77-year-old female patient with both FLT3-ITD and a point mutation in the FLT3-TKD was in remission. The eight patients who developed AML from MDS were assessed separately. Of these, three patients were FLT3+; two patients displayed FLT3-ITD, and one patient harbored a point mutation in the FLT3-TKD. No other genetic aberrations were detected. FLT3+ patients lived for longer than FLT3-patients. These analyses of FLT3 gene mutations in patients from eastern Slovakia are consistent with published data from other databases.

CONCLUSION

The applied PCR method is reliable, relatively fast, and affordable, and can be used for routine monitoring of FLT3 gene mutations. FLT3 mutations can be verified using a microchip as an alternative to capillary electrophoresis. Key words: acute myelogenous leukemia - DNA - PCR - mutation - FLT3-ITD - FLT3-TKD The study was supported by the European Regional Development grant OPVaV-2009/2.2/05- -SORO (ITMS code: 26220220143). The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical paper Submitted: 19. 10. 2017 Accepted: 15. 2. 2018.