Detection Of FLT3 Gene Mutation In Malignant Hematopoietic Patients And Its Clinical Significance

Objectives To study the FLT3 gene expression and its internal tandem duplication in malignant hematopoietic diseases and its clinical significance.Methods PCR and DNA sequencing were used to detect the FLT3/ITD mutation in blast cell of bone marrow from 86 patients with malignant hematopoietic diseases, including 32 acute myeoloid leukemia( AML) cases, 18 acute lympoid leukemia(ALL) cases, 2 acute hybrid leukemia (AHL) cases , 12 myelodys plastic syndromes (MDS) cases , 10 chronic myelogenous leukemia (CML) cases, 3 non-Hodgkin's lymphoma (NHL) cases and 9 multiple myeloma (MM) cases.Results The expression of FLT3/ITD gene were detected in 5 of 32 (15.6%) AML patients, including 1/7 of M3, 1/10 of M4 and 3/10 of M5. More FLT3 aberrations were found in AML M5. No FLT3/ITD was found in 18 ALL, 2 AHL, 12 MDS and 10 CML cases. No FLT3 was found in 3 NHL and 9 MM ases. Sequence analysis of 2 case with abnormal PCR electrophoretic patterns revealed that the ITDs was located within exon 14 from 27 to 63 bp, the ITD was a simple tandem duplication, and it did not altered the reading frame. FLT3/ITD was associated with a higher peripheral white cell count (P<0.01) and a higher percentage of bone marrow blast cells(P<0.01) and a lower complete mission rate tendency.Conclusion More FLT3/ITD mutation occurs in AML M5 patients. Sequence of the mutants was in frame mutation. FLT3/ITD mutation was associated with a higher peripheral white cell count and a higher percentage of bone marrow blast cells and a lower complete remission rate tendency.