Molecular analysis of different FLT3-ITD mutations in acute myeloid leukemia.
Mutation of the FMS-like tyrosine kinase-3 (FLT3) gene occurs with a frequency of 20-25% in acute myeloid leukemia (AML). Different studies have reported conflicting results, stating the importance of the length, position and number of internal tandem duplications (ITDs) for prognostic significance. In the present study, FLT3-ITD mutations were found in 51 (23%) of 218 patients with AML. Using sequence analysis we categorized ITD integration sites according to functional regions of the FLT3 receptor. Median ITD size was 61 bp. The insertion site was strongly correlated with ITD size: more C-terminal located inserted fragments were significantly bigger. Our data confirm that FLT3-ITD mutations identify a subset of young patients with AML with normal cytogenetics but with inferior outcome. Patients with AML with mutation localization outside the juxtamembrane domain showed no correlation with worse prognosis. A high mutant/wild-type ratio appears to have a major impact on the prognostic relevance.
Department of Hematology and Oncology, Charité University School of Medicine, Berlin, Germany. olga.blau@charite.de
Olga
O
Blau
Rimma
R
Berenstein
Annette
A
Sindram
Igor Wolfgang
IW
Blau
D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D020440:Gene Duplication; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000235:genetics* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011379:Prognosis; D012189:Retrospective Studies; D020080:Tandem Repeat Sequences; D055815:Young Adult; D051941:fms-Like Tyrosine Kinase 3 / Q000235:genetics*
D051941:fms-Like Tyrosine Kinase 3