Detection the Frequency and Characteristics of FLT3 Internal Tandem Duplication Mutations by Capillary Electrophoresis Assay and Next-Generation Sequencing in.
BACKGROUND
FLT3-internal tandem duplication mutations (ITDs) are found in approximately 30% of patients with acute myeloid leukemia (AML) and are markers of poor prognosis. However, the characteristics of FLT3/ ITDs in Chinese AML patients have rarely been reported. The aim of this study was to analyze the frequency and characteristics of FLT3/ITDs in Chinese AML patients.


METHODS
In the selected 152 cases of Chinese AML patients, capillary electrophoresis (CE) was used to analyze the frequency and characteristics of FLT3/ITDs. Next-generation sequencing was used to analyze the sequences of FLT3/ITDs positive patients. The differences of clinical features between FLT3/ITD positive group and FLT3/ITD negative group were estimated by statistical analysis.


RESULTS
42 cases (27.6%) were FLT3/ITDs-positive, in which 34 cases (81%) had a single duplication, and the remaining 8 cases (19%) had 2 or more ITDs. Median ITD size was 42 bp and median ITD allelic ratio was 0.25. Using next-generation sequencing, ITDs integrating in non-juxtamembrane (JM) domains were detected in 12 ITDs (24%) and in JM domains were detected in 38 ITDs (76%). Furthermore, duplication of at least one residue between Y591 and Y599 was detected in 48 (96%) of all 50 ITDs, and the insertion site was strongly correlated with ITD size: more C-terminal located inserted fragments were significantly longer.


CONCLUSIONS
Our data provide further evidence of the heterogeneity of FLT3/ITDs among different subgroups in Chinese AML patients. ITDs varied widely, but hotspots were concentrated. These results also suggest that nextgeneration sequencing is a useful method for detection of FLT3/ITDs sequences.
Liang
L
Ma
Yongyue
Y
Cao
Yongwei
Y
Jiang
Xiao
X
Cong
Shuang
S
Lu
Jun
J
Shen
Qian
Q
Liu
Chengwu
C
Han
Yuliang
Y
Zhan
Yongtong
Y
Cao
D000328:Adult; D000368:Aged; D019075:Electrophoresis, Capillary / Q000379:methods*; D005260:Female; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods*; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D020080:Tandem Repeat Sequences / Q000235:genetics*; D051941:fms-Like Tyrosine Kinase 3 / Q000235:genetics*
C497970:FLT3 protein, human; D051941:fms-Like Tyrosine Kinase 3