白血病MLL基因重排及其融合基因检测的临床意义

目的:研究白血病MLL(mixed lineage leukemia)基因重排及其融合基因的检测及其临床意义。方法:采用荧光原位杂交(FISH)检测70例白血病患者MLL基因重排,对于MLL基因重排的患者,用巢式RT-PCR方法检测常见6种MLL融合基因类型。结果:9例白血病有MLL基因重排,发生率为12.86,5例B细胞系急性淋巴细胞白血病(B-ALL),其中融合基因2例为MLL/ENL,1例MLL/AF4,2例未扩出融合基因产物;3例为急性髓细胞白血病M5(AML-M5),其中2例融合基因均为MLL/AF9,1例未扩出融合基因产物;1例为幼年型粒单核细胞白血病(JMML),其融合基因为MLL/ENL。结论:巢式RT-PCR是检测MLL基因重排及其融合基因类型简便有效的方法,MLL基因重排见于B-ALL、AML-M5、JMML,预后差。

Detection and clinical significance of rearrangements of MLL gene and its fusion gene in leukemia

Objective:To study the detection and clinical significance of the rearrangements of MLL gene and its fusion gene in leukemia.Method:Rearrangements of MLL gene of 70 leukemia patients were detected by fluorescence in situ hybridization(FISH) and 6 common MLL fusion genes were detected by nested RT-PCR.Result:9 of 70 leukemic patients were found with rearrangements of MLL gene,the incidence of which was 12.86%.5 of 9 patients were diagnosed as B-ALL.3 patients were diagnosed as AML-M5,1 patient was diagnosed as JMML.Among 5 B-ALL patients,2 patients were confirmed to express MLL/ENL fusion gene,1 patient was confirmed to express MLL/AF4 fusion gene,the other 2 patients did not express the fusion genes.Among 3 AML-M5 patients,2 patients were confirmed to express MLL/MF9 fusion gene,the other 1 patient did not express the fusion gene.The fusion gene of 1 JMML patient with rearrangements of MLL gene was MLL/ENL.Conclusion:Nested RT-PCR is a convenient and effective method to detect the fusion genes resulting from rearrangements of MLL gene.The rearrangements of MLL gene were found in B-ALL,AML-M5 and JMML.It indicates a poor prognosis.