FISH联合multiplex RT-PCR检测MLL基因重排的价值探讨

Diagnostic value of FISH combined with multiplex RT-PCR for detection of MLL rearrangement

目的:采用荧光原位杂交(FISH)与逆转录多重巢式聚合酶链反应(multiplex RT-PCR)技术检测急性白血病中MLL基因重排的情况,分析两者联合应用的诊断价值。方法:对2008年1月～2011年5月在我院诊断为急性白血病的201例患者采用MLL双色断裂分离重排探针进行FISH检测,同时用multiplex RT-PCR技术检测11种较常见的MLL融合基因,观察MLL基因异常的检出率。所有患者均进行常规染色体核型分析(CCA),观察11q23重排率作为对照。结果:共有19例患者出现11q23/MLL基因重排,在急性髓细胞白血病(AML)中的检出13例(10.2%),急性淋巴细胞白血病(ALL)的检出6例(8.2%)。FISH联合multiplex RT-PCR对MLL基因重排的检出率为9.45%,CCA对11q23异常的检出率为5.47%。5例正常核型的患者和3例未涉及11号染色体异常的患者中FISH检出了1例MLL倒位和3例扩增信号,multiplex RT-PCR检出了7例dup MLL(11q23)重排。结论:FISH联合multiplex RT-PCR能提高MLL基因重排检出率。

To analyze the diagnostic value of fluorescence in situ hybridization （FISH） combined with reverse transcription - multiplex nested PCR （ multiplex RT - PCR） for the detection of mixed - lineage leukemia （MLL） gene rearrangement from bone marrow aspirate in the patients with acute leukemia. METHODS： The bone marrow samples were obtained from 201 newly diagnosed acute leukemic patients in our hospital. MLL gene rearrangement was detected by both FISH and multiplex RT - PCR methods. FISH with the MLL dual color ＂break - apart＂ probe was performed following the procedures recommended by the manufacturer. Eleven common fusion transcripts of MLL were also determined by multi- plex RT - PCR assay. Conventional cytogenetic analysis （CCA） was performed on all specimens to observe the abnormality of 11@3. RESULTS： MLL gene rearrangement was observed in 19 patients, including 13 cases （10.2%） of acute mye- loid leukemia （AML） and 6 cases （8.2%） o＇f acute lymphoid leukemia （ALL）. Among the MLL positive specimens, the rate of MLL rearrangement detected by FISH combined with multiplex RT - PCR was 9.45%, but 5.47% by CCA merely. One case of MLL inversion and 3 cases of MLL amplification were found in 5 patients with normal karyotype and 3 patients with cytogenetic abnormalities uninvolving chromosome 11. Multiplex RT - PCR revealed 7 cases of dup （MLL） which failed to show in FISH and CCA. CONCLUSION ： The combination of FISH and multiplex RT - PCR increases the sensi- tivity for detection of MLL rearrangement.