细胞遗传学检测方法对MLL基因异常儿童急性白血病的诊断意义

Diagnostic value of cytogenetics in acute leukemia with MLL gene abnormality

目的探讨常规细胞遗传学(CC)方法和荧光原位杂交(FISH)技术诊断混合谱系白血病(MLL)基因异常、染色体11q23异常儿童急性白血病(AL)的价值。方法选取2016年6月—2021年6月上海市儿童医院收治的初发AL患儿404例,分别采用CC法和FISH技术进行细胞遗传学分析,比较2种方法MLL基因异常检出率差异。结果404例患儿中,采用FISH技术检测出57例(14.1%)MLL基因异常,包括急性淋巴细胞白血病(ALL)患儿40例,其中MLL基因探针信号数目异常23例、MLL基因重排17例;急性髓系白血病(AML)患儿17例,其中MLL基因探针信号数目异常2例,MLL基因重排15例。CC法检出MLL基因异常27例(6.7%),包括ALL患儿15例,其中明确MLL基因重排伙伴基因13例;AML患儿12例,其中明确MLL基因重排伙伴基因11例。2种方法MLL基因异常检出率差异有统计学意义(P<0.001)。结论FISH技术MLL基因异常检出率高于CC法,CC法染色体核型分析可直观呈现MLL基因重排异常类型并明确其伙伴基因;2种方法可优势互补,对MLL基因异常AL的诊断均有较大意义。

Objective To investigate the roles of conventional cytogenetics(CC)and fluorescence in situ hybridization(FISH)in the diagnosis of mixed linage leukemia(MLL)gene abnormality and chromosome 11q23 abnormality in childhood acute leukemia(AL).Methods Totally,404 AL children were enrolled from the Children’s Hospital of Shanghai from June 2016 to June 2021.The cytogenetic analysis was performed by CC and FISH.The determination rates for MLL gene abnormality were compared between the 2 methods.Results There were 404 AL children.The 57 cases of abnormal MLL gene(14.1%)were determined by FISH,which included 40 cases of acute lymphoblastic leukemia(ALL),and there were 23 cases of abnormal MLL gene signal number and 17 cases of MLL rearrangement.There were 17 cases of acute myeloid leukemia(AML),and 2 cases had abnormal MLL gene signal number and 15 cases of MLL rearrangement.Chromosomal abnormalities of MLL gene were determined in 27 cases(6.7%),there were 15 cases of ALL,and MLL rearrangement partner gene was identified in 13 cases.There were 12 cases of AML,and MLL rearrangement partner gene was identified in 11 cases.Conclusions The abnormal rate of MLL gene determined by FISH is higher than that by CC.CC can intuitively present the abnormal types of MLL rearrangement and identify its partner genes.The 2 determination methods play roles in the diagnosis of MLL gene abnormality in AL.