儿童急性髓细胞性白血病细胞遗传学和分子遗传学的初步研究

Classical and molecular cytogenetic abnormalities of childhood acute myeloid leukemia

目的了解儿童急性髓细胞性白血病(AML)染色体及相关融合基因的变化。方法155例AML患儿采用直接法及24h培养法制备染色体,套式逆转录聚合酶链反应(RT-PCR)检测t(8;21)易位的AML1-ETO融合基因,t(15;17)易位的PML-RARα融合基因。LSI-FISH检测MLL融合基因。结果155例AML中,异常核型101例(65·2%),各亚型的异常率为:M577·3%,M365·9%,M263·9%,M462·5%,M660·0%,M142·9%。最常见的数目异常为假二倍体59例(58·4%),最常见的结构异常为t(8;21)31例(32·7%),t(15;17)27例(26·7%),11号染色体异常10例(9·9%),并与M2、M3、M5相关。RT-PCR检测M2、M3相关的融合基因AML1-ETO及PML-RARα均发现了隐匿易位及变异异位,FISH检测11例AML患儿中的MLL基因3例阳性。结论儿童AML进行染色体分析及融合基因的检测,有助于AML诊断及亚型之间的鉴别诊断。

Objective To investigate the chromosomal abnormalities and fusion genes of childhood acute myeloid leukemia（AML）. Methods AML1-ETO fusion gene derived form t （8; 21） and PML-RARα fusion gene derived form t（ 15; 17） were detected with reverse transcription multiplex nested polymerase chain reaction technique（RT-multiplex nested PCR）, and MLL fusion gene with LSI-FISH technique. Results Of 155 cases, 101 patients（65.2%） had cytogenefie abnormalities. The incidences of cytogenetic abnormalities in FAB subtypes were M5 77. 3 %, M3 65.9 %, M263. 9 %, M462.5%,M660%, and M142.9%. The most frequent abnormality of chromosome number was pesudodipiloid（59 cases, 58. 4%）, the most frequent abnormality of chromosome structure was t（8; 21）（31 cases, 32.7%） and t（15; 17） was the second frequent aberration（27 eases, 26.7%）. The abnormality of chromosome 11 was found in 10 eases（9.9%）, which was associated with FAB subtypes M2, M3 and M5. Dormant and variance translocations were found when applying RT-PCR tech- nique to detect AML1-ETO fusion gene and PML-RARα fusion gene, MLL fusion gene was detected with LSI-FISH probe in 3 of 11 AML patients. Conclusion Chromosome analysis and detection of fusion genes are helpful in the diagnosis of AML and the differentiation diagnosis of AML subtype.