一例急性早幼粒细胞白血病同时伴有ins(15;17),t(2;17;20)和三体8异常

目的 对1例伴有ins(15;17),t(2;17;20),+8复杂异常的急性早幼粒细胞白血病(acute promyelocytie leukemia,APE)病例进行细胞和分子遗传学研究.方法 按常规制备染色体,以R显带技术进行核型分析,并先后作多色荧光原位杂交(multiplex fluoresence in situ hybridization,M-FISH)、染色体涂染和PML-RARa双色FISH检测.结果 R显带核型分析为47,XY,2q-,+8,17q+,20p+;M-FISH检测为:47,XY,t(2;17;20)(q24;q21;p13),+8;染色体涂染证实了2qZ4以下片段易位到17q21上和17q21以下片段易位到20p13上;双色FISH示17号染色体上RARa(retinoic acid receptora,RARe)基因部分片段插入到15号染色体形成PNL-RARa融合基因,即ins(15;17)(q22;q21.1q21.3).结论 FISH技术是明确隐匿/插入易位的可靠手段,凡形态学拟诊为APL而常规核型分析未发现t(15;17)者均应进行FISH检测.

Simultaneous presence of ins (15;17),t(2;17;20) and trisomy 8 ha a patient with acute promyelocytic leukemia*

Objective To report a rare complex karyotypic abnormalities including ins (15;17),t (2;17;20)and trisomy 8 in a patient with acute promyelocytic leukemia (APE).Methods Chromosomes were prepared after 24 h culture of bone marrow cells.R-banding technique was used to analyze the karyotype.Multiplex fluorescence in situ hybridization (M-FISH),chromosome painting using whole chromosome paint (WCP) 2,15,17 and 20 and interphaseFISH (I-FISH) using PML-RARa dual-colour dual-fusion translocation probe were performed to ascertain the essence and origin of the abnormal chromosomes detected by conventional karyotypic analysis.Results Karyotypic analysis revealed a karyotype of 47,XY,2q-,+ 8,17q +,20p+.M-FISH analysis showed a karyotype of 47,XY,t(2;17;20) (q24;q21;p13),+ 8,which was confirmed by chromosome painting.PML-RARa fusion gene which lied in the derivative chromosome 15 was detected by I-FISH suggesting a cryptic insertion (15;17)(q22;q21.1q21.3).Conclusion FISH is a reliable method for characterization of cryptic ins (15;17) and other complex translocations.It should be used in all suspected APL patients lacking t(15;17) by conventional karyotypic analysis.