伴有22三体的t(5;17)变异易位急性早幼粒细胞白血病

目的 探讨一例核型为47,XY,t(5;17),+22的少见急性早幼粒细胞白血病(acute promyelo-cytic leukemia,APL)的临床和实验特征.方法 在常规核型分析的基础上,应用荧光原位杂交(fluorescencein situ hybridization,FISH)和多重荧光原位杂交(multiplex fluorescence in situ hybridization,M-FISH)技术进一步检测该病例的细胞遗传学异常,并结合文献分析此类少见变异易位的临床特点.结果 FISH检测PML-RARa阴性,但77%的细胞显示存在17号RARa基因的重排或复制;BCR-ABL阴性,但74%的细胞显示有22号染色体的复制或重排.M-FISH明确RARa基因重排系5号与17号染色体易位所致,并证实了22号三体的存在.结论 变异型t(5;17)易位,形成NPM-RARa融合基因的急性早幼粒细胞白血病是APL中少见的类型.骨髓形态表现为奥氏小体缺如,核型中常伴有其它附加染色体异常,全反式维甲酸(all-trans retinoicacid,ATRA)联合化疗有效,但易复发,合并弥漫性血管内凝血及高白细胞者预后凶险.

A case of acute promyelocytic leukemia with variant t(5;17)and trisomy 22

OBJECTIVE: To report a case of acute promyelocytic leukemia (APL) with variant t(5;17)(q35;q21) and to explore its laboratory and clinical features. METHODS: Conventional cytogenetics (CC) was used for karyotyping. Fluorescence in situ hybridization (FISH) and multiplex fluorescence in situ hybridization (M-FISH) were also performed to identify the chromosomal aberrations. RESULTS: The karyotype of the patient was 47, XY, t(5;17), +22. FISH analysis showed PML-RAR aleph negative but 77% cells had a rearrangement or duplication of the RAR aleph gene. BCR-ABL was negative but 74% cells had abnormality of chromosome 22. M-FISH confirmed the abnormalities are of chromosomes 5 and 17 rearrangement and trisomy 22. CONCLUSION: Variant t(5;17) giving rise to the fusion gene of NPM-RAR aleph rarely occurs in APL patients. No Auer rods were identified by morphological study. It usually contains some extra chromosomal aberrations. It is sensitive to all-trans retinoic acid but has a high risk of relapse. If it goes with diffuse intravascular coagulation or high count of WBC, it usually indicates a poor prognosis.