逆转录-多重巢式聚合酶链反应技术在急性单核系白血病M4/M5 MLL基因重排检测中的应用

目的 探讨逆转录-多重巢式聚合酶链反应（多重PCR）技术在初诊M4／M5患者MLL基因重排检测中的价值。方法 采用骨髓直接或短期培养法制备染色体，应用R显带技术进行核型分析。采用多重PCR技术，检测40例初诊M4／M5患者中5种急性髓系白血病常见的MLL融合基因以及MLL部分串联重复。结果 R显带揭示7有涉及11q23的易位，包括t（6；11）（q27；q23）、t（9；11）（p21；q23）、t（11；17）（q23；q21）、t（11；19）（q23；p13．1），14例有其他核型异常，19例为正常核型。多重PCR证实了7例核型分析显示11q23易位标本中的6例，例3核型分析揭示46，XX，t（6；11）（q27；q23），多重PCR检测MLL/AF6为阴性；19例显带分析为正常核型标本中检出2例MLL部分串联重复。结论 多重PCR是对初诊M4／M5患者进行各种MLL重排筛检的有效方法。     

伴有11q23/MLL重排的儿童急性髓系白血病的临床及实验室分析

目的 分析伴有11q23/混合谱系白血病(mixed lineage leukemia,MLL)基因重排的儿童急性體系白血病(acute myeloid leukemia,AML)的临床和实验室特点.方法 采用骨髓细胞短期培养法和R显带技术对234例初诊AML患儿进行核型分析;采用逆转录-多重巢式聚合酶链反应(多重PCR)技术检测MLL融合基因以及MLL部分串联重复;采用双色MLL基因探针,对其中2例核型分析具有11q23易位而多重PCR检测MLL融合基因呈阴性的患儿样本进行间期双色荧光原位杂交(dual-color fluorescencein situ hybridization,D-FISH)MLL重排检测.结果 R显带提示234例初诊AML患儿中,20例(M5 14例、M4 4例、M2 2例)有涉及11q23的易位,包括t(9;11)(p22;q23)12例,t(1;11)(q21;q23)3例,t(6;11)(q27;q23)2例,t(11;19)(q23;p13)、t(5;11)(q31;q23)和t(X;11)(q24;q23)各1例.多重PCR证实其中18例有MLL的融合转录本,有2例阴性,但D-FISH均检出MLL重排;在其余AML患儿的样本中检出8例(M5 4例、M4 2例、M2和M6各1例)有MLL部分串联重复.本组AML患儿中,11q23/MLL重排的总检出率11.97%(28/234),其中85.7%(24/28)的病例为M4/M5亚型.本组28例伴有11q23/MLL重排患儿,治疗后完全缓解率为53.8%,与对照组(以同期伴有其他异常核型和正常核型的AML-M4/M5患儿共27例作为对照)的90.5%相比,差异有统计学意义(P<0.05).其中2例患儿接受了强烈化疗,分别生存达81和66个月.4例接受了异基因干细胞移植,已分别生存21、20、16和11个月,至今仍在完全缓解中.本组28例伴有11q23/MLL重排患儿的中位生存期为11个月,对照组为15个月,差异无统计学意义(P>0.05).结论 伴有11q23/MLL重排的AML患儿和单核系白血病高度相关.11q23易位和MLL部分串联重复是相互排斥的,二者预后均较差.采用强烈化疗和异基因干细胞移植有望获得较好疗效.多重PCR联合染色体核型分析和D-FISH技术是对初诊AML患者进行各种MLL重排筛检的有效方法.     

伴11号染色体异常的急性髓系白血病的临床和细胞遗传学研究

目的 研究11号染色体异常在急性髓系白血病中的发生率及与临床和预后的关系.方法 采用R带常规显带技术进行染色体检查,对356例急性髓系白血病患者的核型进行分析.结果 356例急性髓系白血病患者中检出11号染色体异常患者34例,占9.55%;其中20例(58.8%)涉及11q23,7例11p15易位(20.6%),5例-11(14.7%),其他少见的核型改变有:+11,t(11;14).11q23中,M4、M5占70%;且有10例同时合并有其他染色体异常.30例进行正规化疗的患者,13例缓解,缓解率低于同期急性髓系白血病的总缓解率(43.3% vs64.0%);伴11q23的急性髓系白血病的缓解率低于染色体正常的急性髓系白血病患者(45% vs67%);11q23伴其他染色体异常的缓解率低于伴单纯11q23者(30% vs60%).7例涉及11p15易位患者3例缓解,2例早期复发.5例-11患者缓解2例.结论 11q23是11号染色体异常中最为常见的核型改变,且多见于急性髓系白血病的M5型,并可能与急性单核细胞白血病的发病有关;伴11号染色体异常的急性髓系白血病患者预后较差.     

联合间期和中期荧光原位杂交检测发现11q23异常伴D13S319缺失急性髓系白血病一例

目的对1例出现11q23异常伴D13S319缺失的罕见急性髓系白血病(acute myeloid leukemia,AML)患者进行多途径细胞遗传学分析,为诊断、治疗及预后分层提供依据。方法应用G+R显带技术对患者24 h培养后的中期分裂相进行染色体核型分析,联合分裂间期和中期荧光原位杂交(fluorescence in situ hybridization,FISH)技术对患者染色体的特定位点进行检测,明确复杂易位和微小缺失片段。结果患者存在混合系白血病基因(mixed lineage leukemia,MLL)重排,形成了MLL-AF10融合基因,并伴有13号染色体D13S319位点的缺失。结论MLL基因重排合并D13S319位点缺失在急性白血病中是否具有双重打击效应应引起临床的重视。在AML患者核型中发现13q-、del(13)(q14)、-13或der(13)任意一种克隆性异常时,应行FISH检测论证及明确缺失片段的大小,以便进行靶向治疗。     

25例急性单核细胞白血病的临床与细胞遗传学分析

目的研究急性单核细胞白血病(acute monocytic leukemia,AML,M5)的细胞遗传学、血液学与预后的相互关系。方法采用骨髓直接法、24h短期培养法及72h培养法制备染色体标本,用R显带技术,对25例M5进行核型分析。结果25例M5中,发现有异常核型17例,发生率68.0%(17/25)。其中9例有11号染色体相关异常,5例有数目异常,3例有其它异常;其中6例涉及两种以上染色体异常。结论11q23是M5中最为常见的染色体核型异常,伴此种核型异常的染色体预后不良,同时发现正常核型缺乏对预后也有不良影响。     

伴22三体急性髓系白血病的inv(16)FISH研究

目的 探讨伴有22三体(+22)的急性髓系白血病(acute myeloid leukemia,AML)中inv(16)的发生率,以及inv(16)荧光原位杂交(interphase fluorescence in situ hybridization,FISH)检测对于+22AML的临床意义.方法 采用红、绿荧光素直接标记的双色断裂点分离的CBFβ基因探针对19例核型分析中伴有+22克隆件异常的AML患者进行间期FISH检测,并与常规细胞遗传学分析结果进行比较.结果 19例+22AML,中FISH检测发现13例(68.4%)为CBFβ重排阳性,包括M4EO 7例,M5 3例,M2a 2例,M1 1例;6例患者CBFβ重排为阴性,包括t(8;21)M2 1例,t(6;11)M5 1例,复杂核型异常2例,不伴有其他异常而以+22作为唯一异常的M2 2例.14例的随访资料显示CBFβ重排阳性的11例中10例尚存活,仅1例死亡,而CBFβ重排阴性的3例均已死亡.结论 +22为inv(16)AML最常见的继发性改变,因此有预测inv(16)AML的价值,+22AML的预后与inv(16)而不是与+22本身相关;FISH检测不仅对于确诊inv(16)有重要价值,而且有助于明确+22AML的预后.     

1058例急性非淋巴细胞白血病的细胞遗传学分析

目的：评估我国大系列急性非淋巴细胞白血病（acute nonlymphocytic leukemia,ANLL)的核型状况。方法：采用直接法和短期培养法制备骨髓细胞染色体,并以R显带为主、G显带为辅对1058例初治的ANLL患者进行染色体核型分析。结果：本组中630例（60％）有克隆性染色体异常。主要异常核型共有25种,其中11种为特异性染色体重排,见于481例,占核型异常患者总数的76％。单纯＋8（21例）为常见的数目异常。t(15;17)(211例）和t（8;21）（200例）为最常见的结构异常。1．1％的M2、72％的M3、71％的M4EO、50％的M2、6％的M5和1．4％的M2分别有t（7;11）、t(15;17)、inv(16)、t(8;21)、t/del(11q23)和t/del(12p)异常,而100％的t(7;11)、100%的t（15;17）、100％的inv(16)、88．5％的t(8;21）、83％的t/del(11q23)和62％的t/del（12p)分别见于M2、M3、M4E0、M2、M5和M2亚型患者。结论：联合应用R带和G带两种常规显带技术,60％的ANLL患者可检出克隆性染色体异常且主要为特异性染色体重排。它们和特定的FAB亚型相关,因而核型是ANLL诊断和分型的一项重要指标。     

多探针荧光原位杂交检测急性髓系白血病常见细胞遗传学异常

目的:评价多探针荧光原位杂交(FISH)在检测急性髓系白血病(AML)常见细胞遗传学异常中的价值,探讨细胞遗传学异常与临床诊断、治疗、预后的关系。方法:采用针对AML/MDS的FISH多探针诊断系统,即以针对AML1/ETO融合基因、PML-RARα融合基因、CBFβ/MYH11融合基因、MLL基因、P53基因、Del(5q)、Del(7q)、Del(20q)8种DNA探针对40例患者进行多探针FISH检测,同时联合染色体核型、临床资料进行研究。结果:40例AML中,共22例多探针FISH检出了细胞遗传学改变,包括:AML1/ETO、PML-RARα、MLL基因断裂重排、Del(5q)、Del(7q)、P53基因缺失、8号染色体三体7种细胞遗传学异常。而常规染色体核型分析仅检出11例遗传学异常。多探针FISH与染色体核型分析的总阳性率分别为57.50%及27.50%。AML1/ETO、PML/RARα阳性者首次诱导化疗效果较理想;而Del(7q)、MLL基因断裂重排阳性、伴复杂细胞遗传学改变者可能预示不良预后。结论:FISH多探针诊断系统检测AML患者常见遗传学异常更省时、准确、高效,有利于完善白血病的分层诊断及指导临床个体化治疗。     

八探针荧光原位杂交联合R显带技术诊断儿童急性髓系白血病CSCD

目的探讨将八探针荧光原位杂交（fluorescence in situ hybridization, FISH）联合R显带染色体核型分析应用于儿童急性髓系细胞白血病（acute mydoid leukemia,AML）诊断的价值。方法应用八探针FISH（AML1／ETO、PML—RARa、CBFβ／MYH11、mL、P53、5q-、7／7q-、20q-等8种DNA探针）和R显带染色体核型分析技术,对214例AML患儿进行了联合检测。结果八探针FISH技术在118例患儿中检出了细胞遗传学改变,总体阳性率为55．1％,包括AML1／ETO、PML／RARa、CBFβ／MYH11、MLL、P53、5q-、7／7q-、20q-等8种细胞遗传学异常。R显带核型分析检出染色体异常55例,阳性率为25．7％,其中4例染色体异常FISH未检出。两种方法检出阳性率的差异有统计学意义（P〈0．05）。结论八探针FISH技术较R显带染色体核型分析具有准确、高效、省时、省力等优点,可与染色体核型分析有效互补,并且每种细胞遗传学异常都可为儿童AML的诊断、预后评估和个体化治疗提供重要依据。     

髓系白血病患者的临床和细胞遗传学研究

目的研究髓系白血病(myeloid leukemia,ML)患者细胞遗传学特点和相关临床表现及预后。方法采用骨髓细胞直接法和(或)不加植物血凝素的24h体外细胞培养法制备骨髓染色体。应用热变性姬姆萨显带技术为主、胰酶消化技术必要时补充,进行染色体核型分析。结果在578例髓系白血病中:急性髓系白血病(acute myeloid leuckemia,AML)420例,223例检出有克隆性染色体异常,占53.1%(223/420)。t(8;21)、t(15;17)、inv(16)、del(11)分别与M2b、M3、M4Eo、M5特异性相关。慢性髓系白血病(chronic myeloid leukemia,CML)158例,153例检出有克隆性染色体异常,占96.8%(153/158例)。t(9;22)与绝大多数CML及少部分M0、M1、M2特异性有关。本组髓系白血病中有18例(AML13例、CML5例)患者,占3.1%(18/578),其细胞遗传学检查未见克隆性染色体异常,与患者的临床表现、骨髓象形态学及免疫学的诊断不尽相同。为此我们应用了荧光原位杂交(fluorescence in situ hybridization,FISH)技术,其中15例结果完全符合临床和髓系白血病的血液学改变,同时也明显提高了临床的诊断率。结论染色体核型分析不但有助于髓系白血病的诊断和鉴别诊断,而且还是临床监测病情缓解和复发、判断疗效的重要指标。在染色体核型分析基础上选用合适的FISH技术,可对大多数髓系白血病患者作出精确的染色体分析。     

MLL rearrangement with t(6;11)(q15;q23) as a sole abnormality in a patient with de novo acute myeloid leukemia: conventional cytogenetics, FISH, and multicolor FISH analyses for detection of rare MLL-related chromosome abnormalities

We report a rare case of acute myeloid leukemia (AML) with t(6;11)(q15;q23) in a 50-year-old female showing a poor prognosis. Bone marrow biopsy revealed markedly hypercellular marrow with infiltrates of myeloblasts, consistent with AML-M2 morphology. The karyotype of this patient was 46,XX,t(6;11)(q15;q23) in all analyzed cells, and the results of fluorescence in situ hybridization (FISH) and multi-color FISH analysis confirmed this unique MLL rearrangement as a sole abnormality. To our knowledge, t(6;11)(q13 approximately q15;q23) is the most rare type of MLL rearrangement involving the long arm of chromosome 6. Only two cases with t(6;11)(q13;q23) and three cases with t(6;11)(q15;q23) have been reported, but detailed clinical or laboratory data were not available. From this report, it is apparent that in a cytogenetic laboratory, the accurate detection of a rare type of MLL rearrangement is very important in the differential diagnosis, prompt treatment, and prediction of prognosis of leukemias.     

Chromosomal aberration of the 11q23 locus in acute leukemia and frequency of MLL gene translocation: results in 378 adult patients

Structural abnormality of the 11q23 band (11q23+) bearing the MLL gene translocation (MLL+) is a recurrent chromosome change observed in 3% to 7% of acute lymphoblastic leukemias and in 3% to 4% of acute myeloblastic leukemias. The resolution of conventional cytogenetics (CC) in detecting 11q23 rearrangement is limited when the translocative partner has a telomeric location; furthermore, CC can barely discriminate between true 11q23+/MLL+ and rearrangements clustering within the 11q22 to approximately 25 region without MLL involvement (MLL-). We characterized a series of 378 consecutive patients with adult acute leukemia by using CC, fluorescence in situ hybridization (FISH), and multiplex karyotyping (M-FISH) analysis. Our aim was to define the frequency of cryptic MLL+ cases and the frequency of MLL+ within 11q22 to approximately 25+ cases. As expected, FISH was more sensitive than CC in detecting MLL+ cases, but rather unexpectedly, 9 (45%) of 20 patients with 11q22 to approximately 25+ were MLL-. A better characterization of 11q22 to approximately 25+/MLL- leukemias is relevant for the identification of new, recurrent translocations. Moreover, these cases should be readily distinguishable from 11q23+/MLL+ cases. We recommend that karyotypic analysis always be complemented by molecular or FISH methods to unravel MLL rearrangements.     

Molecular and fluorescence in situ hybridization analysis of a 10;11 rearrangement in a case of infant acute monocytic leukemia

Fluorescence in situ hybridization (FISH) analysis in a case of infant acute monocytic leukemia M5 revealed a complex rearrangement between chromosomes 10 and 11, leading to the disruption of the MLL gene. Using two painting probes for chromosomes 10 and 11 and a specific probe for the MLL gene localized on 11q23, we observed a paracentric inversion of the 11q13-q23 fragment translocated to 10p12. Molecular analysis showed that AF10 localized on 10p12 was the fusion partner gene of MLL in this rearrangement (10;11). This report underlined the usefulness of FISH and molecular techniques in identifying complex rearrangements.     

Cryptic ins(4;11)(q21;q23q23) detected by fluorescence in situ hybridization: a variant of t(4;11)(q21;q23) in an infant with a precursor B-cell acute lymphoblastic leukemia report of a second case

We report the chromosomal findings in a 4-year-old female with precursor B-cell acute lymphoblastic leukemia (ALL). The diagnostic karyotype showed an isochromosome 7q, i(7)(q10), as well as questionable rearrangements on 9p and 11q. Fluorescence in situ hybridization (FISH) studies on both interphase and metaphase cells using the MLL "break-apart" and the centromeric chromosome 4 probes were instrumental in the characterization of an MLL gene rearrangement, which was cryptic by conventional cytogenetic analysis. Specifically, the FISH pattern was consistent with an insertion of the 5' region of the MLL gene into chromosome 4 at band q21, most likely a variant t(4;11)(q21;q23). This is the second case of FISH detection of an ins(4;11) in ALL. Our case exemplifies the importance of FISH in the further characterization of precursor B-cell ALL cases without any apparent prognostically significant chromosomal abnormalities.     

FISH联合multiplex RT-PCR检测MLL基因重排的价值探讨

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(multiplexRT-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multiplexRT-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multiplexRT-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,multiplexRT-PCR检出了7例dupMLL(11q23)重排。结论:FISH联合multiplexRT-PCR能提高MLL基因重排检出率。     

Jumping translocation at 11q23 with MLL gene rearrangement and interstitial telomeric sequences

myeloid leukemia of acute myeloid leukemia (AML) M5a showing a jumping translocation with a breakpoint at 11q23. Fluorescence in situ hybridization (FISH) demonstrated triplication of the MLL gene and the presence of interstitial telomeric sequences, supporting the role of repetitive sequences in the mechanism of jumping translocations. Southern blot analysis of the MLL breakpoint cluster region showed the presence of an MLL gene rearrangement. Jumping translocation with MLL gene rearrangement is a previously unreported phenomenon in leukemia cytogenetics.     

X chromosome insertion in the MLL gene in a case of childhood acute myeloblastic leukemia

Band 11q23 is known to be involved in translocations and insertions with a variety of partner chromosomes. These lead to MLL rearrangement, resulting in a fusion with numerous genes. We report here the case of a 5-month-old boy presenting with hemianopsia and severe diffuse intravascular coagulopathy in whom a diagnosis of acute myeloblastic leukemia (AML) French-American-British M4 classification was made. Conventional cytogenetic techniques showed an ins(11;X) (q23;q28q12). Fluorescent in situ hybridization (FISH) with whole chromosome paints confirmed this finding. Using a specific probe, the MLL gene was found to be disrupted, a portion of the X chromosome being inserted between the 5' and 3' regions of the MLL gene. Although some cases of insertion involving chromosomes X and 11 have been reported in AML, this appears to be the first case involving band Xq28. We postulate that this chromosomal rearrangement led to the fusion of the 5' region of the MLL gene with a yet unidentified gene located in band Xq28.     

MLL translocations with concurrent 3' deletions: interpretation of FISH results

Rearrangements involving the MLL gene at 11q23 occur in a clinically relevant subgroup of patients with acute lymphoblastic leukemia (ALL) at all ages, and therefore their accurate identification at diagnosis is important. It has become commonplace to screen ALL patients for rearrangements of MLL using a dual-color fluorescence in situ hybridization (FISH) assay. We report on 12 ALL patients with an unusual FISH result consisting of the following signal pattern: one 5' green, no 3' red, and one/two fusion signals. This configuration is consistent with a MLL translocation and simultaneous deletion of 3' MLL-a well-established phenomenon-which has been interpreted as a positive result. G-banded and complementary metaphase FISH analyses confirmed an 11q23/MLL translocation in 8 of the 12 cases, whereas in one case, the identification of a del(11)(q23) was restricted to G-banded analysis only. In three cases, an MLL rearrangement was excluded by extensive FISH analysis and/or Southern blotting. In conclusion, the loss of the 3' MLL signal should not be assumed to be the result of a concurrent translocation and deletion event, and such aberrant FISH signal patterns should be investigated further by alternative methods for determining their MLL status.