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。     

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.     

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。     

急性单核系白血病M4/M5中MLL基因重排的间期荧光原位杂交研究

目的　探讨间期荧光原位杂交 ( fluorescence in situ hybridization,FISH)技术对混合谱系白血病 ( mixed lineage leukemia,ML L)基因重排检测的价值 ;评估 ML L 重排在急性单核系白血病 M4 / M5中的发生率和预后意义。方法　采用骨髓直接法或短期培养法制备染色体 ,应用 R显带技术进行核型分析。采用地高辛标记的跨越 11q2 3断裂位点的单色 ML L探针和间期 FISH技术对 2 3例急性单核系白血病M4 / M5病例进行 ML L重排检测。结果　 R显带揭示 2 3例中 7例有涉及 11q2 3的易位 ,5例有其他核型异常 ,10例核型正常 ,1例核型分析失败。 FISH研究显示 12例有 ML L重排 ,包括 R显带检出 11q2 3异常的7例。结论 FISH技术检测 ML L重排的敏感性明显高于常规细胞遗传学技术 ;ML L重排与急性单核系白血病 M4 / M5高度相关 ,是预后不良的指标     

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.     

11q23易位的急性淋巴母细胞性和急性粒细胞性白血病呈现MLL基因重排

11q23易位畸变经常发生于既有急性淋巴母细胞性白血病又有急性粒细胞性白血病的患儿体内,这种畸变在患有白血病的儿童是一种最常见的遗传突变,且一旦具有11q23易位则患儿的预后相当差。目前主要问题是弄清一个还是几个基因导致这种白血病,作者首先在具有11q23易位的白血病细胞内鉴定出染色体畸变区域,然后克隆出一个基因,命名为MLL,其分而于11q23的断裂处。 作者又从MLL基因cDNA克隆中筛选出一种0.74大小的BamHI片断,为了研究11q23易位畸变时MLL基因的重排发生率,作者分析了61例白血病,3例来自于上述病例的细胞系和20例具有     

血液系统恶性疾病中MLL基因异常的生物学和临床研究进展

MLL基因定位于染色体11q23，是人类急性白血病染色体易位中常见的一种。MLL基因大约能和30多种不同的伙伴基因融合，形成的融合基因编码产生新的融合蛋白。MLL基因异常多见于淋巴系白血病、髓系白血病以及双表型白血病的患者，同时在婴幼儿患者和拓扑异构酶Ⅱ抑制剂引起的继发急性髓系白血病患者中也常常见到，这些患者预后多数不良。     

30例急性髓细胞性白血病细胞遗传学特征

目的对急性髓细胞性白血病(AML)患者的细胞遗传学特征进行调查和分析,探讨FISH在儿童AML临床诊断中的应用。方法回顾性分析河北省儿童医院2011年4月至2013年10月收治的30例AML患儿的FISH及染色体核型结果。结果 1.染色体核型G、R显带方法:分析30例样本,检出18例正常核型,2种(3例)单纯数量异常,2种(6例)单纯结构异常,1例结构伴数量混合异常,2例无分裂相。2.FISH方法:30例AML,12例正常核型,18例结果阳性,包括AML/ETO阳性8例,CBFβ阳性5例,MLL重排2例(1例合并+8),1例21×2,1例+X,+1,+14,1例8+,+21,-Y。22例两种方法检出一致,其中正常核型14例,t(8;21)即AML/ETO阳性4例,inv(16)即CBFβ1例,MLL重排1例,1例21*2,1例+X,+1,+14。结论 FISH与染色体显带技术两种方法具有一致性,FISH异常检出率高于显带技术,且存在统计学差异。FISH技术能够使遗传学异常的检测更准确,在儿童AML的诊断和分型中具有值得推广的临床价值。     

染色体复杂重排的细胞遗传学检测及遗传咨询

目的 以4例染色体复杂重排新核型的确诊为例,探讨这类染色体异常的检测方法及遗传咨询。方法 应用常规G显带技术分析4例复杂易位患者的染色体核型,其中2例为智力低下患者,另2例来自有自然流产史的夫妇。2例智力低下患者应用FISH和CGH技术进一步分析并检测其父母核型。查询相关数据库检索4例核型的发生率。结果 4例患者的核型分别为46,XYqh+,t(1;12;2;10)(q25;q11;p14;p11),inv(1)(p22q25),46,XY,t(7;21;8)(p13;q22;p21),46,XX,t(3;7;10)(q28;p15;q22)和46,XY,t(2;16;5)(q33;p12;q33)。2例有智力低下患者经FISH和CGH检测未发现其他染色体的异常,未见染色体微小重复或缺失。4例核型均为国内外文献未曾报道的新核型。结论 染色体复杂重排的遗传学检测需要综合考虑多种核型分析方法的结果,染色体复杂重排的遗传咨询需要着重结合其重排类型和临床症状进行分析。     

Spectra of chromosomal aberrations in 325 leukemia patients and implications for the development of new molecular detection systems

This study investigated the spectrum of chromosomal abnormalities in 325 leukemia patients and developed optimal profiles of leukemic fusion genes for multiplex RT-PCR. We prospectively analyzed blood and bone marrow specimens of patients with acute leukemia. Twenty types of chromosomal abnormalities were detected in 42% from all patients by commercially available multiplex RT-PCR for detecting 28 fusion genes and in 35% by cytogenetic analysis including FISH analysis. The most common cytogenetic aberrations in acute myeloid leukemia patients was PML/PARA, followed by AML1/MGT8 and MLL1, and in acute lymphoid leukemia patients was BCR/ABL, followed by TEL/AML1 and MLL1 gene rearrangement. Among the negative results for multiplex RT-PCR, clinically significant t(3;3)(q21;q26.2), t(8;14)(q24;q32) and i(17)(q10) were detected by conventional cytogenetics. The spectrum and frequency of chromosomal abnormalities in our leukemia patients are differed from previous studies, and may offer optimal profiles of leukemic fusion genes for the development of new molecular detection systems.     

11q23 abnormalities in patients with acute myelogenous leukemia and myelodysplastic syndrome as detected by molecular and cytogenetic analyses

11q23 chromosomal abnormalities and rearrangement of the mixed lineage leukemia (MLL) gene are important prognostic factors in acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS). However, the presence of 11q23 abnormalities does not always correlate with that of MLL gene rearrangement. We retrospectively compared the occurrence of 11q23 abnormalities (measured by karyotyping) and MLL gene rearrangement (measured by Southern blotting) in bone marrow from 311 consecutive adult patients with AML or MDS. 11q23 abnormalities were found in 18 patients (5.8%), of whom 7 (39%) did not have the MLL gene rearrangement. MLL gene rearrangement was detected in 35 patients (11.2%). Of these 35 patients, only 11 (31%) had cytogenetic evidence of 11q23 abnormalities. None of the 21 patients with chronic myelomonocytic leukemia had 11q23 abnormalities or MLL gene rearrangement. 11q23 abnormalities were associated with shorter survival than was a diploid karyotype. Both cytogenetic and molecular studies should be performed to detect 11q23 abnormalities in patients with AML or MDS.     

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.     

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.     

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.     

Routine fluorescence in situ hybridization with the MLL probe does not reliably detect two separate signals on one chromosome 11 in patients with trisomy 11

Trisomy 11 is considered to be a rare cytogenetic abnormality in myelodysplastic syndromes (MDS) and acute myelogenous leukemia (AML). Duplication of the MLL gene (localized to 11q23) has been found on one chromosome 11 in patients with trisomy 11, detected by DNA techniques. We investigated copy number of MLL in seven patients with trisomy 11 to see if duplication could be assessed by the detection of two separate signals on fluorescence in situ hybridization (FISH). If so, FISH could provide a quick easy screen of MLL status in routine referrals. The diagnostic bone marrow aspirate showed trisomy 11 in five adult patients with MDS/AML as part of a complex karyotype and in two children with acute lymphoblastic leukemia (ALL) as part of a hyperdiploid karyotype. Fluorescence in situ hybridization utilized the suspensions remaining after the cytogenetic harvest. Two FISH probes were used on the adult patients (MLL - Oncor and Vysis), and one (Vysis) for the two children with ALL. Analysis showed that the proximity of the two putative hybridization signals made it very difficult to unambiguously see two separate signals. The hybridisations (Oncor probe) were convincing of MLL duplication (namely two distinct signals) in only one patient, but this was not borne out with the other MLL probe (Vysis). We conclude that conventional FISH with MLL probe is not suited to act as a screen for MLL duplication in patients with trisomy 11.