联合间期和中期荧光原位杂交确定成人急性白血病患者11q23/MLL异常

目的 探讨快速、敏感、有效揭示11q23／MLL基因重排的方法，确定11q23／MLL异常存成人急性白血病（AL）中的发生情况及其临床特征，指导AL风险治疗。方法112例成人AL患者骨髓细胞经24h短期培养按常规方法制备染色体标本，R显带行核型分析；LSIMLL双色分离信号DNA探针行间期荧光原位杂交（FISH）筛选异常信号，有异常信号者行中期FISH确定11q23／MLL基因重排。结果 112例AL患者FISH揭示9例11q23／MLL易位（检出率8．0％），其中常规细胞遗传学分析（CCA）只检出4例（检出率3．6％）。3例CCA示del（11）（q23）者FISH揭示2例为11q23／MLL易位，1例为11号染色体长臂末端缺失。在1例正常核型、1例11q＋和1例无11q23明显异常者，FISH揭示为11q23／MLL易位。除9例易何外，FISH揭示8例存在MLL基因扩增，包括多倍体、均匀染色区（hsr）和双微染色体（dmin）。AL伴11q23／MLL异常者多诊断为B系祖细胞急性淋巴细胞白血病（pro-B ALL）、急性单核细胞白血病（AMoL）或急性双表型白血病（BAL）。结论 使用MLL双色分离信号DNA探针行FISH确定11q23／MLL异常是快速敏感的方法，其检出率高于CCA，有效揭示11q23／MLL易位和扩增。临床诊断pro-B ALL、AMoL或BAL，尤其正常核型者应行FISH以确定11q23／MLL异常。     

常规细胞遗传学分析和荧光原位杂交方法检测白血病11q23/MLL基因重排

本研究比较常规细胞遗传学（conventional cytogenetics,CC）分析,间期荧光原位杂交（fluorescence in situ hybridization,FISH）技术及连续R显带后FISH（sequential R-banding and FISH）检测混合系列白血病（mixed lineage leukemia,MLL）基因重排的应用价值.应用常规细胞遗传学及间期FISH分析我院白血病患者37例,结果显示11q23＋/MLL＋患者10例,11q23^-/MLL＋患者2例（5.4%）,11q23^＋/MLL-患者3例（8.1%）,11q23^-/MLL-患者22例.部分病例CC与间期FISH方法检测11q23/MLL基因重排得到了不一致的结果.对6例患者进行连续R显带后FISH分析后,对照核型和FISH图都能清楚地看到MLL基因易位涉及的染色体.结论：为了给出准确的诊断,在检测11q23/MLL重排时需要进行常规细胞遗传学和间期FISH测定并结合两者结果来评定,必要时需做R显带后FISH或进一步的分子生物学分析.     

间期荧光原位杂交技术检测恶性血液病的11q23/MLL基因重排

目的分析伴有11q23／MLL基因重排的恶性血液病的细胞遗传学特点，探讨荧光原位杂交技术（FISH）在诊断及鉴定恶性血液病11q23／MLL基因重排中的价值。方法用间期FISH分析11q23／MLL基因易位细胞的30例恶性血液病患者的核型特征，用MLL双色分离探针绿色标记在（5′MLL，光谱绿）和（3′MLL，光谱桔红）。结果应用常规细胞遗传学及间期FISH分析白血病患者30例，结果显示11q23＋／MLL＋患者9例（30．0％），12q23-／MLL＋患者4例（13．3％），11q23＋／MLL-患者2例（6．7％），11q23-／MLL-患者15例，检测到部分病例染色体核型分析与间期FISH方法检测11q23异常与MLL基因重排不一致。结论FISH在检测11q23／MLL基因重排方面与传统的常规细胞遗传学相比具有检出率高的优势，能更有效、直观地分析恶性血液病的染色体异常，对于恶性血液病的诊断以及异常染色体的检出具有广泛的应用前景。     

Molecular rearrangements of the MLL gene are present in most cases of infant acute myeloid leukemia and are strongly correlated with monocytic or myelomonocytic phenotypes.

Cytogenetic studies have previously identified abnormalities of chromosome band 11q23 in many cases of infant acute leukemia. Recent studies by ourselves and others have demonstrated breakpoint clustering in acute leukemias bearing translocations involving 11q23, and a Drosophila trithorax gene homologue (called MLL, HRX, or ALL-1) has been shown to span the 11q23 breakpoints of these translocations. To determine if this gene is affected in infant acute myeloid leukemia (AML), we have analyzed 26 infant AML cases for molecular alterations of this 11q23 gene. 15 out of 26 cases studied (58%) showed rearrangement of the MLL gene at the molecular level, and these rearrangements were clustered within an approximately 11-kb region containing nine exons of this gene. Moreover, 14 of the 15 cases with 11q23 rearrangements (93%) had myelomonocytic or monocytic phenotypes (M4 or M5 FAB subtypes, respectively), both of which are associated with a poor prognosis in childhood AML. In contrast, only 1 of 11 nonrearranged cases had an M4 or M5 phenotype (P = 0.00002). Rearrangement also correlated significantly with hyperleukocytosis (P = 0.02), another clinical parameter associated with poor outcome in this disease. Our results demonstrate that molecular rearrangements of MLL are common in M4 or M5 infant AML, and suggest that alteration of this gene may result in abnormal control of proliferation and differentiation in monocytic progenitor cells.     

Simultaneous translocation of both TCR Loci (14q11) with rare partner loci (Xq22 and 12p13) in a case of T-lymphoblastic leukemia

The most common recurrent cytogenetic abnormalities in T-lymphoblastic leukemia (T-acute lymphoblastic leukemia [T-ALL]) involve T-cell receptor (TCR) loci and a variety of partner genes, including HOX11, HOX11L2, MYC, and TAL1. In this report, we present a rare case involving simultaneous translocation of the TCR α/δ loci with different partner loci (Xq22 and 12p13); this resulted in a poor prognosis. Chromosomal analysis showed 46,Y,t(X;14)(q22;q11.2),t(12;14)(p13;q11.2) and FISH analysis by using a T-cell receptor alpha delta DNA probe, Split Signal (DakoCytomation, Denmark), showed translocations at the same TCR α/δ locus on both chromosomes. FISH with 2 bacterial artificial chromosome clones showed break apart signal, which suggests involvement of the IRS4 gene. To our knowledge, this is the first report of T-ALL in which both TCR α/δ loci were translocated with different partner loci, and 1 of the partner loci, Xq22, was a rare translocation partner locus that included IRS4 gene.     

一株伴有t(6;11)(q27;q23)和p53基因异常的人单核细胞白血病细胞系SHI-1的建立及鉴定

目的建立人急性单核细胞白血病(AML—M5b)细胞系并研究其生物学特性。方法从1例AML—M5b患者白血病复发时的骨髓标本分离出单个核细胞，用液体培养法进行培养。采用瑞特染色、电子显微镜、细胞化学染色、流式细胞仪、R显带核型分析、逆转录-聚合酶链反应(RT—PCR)、荧光原位杂交(FISH)、半固体甲基纤维素集落培养、裸小鼠致瘤实验、荧光定量PCR、DNA荧光染色法及支原体肉汤培养法、短串联重复序列(STR)-PCR、p53基因的PCR扩增产物测序、多色FISH(M—FISH)和^3H—TdR掺入实验等方法对SHI-1细胞的生物学特性进行了鉴定、结果建立了1个可持续增殖的人单核细胞白血病细胞系SHI-1；形态学和免疫表型呈现典型的单核系特征；核型分析显示SHI-1细胞系有和患者复发时骨髓细胞完全相同的异常：46，XY，t(6；11)(q27；q23)，del(17)(p11)；RT—PCR检出MLL—AF6融合基因的转录本；FISH俭测结果显示存在6号和11号染色体之间易位、MLL基因的重排和p53基因的缺失；PCR产物测序结果显示1个p53等位基因6号外显子发生点突变ATC→ACC集落培养显示SHI-1细胞具有较强的集落形成能力；皮下接种4只裸小鼠均形成实体肿瘤；荧光定量PCR提示无EB病毒感染；DNA荧光染色法和支原体肉汤培养法术检出支原体；M—FISH证实传代至2003年3月的SHI-1细胞除有t(6；11)、del(17)(p11)外，还有t(7；13)所致的衍生7号染色体、18单体和来自8号染色体的微小体；STR—PCR结果显示SHI-1细胞系确实来自患者原代白血病细胞；IL4-和IL-15可促进SHI-1细胞的增殖，IFN-1、TNFα、IL-2、PDGF和IL-7可抑制SHI-1细胞的增殖。结论SHI-1是1个伴有t(6；11)(q27；q23)和P53基因异常的裸小鼠高致瘤性人单核细胞白血病细胞系，为白血病研究提供了一个新的有价值的工具。     

应用多重套式RT-PCR检测儿童急性淋巴细胞白血病的融合基因

目的　研究染色体结构易位所致的融合基因在儿童急性淋巴细胞白血病 (ALL)的表达。方法　采用多重套式RT PCR结合染色体R带或G带核型分析、流式细胞仪细胞免疫表型检测对 64例儿童ALL进行分析。结果　64例ALL患儿中 23例(36. 0% )具有 13种染色体畸变产生的融合基因,包括E2A/PBX1,E2A/HLF,TEL/AML1,TLS/ERG,MLL/AF4,MLL/AF9,MLL/AF10,MLL/AFX,MLL/AF6,MLL/ELL,dupMLL,TAL1D,HOX11。ALL患儿融合基因和染色体总畸变率为 67. 2%(43 /64)。结论　多重套式RT PCR结合染色体核型、免疫表型是儿童ALL临床诊断、治疗和预后判断的重要依据。     

混合系白血病全长基因在AML-M4/M5患者中的突变检测

急性髓系白血病(AML)-M4、M5常有11号染色体异常,定位于11q23的混合系白血病(MLL)基因异常所形成的MLL-PTD和MLL融合基因在该病的发病机理中具有重要作用。但在该类白血病绝大多数未能检测出染色体水平异常,是否存在MLL基因的其他突变?本研究对MLL全长基因的外显子进行了测序分析。选取25例初发核型正常的AML M4、M5患者(排除MLL融合基因和MLL-PTD及M4eo),进行了MLL全长基因的外显子PCR扩增直接测序分析,对发现的突变在基因组DNA水平进行验证。利用Mass Array方法在正常对照样本和AML扩大样本中对发现的点突变进行检测。结果发现,在MLL的RD、PHD、TAD和SET功能域中存在着高频的缺失、插入及多个点突变;同时对照研究正常样本,发现也存在上述的变异,且突变频率无统计学差别(P>0.05)。结论:检测到的MLL基因发生在mRNA水平的缺失、插入和多个点突变,分别是MLL在转录水平的选择性剪接和MLL的单核苷酸多态性,它们共同构成了MLL的遗传多态性;这些MLL基因遗传多态性可能与AML M4、M5的发病不直接相关,对于治疗、预后及其他生物学表型的意义还有待进一步探讨。     

Cytogenetics of mantle cell lymphoma

AIM: To determine the type and rate of secondary chromosomal aberrations and role in pathogenesis of mantle cell lymphoma (MCL). MATERIAL AND METHODS: Standard cytogenetic examination (SCE) and fluorescent in situ hybridization (FISH) with tests for 11q22/ATM, 13q14, 17p13/p53, 9p21/p16 and chromosome 12 centromere were made in 28 patients. RESULTS: Secondary chromosomal aberrations were detected in 22 patients. Chromosomal abnormalities occurring in more than 2 cases include deletions 6q15-q23 (53% cases); 11q22/ATM (50%); 9p21 (36%, in half the cases deletion 9p21 was biallele); 13q14 (32%); trisomy 3/3q, monosomy 20 and deletions/translocations 1q and 1p (27% and 20%) and deletion 17p13/p53 (18%). Trisomies 12/12q, 6 and 18/18q, monosomies 2 and 16, deletions/translocations 2p and 16p were found in 2 cases each. The FISH technique identified 9 chromosomal anomalies missed at SCE. Deletions 6q15-q23 were seen in patients with privalent lesions of lymph nodes. Deletions 11q, 13q14, 9p21 and 17p13 occur more frequently in transformation and the blastoid variant. Monosomy 20 was found only in patients with large cell transformations. This was the only cytogenetic defect characteristic for transformed cases, in contrast to denovoblastoid ones. Thus, deletions 6q, 11q23, 13q14 and 9p21 are typical for MCL. Deletions 9p21 and 17p13 are more characteristic for large cell variants of the tumor. Deletion 17p13 occurs at the terminal stage of the disease in rapidly growing tumor mass and resistance to chemotherapy. FISH technique is effective in detection of submicroscopic rearrangements especially small deletions. No significant differences were found between transformed and de novo blastoid cases. This shows that the blastoid variant is not a specific biological form, it is rather a less typical manifestation of the disease due to some preclinical cytogenetic disorders. CONCLUSION: Progression and transformation of MCL are related to mutation of proapoptotic genes and genes proteins of which are inhibitors of active complexes of D1 cycline. Specification of these mechanisms requires further investigations in patients with different clinicomorphological forms of the disease at various stages of the disease.     

Cytogenetic disorders in chronic B-cell lymphoid leukemia and their relations with clinicobiological features and prognosis of the disease

AIM: To study a relationship between cytogenetic disorders, clinicobiological characteristics and prognosis in chronic B-cell lymphoid leukemia (B-CLL). MATERIAL AND METHODS: Cytogenetic examination of blood, bone marrow and lymph node cells from 135 patients (90 males and 45 females aged 23-84 years) with chronic B-CLL was made. The patients were followed up from 1 month to 25 years. Before the cytogenetic examination specific therapy was not given. B-CLL was staged by K. Rai, forms--by A.L. Vorobyev and M.D. Brilliant. All the patients have undergone standard cytogenetic examination, FISH with multicolor probe to loci with possible frequent aberrations (del3q14, del11q23, del17p13, trisomia 12), determination of CD38 antigen expression on circulating tumor cells. Mutation status of the genes of immunoglobulins variable region (IgVH) was defined in 61 patients. RESULTS: Del13q14 was detected in 34 cases, del11q23--in 26, trisomia of chromosome 12--in 17 cases, del 17p13--in 8, absence of q-arm of chromosome 13--in 3 cases. 61 patients had no karyotype defects. Three prognostic groups of the patients were identified: favourable prognosis--patients without disorders of karyotype and one chromosomal aberration--del13q14; intermediate prognosis patients with dell1q23 and trisomia of chromosome 12; poor prognosis--patients with del17p13 and complex disorders of karyotype. CONCLUSION. Cytogenetic study help determine prognosis of B-CLL and detect patients in need of early therapy.     

慢性粒细胞白血病患者Ph染色体变异易位的细胞遗传学特征与荧光原位杂交研究

本研究探讨慢性粒细胞白血病(CML)中变异Ph染色体易位的细胞遗传学特征并比较双色单融合(DC-SF)与双色双融合(DCDF)bcr／abl探针荧光原位杂交技术(FISH)在变异易位CML中的应用价值。应用常规细胞遗传学方法分析我院42例CML变异Ph易位患者，其中9例进行DC-SF-FISH和1l例进行DC-DF-FISH研究。结果表明：在642例Ph阳性CML中变异易位42例(6.5％)，简单变异易位42.9％(18／42)，复杂变异易位54.8％(23／42)，遮蔽的或隐匿的Ph易位1例。除4，6号染色体外，其余染色体均被累及。4种类型变异易位分别出现于至少2个病例中。变异易位伴附加异常15例(35.7％)。FISH检测bcr／abl阳性19例(95％)，阴性1例。DC-DF-FISH显示除1例患者部分细胞(8.8％)能检测到abl／bcr融合信号外，其他患者皆缺乏该融合信号。但在易位后的9号和参与变异易位的另外染色体上分别可以见到abl和bcr基因信号。DC-SF-FISH不能观察到信号的变异特征。结论：CML变异Ph易位广泛累及除9，22外其他染色体。部分类型属重现性异常；FISH检测能给予精确的分子诊断．而DC-DF-FISH可提供直观的、准确的分子变异特征分析。     

119例慢性髓细胞白血病急变期核型分析

为了探讨慢性髓细胞白血病急变期（CML-BC）核型变化规律及意义，应用R显带技术对119例CML-BC患者的核型资料进行分析，并在其中随机选出28例以荧光原位杂交法（FlSH）检测衍生9号染色体[der（9）]是否缺失．结果表明：124例核型检查中Ph阴性11例（8．9％），P11阳性113例（91．1％），其中典型易位104例（83．9％），单纯变异易位4例（3．2％），复杂变异易位5例（4．0％）；Ph阴性CML-BC中72．6％伴有附加染色体异常，主要类型是：i（17q）、＋14，Ph阳性者72．3％伴有附加染色体异常，主要类型是：＋Ph、＋8、i（17q）；Ph阴性CML-BC急变时间为2-66月，平均29．0月，Ph阳性者急变时间为1-127月，平均34．2月，两组比较无统计学差异（P〉0．05）；FlSH检测发现5例（5／28，17．9％）der（9）缺失。结论：慢性髓细胞白血病急变期附加染色体异常多见，FlSH技术可有效检测der（9）缺失．     

多重RT-PCR技术联合染色体核型分析在儿童急性淋巴细胞白血病诊断分型中的应用

目的　研究多重逆转录 聚合酶链反应 (RT PCR)技术联合染色体核型分析在急性淋巴细胞白血病 (ALL)诊断分型中的价值。方法　采用多重RT PCR技术 ,染色体R或G显带技术对 5 0例儿童ALL进行分析。结果　 5 0例ALL患儿中 18例 (36 .0 % )分别具有 11种融合基因 ,包括E2A/PBX1、TEL/AML1、TLS/ERG、MLL/AF4、MLL/AF9、MLL/AF10、MLL/AFX、MLL/AF6、MLL/ELL、TAL1D、HOX11。在接受染色体检查的 4 8例ALL患儿中 ,染色体异常有 2 4例 (5 7.1% ) ,其中染色体数目和缺失异常为 18例 ,染色体易位 6例。多重RT PCR和核型分析联合使ALL的遗传学异常检出率增至 70 % (5 0例中 35例 )。结论　多重RT PCR和染色体核型分析两种方法相结合 ,可以相互补充 ,从而提高了ALL患儿遗传学异常的检出率 ,为儿童ALL的诊断、分型和预后判断提供可靠依据。     

二例伴有dic(9;20)(p11-13;q11)急性淋巴细胞白血病患者的临床和实验研究

目的探讨伴有dic（9;20）（p11-13;q11）的急性淋巴细胞白血病（ALL）的细胞形态学、免疫学、细胞遗传学特征和临床特点.方法骨髓细胞经直接法和24h短期培养后按常规方法制备染色体,采用R显带技术进行细胞遗传学分析.分别以9号和20号染色体着丝粒探针进行双色荧光原位杂交（FISH）检测.结果2例患者的临床和血液学改变符合ALL诊断,免疫表型分析B淋系标志阳性（CD10＋、HLA-DR＋）;染色体核型分析显示2例患者均为dic（9;20）：例1为45,XY,der（9）t（9;20）（p11;q11）,-20[20],例2为45,XX,der（9）t（9;20）（p13;q11）,t（9;22）（q34;q11）,-20[10]/46,idem,＋8[16]/47,idem,＋8,＋21[14];其中1例经双色FISH检测证实9号和20号染色体之间发生了相互易位,且形成双着丝粒染色体.结论dic（9;20）（p11-13;q11）是一种少见的重现性核型异常,可能和ALL有特殊的联系.FISH技术是检测该易位的可靠手段.     

Myeloid cell differentiation arrest by miR-125b-1 in myelodysplastic syndrome and acute myeloid leukemia with the t(2;11)(p21;q23) translocation

Most chromosomal translocations in myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) involve oncogenes that are either up-regulated or form part of new chimeric genes. The t(2;11)(p21;q23) translocation has been cloned in 19 cases of MDS and AML. In addition to this, we have shown that this translocation is associated with a strong up-regulation of miR-125b (from 6- to 90-fold). In vitro experiments revealed that miR-125b was able to interfere with primary human CD34⁺ cell differentiation, and also inhibited terminal (monocytic and granulocytic) differentiation in HL60 and NB4 leukemic cell lines. Therefore, miR-125b up-regulation may represent a new mechanism of myeloid cell transformation, and myeloid neoplasms carrying the t(2;11) translocation define a new clinicopathological entity.     

Delving deeper into MALT lymphoma biology

Mucosa-associated lymphoid tissue (MALT) lymphomas can arise in a variety of extranodal sites. Interestingly, at least 3 different, apparently site-specific, chromosomal translocations, all affecting the NF-kappaB pathway, have been implicated in the development and progression of MALT lymphoma. The most common is the translocation t(11;18)(q21;q21), which results in a fusion of the cIAP2 region on chromosome 11q21 with the MALT1 gene on chromosome 18q21 and is present in more than one-third of cases. The frequency of this translocation is site-related: common in the gastrointestinal tract and lung, rare in conjunctiva and orbit, and almost absent in salivary glands, thyroid, liver, and skin. In this issue of the JCI, Hu et al. add to our understanding of the molecular consequences of this translocation, showing that its fusion product, cIAP2-MALT1, may concomitantly contribute to lymphomagenesis both as a tumor suppressor gene and as an oncogene.     

Detection of bone marrow infiltration of lymphoma cells by fluorescence in situ hybridization

BACKGROUND: It is sometimes difficult to detect the bone marrow infiltration of lymphoma cells, because lymphoma cells are not distinguishable from normal lymphocytes due to the similarity of their phenotype. METHODS: Bone marrow involvement of 17 samples of 15 patients with follicular lymphoma, whose lymphoma cells were confirmed to harbor the translocation of chromosome14q32, were examined by microscopic analysis of bone marrow smear and biopsy, flow cytometorical analysis (FCM), chromosomal analysis of G-banding and fluorescence in situ hybridization (FISH). FISH was performed using a probe, which detects the split of IGH gene on 14q32. RESULTS: The positivity of FISH was highest among these methods and FISH was able to detect the bone marrow involvement in one case who was defined as negative by bone marrow biopsy. CONCLUSIONS: FISH can be used for detection of bone marrow involvement of malignant lymphoma that carries chromosomal rearrangement involving 14q32.     

间期荧光原位杂交技术对诊断核心结合因子急性髓系白血病的价值

本研究主要探讨间期荧光原位杂交技术在核心结合因子急性髓系白血病(CBF AML)诊断中的价值。采用间期荧光原位杂交技术(I-FISH),分别应用AML1-ETO双色双融合探针和荧光素直接标记的双色断裂点分离基因探针CBFβ-MYH11检测82例AML-M2及43例AML-M4/M5患者白血病细胞的细胞遗传学异常,并与R显带常规细胞遗传学(CC)检测结果进行比较分析。结果表明:82例AML-M2患者中FISH检测AML1-ETO融合基因阳性患者为25例(30.5%),CC检测存在t(8;21)(q22;q22)染色体异常为23例(28.0%),所有FISH检测AML1-ETO阳性患者中典型的阳性信号模式1R1G2F为22例(88.0%);不典型的信号模式包括1R2G1F和2R1G2F共3例(12.0%)。在所有43例AML-M4/M5患者中,FISH检出inv(16)(p13;q22)/t(16;16)(p13;q22)信号模式(1R1G1F)为10例(23.3%),CC检测出存在inv(16)(p13;q22)/t(16;16)(p13;q22)为2例(4.6%),FISH检测灵敏度显著高于CC(p<0.05)。结论:FISH作为新型细胞遗传学分析技术可以弥补CC技术灵敏度较低、检测周期长等不足,两者结合可以成为CBF AML诊断乃至微小残留病监测的有力工具。     

MLL基因重排急性白血病患儿的临床和生物学特点研究

目的对儿童急性白血病进行混合谱系白血病(mixed lineage leukemia，MLL)基因重排的临床和实验研究：方法应用MLL双色荧光原位杂交(FISH)基因探针进行双色FISH，以13对引物行多重RT—PCR检测融合基冈，并联合染色体R带核型分析及流式细胞仪免疫表型检测，对298例儿童急性白血病中16例含有MLL基因重排患儿进行分析：结果MLL基因重排的白血病在儿童急性白血病中占5.4％，而在婴幼儿白血病中占56．3％；对106例患进行多重RT—PCR，检测到涉及MLL基因重排11例，其中MLL／AF42例，MLL／AF61例，MLL／AF6、MLI／ELL合并MLL／AFX或HOX11各1例，MLL／AF92例，MLL／AF101例，MLI／ELL2例。串联重复dup11q231例，HOX活化1例；27例进行了FISH检测，发现9例有MLL重排，其阳性率为36．0％；16例MLL基因重排患儿中14例(87．5％)有克隆性染色体异常，其中11例累及11号染色体[t(4；11)2例，t(6；11)、t(8；11)、t(7；8；11)、t(9；11)各1例， 112例，11q-3例]；16例MLL基因重排患儿中11例为B系ALL，以B祖细胞或前B细胞白血病为主，5例为急性单核细胞白血病，其中3例有CD7和CD2淋系抗原表达；16例MLL基因重排患儿中8例接受治疗，7例获得完全缓解。结论多重RT—PCR和FISH联合是检测MLL重排最精确和灵敏的方法，MLL基冈重排中包括易位、缺失和重复。MLL基因重排的检测对儿童急性白血病预后判断和治疗方案的选择具有重要意义，并且对WHO分型将其单独列为11q23／MLL白血病提供了有力的依据。