六例20q-继发t(20;21) (q11;q11)易位恶性血液病的临床和细胞遗传学特点

目的 了解20q-继发t(20;21)(q11;q11)核型异常恶性血液病的临床和细胞遗传学特征.方法 采用骨髓细胞短期培养法制备染色体,R显带技术进行核型分析,应用20q11/12双色探针、20号和21号染色体着丝粒探针、20号和21号染色体亚端粒探针以及20号和21号染色体涂染探针对其进行荧光原位杂交分析.结果 6例20q-继发t(20;21)易位核型异常的患者占本院2000年以来经常规核型分析检测出20q-异常患者总数的2.3％(6/257),其中5例为骨髓增生异常综合征患者,1例为急性淋巴细胞白血病患者.6例患者均经以上各种探针荧光原位杂交证实存在20q-,其与21号染色体易位断裂点也均为q11.结论 der(20)del(20)(q11q13)t(20;21)(q11;q11)与i(20q-)一样,是20q-的较少见的再现性衍生异常,多见于中老年患者和髓系疾病,尤其是骨髓增生异常综合征,少数也可见于急性淋巴细胞白血病.提示该类疾病预后较差,易位可能形成新的融合基因从而在该类疾病中起重要作用.     

急性淋巴细胞白血病的t(1;19)(q21;q13)易位

在Kaneko等(1982年)报道的许多急性淋巴细胞白血病(ALL)的患者中,一例非B,非T ALL的3岁女孩,在诊断和复发时都发现有相互易位的改变,t(1;19)(q21;q13)。在第三届白血病染色体专业会议的330例ALL患者中,她是唯一具有此种易位的病例。作者发现一例患有非B,非T高危ALL的22个月的男孩,也具有同样易位。诊断时,其核型为46,XY/47,XY,-F, 2C;复发时,核型为47,XY, 8,-19, t(1;(19)(q21;q13);inv(5)(q13q35)。该病例的t(1;19)易位,系第一号染色体部分三体所致。     

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.     

四例合并继发性der(9)t(9;22)(q34;q11)inv(9)(p22q34)异常的Ph阳性白血病的临床及分子遗传学研究

目的 探讨4例合并继发性der(9)t(9;22)(q34;q11)inv(9)(p22q34)异常的Ph阳性白血病的临床及分子遗传学特征.方法 应用骨髓细胞直接法或短期培养法制备染色体,经R显带进行核型分析.应用BCR/ABL双色双融合探针和9号染色体短臂及长臂涂染探针分别对4例伴有inv(9)(p22q34)的Ph阳性患者标本进行荧光原位杂交(fluorescence in situ hybridization,FISH)和染色体涂染分析.用逆转录PCR检测BCR/ABL融合基因转录本.结果 1例急性髓细胞白血病患者核型中有3种克隆,分别为正常细胞、t(9;22)(q34；q11)异常细胞、同时合并der(9)t(9;22)衍生克隆和Ph以及其它异常,即t(8;12)(q12;p11),der(9) t(9；22)inv(9) (p22q34),der(22)t(9；22)细胞.其余3例慢性粒细胞白血病患者均同时合并Ph和der(9)t(9;22)(q34；q11)inv(9)(p22q34).FISH结果显示,3例有1红1绿两个融合信号、2红2绿1个融合信号、且在中期分裂相中发现1红1绿荧光信号分别位于9号染色体的两端；另1例67.5％的细胞有2红1绿1融合信号,有1绿色信号的缺失即表明BCR基因的缺失.染色体涂抹检测发现4例患者均有9号染色体的倒位.逆转录PCR检测均为b3a2转录本.该继发异常既可发生于Ph阳性CML慢性期或急变期,也可发生于原发性Ph阳性AML.该异常核型可能与预后不良相关.结论 合并继发性der(9)t(9;22)(q34；q11)inv(9)(p22q34)异常的Ph阳性白血病是一种少见但可再现的Ph继发性异常,具有独特的临床和分子遗传学特点.     

一例伴t(14;14)(q11;q32)易位的B细胞急性淋巴细胞白血病的临床和分子细胞遗传学研究

目的 报告1例伴t(14;14)(q11;q32)易位的罕见B细胞急性淋巴细胞白血病(B-lineage acute lymphoblastie leukemia,B-ALL)病例,阐明其临床和分子细胞遗传学特征.方法 分析1例伴t(14;14)(q11;q32)易位B-ALL患者的临床资料;将患者骨髓细胞24h培养后按常规方法制备染色体标本,采用R显带技术进行核型分析;分别应用IGH双色断裂点分离探针、CEBPE双色断裂点分离探针、4号全染色体涂染探针和ALL组合探针进行荧光原位杂交(fluorescence in situ hybridization,FISH)分析.结果 常规细胞遗传学分析显示患者核型为47,XX,+4,t(14;14)(q11;q32)[20],FISH分析进一步证实了这种核型异常.IGH双色断裂点分离探针FISH分析表明t(14;14)(q11;q32)易位累及IGH基因,CEBPE双色断裂点分离探针FISH分析提示t(14;14)(q11;q32)易位中IGH的伙伴基因为CEBPE基因.结论 在B-ALL中t(14;4)(q11;q32)易位同时累及IGH和CEBPE基因为少见的再现性遗传学异常,该异常可定义B-ALL中一种新的亚型.伴有t(14;14)(q11;q32) IGH/CEBPE易位的B-ALL患者可能预后较好.     

t(15;17)的变异型插入易位ins(17;15)(q21;q14q22)的细胞遗传学和分子遗传学研究

目的　报道 1例 t(15 ;17)的变异型插入易位 ins(17;15 ) (q2 1;q14 q2 2 )病例及其染色体涂染、逆转录 - PCR的研究结果。方法　骨髓细胞经直接法或 2 4 h培养和外周血单采白血病细胞培养 6天后制备染色体标本 ,以 R显带技术进行核型分析 ;以 15号和 17号整条染色体涂染探针进行染色体涂染 ;以逆转录 -PCR技术检测 PML - RARα和 RARα- PML融合基因的转录本。结果　该患者骨髓细胞和外周血白血病细胞染色体 R显带核型分析结果均提示 15 q-和 17q ;涂染研究证实 17号染色体长臂插入一段 15号染色体来源的染色体片段 ;逆转录 - PCR检出 PML- RARα融合基因短型转录本 ,未检出 RARα- PML 融合基因的转录本 ,符合 ins(17;15 )所致的遗传学改变。结论　染色体涂染和逆转录 - PCR技术是明确急性早幼粒细胞白血病患者涉及 15和 17号染色体插入易位的可靠手段。     

六例伴t(6;9)(p23;q34)急性髓细胞白血病患者的临床和实验研究

目的 探讨伴t(6;9)(p23;q34)急性髓细胞白血病(acute myeloid leukemia,AML)患者的临床和生物学特点.方法 抽取骨髓细胞按常规制备染色体标本,采用R显带技术进行核型分析;采用标准流式细胞仪和一组单抗检测白血病细胞的抗原表达;应用6号与9号全染色体涂染探针进行染色体荧光原位杂交(fluorescence in situ hybridization,FISH)分析;应用逆转录-PCR技术进行DEK/CAN融合基因和FLT3-ITD突变的检测.结果 t(6;9)易位主要见于M2和M4(M2 4例,M4 2例).所有病例的原始细胞均高表达CD13、CD33,其中4例同时表达HLA-DR、3例同时表达CD34和CD117,1例同时表达CD38,1例同时表达CD15.涂染证实6例患者均涉及6和9号染色体的易位,逆转录-PCR检测显示6例患者的DEK/CAN融合基因均为阳性,其中3例同时存在FLT-ITD突变,6例中的3例经治疗后死亡,生存期分别为3、5和6个月,其余病例仍在缓解中.结论 t(6;9)(p23;q34)为AML少见的再现性异常,伴有t(6;9)(p23;q34)易位的AML具有独特的生物学特征和临床特点,预后大多不良.     

一例伴有t(1;18)(p31;p11)易位的骨髓增生异常综合征

目的报告一例伴有t(1；18)(p31；p11)的骨髓增生异常综合征(myelodysplastic syndrome，MDS)。方法骨髓细胞24h培养后按常规方法制备染色体，采用R显带技术进行染色体核型分析；以1号和18号整条染色体涂染探针对其进行染色体涂染检测。结果常规细胞遗传学方法和染色体涂染分析均证实该患者具有t(1；18)(p31；p11)克隆性染色体异常。结论t(1；18)(p31；p11)易位是一种罕见的再现性染色体核型异常，在MDS中属于首次报道。     

慢粒患者经格列卫治疗后细胞遗传学改变:标准Ph易位t(9;22)(q34;q11)变为变异Ph易位t(21;22)(p11;q11)

目的通过对慢性粒细胞白血病(chronic myeloid leukemia,CML)患者经格列卫药物治疗后细胞遗传学改变的研究,探讨ABL-BCR的表达缺失与获得性格列卫耐药的关系。方法应用R显带技术对染色体进行核型分析,并选用BCR/ABL探针,通过双色荧光原位杂交技术进一步确认遗传学分析。结果患者经格列卫治疗后染色体核型由t(9;22)(q34;q11)变为t(21;22)(p11;q11)。双色荧光原位杂交证实此患者核型应为46,XY,t(9;22;21)(q34;q11;p11)。结论变异Ph易位中ABL-BCR的表达缺失与获得性格列卫耐药有关,荧光原位杂交技术在检测变异易位中起重要作用。     

急性淋巴细胞白血病的t(1;19)断裂点的评论

迄今,又有两组研究单位报道了与作者相同的发现,即急性淋巴细胞白血病(AL-L)患者中存在的t(1;19)易位.有趣的是,三组描述的这类易位,其断裂点仅有微小的区别.Williams等明确断裂点为t(1;19)(q23;p13.3),Carroll等报道的是t(1;19)(q23;q13),而作者发现的是t(1;19)(q21;q13).很明显,这些断裂点的差异甚微,每例均为相同的易位.但作者与Carroll等难于准确分析19号染色体的长臂或短臂,因     

Translocation (8;21) and its variants in acute nonlymphocytic leukemia. The relative importance of chromosomes 8 and 21 to the genesis of the disease

Chromosome analysis was performed in 25 patients with acute nonlymphocytic leukemia (ANLL), mostly of the M2 type. Eighteen had the standard translocation, t(8;21)(q22;q22), four had complex translocations involving 1p36, 11p13, 17p11, and 17p23, respectively, with chromosomes 8 and 21, and the remaining three patients had simple translocations, one with t(3;21)(p14;q22) and two with t(16;21)(p11;q22), without involving chromosome 8. Chromosome abnormalities additional to t(8;21) and its variants that were most frequently observed were -X, -Y, and del(9). Complex translocations are thought to be derived from the standard translocation and to be essentially similar in nature. The finding that chromosome 21 was involved in all of the standard, simple, and complex translocations, and that chromosome 8 was not involved in simple variants suggest a greater weight of chromosome 21 in the relative importance of the two chromosomes to the genesis of ANLL.     

Aneurysmal bone cyst with chromosomal changes involving 7q and 16p

A 6-month-old girl was diagnosed with acute lymphoblastic leukemia (ALL). Chromosome analysis of bone marrow aspirate showed 46,XX,t(4;11)(q21;q23) with an atypical appearance of the 11p on the der(11) chromosome. FISH studies to fully characterize the translocation utilised 8 probes: whole chromosome painting probes for chromosome 11 and chromosome 4; separate chromosome 11 short arm and long arm paints; specific subtelomere probes from 11p, 11q, and 4q; MLL gene probe. Taken together, the results indicated a two-step abnormality: an initial standard t(4;11)(q21;q23), followed by another t(4;11)--this time, between the two derivative chromosomes. The MLL gene was split by the first translocation and its position altered by the second.     

Deletion of 16q11 is a recurrent cytogenetic aberration in acute myeloblastic leukemia during disease progression.

Abnormalities of chromosome 16 other than inv(16)(p13q22), t(16;16)(p13;q22), and del(16)(q22) have not been fully characterized in acute myeloblastic leukemia (AML) and myelodysplastic syndrome (MDS). We report here the first case of AML with del(16)(q11) as a sole abnormality. A 53-year-old woman was initially diagnosed as MDS, refractory anemia with excess of blasts in transformation with normal karyotype. After sixteen months, the disease progressed to overt AML-M1. Myeloblasts were positive for CD13, CD33, and CD34, but negative for HLA-DR. Chromosome analyses of the bone marrow cells showed 46,XX,del(16)(q11) in all metaphase spreads. Multicolor spectral karyotyping also confirmed that del(16)(q11) was not derived from a cryptic translocation, but a simple deletion. Our results, together with three previously reported cases, suggest that del(16)(q11) may be one of the recurrent aberrations in AML and that it could be associated with clonal evolution or disease progression.     

A t(4;11)(q21;p15) in a case of T-cell lymphoma and a case of acute myelogenous leukemia

The translocation (4;11)(q21;p15) has been observed in acute lymphoblastic as well as acute myeloid leukemias (ALL and AML, respectively). We report the first case of T-cell lymphoma with t(4;11)(q21;p15) and a case of AML. The clinical history of and cytogenetics in the latter is suggestive of a secondary leukemia; his karyotype revealed emergence of a t(3;11)(q21;q13) in addition to the t(4;11). Previously reported cases with t(4;11)(q21;p15) are reviewed, clinical and morphological characteristics of cases with t(4;11)(q21;q23) and t(4;11)(q21;p15) are compared, and chromosome abnormalities involving the NUP98 gene in hematologic malignant disorders are reviewed.     

Different mechanisms lead to a karyotypically identical t(20;21) in myelodysplastic syndrome and in acute myelocytic leukemia

A new t(20;21)(q11;q11), associated with a deletion on the long arm of chromosome 20, was found in one patient with an acute myelocytic leukemia (AML) and in one with myelodysplastic syndrome (MDS). In both cases deletion was interstitial, extending from band q11 to band q13, as shown by comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH). FISH analysis with whole arm paints, subtelomeric probes, and locus-specific probes for the long arms of chromosomes 20 and 21 revealed in patient 1 a reciprocal translocation between the deleted 20q and the long arm of chromosome 21, that is, del(20)(q11q13)t(20;21)(q11;q11), and in patient 2, material from 21q was inserted into the deleted 20q, that is, del(20)(q11q13)ins(20;21)(q11;q11q22). This is the first identification of a complex 20;21 rearrangement in MDS/AML. Deletion at 20q and juxtaposition between 20q11 and 21q11 appear to be the critical genomic events.     

An unusual three-way translocation t(21;8;1)(q22;q22;q32) in a case of acute myeloid leukemia (M2)

Variant forms of the classic translocation t(8;21) are uncommon and account approximately 3% of all t(8;21)(q22;q22) in acute myeloid leukemia (AML) patients. These forms involve chromosomes 8, 21, and other chromosomes. Here we report a Tunisian patient with a complex rearrangement t(21;8;1)(q22;q22;q32) revealed by conventional chromosomal study at diagnosis. Fluorescence in situ hybridization study revealed the presence of the AML1-ETO chimeric gene on the derivative chromosome 8. To the best of our knowledge, this is the second case of t(21;8;1) of AML-M2 reported in the literature with the involvement of the same breakpoint at 1q32. This illustrates that this complex translocation is rarely encountered in AML and reinforces the fact that this region may harbour a critical gene candidate that may play an important role in the pathogenesis of AML. More cases are needed to elucidate its clinical features and prognosis.