Trisomy 21 is a recurrent secondary aberration in childhood acute lymphoblastic leukemia with TEL/AML1 gene fusion.

TEL/AML1 gene fusion is the most frequent genetic lesion in pediatric acute lymphoblastic leukemia (ALL). It occurs as a consequence of the cryptic chromosomal translocation t(12;21)(p13;q22). In a cohort of 50 RT-PCR-positive TEL/AML1 patients, karyotype examination by GTG banding and fluorescence in situ hybridization (FISH) allowed us to identify chromosome anomalies in addition to the already existing t(12;21). Secondary aberrations were found in 29 out of 41 patients (71%) at initial diagnosis and in all 9 patients with relapse. Structural rearrangements affected chromosome arms 2p, 2q, 5q, 9p, 12p (n = 2), 6q, 11p (n = 3), and 21q (n = 4). An extra chromosome 21 was found to be the most frequent anomaly. It was detected in 6 out of 41 patients at initial diagnosis (15%) and in 7 out of the 9 patients at relapse. No karyotype with trisomy 21 exceeded 47 chromosomes. Gain of chromosome 21 was the sole anomaly in GTG-banding analysis in 2/41 patients at initial diagnosis and in 4/9 at relapse. Notably, chromosome painting analysis performed in 11 out of the 13 patients with an extra chromosome 21 revealed duplication of the normal chromosome 21 in 8, and duplication of der(21)t(12;21) in 3 patients. Furthermore, gain of der(21)t(12;21) chromosome was confined exclusively to the relapse patients.     

Karyotypic analysis of two related cervical carcinoma cell lines that contain human papillomavirus type 18 DNA and express divergent differentiation

The cell lines C-4I and C-4II were established in culture from a nonkeratinizing squamous carcinoma of the uterine cervix. Both lines contain human papillomavirus (HPV) type 18 DNA (Brandt et al., Cold Spring Harbor Laboratories, 5:179, 1987) and both are hypodiploid with similar, but not identical, karyotypes. Each line expresses multiple characteristics of ectocervical epithelial differentiation, but the characteristics differ between the lines. In the present study, G banding of the lines showed that cells of both lines have two normal chromosomes 1-5, 8-10, 13, 16, and 17, one normal chromosome 12 and 14, and no normal chromosomes 15 and 18. The lines share three abnormal chromosomes, der(8)t(8q;12q), der(18)t(18q;?), and i(5p). There are specific differences between the lines. C-4I has two normal chromosomes 6, while C-4II has one; C-4II has two chromosomes 11 and der(18)t(18q;?), while C-4I lacks both chromosomes 11 and has one der(18)t(18q;?). Each line has unique markers that include del(11)(p11), del(22)(q12), and del(21)(q21) in C-4I and i(15q), der(X)t(Xq;9p), der(6)t(6p;14q), and del(4)(q21) in C-4II. The results show that these phenotypically distinct lines are derived from the same clone and that the 8q arm (the site of HPV 18 integration) is present in three copies in both lines. They also define several chromosome rearrangements that are compatible with the expression of specific differentiation markers.     

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.     

Translocation (9;11)(p21;q23) in a case of acute myeloblastic leukemia (AML-M2)

A patient with acute myeloblastic leukemia (AML-M2) and a balanced translocation, t(9;11)(p21;q23), is described. The translocation appears to be the same as that previously reported in some patients with acute monoblastic leukemia (AMoL-M5). This suggests that, although t(9;11)(p21;q23) frequently may be associated with AMoL, the translocation may not be specific for that disorder.     

Origins of accessory small ring marker chromosomes derived from chromosome 1

Three patients with accessory small ring chromosomes derived from chromosome 1 are presented together with additional clinical details and cytogenetic analyses of a previously reported patient. Cytogenetic analysis was undertaken by FISH using a reverse painting probe generated from one of the patients by microdissection of the r(1) chromosome and with a BAC923C6 which maps to 1p12. Results indicated that patients with r(1) chromosomes consisting of 1q12 heterochromatin and short arm pericentric euchromatin which extends to at least the BAC923C6 were associated with a normal or mild phenotype. Patients with abnormal phenotypes possessed two types of rings. One patient had evidence for contiguous pericentric short arm euchromatin which extended from the centromere to beyond the BAC923C6. Two patients showed molecular cytogenetic results which were compatible with non-contiguous chromosome 1 euchromatin. The diversity of origin of r(1)s will hamper attempts to define phenotype/genotype relationships.     

Identification of t(15;17) and a segmental duplication of chromosome 11q23 in a patient with acute myeloblastic leukemia M2

A 32-year-old man was newly diagnosed with acute myelocytic leukemia, classified as acute myeloblastic leukemia with maturation (AML-M2) according to the French-American-British classification system. Conventional chromosome analysis before chemotherapy treatment revealed an abnormal karyotype: a possible segmental duplication of 11q23, plus a translocation between chromosomes 15 and 17 [t(15;17) (q22;q21.1)] in the majority of cells analyzed. Fluorescence in situ hybridization analysis using commercially available probes confirmed the cytogenetic findings. To our knowledge, this is the first report of a combination of t(15;17) and a segmental duplication of 11q23 in a patient with AML-M2.     

dic(9; 20): A new recurrent chromosome abnormality in adult acute lymphoblastic leukemia

Loss of chromosome 20 and rearrangement of the short arm of chromosome 9 were identified by banding analysis of three adult patients with acute lymphoblastic leukemia (ALL). The G-banding pattern suggested and identical deletion of 9p, but, also, an unbalanced translocation with chromosome 20 was taken into consideration. Dual-color chromosome painting with probes for chromosomes 9 and 20 revealed the presence of material from chromosome 20 at the short arm of the abnormal chromosome 9 in all three cases. Centromeric alpha-satellite DNA of both chromosome 9 and chromosome 20 was demonstrated by fluorescence in situ hybridization and indicated the presence of a dicentric chromosome. The hybridization of a YAC clone of the short arm of chromosome 20 proved that the dicentric chromosome contained the short arm of chromosome 20, which had been suspected from the G-banding pattern. Thus, the rearrangement was interpreted as dic(9; 20)(pl I;qi I . ? I). Because this was the sole chromosome abnormality in two patients, dic(9; 20) may be a primary chromosome aberration in ALL. In one case, a 9q⁺ chromosome derived from a Philadelphia (Ph) translocation was involved in the formation of the dicentric chromosome. Immunophenotyping revealed CD 1o⁺ B-cell precursor ALL in all three cases. Whereas the two patients in whom dic(9; 20) was the sole cytogenetically detectable change are in continuous complete remission for 10 and 45 months, respectively, the Ph⁺ patient relapsed with leukemia and died 8 months after diagnosis. © 1995 Wiley-Liss, Inc.     

A novel subtelomeric translocation t(5;9) and a deletion of the RB1 gene in a patient with acute myeloid leukemia (AML-M0)

No chromosomal rearrangements have been identified as specifically associated with minimally differentiated acute myeloid leukemia (AML-M0). Several research groups studied the cytogenetic features of AML-M0 and found that as much as 81% of patients with AML-M0 had chromosomal rearrangements; primarily -5/5q- and/or -7/7q- deletions or translocations involving 12p. A patient, who was diagnosed with AML-M0 eighteen months ago, was referred for cytogenetic evaluation for possible AML relapse. A subtle, cryptic t(5;9)(q35.3;q34.3), plus a deletion of the RB1 gene were detected in 18 out of 20 cells analyzed by FISH utilizing the TelVysion assay kit. To rule out the possibility that these chromosomal changes were related to the relapse of AML in this case, we repeated the same FISH test on the specimen at initial diagnosis before any treatment. The same abnormalities were found. To our knowledge, this is the first case reported with subtelomeric t(5;9)(q35.3;q34.3) and the deletion of the RB1 gene in a patient with AML-M0. Whether the t(5;9) combined with the deletion of the RB1 gene plays an important role in the development of AML-M0 warrants further investigation.     

Diagnosis of four chromosome abnormalities of unknown origin by chromosome microdissection and subsequent reverse and forward painting

A molecular cytogenetic method consisting of chromosome microdissection and subsequent reverse/forward chromosome painting is a powerful tool to identify chromosome abnormalities of unknown origin. We present 4 cases of chromosome structural abnormalities whose origins were ascertained by this method. In one MCA/MR patient with an add(5q)chromosome, fluorescence in situ hybridization (FISH), using probes generated from a microdissected additional segment of the add(5q) chromosome and then from a distal region of normal chromosome 5, confirmed that the patient had a tandem duplication for a 5q35-qter segment. Similarly, we ascertained that an additional segment of an add(3p) chromosome in another MCA/MR patient had been derived from a 7q32-qter segment. In a woman with a history of successive spontaneous abortions and with a minute marker chromosome, painting using microdissected probes from the whole marker chromosome revealed that it was i(15)(p10) or psu dic(15;15)(q11;q11). Likewise, a marker observed in a fetus was a ring chromosome derived from the paracentromeric region of chromosome 19. We emphasize the value of the microdissection-based chromosome painting method in the identification of unknown chromosomes, especially for marker chromosomes. The method may contribute to a collection of data among patients with similar or identical chromosome abnormalities, which may lead to a better clinical syndrome delineation. © 1996 Wiley-Liss, Inc.     

多重荧光原位杂交结合染色体涂抹技术检测骨髓增生异常综合征复杂核型异常

目的探讨多重荧光原位杂交(multiplex fluorescence in situ hybridization,M-FISH)及全染色体涂抹(whole chromosome painting,WCP)技术在骨髓增生异常综合征(myelodysplastic syndromes,MDS)复杂核型异常检测中的价值。方法对7例常规R显带具有复杂染色体异常的MDS患者应用M-FISH技术确定复杂染色体的重排及标记染色体的组成,识别微小易位。并进一步采用双色WCP技术验证M-FISH检测的结果。结果M-FISH不仅证实了R显带的结果,而且确定了R带核型分析没有确定的6种标记染色体、9种有不明来源的额外物质增加的染色体、5种衍生染色体的组成和来源及4种被忽略的微小易位。涉及17号染色体的异常及-5/5q-是MDS最为常见的两种染色体异常。WCP技术纠正了一些M-FISH漏检及误检的异常。结论M-FISH是明确复杂染色体异常的很有用的分子生物学工具,WCP是M-FISH技术的重要补充,R带核型分析结合分子细胞遗传学工具M-FISH和WCP可以更加准确地描述复杂染色体异常。     

Two novel translocations disrupt the RUNX1 gene in acute myeloid leukemia

Translocations involving 21q22 are commonly observed in both de novo and therapy-related acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). They often result in the disruption of RUNX1 and give rise to fusion genes consisting of RUNX1 and different partner genes, which contribute to leukemogenesis. To date, at least 21 such translocations are known from the literature. Here we report two novel translocations involving the RUNX1 gene: t(1;21)(q12;q22) in a 53-year-old woman with AML-M5b and t(11;21)(q13;q22) in a 65-year-old man with AML-M2. The abnormalities revealed by R-banding karyotypic analysis were confirmed with interphase and metaphase fluorescence in situ hybridization (FISH), chromosome painting, and M-FISH.     

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。     

Comparative Karyotype of Rat and Mouse Using Bidirectional Chromosome Painting

A comparative karyotype of rat (Rattus norvegicus) and mouse (Mus musculus) based on chromosome G-banding morphology, heterologous chromosome painting results and available gene mapping data is proposed. Whole chromosome painting probes from both species were generated by PARM-PCR amplification of flow sorted chromosomes. Bidirectional chromosome painting identifies 36 segments of syntenic homology and allows us to propose a nearly complete comparative karyotype of mouse and rat (except for RNO 13 p and RNO 19 p12-13). Seven segments completely covered the RNO chromosomes 3, 5, 8, 11, 12, 15 and 18. Eight segments completely covered the MMU chromosomes 3, 4, 6, 7, 9, 12, 18 and 19. The RNO chromosomes 5, 8, 18 show complete homology with the MMU chromosomes 4, 9 and 18, respectively. Bidirectional hybridization results clearly assign 16 segments to subchromosomal regions in both species. Interpretation of the results allows subchromosomal assignment of all the remaining segments apart from seven distributed on chromosomes MMU 15, MMU 10 B2-D3 and MMU 17 E3-E5. The proposed comparative karyotype shows overall agreement with available comparative mapping data. The proposed repartition of syntenic homologous segments between the two species provides useful data for gene-mapping studies. In addition, these results will enable the reconstruction of the karyotype of the Cricetidae and Muridae common ancestor and the definition of the precise rearrangements which have occurred in both mouse and rat lineages during evolution. This revised version was published online in August 2006 with corrections to the Cover Date.     

Cytogenetic findings in 31 papillary thyroid carcinomas

Chromosome studies performed on 3I papillary thyroid carcinomas (PTCs) revealed clonal numerical and structural abnormalities in I2 tumors. The numerical clonal aberrations found were trisomy 2, trisomy 7, and loss of the Y chromosome. A nonrandom telomeric association, tas( I5; I6)(p I3; p I3), was observed in one carcinoma. Structural alterations with a breakpoint at I0q II.2 were detected in two tumors. Other chromosomes involved in rearrangements were chromosomes I, 2, 3, 5, 7, 9, II, 12, and 14. The observation of clonal changes of chromosome 2 [i(2)(qI0) and trisomy 2] in two tumors, which were both histologically classified as tall-cell PTC variants, suggests that gain of 2q may be important in the development of this morphological variant. © 1995 Wiley-Liss, Inc.     

Translocation 1;19--a new cytogenetic abnormality in acute lymphocytic leukemia

A study of the chromosomes of 125 consecutive patients with acute lymphocytic leukemia (ALL) showed the same translocation between chromosomes #1 and #19 in 5 patients. In 4 of the 5, the t(1;19)(q21;q13) was present at diagnosis. The fifth patient, who had Philadelphia chromosome positive (Ph1+) ALL, developed t(1;19) in first relapse. Trisomy 1q was involved in 2 of the 5 patients; 3 patients had additional abnormalities. All patients had low white cell counts at presentation (less than 35 X 10(9)/L), and the 4 patients tested had common ALL antigen (CALLA) positive leukemic blast cells. All achieved complete remission, including the Ph1+ ALL patient in first relapse, and survival times ranged from 4 to 21+ mo from the time the t(1;19) first appeared. Our data suggest that t(1;19) is a previously unrecognized nonrandom structural abnormality in ALL that is also found in other lymphoid malignancies. Unlike the other specific translocations, it is not associated with a poor prognosis.     

Cytogenetic aberrations in adult acute lymphocytic leukemia: optimal technique may influence the results.

The aim of the present study was to analyse the distribution of cytogenetic aberrations in adult ALL in a population based material and compare the results with literature data. Forty-one patients were diagnosed during a 12-year period. The age varied between 14 and 82 (mean 37, median 32). Thirty-two patients were cytogenetically investigated and in all cases analysable metaphases were obtained (range 10-29, mean 24, median 25, success rate: 100%). Nine (28%) patients had a T-phenotype and 23 (72%) had a pre-B phenotype. High hyperdiploidy was found in four patients (13%). Hypodiploidy was found in 5 patients (16%), 10 (31%) had a pseudodiploid chromosome mode and four (13%) showed low hyperdiploidy (chromosome mode 47-51). Chromosomes 10 and 18 were most frequently involved in numerical aberrations. Structural aberrations most frequently involved chromosomes 6, 9 and 22. t(9;22) was seen in six cases (19%), del(6q) in five cases (16%) and der(9p) in five cases (16%). High hyperdiploid clones, which are associated with a favorable prognosis, were found with the same frequency as in other studies. The frequency of t(9;22) was 19% in our study, others have found frequencies between 11% and 30%. Compared to previously published studies our patients with t(9;22) were younger. Furthermore, those with del(6q) were older, showing a median age equivalent to the patient group as a whole. The differences between our data and previously published studies may be explained by population-based derived data and especially by an optimal technique in obtaining metaphases.