Abnormalities of chromosomes 7 and 22 in human malignant pleural mesothelioma: correlation between Southern blot and cytogenetic analyses.

Southern blot hybridization studies were performed on 23 mesothelioma primary tumor specimens to detect chromosome 1-, 7-, and 22-specific numerical changes, gene amplifications, and gene rearrangements. The molecular findings were compared with previous cytogenetic findings. No gene rearrangements or amplifications were detected. A numerical abnormality of chromosome 7 was detected by Southern blot analysis in two cases in which no numerical abnormality had been detected by the previous chromosome study. A numerical aberration of chromosome 22 was detected in five cases, which was compatible with the cytogenetic finding of monosomy 22 in these cases. The Southern blot results for the copy numbers of chromosomes 7 and 22 were concordant with the cytogenetic findings in 65%-80% of the cases.     

Comparative genomic hybridization detects multiple chromosomal amplifications and deletions in undifferentiated embryonal sarcoma of the liver

Undifferentiated embryonal sarcoma (UES) is the third most common hepatic malignancy in children. Previous reports have described a broad range of complex cytogenetic abnormalities in individual cases of hepatic UES. Herein we report the cytogenetic findings of six cases of hepatic UES at our institution analyzed by conventional cytogenetic methods and comparative genomic hybridization (CGH). The CGH demonstrated several chromosomal gains and deletions in each case, but there was no specific abnormality seen in every case. Patterns of chromosomal changes included gains of chromosome 1q (four cases), 5p (four cases), 6q (four cases), 8p (three cases), and 12q (three cases), and losses of chromosome 9p (two cases), 11p (two cases), and chromosome 14 (three cases). The three cases in which CGH showed gains in the 12q region were studied specifically for amplifications of MDM2 and CDK4, two genes that have been shown to be amplified in other soft tissue sarcomas. However, Southern analysis showed no amplification of MDM2 or CDK4 in these three cases. Further analysis will be needed to determine the critical events in the pathogenesis of these malignant pediatric liver tumors.     

Detection of numerical chromosomal abnormalities in neoplastic hematopoietic cells by in situ hybridization with a chromosome-specific probe.

The feasibility of using molecular hybridization techniques for the detection of malignant clones that contain numerical chromosomal abnormalities was tested in clinical specimens from patients who had hematologic malignancies. A biotinylated DNA probe specific for chromosome 9 was used for in situ hybridization to interphase and terminally differentiated cells, and fluoresceinated avidin or avidin followed by biotinylated alkaline phosphatase was used for probe detection. In a blinded analysis of ten clinical samples from patients with hematologic malignancies and cytogenetically documented monosomy 9 or trisomy 9, the abnormality was identified correctly in each of five cases of monosomy 9 and five cases of trisomy 9. In two cases of trisomy 9, the detection of this numerical chromosomal abnormality in nuclei of segmented neutrophils permitted the deduction that some granulocytic cells were derived from the abnormal clone, but were still capable of terminal differentiation. Analysis of the position of the probe signal in such nuclei did not disclose any ordered localization of the chromosome 9 homologues with respect to segmentation. These results demonstrate that interphase cytogenetic analysis is feasible in peripheral blood and bone marrow specimens, and that this technique may be a useful adjunct to conventional cytogenetic analysis for the clinical management of patients with hematopoietic malignancies.     

Complex cytogenetic changes in benign neoplasms. Report of six lipomas

We report the detailed cytogenetic findings from short-term cultures of six lipomas with complex chromosomal abnormalities. In all six cases, the abnormality occurred in two stages; an initial inversion, translocation, or insertion of the involved chromosome(s) followed by a subsequent rearrangement of the resultant derivative chromosome(s). A striking feature of these rearrangements was the consistent involvement of bands q13 - q14 on chromosome 12 in all the abnormalities. This region has been shown to be specifically rearranged in most of the lipomas studied. The other chromosomes involved in the rearrangements were chromosomes 1 in four cases, 5 and 9 in two cases each, and 2, 3, 4, 7, and 10 in one case each. Our findings and published findings show that, with a few exceptions, benign tumors that were previously considered cytogenetically normal, are characterized not only by specific numerical and structural changes but may also contain complex chromosome rearrangements that are generally considered a hallmark of advanced malignancy. In benign tumors, this suggests that the genes at the region of the breakpoints may represent proliferation-related genes or that benign tumors with such complex aberrations represent neoplasms potentially capable of undergoing transformation to malignancy, or both.     

Detection of deletions in de novo “balanced” chromosome rearrangements: Further evidence for their role in phenotypic abnormalities

Purpose: The purpose of this study was to test the hypothesis that deletions of varying sizes in de novo apparently balanced chromosome rearrangements are a significant cause of phenotypic abnormalities.Methods: A total of fifteen patients, with seemingly balanced de novo rearrangements by routine cytogenetic analysis but with phenotypic anomalies, were systematically analyzed. We characterized the breakpoints in these fifteen cases (two of which were ascertained prenatally), using a combination of high-resolution GTG-banding, fluorescence in situ hybridization (FISH) with bacterial artificial chromosomes (BACs), and data from the Human Genome Project.Results: Molecular cytogenetic characterization of the 15 patients revealed nine with deletions, ranging in size from 0.8 to 15.3 Mb, with the number of genes lost ranging from 15 to 70. In five of the other six cases, a known or putative gene(s) was potentially disrupted as a result of the chromosomal rearrangement. In the remaining case, no deletions were detected, and no known genes were apparently disrupted.Conclusions: Our study suggests that the use of molecular cytogenetic techniques is a highly effective way of systematically delineating chromosomal breakpoints, and that the presence of deletions of varying size is an important cause of phenotypic abnormalities in patients with “balanced” de novo rearrangements.     

Frequent gain of chromosome 19 in megakaryoblastic leukemias detected by comparative genomic hybridization

Acute megakaryocytic leukemia is a rare subtype of AML that is often difficult to diagnose; it is most commonly associated with Down syndrome in children. To identify chromosomal imbalances and rearrangements associated with acute megakaryocytic leukemia, we used G-banding, comparative genomic hybridization (CGH), and whole chromosome painting (WCP) on a variety of primary patients' samples and leukemia cell lines. The most common abnormality was gain of chromosome 19 or arm 19q, which was detected by CGH in four of 12 (33.3%) primary samples and nine of 11 (81.8%) cell lines. In none of the primary samples was this abnormality detected by G-banding analysis. WCP was used to define further the nature of the chromosome 19 gain in the cell lines, which was found to be due to the presence of additional 19q material on marker chromosomes or to cryptic translocations involving 19q. The most common chromosomal loss--detected only in the cell lines--was deletion of chromosomal band 13q14, which was seen in six of 11 (54.5%) cell lines. Other recurrent changes included gains of 1p, 6p, 8q, 11q, 15q, 17q, and 21q and losses of 2, 4q, 5q, 7q, 9p, and 11p. Combining conventional and molecular cytogenetic analyses defined recurrent clonal chromosomal abnormalities, which will aid in the identification of critical genes that are abnormal in acute megakaryocytic leukemia cells.     

Molecular cytogenetic characterization of Sézary syndrome

Sézary syndrome (SS) is a rare form of erythrodermic cutaneous T‐cell lymphoma with hematological involvement and a poor prognosis. At present little is known about the molecular pathogenesis of this malignancy. To address this issue, we analyzed 28 SS cases through the use of molecular cytogenetic techniques. Conventional cytogenetic analysis showed 12 of 28 cases with clonal chromosome abnormalities (43%). Seven cases had aberrations affecting chromosomes 1 and 17; five demonstrated rearrangement of chromosomes 10 and 14; four presented with an abnormality of 6q. Multiplex‐fluorescence in situ hybridization (M‐FISH) revealed complex karyotypes in 6 of 17 cases (35%), and recurrent der(1)t(1;10)(p2;q2) and der(14)t(14;15)(q;q?) translocations were each identified in two cases, and confirmed by dual‐color FISH. There was an overall difference in the incidence of clonal abnormalities detected by G‐banded karyotyping and M‐FISH. In addition, comparative genomic hybridization studies revealed chromosome imbalances (CIs) in 9 of 20 cases (45%), with a mean DNA copy number change per sample of 1.95 ± 2.74, and losses (mean: 1.25 ± 1.77) more frequent than gains (mean: 0.7 ± 1.26). The most common CIs noted were loss of 1p, followed by losses of 10/10q, 17p, and 19, and gains of 17q and 18. Furthermore, in conjunction with this study a systematic literature review was conducted, which showed a high frequency and consistent pattern of chromosome changes in SS. These findings suggest that chromosomal instability is common in SS, although there are specific chromosomal abnormalities that appear to be characteristic, and the identification of two different recurrent chromosome translocations provides the basis for further studies. © 2003 Wiley‐Liss, Inc.     

Combined spectral karyotyping and DAPI banding analysis of chromosome abnormalities in myelodysplastic syndrome.

Spectral karyotyping (SKY) is a new molecular cytogenetic technique that allows simultaneous visualization of each chromosome in a different color. We have used SKY for comprehensive analysis of 20 myelodysplastic syndromes (MDSs) (13 primary MDSs, 3 therapy-related MDSs, and 4 acute leukemias developed from MDS, including 1 cell line established from a secondary leukemia), previously analyzed by G-banding. To locate the chromosomal breakpoints, DAPI-counterstained band images from all metaphases were transformed to G-band-like patterns. By using SKY, it was possible to identify the origin and organization of all clonal marker chromosomes (mar), as well as the origin of all abnormalities defined as additional material of unknown origin (add) or homogeneously staining regions (hsr) by G-banding. In total, SKY identified the chromosomal basis of 38 mar, add, and hsr, corrected 8 abnormalities misidentified by G-banding, and revealed 6 cryptic translocations in 5 cases. Total or partial chromosomal loss (mainly of -5/5q- and -7/7q-) is the most frequent cytogenetic abnormality in MDS. In 3 of 11 cases with -5/5q- and in 4 of 8 with -7/7q-, lost material was detected by SKY in unbalanced translocations. A total of 60 chromosomal losses were identified by G-banding in 16 cases with multiple chromosome abnormalities involving at least 3 chromosomes. For 26 of these losses (43%), SKY analysis suggested that the losses were not complete, but had been translocated to a variety of partner chromosomes. Moreover, SKY analysis revealed that a ring chromosome in a case of acute leukemia developed from MDS contained three to six segments that originated from chromosome 21 material. Fluorescence in situ hybridization showed the amplification of the AML1 gene on regions derived from chromosome 21, providing the first evidence of amplification involving this gene in MDS. Genes Chromosomes Cancer 26:336-345, 1999.     

Subgroups of uterine leiomyomas based on cytogenetic analysis.

Chromosomes from 39 cases of benign uterine leiomyomas were studied. Consistent chromosomal abnormalities were detected in 15 cases (38.5%). Abnormalities involving chromosomes 12 and 14 with or without additional chromosomal changes were found in five cases (12.8%). Deletion of chromosome 7 was detected in five cases; in three cases (7.6%), this was the only abnormality present. Complex translocations involving X, 5, and 14 as well as X, 3, and 14 were observed in one case each. Insertion of a portion of chromosome 4 to chromosome 1, deletion involving chromosome 3, and nonreciprocal translocation between chromosomes 14 and 15 were observed in one case each. Monosomy 22, with a derived chromosome 14, was observed in one case. Trisomy 7 was also identified in one case. The structural and numeric abnormalities involved chromosomes X, 1, 2, 3, 4, 5, 6, 7, 9, 10, 12, 13, 14, 15, and 22. A normal 46,XX stem line with one or two abnormal cells was observed in 20 cases. Only normal karyotypes were obtained in the remaining four cases. A review of the literature and the results of our study indicate that uterine leiomyomas may be divided into eight groups based on cytogenetic analysis.     

A molecular cytogenetic study of chromosome 3 rearrangements in small cell lung cancer: consistent involvement of chromosome band 3q13.2.

To more precisely determine the nature of chromosome 3 rearrangements in small cell lung carcinomas (SCLCs), we have applied molecular cytogenetic technologies to a newly characterized SCLC tumor and five SCLC cell lines. Fluorescent in situ hybridization, chromosome microdissection, and, on the previously uncharacterized tumor, spectral karyotyping was utilized to determine chromosome 3 rearrangements. In all cases, our studies were performed on previously G-banded chromosomes in a sequential manner to facilitate a direct comparison. A consistent breakpoint on the long arm of chromosome 3 at band 3q13.2 was identified in all six tumors. This breakpoint was commonly the result of complex chromosomal rearrangements. Loss of the entire short arm of a chromosome 3 was noted in all six tumor cultures. Two of these cell lines had two sublines, one of which contained a 3q13.2 rearrangement and the other of which contained a chromosome rearrangement that resulted in loss of a chromosome 3 short arm. This consistent rearrangement at chromosome band 3q13.2, as demonstrated by molecular cytogenetic methods, may indicate the location of a gene important in the tumorigenesis of SCLC.     

Cytogenetic study of six cases of radiation-induced meningiomas

It is known that, following radiotherapy, secondary cancer may occur after a long latent period. Few cytogenetic studies have been reported on tumors of the central nervous system occurring after radiotherapy. We report the cytogenetic study of six cases of radiation-induced meningiomas. In all cases, we observed the same chromosome abnormality, der(1)(1qter-->1p11::22q12-->22pter). SKY and CGH techniques allowed us to identify the chromosomal abnormalities. We suggest that a gene localized on 1p13 is involved in radiation-induced meningiomas.     

A novel recurrent chromosomal aberration involving chromosome 7 in childhood myelodysplastic syndrome

Monosomy 7 and/or deletion of the long arm of chromosome 7 is a common cytogenetic aberration in children with myelodysplastic syndrome (MDS) and is associated with poor outcome. In this report, we present an unusual cytogenetic abnormality leading to loss of both the whole short and whole long arms of chromosome 7, which was found in the bone marrow cells of three pediatric patients with MDS. Using a combination of conventional and molecular cytogenetic methods, a tiny “dot-like” marker chromosome was found and described as der(7)del(7)(p11)del(7)(q11). Together with one previously published case, this chromosomal aberration represents a new rare recurrent karyotypic abnormality involving chromosome 7 in children with MDS.     

细菌人工染色体微珠联合染色体核型分析在产前诊断中的价值研究

目的探讨细菌人工染色体微珠(BACs-on-Beads,BoBs)联合染色体核型分析在产前诊断中的价值。方法2016年6月至2019年1月在本院接受侵入性产前诊断的2500例单胎妊娠孕妇作为研究对象,均采集羊水。同时进行羊水细胞的BoBs检测和染色体G显带核型分析。结果BoBs技术共检出93例胎儿染色体异常,检出率为3.72%,其中染色体数目异常78例(4例13号染色体三体,19例18号染色体三体,34例21号染色体三体,9例XXX,6例XXY,6例XYY)、染色体结构异常9例(6例未被核型分析检出)、嵌合型染色体6例。在6例染色体结构异常的胎儿中,DiGeorge综合征和Williams-Beuren综合征各1例,其余4例为染色体微缺失/微重复综合征。核型分析对胎儿异常的检出率为4.56%(114/2500),核型分析对染色体数目异常的检出率与BoBs检测相同。核型分析额外检出21例染色体结构异常和6例嵌合型染色体。结论染色体核型分析联合BoBs技术发挥了细胞遗传学和分子遗传学的技术优势,极大提高了染色体异常的检出率,值得在临床应用和推广。     

Malignant and reactive erythroblasts in erythroleukemia (M6)

A cytogenetic and cytological study of 16 cases of erythroleukemia (M6) is reported. No chromosomal abnormalities were observed in 10 cases. Abnormalities were present in the other 6 cases, of which 4 were complex abnormalities. It was not possible to establish any correlation between the occurrence of morphologic abnormalities of the erythroid and megakaryocyte-platelet series and the presence of cytogenetic defects. Studies of mitoses by cytologic and cytogenetic methods concurrently performed in some cases suggest that two types of erythroleukemia can be distinguished: (1) cases with chromosomal abnormalities and a persistence of erythroblast mitoses in vitro (which suggests that the erythroblasts belong to the leukemic clone) and (2) cases with no chromosome abnormality and a disappearance of erythroblast mitoses after culture, suggesting that the erythroblasts are not members of the leukemic clone.     

Characterization of complex chromosomal abnormalities in uveal melanoma by fluorescence in situ hybridization, spectral karyotyping, and comparative genomic hybridization

Several nonrandom recurrent chromosomal changes are observed in uveal melanoma. Some of these abnormalities, e.g., loss of chromosome 3, gain of the q arm of chromosome 8, and chromosome 6 abnormalities, are of prognostic value. Cytogenetic analysis and/or fluorescence in situ hybridization (FISH) are used to detect these changes. In some cases, however, detailed cytogenetic analysis is not possible due to the presence of complex abnormalities. To define more accurately these cytogenetic changes, we have applied comparative genomic hybridization (CGH) and/or spectral karyotyping (SKY) to two uveal melanoma cell lines and five primary uveal melanomas, with partially defined and/or complex abnormalities. SKY provided additional information on 34/39 partially defined aberrant chromosomes and revealed a new abnormality, a der(17)t(7;17)(?;q?), that had not been recognized by conventional cytogenetics. Additionally, using SKY, abnormalities involving chromosome 6 or 8 were found to be twice as common as observed with cytogenetic analysis. CGH was especially useful in assigning the abnormalities identified by SKY to specific chromosomal regions and, in addition, resulted in the detection of a small deletion of chromosome region 3q13 approximately 21. We conclude that SKY and CGH, as methods complementary to cytogenetic and FISH analysis, provide more complete information on the chromosomal abnormalities occurring in uveal melanoma.     

Correlation of cytogenetic analysis and loss of heterozygosity studies in human diffuse astrocytomas and mixed oligo-astrocytomas.

The aims of this study were to correlate cytogenetic studies and molecular genetic loss of heterozygosity (LOH) analyses in human astrocytomas and mixed oligo-astrocytomas, and to locate putative tumor suppressor genes on chromosome 10. Paired blood and tumor samples from 53 patients were analyzed. The tumors included 45 diffuse astrocytomas (39 grade 4, 4 grade 3, and 2 grade 2), 1 astroblastoma, and 7 mixed oligo-astrocytomas (2 grade 4, 4 grade 3, and 1 grade 2). By cytogenetic analyses the most common numeric chromosome abnormalities were +7, -10, -13, -14, -17, +19, -22, and -Y. The most common structural abnormalities involved chromosome arms 1p, 1q, 5p, and 9p. By LOH and dosage analysis the most common molecular genetic abnormalities were of chromosome arms 5p, 6p, 7q, 9p, 10p, 10q, 13q, 14q, 17p, and 19p. When the results of all methods were combined, the most commonly abnormal chromosomes were, in descending frequency, 10, Y, 17, 7, 13, and 9. In 80 percent of cases the cytogenetic and molecular genetic studies were concordant. LOH studies were more sensitive in detecting loss of genetic material than cytogenetic analyses and accounted for 60% of the discordant results. When there were structural abnormalities, such as translocations or inversions, cytogenetic analysis was more sensitive in detecting an abnormality than molecular genetic studies. In addition to the 24 tumors which appeared to lose an entire copy of chromosome 10, there were 10 tumors with molecular genetic or cytogenetic evidence of loss of only a portion of chromosome 10. The genetic analyses of these tumors suggest that there are 2 regions on chromosome 10 that may contain potential tumor suppressor genes. One lies distal to locus D10S22 from 10q22 to 10qter, and the other lies proximal to locus TST1 on the 10q arm near the centromere or on the 10p arm.     

Loss of 1p and 7p in radiation-induced meningiomas identified by comparative genomic hybridization

Cytogenetic and molecular studies of radiation-induced meningiomas (RIM) are rare and controversial. While comparative genomic hybridization (CGH) analysis identified monosomy 22 as the predominant change in RIM, occurring in frequencies comparable to those found in spontaneous meningioma (SM), molecular genetic analysis shows infrequent loss of chromosome 22 DNA markers. We have performed CGH analysis of six additional cases of RIM and detected an unbalanced genome in five of 6 cases. Loss of 1p and 7p was identified in the majority of RIM with an abnormal karyotype (4/5 cases), whereas loss of 6q occurred in three of five cases. Only one of five RIM had monosomy for chromosome 22. Loss of 7p is not frequently reported in SM and yet it was detected in four of 5 RIM with an abnormal karyotype in our study. Molecular and cytogenetic studies of chromosome 7 copy number should be attempted on a larger number of RIM to further investigate the role of 7p loss in RIM.