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Numerical Chromosomal Abnormalities (numerical + chromosomal_abnormality)
Selected AbstractsNumerical chromosomal abnormalities in equine embryos produced in vivo and in vitroMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 1 2005B.P.B. Rambags Chromosomal aberrations are often listed as a significant cause of early embryonic death in the mare, despite the absence of any concrete evidence for their involvement. The current study aimed to validate fluorescent in situ hybridization (FISH) probes to label specific equine chromosomes (ECA2 and ECA4) in interphase nuclei and thereby determine whether numerical chromosome abnormalities occur in horse embryos produced either in vivo (n,=,22) or in vitro (IVP: n,=,20). Overall, 75% of 36,720 and 88% of 2,978 nuclei in the in vivo developed and IVP embryos were analyzable. Using a scoring system in which extra FISH signals were taken to indicate increases in ploidy and "missing" signals were assumed to be "false negatives," 98% of the cells were scored as diploid and the majority of embryos (30/42: 71%) were classified as exclusively diploid. However, one IVP embryo was recorded as entirely triploid and a further seven IVP and four in vivo embryos were classified as mosaics containing diploid and polyploid cells, such that the incidence of apparently mixoploid embryos tended to be higher for IVP than in vivo embryos (P,=,0.118). When the number of FISH signals per nucleus was examined in more detail for 11 of the embryos, the classification as diploid or polyploid was largely supported because 2,174 of 2,274 nuclei (95.6%) contained equal numbers of signals for the two chromosomes. However, the remaining 100 cells (4.4%) had an uneven number of chromosomes and, while it is probable that many were artefacts of the FISH procedure, it is also likely that a proportion were the result of other types of aneuploidy (e.g., trisomy, monosomy, or nullisomy). These results demonstrate that chromosomally abnormal cells are present in morphologically normal equine conceptuses and suggest that IVP may increase their likelihood. Definitive distinction between polyploidy, aneuploidy and FISH artefacts would require the use of more than one probe per chromosome and/or probes for more than two chromosomes. © 2005 Wiley-Liss, Inc. [source] Multiplex fluorescence in situ hybridization in identifying chromosome involvement of complex karyotypes in de novo myelodysplastic syndromes and acute myeloid leukemiaINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 1p1 2010W. XU Summary Complex chromosomal aberrations (CCA) can be detected in a substantial proportion of myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML), which are associated with very poor prognosis. Conventional cytogenetics (CC) cannot accurately define the specific alterations in CCA. Multiplex fluorescence in situ hybridization (M-FISH) allows the comprehensive identification of CCA. In this study, M-FISH was used in 16 patients with de novo MDS and 22 with AML with CCA detected by R-banding CC, and revealed 206 aberrations involved all 24 chromosomes, including 73 numerical chromosomal abnormalities and 133 structural abnormalities. The chromosomes most often involved were, by decreasing incidence, 5, 17, 8, 11, 7 and 21 in 57.9%, 55.3%, 44.7%, 36.8%, 34.2% and 34.2% of the cases, respectively. There were 98 unbalanced translocations, which were the most frequently observed aberrations in our study. Derivative chromosome 5 and 8 were implicated most often. The other derivatives were der(11), der(12), der(7), der(14), der(15) and der(17). Fourteen balanced translocations were detected in our series, and the most frequent reciprocal translocations was t(8;21). Fifty-five monosomies, 15 partial deletions, and 18 trisomies were found in all patients. The most frequently observed were ,5/5q,, ,17/17q,, ,7, ,18, ,21, ,19, and trisomy of chromosome 8 and 6. There were some abnormalities that have not been previously described, including two complex t(8;21) and seven unbalanced translocations. M-FISH could refine CCA, find or correct the missed or misidentified aberrations by CC analysis. Our findings confirmed that M-FISH was a powerful molecular cytogenetic tool to characterize complex karyotypes in MDS and AML. [source] Cytogenetic analysis of pediatric anaplastic large cell lymphoma,PEDIATRIC BLOOD & CANCER, Issue 3 2010Lara Mussolin PhD Abstract Background Anaplastic large cell lymphoma (ALCL) constitutes approximately 15% of pediatric and 3% of adult non-Hodgkin lymphomas. Most pediatric cases harbor the reciprocal translocation t(2;5)(p23;q35), involving the alk gene. Cytogenetic studies of ALCL have mostly been published as case-reports. The aim of this study was to determine the cytogenetic profiles of a series of pediatric ALCL and to compare them with pediatric and adult ALCL from the literature. Methods Eighteen children treated at our Institution were studied by standard cytogenetic analysis and RT-PCR for the specific t(2;5) translocation product. Comparative analysis was performed on our findings and on the karyotypes of 48 pediatric and 39 adult ALCL reported in the literature. Results Karyotype was obtained in 16/18 ALCL: 9 showed translocation t(2;5) and 1 an alk variant form. Structural and numeric chromosomal abnormalities were identified in both pediatric and adult series. Trisomies were found preferentially in pediatric patients (P,=,0.013) and monosomies in adults (P,=,0.038). Trisomy 7 was found in 22% (13/59) of pediatric cases with abnormal karyotype and only in 5% (2/38) of adults; monosomy of chromosome 13 in 13% (5/38) of adults and only in 2% (1/59) of pediatric patients and monosomy of chromosome 15 in 16% (6/38) of adults and in none of the pediatric ALCL. Conclusion Our data suggest that pediatric and adult ALCL are characterized by different numerical chromosomal abnormalities. Larger prospective studies may elucidate their potential prognostic impact. Pediatr Blood Cancer. 2010;55:446,451. © 2010 Wiley-Liss, Inc. [source] Cytogenetic analysis of trophoblasts by comparative genomic hybridization in embryo-fetal development anomaliesPRENATAL DIAGNOSIS, Issue 8 2001A. C. Tabet Abstract Cytogenetic studies of spontaneous abortions or intrauterine fetal death depend on conventional tissue culturing and karyotyping. This technique has limitations such as culture failure and selective growth of maternal cells. Fluorescent in situ hybridization (FISH) using specific probes permits diagnosis of aneuploidies but is limited to one or a few chromosomal regions. Comparative genomic hybridization (CGH) provides an overview of chromosomal gains and losses in a single hybridization directly from DNA samples. In a prospective study, we analyzed by CGH trophoblast cells from 21 fetuses in cases of spontaneous abortions, intrauterine fetal death or polymalformed syndrome. Six numerical chromosomal abnormalities including one trisomy 7, one trisomy 10, three trisomies 18, one trisomy 21 and one monosomy X have been correctly identified by CGH. One structural abnormality of the long arm of chromosome 1 has been characterized by CGH. One triploidy and two balanced pericentromeric inversions of chromosome 9 have not been identified by CGH. Sexual chromosomal constitutions were concordant by both classical cytogenetic technique and CGH. Contribution of trophoblast analysis by CGH in embryo-fetal development anomalies is discussed. Copyright © 2001 John Wiley & Sons, Ltd. [source] | |||||||||||||