Single-cell chromosomal imbalances detection by array CGH
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE4244 | GEO | 2006/02/16
SECONDARY ACCESSION(S): PRJNA94905
REPOSITORIES: GEO
Similar Datasets
Project description:In this study, we extend array CGH technology by making the accurate detection of segmental aneusomies possible from a single lymphoblast and fibroblast following Phi29 DNA polymerase amplification Array CGH experiments were performed on two segmental aneusomic cell lines derived from patients. As a proof of principle, an interstitial 4q-deletion (46, XX, del(4)(q13.1q22.3)) fibroblast cell line and an unbalanced reciprocal translocation involving chromosomes 14 and X (46, XX, der (X) t(X;14)(q21.3;q23.1)) EBV cell line were used. Array CGH experiments were performed using gDNA from the two cell lines to define the exact size of each rearrangement. For the 4q-deletion cell line, the size of the deleted region was 34 Mb corresponding to 39 clones spotted on the array (from RP11-340A13 to RP11-44P19). For the EBV cell line, the size of the 14q-duplication was 47 Mb corresponding to 63 clones (from RP11-62H20 to CTC-820M16) and the Xq-deletion was 58 Mb corresponding to 70 clones (from RP3-380C13 to RP11-218L14). For each cell line, three single cells were amplified. Following DNA amplification, all cells showed the expected DNA yields (n=6; ï?³ = 2.36 µg ï?± 0.12). Sex-mismatch array CGH experiments were conducted on amplified DNA samples obtained from the 4q-deletion cell line. Using the chromosome specific threshold obtained from our 18 experiments, sex chromosome and autosome ploidy levels were accurately identified with no false negative and no false positive results. Averaging the 39 clones within the chromosome 4q-deleted region enabled the accurate detection of the deletions. For each of the three amplified single-cell DNA of the unbalanced reciprocal translocation involving chromosomes 14 and X, male and female gDNA were used as references. Sex chromosome and autosome ploidy levels were accurately identified. Averaging intensity ratios of the 63 clones within the chromosome 14 duplicated region enabled the accurate detection of the duplications in the three replicate experiments. When, respectively, male or female gDNA were used as a reference, the average log2 mean ratio of the Xq-deleted region was â??0.04 or â??0.93, close to the theoretical expected value of 0 or minus 1. Interestingly, the log2 mean ratios of chromosomes 1 to 22 were highly similar when the same single cell amplified DNA was used for the two experiments using respectively female and male DNA as a reference. Hence, array CGH intensity ratio profiles were very reproducible.
2010-07-01 | E-GEOD-4244 | biostudies-arrayexpress
Project description:In this study, we extend array CGH technology by making the accurate detection of chromosomal imbalances possible from a single fibroblast and blastomere following Phi29 DNA polymerase amplification. Keywords: CGH
2006-02-01 | GSE3642 | GEO
Project description:Genomic imbalances are a major cause of constitutional and acquired disorders. Therefore, aneuploidy screening has become the cornerstone of preimplantation, prenatal and postnatal genetic diagnosis, as well as a routine aspect of the diagnostic workup of many acquired disorders. Recently, array comparative genomic hybridization (array CGH) has been introduced as a rapid and high-resolution method for the detection of both benign and disease-causing genomic copy-number variations. Until now, array CGH has been performed using a significant quantity of DNA derived from a pool of cells. Here, we present an array CGH method that accurately detects chromosomal imbalances from a single lymphoblast, fibroblast and blastomere within a single day. Trisomy 13, 18, 21 and monosomy X, as well as normal ploidy levels of all other chromosomes, were accurately determined from single fibroblasts. Moreover, we showed that a segmental deletion as small as 34 Mb could be detected. Finally, we demonstrated the possibility to detect aneuploidies in single blastomeres derived from preimplantation embryos. This technique offers new possibilities for genetic analysis of single cells in general and opens the route towards aneuploidy screening and detection of unbalanced translocations in preimplantation embryos in particular.
| S-EPMC3303179 | biostudies-literature
Project description:In this study, we extend array CGH technology by making the accurate detection of chromosomal imbalances possible from a single fibroblast and blastomere following Phi29 DNA polymerase amplification. Firstly, array CGH experiments were performed on four different fibroblast cell lines, derived from patients affected by, respectively, trisomy 13, 18, 21, and monosomy X. For each cell line, three single cells were amplified. Following DNA amplification, all cells showed the expected DNA yields (n=12; 1.87 µg plus:minus 0.39). Sex-mismatch array CGH experiments were conducted on amplified DNA samples obtained from each cell. Sex chromosome ploidy levels, as well as all expected autosomal abnormalities were clearly identified. Secondly, we applied single-cell aneuploidy screening for the detection of chromosomal imbalances in preimplantation embryos. DNA from blastomeres from three 7-8 cell-stage embryos was amplified by ï¦29 DNA polymerase. Following DNA amplification, all cells yielded the expected amount of DNA (n=16; 2.45 µg plus:minus 0.41). Chromosomal aneuploidies were accurately detected using a simple and rapid array CGH protocol.
2010-07-01 | E-GEOD-3642 | biostudies-arrayexpress
Project description:Highly specific amplification of complex DNA pools without bias or template-independent products (TIPs) remains a challenge. We have developed a procedure using phi29 DNA polymerase and trehalose and optimized control of amplification to create micrograms of specific amplicons without TIPs from down to sub-femtograms of DNA. The amplicons from 5 ng and 0.5 ng DNA, which were from originally good quality of gDNA (05-050), or partially degraded gDNA (04-018), faithfully demonstrated all previously known heterozygous segmental duplications and deletions (3 Mb to 18 kb) located on chromosome 22 and even a homozygous deletion smaller than 1 kb with high resolution chromosome-wide CGH. Specifically, HR-CGH with 5 ng-input gDNA-derived amplicon detected all previously known chromosomal segmental aberrations in chromosome 22 in samples from two different probands, and was indistinguishable from the HR-CGH result with native gDNA from the same probands (Fig. 4, Fig. S3 and S4). The break points were also precisely demonstrated. These include a heterozygous genomic segmental duplication (3 copies, 3 Mb in size, sample 05-050, Fig. 4) and 2 different heterozygous deletions (1 copy, 1.4 Mb and 18 kb respectively, sample 04-018, Fig. S4), all of which are located in or bounded by regions of low copy repeats (LCRs). In addition, a previous known homozygous deletion of 975 bp (in 04-018 and 05-050) was again accurately demonstrated (05-050 data showed in Fig. 4c), although sometimes (04-018) the data was a little noisier than with unamplified DNA (Fig. S4d). In contrast, the Wpa-40oC resulted in abundant signal noise and failed in detection of these copy number aberrations (Fig. 4, Fig. S3, S4). Impressively, HR-CGH with 0.5 ng gDNA-derived amplicons via Wpa also clearly detected the known CNVs, although noisier (Fig. S4). The 0.1ng gDNA derived amplicons via Wpa could not unambiguously show CNVs because of higher variability of signals, but the CNVs’ patterns were mostly well maintained (Fig. S4 for 04-018). We did also notice some locus-imbalance in the amplicon, however this was minimized, and was reproducible when the input was above a certain threshold amount, and it could be well compensated if the same amplified reference sample was applied in parallel as showed above. Keywords: Whole-pool amplification, high resolution comparative genome hybridization (HR-CGH)
2008-09-24 | GSE12731 | GEO
Project description:Comparative genomic hybridization microarrays (array CGH or molecular karyotyping) for the detection of congenital chromosomal aberrations is the application of microarray technology that is coming fastest into routine clinical application. When using a two-channel microarray of genomic DNA probes for array CGH, the basic setup consists in hybridizing a patient sample against a normal reference sample and detecting copy number variations through the deviation of fluorescent signal intensity between patient and normal reference. Two major disadvantages of this setup are (1) the use of half of the resources to measure a (little informative) reference sample and (2) the possibility that deviating signals are caused by benign copy number variation in the “normal” reference instead of a patient aberration. We therefore propose a new experimental loop design that compares three patients in three hybridizations (Patient 1 vs. Patient 3, Patient 3 vs. Patient 2, and Patient 2 vs. Patient 1). We develop and compare two statistical methods (linear models of log ratios and mixed models of absolute measurements). In an analysis of data from 27 patients seen at our genetics center, this new setup together with the linear model analysis significantly overcomes the limitations of the classical setup. Furthermore, we observed that the linear models of the log-ratios had a higher signal-to-noise ratio than the mixed models of the absolute intensities. These improvements are important to guarantee a maximal efficiency of array CGH in a clinical setting and will therefore contribute to its quick adoption as a routine diagnostic tool. The method is implemented as a web application and is available at www.esat.kuleuven.be/loop. Keywords: comparative genomic hybridization
2007-12-01 | GSE6538 | GEO
Project description:gDNA was obtained from 26 frozen ERMS tumors for aCGH and copy number analysis Tumors compared to nimblegen pooled male reference, using 2.1 Million probe Nimblegen array CGH Build 18 NCBI36
2011-03-01 | GSE27392 | GEO
Project description:Isolated deletions of the long arm of chromosome 5 (del(5q)) are observed in 10% of myelodysplastic syndromes (MDS) and are associated with a more favorable prognosis, although the clinical course varies considerably. If one or more additional chromosomal aberration/s are present this correlates with a significant shorter overall survival. To assess the frequency of hidden abnormalities in cases with an isolated cytogenetic del(5q), we have performed a genome wide high resolution 44K 60mer oligonucleotide array CGH study using DNA from bone marrow cells of 12 MDS and one AML patient. Additional chromosomal aberrations were identified in three of 13 cases (23%): in one case, a single additional hidden 5.6 Mb deletion of 13q14 and in two cases, multiple larger aberrations involving many chromosomes. Fluorescence in situ hybridization (FISH) demonstrated that aberrations present in only 10% of the bone marrow cells were detectable by aCGH. Furthermore with oligonucleotide aCGH the deletion end points in 5q were mapped precisely, revealing a cluster of proximal break points in band q14.3 (n=8) and a distal cluster between bands q33.2 to q34 (n=11). This study shows the high resolution of oligonucleotide CGH arrays for precisely mapping genomic alterations and for refinement of deletion end points. In addition the high sensitivity of this method enables the study of whole bone marrow cells from MDS patients, a disease with a low blast count. Future studies of more patients with isolated del(5q) for hidden abnormalities will be necessary to evaluate the impact of these on the variable prognosis in these patients and to further define new genetic subgroups. Keywords: Myelodysplastic syndromes, MDS, array CGH, del(5q), hidden aberrations
2007-09-11 | GSE8804 | GEO
Project description:Albinism Family Array CGH Data
| PRJNA785601 | ENA
Project description:This SuperSeries is composed of the following subset Series: GSE19360: Integrated array-CGH and expression microarray analyses on medulloblastomas in heterozygous Ptch1 mice, expression GSE19381: Integrated array-CGH and expression microarray analyses on medulloblastomas in heterozygous Ptch1 mice, aCGH 1 GSE19382: Integrated array-CGH and expression microarray analyses on medulloblastomas in heterozygous Ptch1 mice, aCGH 2 Refer to individual Series
2010-07-14 | E-GEOD-19384 | biostudies-arrayexpress