Towards a comprehensive structural variation map of an individual human genome
- Andy W Pang1, 2,
- Jeffrey R MacDonald2,
- Dalila Pinto2,
- John Wei2,
- Muhammad A Rafiq2,
- Donald F Conrad3,
- Hansoo Park4,
- Matthew E Hurles3,
- Charles Lee4,
- J Craig Venter5,
- Ewen F Kirkness5,
- Samuel Levy5,
- Lars Feuk†2, 6Email author and
- Stephen W Scherer†1, 2Email author
© Pang et al.; licensee BioMed Central Ltd. 2010
Received: 20 February 2010
Accepted: 19 May 2010
Published: 19 May 2010
Several genomes have now been sequenced, with millions of genetic variants annotated. While significant progress has been made in mapping single nucleotide polymorphisms (SNPs) and small (<10 bp) insertion/deletions (indels), the annotation of larger structural variants has been less comprehensive. It is still unclear to what extent a typical genome differs from the reference assembly, and the analysis of the genomes sequenced to date have shown varying results for copy number variation (CNV) and inversions.
We have combined computational re-analysis of existing whole genome sequence data with novel microarray-based analysis, and detect 12,178 structural variants covering 40.6 Mb that were not reported in the initial sequencing of the first published personal genome. We estimate a total non-SNP variation content of 48.8 Mb in a single genome. Our results indicate that this genome differs from the consensus reference sequence by approximately 1.2% when considering indels/CNVs, 0.1% by SNPs and approximately 0.3% by inversions. The structural variants impact 4,867 genes, and >24% of structural variants would not be imputed by SNP-association.
Our results indicate that a large number of structural variants have been unreported in the individual genomes published to date. This significant extent and complexity of structural variants, as well as the growing recognition of their medical relevance, necessitate they be actively studied in health-related analyses of personal genomes. The new catalogue of structural variants generated for this genome provides a crucial resource for future comparison studies.
Comprehensive catalogues of genetic variation are crucial for genotype and phenotype correlation studies [1–8], in particular when rare or multiple genetic variants underlie traits or disease susceptibility [9, 10]. Since 2007, several personal genomes have been sequenced, capturing different extents of their genetic variation content (Additional file 1) [1–8, 11]. In the first publication (J Craig Venter's DNA named HuRef) , variants were identified based on a comparison of the Venter assembly to the National Center for Biotechnology Information (NCBI) reference genome (build 36). In total, 3,213,401 SNPs and 796,167 structural variants (SVs; here SV encompasses all non-SNP variation) were identified in that study. Similar numbers of SNPs, but significantly less SVs (ranging from approximately 137,000 to approximately 400,000) are reported in other individual genome sequencing projects [2–4, 6–8, 11]. It is clear that even with deep sequence coverage, annotation of structural variation remains very challenging, and the full extent of SV in the human genome is still unknown.
Microarrays [12–14] and sequencing [15–18] have revealed that SV contributes significantly to the complement of human variation, often having unique population  and disease  characteristics. Despite this, there is limited overlap in independent studies of the same DNA source [21, 22], indicating that each platform detects only a fraction of the existing variation, and that many SVs remain to be found. In a recent study using high-resolution comparative genomic hybridization arrays, the authors found that approximately 0.7% of the genome was variable in copy number in each hybridization of two samples . Yet, these experiments were limited to the detection of unbalanced variation larger than 500 bp, and the total amount of variation between two genomes would therefore be expected to exceed 0.7%.
Structural variants detected by different methods
Minimum size (bp)
Median size (bp)
Maximum size (bp)
Total size (bp)
Assembly comparison a
Agilent 24 M
NimbleGen 42 M
Illumina 1 M
Custom Agilent 244 k
Non-redundant total b
Several different analytical and experimental strategies were employed to exhaustively analyze the Venter genome for SV. An overview of the different analyses performed is shown in Figure 1.
We first used computational strategies to extract additional SV information from the existing Sanger-based sequencing data generated as paired-end (or mate-pair) reads from clone libraries of defined size . First, we adopted a paired-end mapping approach [15, 17, 18] and aligned 11,346,790 mate-pairs from libraries with expected clone sizes of 2, 10 or 37 kb (Additional file 2) to the NCBI build 36 assembly. We found that 97.3% of mate-pairs had the expected mapping distance and orientation. Mate-pairs discordant in orientation or mapping distance were used to identify variants, and we required each event to be supported by at least two clones. In total, this strategy was used to identify 780 insertions, 1,494 deletions and 105 inversions (Figure 1; Table 1; Additional file 3). In an independent analysis of the same underlying sequencing data, we then captured SVs by examining the alignment profiles of 31,546,016 paired and unpaired reads to search for intra-alignment gaps . The presence of an intra-alignment gap in the sequence read (query sequence) or in the reference genome (target sequence) would indicate a putative insertion or deletion event, respectively. The identification of such a 'split-read' alignment signature complements the mate-pair approach, as significantly smaller insertions and deletions can be discovered. We required at least two overlapping split-reads having an alignment gap >10 bp to call a variant. A total of 8,511 insertions and 11,659 deletions ranging from 11 to 111,714 bp in size were identified (Figure 1; Table 1; Additional file 4).
Array based variation
We used two ultra-high density custom comparative genomic hybridization (CGH) array sets and two commonly used SNP genotyping arrays to identify relative gains and losses. A significant amount of variation was detected from the two custom CGH arrays: an Agilent oligonucleotide array set with 24 million features (Agilent 24 M) , and a NimbleGen oligonucleotide array set containing 42 million features (NimbleGen 42 M) . The Agilent platform identified 194 duplications and 319 deletions, while the NimbleGen array set detected 366 gains and 358 losses, ranging in size from 439 bp to 852 kb, in Venter (Figure 1; Table 1; Additional files 5 and 6). Furthermore, we scanned the Venter genome using Affymetrix SNP Array 6.0 and Illumina BeadChip 1 M, and the results are summarized in Table 1 plus Additional files 7 and 8.
Most microarrays used for CNV analyses are designed based on the NCBI assemblies. Therefore, any region where the reference exhibits the deletion allele of an indel, or sequences mapping to gaps in the assembly, will not be targeted. In previous studies [16, 24], many unknown DNA segments were identified to have no or poor alignment to the NCBI reference when compared to the Celera R27C assembly. To capture genetic variation in such potentially novel sequences, we designed a custom Agilent 244 K array to target those scaffold sequences at least 500 bp in length. We then performed CGH on seven HapMap individuals and detected 231 regions (101 gains and 130 losses) in 161 scaffolds to be variable (Additional file 9). Of these, we found 44 gains and 7 losses in 36 Celera scaffolds were specific to Venter (Figure 1, Table 1). Using paired-end mapping, as well as cross-species genome comparison with the chimpanzee, we were able to find a placement in NCBI build 36 for 25 of 36 scaffolds that were copy number variable in Venter. Two of the scaffolds were mapped to regions containing assembly gaps, 15 of 25 anchored scaffolds corresponded to insertion events also detected elsewhere [15, 18], and the remaining eight represent new insertion findings (Additional file 10).
Validation of findings
We used several computational and experimental approaches to validate our SV findings. We performed experimental validation by PCR amplification and gel-sizing and confirmed 89 of the 96 (93%) SVs predicted by sequence analysis (Additional files 11 and 12). Using quantitative real-time PCR (qPCR), we validated 20 of 25 (80.0000%) CNVs detected by microarrays, and most of these CNVs were from the custom Agilent 244 K array covering sequences not in the NCBI assembly (Additional file 13). Inversion predictions were tested by fluorescence in situ hybridization (FISH) . In one such finding, a predicted 1.1-Mb inversion at 16p12 was identified to be homozygous in Venter and in all of the seven additional HapMap samples from four populations tested, suggesting that the reference at this locus represents a rare allele, or is incorrectly assembled (Additional file 14).
We then compared the SVs identified here with the previous assembly comparison-based analysis of the same genome , and found that 11,140 variants were in common. We noticed that our multi-platform method excelled in calling large variants. In fact, even after excluding all of the small variants (≤ 10 bp) from the previous Levy at al. study , we still observed that the current study tended to find larger SVs (a current average of 1,909.3 bp now versus a previous average of 113.4 bp). Additional file 15 shows that the sensitivity of assembly comparison dropped as size increased to over 1 kb, and the proportion of larger SVs significantly increased as a result of the present study (Figure 2b, c).
Finally, we determined the number of calls in this study that were either verified by another platform in this study or found in the Database of Genomic Variants . In total, we computationally confirmed 15,642 (65.6%) of our current calls: 6,301 were gains; 9,726 were losses; and 65 were inversions.
Next, we compared the variants discovered by the two whole genome CGH array sets, NimbleGen 42 M and Agilent 24 M, and investigated the primary reason for the discordance between the two data sets. Not surprisingly, a substantial portion of the discordant calls can be explained by the difference in probe coverage. In fact, approximately 70% of the unique calls on the NimbleGen 42 M array had inadequate probe coverage on the Agilent 24 M array to be able to call variants, and approximately 30% vice versa (Additional file 16). After that, we compared the number of calls uniquely identified by the SNP-genotyping microarrays, and we identified 12 and 0 novel SVs contributed by Affymetrix 6.0 and Illumina 1 M, respectively. Of the 12 new Affymetrix calls, 9 are located in complex regions containing blocks of segmental duplications.
Subsequently, when looking for enrichment of genomic features among variants detected by different approaches, we found that there was a significant enrichment (P < 0.01) of short interspersed nuclear elements (SINEs) in deletions called by sequencing-based approaches (mate-pair and split-read), but not in deletions called by the microarrays. Microarrays have low sensitivity for detecting copy number change of SINEs (for example, Alu elements), as these regions cannot be uniquely targeted by short oligo probes, and over-saturation of probe fluorescence would prevent an accurate high copy count. Meanwhile, the sequencing methods employed here do not rely on alignments within the repeat itself, and consequently they are readily able to detect gains and losses of these high-copy repeats. The complete result for enrichment of SVs with various genomic features is shown in Additional file 17.
Finally, one of the main challenges of genome assembly is to correctly assemble both alleles in regions of SV. To identify heterozygous events among the split-read indels, we searched for evidence of an alternative allele. Indels were determined to be heterozygous if two or more sequence reads could be aligned that supported the NCBI build 36 allele. From the split-read dataset alone, we identified 4,476 of 8,511 (52.6%) insertions and 6,906 of 11,659 (59.2%) deletions as heterozygous. Additionally, we found that of the 10,834 split-read indels that overlapped with results from the Levy et al. study , 4,332 events annotated as heterozygous in our results were previously classified as homozygous (Additional file 4). These differences highlight the difficulty of assembling both alternative alleles in regions of SV, leading to an underestimate of the heterozygosity in Levy et al. .
The total variation content of the Venter genome
In an attempt to estimate the total variation content in the Venter genome, we combined the SVs previously described in the Venter genome in the Levy et al. paper  with the variants discovered in this study, to generate a non-redundant set of variants. We determined that 48,777,466 bp was structurally variable, of which 19,981,062 bp belonged to gains, 19,539,369 bp to losses, and 9,257,035 bp to balanced inversions (Table 1). A vast majority of this variation was discovered in the current analyses (83.3% or 40,625,059 bp) of the Venter genome. Therefore, our significant contribution in detecting novel calls underscores the importance of using multiple analysis strategies for detecting SV in the human genome. See Additional file 18 for the location of SVs >1 kb, and Additional files 19, 20 and 21 for a complete list of variation in the Venter genome.
Comparison with other personal genomes
Functional importance of structural variation
Genomic landscape and structural variants in the Venter genome*
Total non-redundant gainsb
Total non-redundant lossesc
Genomic feature (number of entries)a
Number of (%) genomic features
Number of (%) structural variants
Number of (%) genomic features
Number of (%) structural variants
RefSeq gene locid (20,174)
RefSeq gene entire transcript locie (20,174)
RefSeq gene exonsf (20,174)
Enhancer elements (837)
Stop codonsg (30,885)
OMIM disease gene loci (3,737)
OMIM disease gene exons (3,737)
Autosomal dominant gene loci (316)
Autosomal dominant gene exons (316)
Autosomal recessive gene loci (472)
Autosomal recessive gene exons (472)
Cancer disease gene loci (363)
Cancer disease gene exons (363)
Dosage sensitive gene loci (145)
Dosage sensitive gene exons (145)
Genomic disorders (52)
Pharmacogenetic gene loci (186)
Pharmacogenetic gene exons (186)
Imprinted gene loci (59)
Imprinted gene exons (59)
GWAS loci (419)
GWAS SNPs (419)
CpG islands (14,867)
DNAseI hypersensitivity sites (95,709)
Recombination hotspots (32,996)
Segmental duplications (51,809)
Ultra-conserved elements (481)
Affy 6.0 SNPsh (907,691)
Illumina 1 M SNPsi (1,048,762)
Currently, direct-to-consumer testing companies and genome-wide association studies mainly use microarray-based SNP data [26, 27], but SVs are typically not considered. Venter indels/CNVs, however, overlap with 4,565 and 7,047 of SNPs on the Affymetrix SNP-Array 6.0 and Illumina-BeadChip 1 M products (two commonly used arrays) potentially impacting genotype calling, most notably when deletions are involved.
Human geneticists have long sought to know the extent of genetic variation and here, in the most comprehensive analysis to date, we present the latest estimates of greater than 1% within an individual genome. Using multiple computational and experimental approaches, this study substantially expands on the SV map initially constructed by Levy and colleagues ; more than 80% of the total 48,777,466 structurally variable bases have not been reported from the original sequencing of the Venter genome.
Our study here differs from previous studies in many ways. Our mate-pair approach makes use of multiple different clone insert sizes, ranging from 2 to 37 kb, and this enables us to detect a wide size range of variants compared to previous paired-end mapping focused studies [15, 17, 18]. Furthermore, the long sequence reads used here increase alignment accuracy, and enable the identification of intra-alignment gaps. Using microarrays, we are able to identify large size variants that can be challenging to identify by sequencing.
Furthermore, our results highlight that each variation-discovery strategy has limitations and that no single approach can capture the entire spectrum of genetic variation, thus emphasizing the importance of applying multiple strategies in SV detection. Figure 4 shows that the variation distribution of other personal genome sequencing studies, which relied almost exclusively on NGS technology, is substantially lower than the Venter annotation across many size ranges.
There are still some regions, such as heterochromatin (Additional file 18) and highly identical segmental duplication regions, where all of the current approaches have limited detection capabilities. To prevent false discovery, we have used stringent alignment criteria, excluded alignments to multiple high-identity sequences, and will therefore likely miss variants within or flanking these sequences. Insufficient probe coverage and low intensity ratio fold-change also prevent microarrays from capturing CNV of highly repetitive sequences (for example, Alu elements). As such, we suspect there will be more variants to be discovered, but their ascertainment will require specialized experimental [18, 28] and algorithmic [29–31] approaches. Further increases in read-depth can yield new variants. Indeed, the greatest relative number of SVs discovered in Venter is in the 10-kb size range (Figure 2), corresponding to the interval with the highest clone coverage  (Additional file 2). As expected, our results also show that using several libraries with different insert size leads to increased variation discovery.
The importance of SV to gene expression (direct and indirect) , protein structure , and chromosome stability [34, 35] is being increasingly recognized in normal development and disease [9, 20]. At the same time we show that SVs are: 1, grossly under-represented in published NGS sequencing projects; 2, not always imputable by SNP-based association; 3, ubiquitous along chromosomes impacting all known functional genomic features; and 4, often large, complex, and under negative or purifying selection [19, 36]. Coupling these observations with conjectures that prophylactic decisions will be best informed by higher-penetrance rare alleles  and that common SNPs explain only a proportion of heritability  argue persuasively that SVs should gain more prominence in genomic medicine.
Our results present the most thorough estimate to date of the total complement of genetic variation across the entire size spectrum in a human genome. Our findings indicate that, to date, NGS-based personal genome studies, despite having generated a significant amount of valuable genomic information, have captured only a fraction of SVs, with substantial gaps in discovery at specific points along the size range of variation. Our data indicate that SV discovery is largely dependent on the strategy used, and presently there is no single approach that can readily capture all types of variation and that a combination of strategies is required. The data also show that structural variation impact many genes that have been linked to human disease phenotypes, and that interpretation of these data is complex . Current genotyping services offered in the personal genomics field do not always include screening for SVs, and we find that interpretation of current SNP-based screening may be significantly impacted by the existence of SVs. We also show that many SVs will not be amenable to capture using imputation strategies from high density SNP data, arguing for direct detection of SVs as a complement to SNP analysis.
Materials and methods
The sequence data of J Craig Venter's genome (or the Venter genome) used for analysis was originally produced through experiments performed in the Venter et al.  and Levy et al.  studies. The sequence trace data and information files were downloaded from NCBI. In this study, we aligned 31,546,016 Venter sequences to the NCBI human genome assembly build 36 using BLAT . For paired-end mapping, the optimal placement of clone ends was determined by a modified version of the scoring scheme used in Tuzun et al. . We categorized mate-pairs that mapped less than three standard deviations from the expected clone size as putative insertions, greater than three standard deviations as putative deletions, and in the wrong orientation as putative inversions. We required each variant to be confirmed by at least two clones, and for indels, we required the clones to be from libraries of the same average insert size (2 kb, 10 kb or 37 kb). To identify small variants, the read alignment profiles were further examined for an intra-alignment gap with size greater than 10 bp. Two independent 'split-reads' were required to call a putative variant.
An Agilent 24 million features CGH array set (Agilent 24 M) was designed with 23.5 million 60-mer oligonucleotide probes tiled along the NCBI build 36 assembly. The Venter genomic DNA was co-hybridized with the female sample NA15510 from the Polymorphism Discovery Resource . The statistical algorithm ADM-2 by Agilent Technologies was used to identify CNVs based on the combined log 2 ratios. Similar experimental procedures and analyses are described in other studies [7, 41]. Additionally, a custom NimbleGen 42 million features CGH microarray (NimbleGen 42 M) was used in this study - its design, experimental procedures and data analysis have been described in detail elsewhere [19, 22]. Venter genomic DNA was also co-hybridized with the sample NA15510. For both the Agilent 24 M and NimbleGen 42 M arrays, CNVs with >50% reciprocal overlap and opposite orientation of variants identified in NA15510 in Conrad et al.  were removed, as these were specific to the reference.
The Venter sample was also run on the Affymetrix SNP Array 6.0 and Illumina BeadChip 1 M genotyping arrays. We followed the protocol recommended by the manufacturers. For Affymetrix 6.0, the default parameters in the BirdSeed v2 algorithm were used to perform SNP calling. Partek Genomics Suite (Partek Inc., St. Louis, Missouri, USA), Genotyping Console (Affymetrix, Inc., Santa Clara, California, USA), BirdSuite  and iPattern (J Zhang et al., manuscript submitted) were used to call CNVs. For Illumina 1 M, the SNP calling was done using the BeadStudio software. QuantiSNP  and iPattern were used to identify CNVs. For both platforms, only variants confirmed by at least two calling algorithms were included in the final set of calls.
The Agilent Custom Human 244 K CGH array (Agilent 244 K) was designed to target 9,018 sequences >500 bp in length that were annotated as 'unmatched' sequences in Khaja et al. . CGH experiments were performed with genomic DNA from Venter and six HapMap samples, hybridized against reference NA10851. Feature extraction and normalization were performed using the Agilent feature extraction software. The programs ADM-1 in the DNA Analytics 4.0 suite (Agilent Technologies, Santa Clara, California, USA), and GADA  were independently used to call CNVs, and those that were confirmed by both algorithms were then used in this study.
Non-redundant variant data set
To generate a non-redundant set of Venter variants, we combined the lists of SVs generated. For CNVs, to determine if two calls are the same, we required that they shared a minimum of 50% size reciprocal overlap; for inversions, we required that they shared at least one boundary. For those calls that were indicated to be the same variant, we recorded the one with the best size/boundary estimate (with preference given to assembly comparison, then split-read, NimbleGen-42 M, Agilent 24 M, mate-pair, Affymetrix 6.0, and Illumina 1 M, in that order). For this analysis, we excluded variants called in the custom Agilent 244 K arrays.
PCR and quantitative real-time PCR validation
We used multiple computational and experimental approaches to validate SVs found in this project. PCR primers were designed to target flanking sequences of indels detected by sequencing-based methods, such that PCR products representing the different alleles can be differentiated on a 1.5% agarose gel. DNA from Venter and five HapMap individuals of European ancestry were tested in PCR experiments. Amplifications and deletions detected by CGH arrays were tested by qPCR. DNA from Venter and six additional control individuals were used to assess the variability in copy number. Each assay was run in triplicate and the FOXP2 gene was used as the reference for relative quantifications. See Additional file 12 for all primer sequences.
To validate large variants, FISH experiments were performed using fosmid clones as probes on a lymphoblastoid cell line from Venter and seven other HapMap individuals. Five metaphases were first imaged to check for correct chromosome localization and hybridization, and then interphase FISH was performed to validate predicted inversions, similar to the protocol outlined in the Feuk et al. study  with the addition of the aqua probe, DEAC-5-dUTP (Perkin Elmer, Waltham, Massachusetts, USA; NEL455).
Overlap with other datasets, genomic features and between subsets of data in the current paper was performed using custom PERL scripts. When comparing variants, two sites were considered overlapping if the reciprocal overlap among their estimated sizes was ≥ 50%. Data sources used for the annotations of overlaps with genomic features are listed in Additional file 17. To evaluate significance, we created 1,000 randomized sets of simulated variant calls and performed overlap analysis against the same data source. For each simulation, we recorded the number of instances where we observed a higher number of overlaps than the real variant data set. A P-value was computed as the fraction of simulations whose number of overlaps was greater than the number of real overlaps.
Structural variation imputation
Using a cutoff of 50% reciprocal overlap, there were 405 sites of overlap between the Venter and genotyped, validated Genome Structural Variation (GSV) loci. The best r2 value was computed between each of those GSV CNVs and a European's HapMap SNP in the neighboring genomic region. Here, we defined a minimum threshold of r2 = 0.8, below which the Venter SVs were deemed not well imputed by SNP. Detailed description on genotyping, phasing, and tagging calls onto haplotypes defined by HapMap SNPs is presented in the Conrad et al. study .
The sequence trace files generated from previous studies [1, 39] can be obtained from the 'NCBI Trace Archive', using queries [CENTER_NAME = "JCVI" and SPECIES_CODE = "HOMO SAPIENS" and center_project = "GENOMIC-SEQUENCING-DIPLOID-HUMAN-REFERENCE-GENOME"], [INSERT_SIZE = 10201 and CENTER_NAME = "CRA" and SPECIES_CODE = "homo sapiens"], and [INSERT_SIZE = 1925 and CENTER_NAME = "CRA" and SPECIES_CODE = "homo sapiens"]. All of the microarray data generated in this study are available at the Gene Expression Omnibus (GEO) under the accession number [GEO:GSE20290]. The SV locations, size, and zygosity (when available), are reported in Additional files 3, 4, 5, 6, 7, 8 and 9, and a non-redundant set of variant data in the Venter genome is reported in Additional files 19, 20 and 21.
comparative genomic hybridization
copy number variation
fluorescence in situ hybridization
Genome Structural Variation
National Center for Biotechnology Information
next generation sequencing
Online Mendelian Inheritance in Man
quantitative real-time PCR
short interspersed nuclear element
single nucleotide polymorphism
The work is supported by Genome Canada/Ontario Genomics Institute, the Canadian Institutes of Health Research (CIHR), the McLaughlin Centre for Molecular Medicine, the Canadian Institute for Advanced Research, and the Hospital for Sick Children (SickKids) Foundation. AWP holds the Natural Sciences and Engineering Research Council of Canada (NSERC) Alexander Graham Bell Canada Graduate Scholarship. DP is supported by fellowships from the Royal Netherlands Academy of Arts and Sciences (TMF/DA/5801) and the Netherlands Organization for Scientific Research (Rubicon, 825.06.031). LF is supported by the Göran Gustafsson Foundation and the Swedish Foundation for Strategic Research. SWS holds the GlaxoSmithKline-CIHR Pathfinder Chair in Genetics and Genomics at the University of Toronto and Hospital for Sick Children.
- Levy S, Sutton G, Ng PC, Feuk L, Halpern AL, Walenz BP, Axelrod N, Huang J, Kirkness EF, Denisov G, Lin Y, MacDonald JR, Pang AW, Shago M, Stockwell TB, Tsiamouri A, Bafna V, Bansal V, Kravitz SA, Busam DA, Beeson KY, McIntosh TC, Remington KA, Abril JF, Gill J, Borman J, Rogers YH, Frazier ME, Scherer SW, Strausberg RL, et al: The diploid genome sequence of an individual human. PLoS Biol. 2007, 5: e254-10.1371/journal.pbio.0050254.PubMedPubMed CentralView ArticleGoogle Scholar
- Wheeler DA, Srinivasan M, Egholm M, Shen Y, Chen L, McGuire A, He W, Chen YJ, Makhijani V, Roth GT, Gomes X, Tartaro K, Niazi F, Turcotte CL, Irzyk GP, Lupski JR, Chinault C, Song XZ, Liu Y, Yuan Y, Nazareth L, Qin X, Muzny DM, Margulies M, Weinstock GM, Gibbs RA, Rothberg JM: The complete genome of an individual by massively parallel DNA sequencing. Nature. 2008, 452: 872-876. 10.1038/nature06884.PubMedView ArticleGoogle Scholar
- Bentley DR, Balasubramanian S, Swerdlow HP, Smith GP, Milton J, Brown CG, Hall KP, Evers DJ, Barnes CL, Bignell HR, Boutell JM, Bryant J, Carter RJ, Keira Cheetham R, Cox AJ, Ellis DJ, Flatbush MR, Gormley NA, Humphray SJ, Irving LJ, Karbelashvili MS, Kirk SM, Li H, Liu X, Maisinger KS, Murray LJ, Obradovic B, Ost T, Parkinson ML, Pratt MR, et al: Accurate whole human genome sequencing using reversible terminator chemistry. Nature. 2008, 456: 53-59. 10.1038/nature07517.PubMedPubMed CentralView ArticleGoogle Scholar
- Wang J, Wang W, Li R, Li Y, Tian G, Goodman L, Fan W, Zhang J, Li J, Zhang J, Guo Y, Feng B, Li H, Lu Y, Fang X, Liang H, Du Z, Li D, Zhao Y, Hu Y, Yang Z, Zheng H, Hellmann I, Inouye M, Pool J, Yi X, Zhao J, Duan J, Zhou Y, Qin J, et al: The diploid genome sequence of an Asian individual. Nature. 2008, 456: 60-65. 10.1038/nature07484.PubMedPubMed CentralView ArticleGoogle Scholar
- Ley TJ, Mardis ER, Ding L, Fulton B, McLellan MD, Chen K, Dooling D, Dunford-Shore BH, McGrath S, Hickenbotham M, Cook L, Abbott R, Larson DE, Koboldt DC, Pohl C, Smith S, Hawkins A, Abbott S, Locke D, Hillier LW, Miner T, Fulton L, Magrini V, Wylie T, Glasscock J, Conyers J, Sander N, Shi X, Osborne JR, Minx P, et al: DNA sequencing of a cytogenetically normal acute myeloid leukaemia genome. Nature. 2008, 456: 66-72. 10.1038/nature07485.PubMedPubMed CentralView ArticleGoogle Scholar
- Ahn SM, Kim TH, Lee S, Kim D, Ghang H, Kim D, Kim BC, Kim SY, Kim WY, Kim C, Park D, Lee YS, Kim S, Reja R, Jho S, Kim CG, Cha JY, Kim KH, Lee B, Bhak J, Kim SJ: The first Korean genome sequence and analysis: Full genome sequencing for a socio-ethnic group. Genome Res. 2009, 19: 1622-1629. 10.1101/gr.092197.109.PubMedPubMed CentralView ArticleGoogle Scholar
- Kim JI, Ju YS, Park H, Kim S, Lee S, Yi JH, Mudge J, Miller NA, Hong D, Bell CJ, Kim HS, Chung IS, Lee WC, Lee JS, Seo SH, Yun JY, Woo HN, Lee H, Suh D, Lee S, Kim HJ, Yavartanoo M, Kwak M, Zheng Y, Lee MK, Park H, Kim JY, Gokcumen O, Mills RE, Zaranek AW, et al: A highly annotated whole-genome sequence of a Korean individual. Nature. 2009, 460: 1011-1015.PubMedPubMed CentralGoogle Scholar
- McKernan KJ, Peckham HE, Costa GL, McLaughlin SF, Fu Y, Tsung EF, Clouser CR, Duncan C, Ichikawa JK, Lee CC, Zhang Z, Ranade SS, Dimalanta ET, Hyland FC, Sokolsky TD, Zhang L, Sheridan A, Fu H, Hendrickson CL, Li B, Kotler L, Stuart JR, Malek JA, Manning JM, Antipova AA, Perez DS, Moore MP, Hayashibara KC, Lyons MR, Beaudoin RE, et al: Sequence and structural variation in a human genome uncovered by short-read, massively parallel ligation sequencing using two-base encoding. Genome Res. 2009, 19: 1527-1541. 10.1101/gr.091868.109.PubMedPubMed CentralView ArticleGoogle Scholar
- Feuk L, Carson AR, Scherer SW: Structural variation in the human genome. Nat Rev Genet. 2006, 7: 85-97. 10.1038/nrg1767.PubMedView ArticleGoogle Scholar
- Bodmer W, Bonilla C: Common and rare variants in multifactorial susceptibility to common diseases. Nat Genet. 2008, 40: 695-701. 10.1038/ng.f.136.PubMedPubMed CentralView ArticleGoogle Scholar
- Drmanac R, Sparks AB, Callow MJ, Halpern AL, Burns NL, Kermani BG, Carnevali P, Nazarenko I, Nilsen GB, Yeung G, Dahl F, Fernandez A, Staker B, Pant KP, Baccash J, Borcherding AP, Brownley A, Cedeno R, Chen L, Chernikoff D, Cheung A, Chirita R, Curson B, Ebert JC, Hacker CR, Hartlage R, Hauser B, Huang S, Jiang Y, Karpinchyk V, et al: Human genome sequencing using unchained base reads on self-assembling DNA nanoarrays. Science. 2010, 327: 78-81. 10.1126/science.1181498.PubMedView ArticleGoogle Scholar
- Iafrate AJ, Feuk L, Rivera MN, Listewnik ML, Donahoe PK, Qi Y, Scherer SW, Lee C: Detection of large-scale variation in the human genome. Nat Genet. 2004, 36: 949-951. 10.1038/ng1416.PubMedView ArticleGoogle Scholar
- Sebat J, Lakshmi B, Troge J, Alexander J, Young J, Lundin P, Maner S, Massa H, Walker M, Chi M, Navin N, Lucito R, Healy J, Hicks J, Ye K, Reiner A, Gilliam TC, Trask B, Patterson N, Zetterberg A, Wigler M: Large-scale copy number polymorphism in the human genome. Science. 2004, 305: 525-528. 10.1126/science.1098918.PubMedView ArticleGoogle Scholar
- Redon R, Ishikawa S, Fitch KR, Feuk L, Perry GH, Andrews TD, Fiegler H, Shapero MH, Carson AR, Chen W, Cho EK, Dallaire S, Freeman JL, Gonzalez JR, Gratacos M, Huang J, Kalaitzopoulos D, Komura D, MacDonald JR, Marshall CR, Mei R, Montgomery L, Nishimura K, Okamura K, Shen F, Somerville MJ, Tchinda J, Valsesia A, Woodwark C, Yang F, et al: Global variation in copy number in the human genome. Nature. 2006, 444: 444-454. 10.1038/nature05329.PubMedPubMed CentralView ArticleGoogle Scholar
- Tuzun E, Sharp AJ, Bailey JA, Kaul R, Morrison VA, Pertz LM, Haugen E, Hayden H, Albertson D, Pinkel D, Olson MV, Eichler EE: Fine-scale structural variation of the human genome. Nat Genet. 2005, 37: 727-732. 10.1038/ng1562.PubMedView ArticleGoogle Scholar
- Khaja R, Zhang J, MacDonald JR, He Y, Joseph-George AM, Wei J, Rafiq MA, Qian C, Shago M, Pantano L, Aburatani H, Jones K, Redon R, Hurles M, Armengol L, Estivill X, Mural RJ, Lee C, Scherer SW, Feuk L: Genome assembly comparison identifies structural variants in the human genome. Nat Genet. 2006, 38: 1413-1418. 10.1038/ng1921.PubMedPubMed CentralView ArticleGoogle Scholar
- Korbel JO, Urban AE, Affourtit JP, Godwin B, Grubert F, Simons JF, Kim PM, Palejev D, Carriero NJ, Du L, Taillon BE, Chen Z, Tanzer A, Saunders AC, Chi J, Yang F, Carter NP, Hurles ME, Weissman SM, Harkins TT, Gerstein MB, Egholm M, Snyder M: Paired-end mapping reveals extensive structural variation in the human genome. Science. 2007, 318: 420-426. 10.1126/science.1149504.PubMedPubMed CentralView ArticleGoogle Scholar
- Kidd JM, Cooper GM, Donahue WF, Hayden HS, Sampas N, Graves T, Hansen N, Teague B, Alkan C, Antonacci F, Haugen E, Zerr T, Yamada NA, Tsang P, Newman TL, Tuzun E, Cheng Z, Ebling HM, Tusneem N, David R, Gillett W, Phelps KA, Weaver M, Saranga D, Brand A, Tao W, Gustafson E, McKernan K, Chen L, Malig M, et al: Mapping and sequencing of structural variation from eight human genomes. Nature. 2008, 453: 56-64. 10.1038/nature06862.PubMedPubMed CentralView ArticleGoogle Scholar
- Conrad DF, Pinto D, Redon R, Feuk L, Gokcumen O, Zhang Y, Aerts J, Andrews TD, Barnes C, Campbell P, Fitzgerald T, Hu M, Ihm CH, Kristiansson K, Macarthur DG, Macdonald JR, Onyiah I, Pang AW, Robson S, Stirrups K, Valsesia A, Walter K, Wei J, Tyler-Smith C, Carter NP, Lee C, Scherer SW, Hurles ME: Origins and functional impact of copy number variation in the human genome. Nature. 2010, 464: 704-712. 10.1038/nature08516.PubMedPubMed CentralView ArticleGoogle Scholar
- Buchanan JA, Scherer SW: Contemplating effects of genomic structural variation. Genet Med. 2008, 10: 639-647. 10.1097/GIM.0b013e318183f848.PubMedView ArticleGoogle Scholar
- Harismendy O, Ng PC, Strausberg RL, Wang X, Stockwell TB, Beeson KY, Schork NJ, Murray SS, Topol EJ, Levy S, Frazer KA: Evaluation of next generation sequencing platforms for population targeted sequencing studies. Genome Biol. 2009, 10: R32-10.1186/gb-2009-10-3-r32.PubMedPubMed CentralView ArticleGoogle Scholar
- Scherer SW, Lee C, Birney E, Altshuler DM, Eichler EE, Carter NP, Hurles ME, Feuk L: Challenges and standards in integrating surveys of structural variation. Nat Genet. 2007, 39: S7-15. 10.1038/ng2093.PubMedPubMed CentralView ArticleGoogle Scholar
- Mills RE, Luttig CT, Larkins CE, Beauchamp A, Tsui C, Pittard WS, Devine SE: An initial map of insertion and deletion (INDEL) variation in the human genome. Genome Res. 2006, 16: 1182-1190. 10.1101/gr.4565806.PubMedPubMed CentralView ArticleGoogle Scholar
- Istrail S, Sutton GG, Florea L, Halpern AL, Mobarry CM, Lippert R, Walenz B, Shatkay H, Dew I, Miller JR, Flanigan MJ, Edwards NJ, Bolanos R, Fasulo D, Halldorsson BV, Hannenhalli S, Turner R, Yooseph S, Lu F, Nusskern DR, Shue BC, Zheng XH, Zhong F, Delcher AL, Huson DH, Kravitz SA, Mouchard L, Reinert K, Remington KA, Clark AG, et al: Whole-genome shotgun assembly and comparison of human genome assemblies. Proc Natl Acad Sci USA. 2004, 101: 1916-1921. 10.1073/pnas.0307971100.PubMedPubMed CentralView ArticleGoogle Scholar
- Feuk L, MacDonald JR, Tang T, Carson AR, Li M, Rao G, Khaja R, Scherer SW: Discovery of human inversion polymorphisms by comparative analysis of human and chimpanzee DNA sequence assemblies. PLoS Genet. 2005, 1: e56-10.1371/journal.pgen.0010056.PubMedPubMed CentralView ArticleGoogle Scholar
- Fox JL: What price personal genome exploration?. Nat Biotechnol. 2008, 26: 1105-1108. 10.1038/nbt1008-1105.PubMedView ArticleGoogle Scholar
- Ng PC, Murray SS, Levy S, Venter JC: An agenda for personalized medicine. Nature. 2009, 461: 724-726. 10.1038/461724a.PubMedView ArticleGoogle Scholar
- Alkan C, Kidd JM, Marques-Bonet T, Aksay G, Antonacci F, Hormozdiari F, Kitzman JO, Baker C, Malig M, Mutlu O, Sahinalp SC, Gibbs RA, Eichler EE: Personalized copy number and segmental duplication maps using next-generation sequencing. Nat Genet. 2009, 41: 1061-1067. 10.1038/ng.437.PubMedPubMed CentralView ArticleGoogle Scholar
- Lee S, Cheran E, Brudno M: A robust framework for detecting structural variations in a genome. Bioinformatics. 2008, 24: i59-67. 10.1093/bioinformatics/btn176.PubMedPubMed CentralView ArticleGoogle Scholar
- Chen K, Wallis JW, McLellan MD, Larson DE, Kalicki JM, Pohl CS, McGrath SD, Wendl MC, Zhang Q, Locke DP, Shi X, Fulton RS, Ley TJ, Wilson RK, Ding L, Mardis ER: BreakDancer: an algorithm for high-resolution mapping of genomic structural variation. Nat Methods. 2009, 6: 677-681. 10.1038/nmeth.1363.PubMedPubMed CentralView ArticleGoogle Scholar
- Lam HY, Mu XJ, Stutz AM, Tanzer A, Cayting PD, Snyder M, Kim PM, Korbel JO, Gerstein MB: Nucleotide-resolution analysis of structural variants using BreakSeq and a breakpoint library. Nat Biotechnol. 2010, 28: 47-55. 10.1038/nbt.1600.PubMedPubMed CentralView ArticleGoogle Scholar
- Stranger BE, Forrest MS, Dunning M, Ingle CE, Beazley C, Thorne N, Redon R, Bird CP, de Grassi A, Lee C, Tyler-Smith C, Carter N, Scherer SW, Tavare S, Deloukas P, Hurles ME, Dermitzakis ET: Relative impact of nucleotide and copy number variation on gene expression phenotypes. Science. 2007, 315: 848-853. 10.1126/science.1136678.PubMedPubMed CentralView ArticleGoogle Scholar
- Ng PC, Levy S, Huang J, Stockwell TB, Walenz BP, Li K, Axelrod N, Busam DA, Strausberg RL, Venter JC: Genetic variation in an individual human exome. PLoS Genet. 2008, 4: e1000160-10.1371/journal.pgen.1000160.PubMedPubMed CentralView ArticleGoogle Scholar
- Baptista J, Mercer C, Prigmore E, Gribble SM, Carter NP, Maloney V, Thomas NS, Jacobs PA, Crolla JA: Breakpoint mapping and array CGH in translocations: comparison of a phenotypically normal and an abnormal cohort. Am J Hum Genet. 2008, 82: 927-936. 10.1016/j.ajhg.2008.02.012.PubMedPubMed CentralView ArticleGoogle Scholar
- Higgins AW, Alkuraya FS, Bosco AF, Brown KK, Bruns GA, Donovan DJ, Eisenman R, Fan Y, Farra CG, Ferguson HL, Gusella JF, Harris DJ, Herrick SR, Kelly C, Kim HG, Kishikawa S, Korf BR, Kulkarni S, Lally E, Leach NT, Lemyre E, Lewis J, Ligon AH, Lu W, Maas RL, MacDonald ME, Moore SD, Peters RE, Quade BJ, Quintero-Rivera F, et al: Characterization of apparently balanced chromosomal rearrangements from the developmental genome anatomy project. Am J Hum Genet. 2008, 82: 712-722. 10.1016/j.ajhg.2008.01.011.PubMedPubMed CentralView ArticleGoogle Scholar
- Pinto D, Marshall C, Feuk L, Scherer SW: Copy-number variation in control population cohorts. Hum Mol Genet. 2007, 16 (Spec No 2): R168-173. 10.1093/hmg/ddm241.PubMedView ArticleGoogle Scholar
- Maher B: Personal genomes: The case of the missing heritability. Nature. 2008, 456: 18-21. 10.1038/456018a.PubMedView ArticleGoogle Scholar
- Lee C, Scherer SW: The clinical context of copy number variation in the human genome. Expert Rev Mol Med. 2010, 12: e8-10.1017/S1462399410001390.PubMedView ArticleGoogle Scholar
- Venter JC, Adams MD, Myers EW, Li PW, Mural RJ, Sutton GG, Smith HO, Yandell M, Evans CA, Holt RA, Gocayne JD, Amanatides P, Ballew RM, Huson DH, Wortman JR, Zhang Q, Kodira CD, Zheng XH, Chen L, Skupski M, Subramanian G, Thomas PD, Zhang J, Gabor Miklos GL, Nelson C, Broder S, Clark AG, Nadeau J, McKusick VA, Zinder N, et al: The sequence of the human genome. Science. 2001, 291: 1304-1351. 10.1126/science.1058040.PubMedView ArticleGoogle Scholar
- Kent WJ: BLAT--the BLAST-like alignment tool. Genome Res. 2002, 12: 656-664.PubMedPubMed CentralView ArticleGoogle Scholar
- Park H, Kim JI, Ju YS, Gokcumen O, Mills RE, Kim S, Lee S, Suh D, Hong D, Kang HP, Yoo YJ, Shin JY, Kim HJ, Yavartanoo M, Chang YW, Ha JS, Chong W, Hwang GR, Darvishi K, Kim H, Yang SJ, Yang KS, Hurles ME, Scherer SW, Carter NP, Tyler-Smith C, Lee C, Seo JS: Discovery of common Asian copy number variants using integrated high-resolution array CGH and massively parallel DNA sequencing. Nat Genet. 2010, 42: 400-405. 10.1038/ng.555.PubMedPubMed CentralView ArticleGoogle Scholar
- Korn JM, Kuruvilla FG, McCarroll SA, Wysoker A, Nemesh J, Cawley S, Hubbell E, Veitch J, Collins PJ, Darvishi K, Lee C, Nizzari MM, Gabriel SB, Purcell S, Daly MJ, Altshuler D: Integrated genotype calling and association analysis of SNPs, common copy number polymorphisms and rare CNVs. Nat Genet. 2008, 40: 1253-1260. 10.1038/ng.237.PubMedPubMed CentralView ArticleGoogle Scholar
- Colella S, Yau C, Taylor JM, Mirza G, Butler H, Clouston P, Bassett AS, Seller A, Holmes CC, Ragoussis J: QuantiSNP: an Objective Bayes Hidden-Markov Model to detect and accurately map copy number variation using SNP genotyping data. Nucleic Acids Res. 2007, 35: 2013-2025. 10.1093/nar/gkm076.PubMedPubMed CentralView ArticleGoogle Scholar
- Pique-Regi R, Monso-Varona J, Ortega A, Seeger RC, Triche TJ, Asgharzadeh S: Sparse representation and Bayesian detection of genome copy number alterations from microarray data. Bioinformatics. 2008, 24: 309-318. 10.1093/bioinformatics/btm601.PubMedPubMed CentralView ArticleGoogle Scholar
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