• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2393-2399
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• 2013

Objective: Mitochondrial DNA (mtDNA) is considered a hotspot of mutations in various tumors. However, the relationship between microsatellite instability (MSI) and mtDNA copy number alterations in lung cancer has yet to be fully clarifieds. In the current study, we investigated the copy number and MSI of mitochondrial genome in lung carcinomas, as well as their significance for cancer development. Methods: The copy number and MSI of mtDNA in 37 matched lung carcinoma/adjacent histological normal lung tissue samples were examined by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) assays for sequence variation, followed by sequence analysis and fluorogenic 5'-nuclease real-time PCR. Student's t test and linear regression analyses were employed to analyze the association between mtDNA copy number alterations and mitochondrial MSI (mtMSI). Results: The mean copy number of mtDNA in lung carcinoma tissue samples was significantly lower than that of the adjacent histologically normal lung tissue samples (p<0.001). mtMSI was detected in 32.4% (12/37) of lung carcinoma samples. The average copy number of mtDNA in lung carcinoma samples containing mtMSI was significantly lower than that in the other lung carcinoma samples (P<0.05). Conclusions: Results suggest that mtMSI may be an early and important event in the progression of lung carcinogenesis, particularly in association with variation in mtDNA copy number.

• Genomics & Informatics
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• v.10 no.1
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• pp.65-67
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• 2012

We have discovered copy number variations (CNVs) in 3,578 Korean individuals with the Affymetrix Genome-Wide SNP array 5.0, and 4,003 copy number variation regions (CNVRs) were defined in a previous study. To explore the details of the variants easily in related studies, we built a database, cataloging the CNVs and related information. This system helps researchers browsing these variants with gene and structure variant annotations. Users can easily find specific regions with search options and verify them from system-integrated genome browsers with annotations.

• Genomics & Informatics
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• v.8 no.2
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• pp.76-80
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• 2010

Although autism spectrum disorder (ASD) has been thought to have a substantial genetic background, major contributing genes have yet to be identified or successfully replicated. Immunological dysfunction has been suggested to be associated with ASD, and T cell-mediated immunity was considered important for the development of ASD. In this study, we analyzed 163 ASD subjects and 97 normal controls by genomic quantitative PCR to evaluate the association between the copy number variation of the 7q34 locus, harboring the TCRB gene, and ASDs. As a result, there was no significant difference of the frequency distribution of TCRB copy numbers between ASD cases and normal controls. TCRB gene copy numbers ranged from 0 to 5 copies, and the frequency distribution of each copy number was similar between the two groups. The proportion of the individuals with <2 copies of TCRB was 52.8% (86/163) in ASD cases and 57.1% (52/91) in the control group (p=0.44). The proportion of individuals with >2 copies of TCRB was 11.7% (19/163) in ASD cases and 12.1% (11/91) in the control group (p=0.68). After the effects of sex were adjusted by logistic regression, ORs for individuals with <2 copies or >2 copies showed no significant difference compared with the diploid copy number as reference (n=2). Although we could not see the positive association, our results will be valuable information for mining ASD-associated genes and for exploring the role of T cell immunity further in the pathogenesis of ASD.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.2
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• pp.205-212
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• 2008

Genetic variation in the human genome occurs on various levels; from the single nucleotide polymorphism to large, microscopically visible chromosome anomalies. It can be present in many forms, including variable number of tandem repeat (VNTRs; e.g., mini- and microsatellites), presence/absence of transposable elements (e.g., Alu elements), single nucleotide polymorphisms, and structural alterations (e.g., copy number variation, segmental duplication, inversion, translocation). Until recently SNPs were thought to be the main source of genetic and phenotypic human variation. However, the use of methods such as array comparative genomic hybridization (array CGH) and fluorescence in situ hybridization (FISH) have revealed the presence of copy number variations(CNVs) ranging from kilobases (kb) to megabases (Mb) in the human genome. There is great interest in the possibility that CNVs playa role in the etiology of common disease such as HIV-1/AIDS, diabetes, autoimmune disease, heart disease and cancer. The discovery of widespread copy number variation in human provides insights into genetic variability among populations and provides a foundation for studies of the contribution of CNVs to evolution and disease.

• Genomics & Informatics
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• v.6 no.3
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• pp.126-129
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• 2008

The robust identification and comprehensive profiling of copy number alterations (CNAs) is highly challenging. The amount of data obtained from high-throughput technologies such as array-based comparative genomic hybridization is often too large and it is required to develop a comprehensive and versatile tool for the detection and visualization of CNAs in a genome-wide scale. With this respective, we introduce a software framework, CGHscape that was originally developed to explore the CNAs for the study of copy number variation (CNV) or tumor biology. As a standalone program, CGHscape can be easily installed and run in Microsoft Windows platform. With a user-friendly interface, CGHscape provides a method for data smoothing to cope with the intrinsic noise of array data and CNA detection based on SW-ARRAY algorithm. The analysis results can be demonstrated as log2 plots for individual chromosomes or genomic distribution of identified CNAs. With extended applicability, CGHscape can be used for the initial screening and visualization of CNAs facilitating the cataloguing and characterizing chromosomal alterations of a cohort of samples.

• Genomics & Informatics
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• v.6 no.1
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• pp.1-7
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• 2008

The widespread presence of large-scale genomic variations, termed copy number variation (CNVs), has been recently recognized in phenotypically normal individuals. Judging by the growing number of reports on CNVs, it is now evident that these variants contribute significantly to genetic diversity in the human genome. Like single nucleotide polymorphisms (SNPs), CNVs are expected to serve as potential biomarkers for disease susceptibility or drug responses. However, the technical and practical concerns still remain to be tackled. In this review, we examine the current status of CNV DBs and research, including the ongoing efforts of CNV screening in the human genome. We also discuss the characteristics of platforms that are available at the moment and suggest the potential of CNVs in clinical research and application.

• The KIPS Transactions:PartD
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• v.18D no.2
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• pp.89-100
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• 2011

The CNV (Copy Number Variation) which is one of the genetic structural variations in human genome is closely related with the function of gene. In particular, the genome-wide association studies for genetic diseased persons have been researched. However, there have been few studies which infer the genetic function of CNV with normal human. In this paper, we propose the analysis method to reveal the functional relationship between common CNV and genes without considering their genomic loci. To achieve that, we propose the data integration method for heterogeneity biological data and novel measurement which can calculate the correlation between common CNV and genes. To verify the significance of proposed method, we has experimented several verification tests with GO database. The result showed that the novel measurement had enough significance compared with random test and the proposed method could systematically produce the candidates of genetic function which have strong correlation with common CNV.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.12
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• pp.1691-1694
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• 2014

Copy number variation (CNV) or single nucleotide phlyorphism (SNP) is useful genetic resource to aid in understanding complex phenotypes or deseases susceptibility. Although thousands of CNVs and SNPs are currently avaliable in the public databases, they are somewhat difficult to use for analyses without visualization tools. We developed a web-based tool called the VCS (visualization of CNV or SNP) to visualize the CNV or SNP detected. The VCS tool can assist to easily interpret a biological meaning from the numerical value of CNV and SNP. The VCS provides six visualization tools: i) the enrichment of genome contents in CNV; ii) the physical distribution of CNV or SNP on chromosomes; iii) the distribution of log2 ratio of CNVs with criteria of interested; iv) the number of CNV or SNP per binning unit; v) the distribution of homozygosity of SNP genotype; and vi) cytomap of genes within CNV or SNP region.

• Genomics & Informatics
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• v.12 no.4
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• pp.136-144
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• 2014

Besides single-nucleotide variants in the human genome, large-scale genomic variants, such as copy number variations (CNVs), are being increasingly discovered as a genetic source of human diversity and the pathogenic factors of diseases. Recent experimental findings have shed light on the links between different genome architectures and CNV mutagenesis. In this review, we summarize various genomic features and discuss their contributions to CNV formation. Genomic repeats, including both low-copy and high-copy repeats, play important roles in CNV instability, which was initially known as DNA recombination events. Furthermore, it has been found that human genomic repeats can also induce DNA replication errors and consequently result in CNV mutations. Some recent studies showed that DNA replication timing, which reflects the high-order information of genomic organization, is involved in human CNV mutations. Our review highlights that genome architecture, from DNA sequence to high-order genomic organization, is an important molecular factor in CNV mutagenesis and human genomic instability.

• Communications for Statistical Applications and Methods
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• v.16 no.6
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• pp.1037-1046
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• 2009

Copy number variations(CNVs) are known as one of the most important factors in susceptibility to genetic disorders because they affect expression levels of genes. In previous studies, pyrosequencing, mini-sequencing real-time polymerase chain reaction(PCR), invader assays and other techniques have been used to detect CNVs. However, the higher the copy number in a genome, the more difficult it is to resolve the copies, so a more accurate method for measuring CNVs and assigning genotype is needed. PCR followed by a quantitative oligonucleotide ligation assay(qOLA) was developed for quantifying CNVs. The aim of this study was to compare the two methods for detecting and quantifying the CNVs of duplicated gene: the published pyrosequencing assay(pyro_CNV) and the newly developed qOLA_CNV. The accuracy and precision of the assay were evaluated for porcine KIT, which was selected as a model locus. Overall, the root mean squares(RMSs) of bias and standard deviation of qOLA_CNV were 2.09 and 0.45, respectively. These values are less than half of those of pyro CNV.