• 응용통계연구
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• 제24권5호
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• pp.847-859
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• 2011

cDNA microarray-based comparative genomic hybridization(CGH) data includes low-intensity spots and thus a statistical strategy is needed to detect subtle differences between different cancer classes. In this study, genes displaying a high frequency of alteration in one of the different classes were selected among the pre-selected genes that show relatively large variations between genes compared to total variations. Utilizing copy-number changes of the selected genes, this study suggests a statistical approach to predict patients' classes with increased performance by pre-classifying patients with similar genetic alteration scores. Two-stage logistic regression model(TLRM) was suggested to pre-classify homogeneous patients and predict patients' classes for cancer prediction; a decision tree(DT) was combined with logistic regression on the set of informative genes. TLRM was constructed in cDNA microarray-based CGH data from the Cancer Metastasis Research Center(CMRC) at Yonsei University; it predicted the patients' clinical diagnoses with perfect matches (except for one patient among the high-risk and low-risk classified patients where the performance of predictions is critical due to the high sensitivity and specificity requirements for clinical treatments. Accuracy validated by leave-one-out cross-validation(LOOCV) was 83.3% while other classification methods of CART and DT performed as comparisons showed worse performances than TLRM.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2006년도 Principles and Practice of Microarray for Biomedical Researchers
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• pp.71-76
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• 2006

Comparative genomic hybridization (CGH) is a technique for studying chromosomal changes in cancer. As cancerous cells multiply, they can undergo dramatic chromosomal changes, including chromosome loss, duplication, and the translocation of DNA from one chromosome to another. Chromosome aberrations have previously been detected using optical imaging of whole chromosomes, a technique with limited sensitivity, resolution, quantification, and throughput. Efforts in recent years to use microarrays to overcome these limitations have been hampered by inadequate sensitivity, specificity and flexibility of the microarray systems. The oligonucleotide CGH microarray system overcomes several scientific hurdles that have impeded comparative genomic studies of cancer. This new system can reliably detect single copy deletions in chromosomes. The system includes a whole human genome microarray, reagents for sample preparation, an optimized microarray processing protocol, and software for data analysis and visualization. In this study, we determined the sensitivity, accuracy and reproducibility of the new system. Using this assay, we find that the performance of the complete system was maintained over a range of input genomic DNA from 5 ug down to 0.15 ug.

• Molecules and Cells
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• 제24권1호
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• pp.105-112
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• 2007

Most neuroblastoma cells have chromosomal aberrations such as gains, losses, amplifications and deletions of DNA. Conventional approaches like fluorescence in situ hybridization (FISH) or metaphase comparative genomic hybridization (CGH) can detect chromosomal aberrations, but their resolution is low. In this study we used array-based comparative genomic hybridization to identify the chromosomal aberrations in human neuroblastoma SH-SY5Y cells. The DNA microarray consisting of 4000 bacterial artificial chromosome (BAC) clones was able to detect chromosomal regions with aberrations. The SH-SY5Y cells showed chromosomal gains in 1q12~ q44 (Chr1:142188905-246084832), 7 (over the whole chro-mosome), 2p25.3~p16.3 (Chr2:18179-47899074), and 17q 21.32~q25.3 (Chr17:42153031-78607159), while chromosomal losses detected were the distal deletion of 1p36.33 (Chr1:552910-563807), 14q21.1~q21.3 (Chr14:37666271-47282550), and 22q13.1~q13.2 (Chr22:36885764-4190 7123). Except for the gain in 17q21 and the loss in 1p36, the other regions of gain or loss in SH-SY5Y cells were newly identified.

• Journal of Genetic Medicine
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• 제8권1호
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• pp.62-66
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• 2011

14q32.33을 포함한 14번 염색체 장완 결실은 드문 질환이다. 14번 염색체의 말단 결실은 여러 임상증상을 공통적으로 보일 수 있으나 결실 절단부 (breakpoint)에 따라 표현형이 다양하게 발생할 수 있다. 저자들은 경련을 동반한 5세 여아에서 array comparative genomic hybridization (array-CGH)와 fluorescence in situ hybridization (FISH) 방법을 이용하여 이전 보고에 비해 가장 작은 14q32.33부위의 0.33 Mb 크기의 말단 결실과 심하지 않은 표현형을 보이는 1례를 경험 하였기에 문헌고찰과 함께 보고하는 바이다.

• Clinical and Experimental Pediatrics
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• 제60권9호
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• pp.282-289
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• 2017

Purpose: Recent advancements in molecular techniques have greatly contributed to the discovery of genetic causes of unexplained developmental delay. Here, we describe the results of array comparative genomic hybridization (CGH) and the clinical features of 27 patients with global developmental delay. Methods: We included 27 children who fulfilled the following criteria: Korean children under 6 years with global developmental delay; children who had at least one or more physical or neurological problem other than global developmental delay; and patients in whom both array CGH and G-banded karyotyping tests were performed. Results: Fifteen male and 12 female patients with a mean age of $29.3{\pm}17.6months$ were included. The most common physical and neurological abnormalities were facial dysmorphism (n=16), epilepsy (n=7), and hypotonia (n=7). Pathogenic copy number variation results were observed in 4 patients (14.8%): 18.73 Mb dup(2)(p24.2p25.3) and 1.62 Mb del(20p13) (patient 1); 22.31 Mb dup(2) (p22.3p25.1) and 4.01 Mb dup(2)(p21p22.1) (patient 2); 12.08 Mb del(4)(q22.1q24) (patient 3); and 1.19 Mb del(1)(q21.1) (patient 4). One patient (3.7%) displayed a variant of uncertain significance. Four patients (14.8%) displayed discordance between G-banded karyotyping and array CGH results. Among patients with normal array CGH results, 4 (16%) revealed brain anomalies such as schizencephaly and hydranencephaly. One patient was diagnosed with Rett syndrome and one with $M{\ddot{o}}bius$ syndrome. Conclusion: As chromosomal microarray can elucidate the cause of previously unexplained developmental delay, it should be considered as a first-tier cytogenetic diagnostic test for children with unexplained developmental delay.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2004년도 The 3rd Annual Conference for The Korean Society for Bioinformatics Association of Asian Societies for Bioinformatics 2004 Symposium
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• pp.131-137
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• 2004

DNA 단계에서의 유전자의 증폭과 소실은 종양의 발생과 진행에 중요한 역할을 한다. 유전자의 변화를 관찰하기 위해서 Comparative Genomic Hybridization(CGH) 기술이 많이 이용되어져 왔다. 최근에는 이러한 CGH 기술을 응용하여 cDNA microarray 를 이용한 고밀도 CGH(Microarray-CGH) 기술이 보고 되고 있다. Microarray-CGH 에서 유전자별 변화 정도를 유전자의 log-비의 값의 변화 정도와 염색체 위치 정보를 이용하여 DNA 단계에서의 유전자의 변화 정도를 확인 할 수 있다. 또한 동일한 유전자의 칩을 사용하여 RNA단계에서의 발현 양상과 직접 비교할 수 있는 장점이 있다. 현재 microarray 분석법은 많이 개발되고 실용화 되고 있으나 Microarray-CGH 분석을 위한 프로그램들은 아직 초보 단계며, 생물학자들이 사용하기 힘들고, 프로그램에 분석 자료를 적용하기 어려운 경향이 있다. 위와 같은 단점을 보완하기 위해서 개발된 CAMVS(V1.0) 프로그램은 S-plus(2000)을 기반으로 개발하였고, 복잡한 분석보다는 모든 결과들을 이미지화 할 수 있으며 파일로 결과를 쉽게 확인할 수 있도록 디자인하였다. CAMVS(V1.0)는 전체 염색체를 각 실험별로 비교 분석하는 부분, 특정 염색체를 특정 실험별로 비교 분석하는 부분과 실험간의 차이를 통계적으로 비교 분석하는 3 가지 카테고리로 구성되어 있다. 쉬운 알고리즘과 사용의 편리함, 분석결과의 다양한 그래픽, 새로운 알고리즘 추가의 용이성 등이 CAMVS(V1.0)가 가지고 있는 장점이며, Microarray-CGH를 분석하는데 아주 유용한 분석 도구이다.

• Journal of Microbiology and Biotechnology
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• 제20권12호
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• pp.1637-1646
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• 2010

The bacterium Deinococcus radiodurans is one of the most resistant organisms to ionizing radiation and other DNA-damaging agents. Although, at present, 30 Deinococcus species have been identified, the whole-genome sequences of most species remain unknown, with the exception of D. radiodurans (DRD), D. geothermalis, and D. deserti. In this study, comparative genomic hybridization (CGH) microarray analysis of three Deinococcus species, D. radiopugnans (DRP), D. proteolyticus (DPL), and D. radiophilus (DRPH), was performed using oligonucleotide arrays based on DRD. Approximately 28%, 14%, and 15% of 3,128 open reading frames (ORFs) of DRD were absent in the genomes of DRP, DPL, and DRPH, respectively. In addition, 162 DRD ORFs were absent in all three species. The absence of 17 randomly selected ORFs was confirmed by a Southern blot. Functional classification showed that the absent genes spanned a variety of functional categories: some genes involved in amino acid biosynthesis, cell envelope, cellular processes, central intermediary metabolism, and DNA metabolism were not present in any of the three deinococcal species tested. Finally, comparative genomic data showed that 120 genes were Deinococcus-specific, not the 230 reported previously. Specifically, ddrD, ddrO, and ddrH genes, previously identified as Deinococcus-specific, were not present in DRP, DPL, or DRPH, suggesting that only a portion of ddr genes are shared by all members of the genus Deinococcus.

• Clinical and Experimental Pediatrics
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• 제59권2호
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• pp.91-95
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• 2016

We report the case of a 22-month-old boy with a new mosaic partial unbalanced translocation of 1q and 18q. The patient was referred to our Pediatric Department for developmental delay. He showed mild facial dysmorphism, physical growth retardation, a hearing disability, and had a history of patent ductus arteriosus. White matter abnormality on brain magnetic resonance images was also noted. His initial routine chromosomal analysis revealed a normal 46,XY karyotype. In a microarray-based comparative genomic hybridization (aCGH) analysis, subtle copy number changes in 1q32.1-q44 (copy gain) and 18q21.33-18q23 (copy loss) suggested an unbalanced translocation of t(1;18). Repeated chromosomal analysis revealed a low-level mosaic translocation karyotype of 46,XY,der(18)t(1;18) (q32.1;q21.3)[12]/46,XY[152]. Because his parents had normal karyotypes, his translocation was considered to be de novo. The abnormalities observed in aCGH were confirmed by metaphase fluorescent in situ hybridization. We report this patient as a new karyotype presenting developmental delay, facial dysmorphism, cerebral dysmyelination, and other abnormalities.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2001년도 제2회 생물정보 워크샵 (DNA Chip Bioinformatics)
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• pp.61-86
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• 2001

All cancers are caused by abnormalities in DNA sequence. Throughout life, the DNA in human cells is exposed to mutagens and suffers mistakes in replication, resulting in progressive, subtle changes in the DNA sequence in each cell. Since the development of conventional and molecular cytogenetic methods to the analysis of chromosomal aberrations in cancers, more than 1,800 recurring chromosomal breakpoints have been identified. These breakpoints and regions of nonrandom copy number changes typically point to the location of genes involved in cancer initiation and progression. With the introduction of molecular cytogenetic methodologies based on fluorescence in situ hybridization (FISH), namely, comparative genomic hybridization (CGH) and multicolor FISH (m-FISH) in carcinomas become susceptible to analysis. Conventional CGH has been widely applied for the detection of genomic imbalances in tumor cells, and used normal metaphase chromosomes as targets for the mapping of copy number changes. However, this limits the mapping of such imbalances to the resolution limit of metaphase chromosomes (usually 10 to 20 Mb). Efforts to increase this resolution have led to the "new"concept of genomic DNA chip (1 to 2 Mb), whereby the chromosomal target is replaced with cloned DNA immobilized on such as glass slides. The resulting resolution then depends on the size of the immobilized DNA fragments. We have completed the first draft of its Korean Genome Project. The project proceeded by end sequencing inserts from a library of 96,768 bacterial artificial chromosomes (BACs) containing genomic DNA fragments from Korean ethnicity. The sequenced BAC ends were then compared to the Human Genome Project′s publicly available sequence database and aligned according to known cancer gene sequences. These BAC clones were biotinylated by nick translation, hybridized to cytogenetic preparations of metaphase cells, and detected with fluorescein-conjugated avidin. Only locations of unique or low-copy Portions of the clone are identified, because high-copy interspersed repetitive sequences in the probe were suppressed by the addition of unlabelled Cotl DNA. Banding patterns were produced using DAPI. By this means, every BAC fragment has been matched to its appropriate chromosomal location. We have placed 86 (156 BAC clones) cytogenetically defined landmarks to help with the characterization of known cancer genes. Microarray techniques would be applied in CGH by replacement of metaphase chromosome to arrayed BAC confirming in oncogene and tumor suppressor gene: and an array BAC clones from the collection is used to perform a genome-wide scan for segmental aneuploidy by array-CGH. Therefore, the genomic DNA chip (arrayed BAC) will be undoubtedly provide accurate diagnosis of deletions, duplication, insertions and rearrangements of genomic material related to various human phenotypes, including neoplasias. And our tumor markers based on genetic abnormalities of cancer would be identified and contribute to the screening of the stage of cancers and/or hereditary diseases

• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권2호
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• pp.205-212
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• 2008

인간 게놈의 DNA서열의 차이는 개개인의 특이성을 의미하기 때문에 염기서열의 변화는 질병에 대한 감수성, 약물에 대한 반응 등 개인의 성향에 큰 영향을 미치게 된다. 인간 게놈에는 여러 가지 형태의 유전적 변이가 존재하지만 그 중 단일염기다형성이 인간의 유전적, 표현형의 다양성을 설명하는 주된 유전적 변이로 생각되었으나 최근 유전체 전체 분석법의 발전으로 1 kb 이상 크기의 CNV의 발견으로 개체간의 유전적 다양성에 대한 더 많은 이해가 가능하게 되었고, 진화와 유전 질환에 대한 CNV의 역할을 조사하는 연구의 기초를 제공하게 되었다. 현재 인간게놈의 CNV를 찾아내고 특성화 작업을 목표로 하는 The Copy Number Variation Project를 위해 The Wellcome Trust Institute (Hinxton, United Kingdom), Hospital for Sick Children (Toronto), University of Tokyo (Tokyo), Affymetrix (Santa Clara, CA), 그리고 Harvard Medical School/Brigham and Women's Hospital (Boston, MA) 등이 참여하는 international consortium이 구성되어 보다 심도 있는 연구가 진행되고, 또한 향후 진보된 DNA microarray-based technology와 서열화 기술의 개발로 인간 게놈 상의 모든 유전적 변이를 발견하게 되고 포괄적인 CNV 지도를 완성하고 인간 유전자 다양성 인간의 진화, 유전적 질환 개인 맞춤형 의학에 대한 새로운 이해와 연구가 가능하게 될 것으로 기대된다.