• Proceedings of the Korean Society for Bioinformatics Conference
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• 2006.02a
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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.

• Genomics & Informatics
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• v.2 no.1
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• pp.30-35
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• 2004

To investigate the XIST gene expression and its effect in a Klinefelter's patient, we used Klinefelter's syndrome (XXY) patient with azoospermia and also used a normal male (XY) and a normal female (XX) as the control, We were performed cytogenetic analysis, Y chromosomal microdeletion assay (Yq), semi-quantitative RT-PCR, and the Northern blot for Klinefelter's syndrome (KS) patient, a female and a male control, We extracted total RNA from the KS patient, and from the normal cells of the female and male control subjects using the RNA prep kit (Qiagen), cDNA microarray contained 218 human X chromosome-specific genes was fabricated. Each total RNA was reverse transcribed to the first strand cDNA and was labeled with Cy-3 and Cy-5 fluorescein, The microarray was scanned by ScanArray 4000XL system. XIST transcripts were detected from the Klinefelters patient and the female by RT-PCR and Northern blot analysis, but not from the normal male, In the cDNA microarray experiment, we found 24 genes and 14 genes are highly expressed in KS more than the normal male and females, respectively. We concluded that highly expressed genes in KS may be a resulted of the abnormal X inactivation mechanism.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2006.02a
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• pp.98-107
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• 2006

Chromosomal copy number changes (aneuploidies) are common in human populations. The extra chromosome can affect gene expression by whole-genome level. By gene expression microarray analysis, we want to find aberrant gene expression due to aneuploidies in Klinefelter (+X) and Down syndrome (+21). We have analyzed the inactivation status of X-linked genes in Klinefelter Syndrome (KS) by using X-linked cDNA microarray and cSNP analysis. We analyzed the expression of 190 X-linked genes by cDNA microarray from the lymphocytes of five KS patients and five females (XX) with normal males (XY) controls. cDNA microarray experiments and cSNP analysis showed the differentially expressed genes were similar between KS and XX cases. To analyze the differential gene expressions in Down Syndrome (DS), Amniotic Fluid (AF)cells were collected from 12 pregnancies at $16{\sim}18$ weeks of gestation in DS (n=6) and normal (n=6) subjects. We also analysis AF cells for a DNA microarray system and compared the chip data with two dimensional protein gel analysis of amniotic fluid. Our data may provide the basis for a more systematic identification of biological markers of fetal DS, thus leading to an improved understanding of pathogenesis for fetal DS.

• Journal of Genetic Medicine
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• v.7 no.2
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• pp.111-118
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• 2010

Chromosomal microarray analysis (CMA) enables the genome-wide detection of submicroscopic chromosomal imbalances with greater precision and accuracy. In most other countries, CMA is now a commonly used clinical diagnostic test, replacing conventional cytogenetics or targeted detection such as FISH or PCR-based methods. Recently, some consensus statements have proposed utilization of CMA as a first-line test in patients with multiple congenital anomalies not specific to a well-delineated genetic syndrome, developmental delay/intellectual disability, or autism spectrum disorders. CMA can be used as an adjunct to conventional cytogenetics to identify chromosomal abnormalities observed in G-banding analysis in constitutional or acquired cases, leading to a more accurate and comprehensive assessment of chromosomal aberrations. Although CMA has distinct advantages, there are several limitations, including its inability to detect balanced chromosomal rearrangements and low-level mosaicism, its interpretation of copy number variants of uncertain clinical significance, and significantly higher costs. For these reasons, CMA is not currently a replacement for conventional cytogenetics in prenatal diagnosis. In clinical applications of CMA, knowledge and experience based on genetics and cytogenetics are required for data analysis and interpretation, and appropriate follow-up with genetic counseling is recommended.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.4
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• pp.375-381
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• 2018

Cytogenetic analysis plays an important role in examinations of a variety of human disorders. Over the years, cytogenetic analysis has evolved to a great extent and become a part of routine laboratory testing; the analysis provides significant diagnostic and prognostic results for human diseases. Microarray in conjunction with molecular cytogenetics and conventional chromosome analysis has transformed the outcomes of clinical cytogenetics. The advantages of microarray technologies have become obvious to the medical and laboratory community involved in genetic diagnosis, resulting in greatly improved visualization and validation capabilities. This article reviews how the field is moving away from conventional cytogenetics towards molecular approaches for the identification of pathogenic genomic imbalances and discusses practical considerations for the routine implementation of these technologies in genetic diagnosis.

• Journal of Yeungnam Medical Science
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• v.40 no.4
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• pp.419-422
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• 2023

Septo-optic dysplasia (SOD) is a rare congenital anomaly that is clinically defined by developmental delay and characteristic brain magnetic resonance imaging findings, including optic nerve hypoplasia, pituitary hormone abnormalities, and midline brain defects. The occurrence of SOD is generally sporadic; however, it can be inherited rarely. Although an association with HESX1, SOX2, and SOX3 mutations has been identified, the detailed etiology is multifactorial and unclear. Here, we present the case of a 7-year-old girl who was clinically diagnosed with SOD and 15q13.3 duplication. Patients with duplication at chromosome 15q13.3 were reported to be diagnosed with autism spectrum disorder, epilepsy, and schizophrenia in previous studies. The relationship between SOD and the microduplication of 15q13.3 has not yet been explored. In this study, we suggest that there may be an association between chromosome 15q13.3 microduplication and SOD.

• Journal of Genetic Medicine
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• v.18 no.1
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• pp.31-37
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• 2021

Purpose: To summarize the results of chromosomal microarray analysis (CMA) for copy number variants (CNVs) detection and clinical utility in a single tertiary hospital. Materials and Methods: We performed CMA in 46 patients over the course of two years. Detected CNVs were classified into five categories according to the American College of Medical Genetics and Genomics guidelines and correlated with clinical manifestations. Results: A total of 31 CNVs were detected in 19 patients, with a median CNV number per patient of two CNVs. Among these, 16 CNVs were classified as pathogenic (n=3) or likely pathogenic (LP) (n=11) or variant of uncertain significance (n=4). The 16p11.2 deletion and 16p13.11 deletion classified as LP were most often detected in 6.5% (3/46), retrospectively. CMA diagnostic yield was 24.3% (9/37 patients) for symptomatic patients. The CNVs results of the commercial newborn screening test using next generation sequencing platforms showed high concordance with CMA results. Conclusion: CMA seems useful as a first-tier test for developmental delay with or without congenital anomalies. However, the classification and interpretation of CMA still remained a challenge. Further research is needed for evidence-based interpretation.

• Journal of Genetic Medicine
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• v.15 no.2
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• pp.115-119
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• 2018

The 16p11.2 microdeletion has been reported in patients with developmental delays and intellectual disability. The distal 220- kb deletion in 16p11.2 is associated with developmental delay, autism spectrum disorder, epilepsy, and obesity at a young age. We have reported a case of distal 16p11.2 deletion syndrome in a preterm infant with unusual facial morphology and congenital heart disease. We suggest using chromosome microarray analysis to detect chromosomal abnormalities in newborns, especially preterm infants with unusual morphologies.

• Journal of Genetic Medicine
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• v.16 no.2
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• pp.76-80
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• 2019

About 15% to 20% of all clinically recognized pregnancies result in spontaneous abortion or miscarriage, and chromosomal anomalies can be identified in up to 50% of first trimester miscarriages. Chromosomal microarray analysis (CMA) is currently considered first-tier testing for detecting fetal chromosomal abnormalities and is supported by the absence of cell culture failure or erroneous results due to cell contamination in pregnancy loss. Triploidy is a lethal chromosome number abnormality characterized by an extra haploid set of chromosomes. Triploidy is one of the most common chromosomal aberrations in first trimester spontaneous abortions. Here, we report two cases of triploidy abortion that were not detected using array comparative genomic hybridization-based CMA. The aim of this report was to remind clinicians of the limitations of chromosomal testing and the misdiagnosis that can result from biased test selection.

• Journal of Interdisciplinary Genomics
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• v.1 no.1
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• pp.10-13
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• 2019

A 10-year and 5 month-old girl with developmental delay, intellectual disability, attention deficit hyperactivity disorder, poor weight gain, and microcephaly was transferred to our pediatric clinic for genetic evaluation. Her height was within the 5-10th percentile, and her weight was under the 3rd percentile. On the social maturity scale, her developmental status was scored as 3 years 9 months for social age, and the social quotient was 35.98. A chromosomal microarray analysis was performed and the microduplication at chromosome 16p was observed: arr[GRCh37] 16p11.2 (29580020_30190029)${\times}3$. Currently, the patient is diagnosed with Grade 2 intellectual disability and is attending a computerized cognitive rehabilitation class twice weekly. In addition, nutritional support and growth follow up are also ensured in the Pediatric Gastrointestinal and Endocrinology clinic.