• 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.

• Journal of Genetic Medicine
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• 제2권2호
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• pp.71-77
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• 1998

Comparative genomic hybridization (CGH) can now be applied to detect the origin of extra or missing chromosomal material in cases with common unbalanced aberrations and in prenatal investigations. This method has been used in 13 cases of fetal samples for this study; 3 for amniocytes, 2 for cord blood and 8 for abortus tissues. These samples were previously subjected to GTG-banding. Our study showed aneuploidy in 8 cases, and partial monosomy, partial trisomy or marker chromosome in the remaining 5. The CGH disclosed further small genetic imbalances in 4 of all 13 cases: a prenatal sample showing del(20)(q13) by GTG confirmed a loss of the segment 20p13-pter by CGH; a marker chromosome manifested normal CGH profile; chromosome der(?)(?;15) found in an abortus sample by GTG turned out to be a loss of 15pter-q14 (partial monosomy) and a gain of 10pter-q22 (partial trisomy); the der(15) shown by GTG represented partial trisomy of 3q24-qter. These findings show that CGH is very useful and efficient for cytogenetic investigations of clinical cases.

• Journal of Interdisciplinary Genomics
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• 제5권2호
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• pp.24-28
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• 2023

Chromosomal microarray (CMA) is primarily recommended for detecting clinically significant copy number variants (CNVs) in the genetic diagnosis of developmental delay, intellectual disability, autism, and congenital malformations. Prenatal CMA is recommended when a fetus has major congenital malformations. The main principles of CMA can be divided into array comparative genomic hybridization and single-nucleotide polymorphism arrays. In the current CMA platforms, these two principles are combined, and detection of genetic abnormalities including CNVs and absence of heterozygosity is facilitated. In this review, I described practical assessment of CMA testing regarding to laboratory management of CMA, interpretation of CNVs, and special considerations for comprehensive genetic counseling.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2003년도 제40회 국제학술심포지움
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• pp.14-27
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• 2003

The genomes of Arabidopsis and rice have been fully sequenced. Genomic sequencing provides global information about genome structure and organization. A comprehensive research account of our recent studies conducted on genome painting, comparative genomics and genome fusion is provided in order to project the prospects of plant cytogenetic research in post-genomics era. Genome analysis by GISH using genome painting is demonstrated as an excellent means suitable for visualization of a whole genome, since total genomic DNA representing the overall molecular composition of the genome is used as a probe. FISH on extended DNA fibers has been developed for high-resolution FISH and has contributed to determining the copy number and order of genes. We have also mapped a number of genes involving starch synthesis on wheat chromosomes by FISH and compared the position of these genes on linkage map of rice. Macro synteny between wheat and rice can be observed by comparing the location of these genes in spite of the fact that the size of DNA per chromosome differs by 20 fold in two. Moreover, to approach our goal towards making bread and udon noodles from rice flour in future by incorporating bread making and the noodle qualifies in rice, we have been successful in introducing large genomic DNA fragments containing agronomically important genes of wheat into a rice by successive introduction of large insert BAC clones, there by expanding genetic variability in rice. We call this method genome fusion.

• Journal of Genetic Medicine
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• 제16권2호
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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 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.

• 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.

• Molecular & Cellular Toxicology
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• 제4권3호
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• pp.246-252
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• 2008

Tumor tissue is usually contaminated by normal tissue components, which reduces the sensitivity of analysis for exploring genetic alterations. Although microdissection has been adopted to minimize the contamination of tumor DNA with normal cell components, there is a concern over the amount of microdissected DNA not enough to be applied to array-CGH reaction. To amplify the extracted DNA, several whole genome amplification (WGA) methods have been developed, but objective comparison of the array-CGH outputs using different types of WGA methods is still scarce. In this study, we compared the performance of non-amplified microdissected DNA and DNA amplified in 2 WGA methods such as degenerative oligonucleotide primed (DOP)-PCR, and multiple strand displacement amplification (MDA) using Phi 29 DNA polymerase. Genomic DNA was also used to make a comparison. We applied those 4 DNAs to whole genome BAC array to compare the false positive detection rate (FPDR) and sensitivity in detecting copy number alterations under the same hybridization condition. As a result microdissected DNA method showed the lowest FPDR and the highest sensitivity. Among WGA methods, DOP-PCR amplified DNA showed better sensitivity but similar FPDR to MDA-amplified method. These results demonstrate the advantage and applicability of microdissection for array-CGH analysis, and provide useful information for choosing amplification methods to study copy number alterations, especially based on precancerous and microscopically invaded lesions.

• 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.

• Clinical and Experimental Pediatrics
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• 제55권12호
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• pp.487-490
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• 2012

We report a case of isodicentric chromosome 15 (idic(15) chromosome), the presence of which resulted in uncontrolled seizures, including epileptic spasms, tonic seizures, and global developmental delay. A 10-month-old female infant was referred to our pediatric neurology clinic because of uncontrolled seizures and global developmental delay. She had generalized tonic-clonic seizures since 7 months of age. At referral, she could not control her head and presented with generalized hypotonia. Her brain magnetic resonance imaging scans and metabolic evaluation results were normal. Routine karyotyping indicated the presence of a supernumerary marker chromosome of unknown origin (47, XX +mar). An array-comparative genomic hybridization (CGH) analysis revealed amplification from 15q11.1 to 15q13.1. Subsequent fluorescence in situ hybridization analysis confirmed a idic(15) chromosome. Array-CGH analysis has the advantage in determining the unknown origin of a supernumerary marker chromosome, and could be a useful method for the genetic diagnosis of epilepsy syndromes associated with various chromosomal aberrations.