• Clinical and Experimental Pediatrics
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• v.48 no.12
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• pp.1389-1389
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• 2005

The long arm duplication of chromosome 3 was reported for the first time in 1966 by Falek et al., and Hirschhorn et al. came to identify the duplication of 3q21${\rightarrow}$qter region in 1973. In most cases of duplication 3q syndrome patients, pure duplication of 3qter is believed to be rare and is often reported accompanied with deletion of another segment of the chromosome. Approximately 75 percent of parents of the patient in the meantime have been demonstrated to have unbalanced translocations or inversions of the chromosome. Partial deletion of the distal part of the short arm of chromosome 3 was first reported by Verjaal and De Nef in 1978 and terminal deletion of chromosome 3 (3p25-qter) has been observed in most cases. In karyotyping of chromosomes of immature infants showing the manifestations of flat occiputs, low set ears, hypertelorism, broad nasal roots, thin lips, web necks, hypotonia, hypertrichosis skin, cryptorchidism etc, we experienced a case diagnosed as 46,XY, rec(3)dup(3)(q21)del(3)(p25)inv(3)(p25q21).

• Neonatal Medicine
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• v.16 no.1
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• pp.76-80
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• 2009

A male baby with intrauterine growth retardation had a short neck, small hands and feet, hypospadia, both grade I hydronephrosis, type II atrial septal defect, and moderate valvular pulmonary stenosis. The routine chromosome and banding analyses revealed a 46,XY,rec(8)del(8)(p21)dup(8) (q24.1)inv(8)(p21q24.1)pat chromosome constitution. His mother has normal chromosomes, but the father had 46,XY,inv(8)(p21q24.n Also his uncle had an inv(8) chromosome constitution. We used lymphocytes and examined 40 mitotic cells. All mitotic cells showed deletion of 8p21-->pter and duplication of 8q24.1 -->qter. Because Sp21 involves secretion of macrophage and lymphocyte against cancer cells, long-term follow-up for cancer will be needed.

• Genomics & Informatics
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• v.1 no.2
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• pp.101-107
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• 2003

Loss of heterozygosity (LOH) has been used to detect deleted regions of a specific chromosome in cancer cells. LOH on chromosome 16q has been reported to occur frequently in progressed hepatocellular carcinoma (HCC). Liver tissues from 37 Korean HCC patients were analyzed for LOH by using 25 polymorphic microsatellite markers distributed along 16q. Out of the 37 HCC patients studied, 21 patients (56.8%) showed LOH in various regions of 16q with at least one polymorphic marker. Puring the analysis of these 21 LOH cases, 6 patients showed interstitial LOHs in which the boundary of the LOH region was defined. With two rounds of LOH analysis, five commonly occurring interstitial LOH regions were identified; 16q21-22.1, 16q22.2 - 22.3, 16q22.3, 16q23.2 and 16q23.3 - 24.1. Among the five LOH regions the 16q23.3 - 24.1 region has been reported to be related with chromosome instability. A complete physical map, which covers the 3.2 Mb region of 16q23.3 - 24.1 (D16S402 and D16S486), was constructed to identify novel candidate tumor suppressor genes. We provide the minimally tiling path map consisting of 28 BAC clones. There was one gap between NT_10422.11 and NT_019609.9 of the human genome sequence contig (NCBI sequence build 33, April 29, 2003). This gap can be filled by sequencing the R-1425M20 clone which bridges these sequence contigs.

• Clinical and Experimental Pediatrics
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• v.45 no.7
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• pp.917-922
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• 2002

An unbalanced translocation is frequently the result of inheritance of an unbalanced haploid set from a parent with a balanced translocation. Families in which one parent is a balanced translocation carrier fall into the following classes : Those in which none of the possible abnormal offsprings is viable; Those in which one type of offspring, usually the one with the smaller deletion, is born alive; Those in which two types of abnormal offspring are viable. We report a neonate whose karyotype was 46,XX,der(2)t(2;7)(q21;p21.2),der(20)t(2;20)(q21;p13). She was small for her gestational age and had multiple anomalies such as exophthalmos, corneal opacity, short neck, tongue tie, clinodactyly, atrial septal defect, patent ductus arteriosus and ventriculomegaly. Moreover, her mother's karyotype was 46,XX,der(2)t(2;7)(q21;p21.2),del(16)(q22.1),der(20)t(2;20)(q21;p13) but her father had normal karyotype. The same derivative chrosomes were found between mother and her infant, except for del(16)(q22.1) in her mother and these same unbalanced translocations in a two-generation family are extremely rare.

• Clinical and Experimental Pediatrics
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• v.46 no.3
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• pp.291-294
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• 2003

Ring chromosome 21 causes a multitude of phenotypes, ranging from severe abnormalities to normal. The proposed mechanism of ring formation, breakage of both short and long arms of a chromosome with subsequent end to end fusion, remains unproven. We encountered a 4-year-old boy who presented developmental delay, microcephaly, micrognathia, hypertelorism, low-set ears, mild optic nerve hypoplasia, cleft lip and palate, scoliosis and left foot valgus, but normal brain MRI. Chromosome study from peripheral blood showed 46,XY, r(21)(p11.2q22.1) karyotype. The authors report the first case of ring chromosome 21 in Korea with a review of the literature.

• Clinical and Experimental Pediatrics
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• v.46 no.8
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• pp.831-835
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• 2003

Holoprosencephaly of unknown definite causes, has been associated with several chromosome abnormalities involving the autosomes and the sex chromosomes. The most commonly reported associations include dup(3p), del(7q), deletions of chromosome 13, trisomy 13, trisomy 18, and triploidy. In previously reported cases in Korea, none were associated with chromosome 21 anomalies. In conclusion, we reported the first case of holoprosencephaly(semilobar type) associated with pure monosomy 21. We experienced a semilobar type holoprosencephaly with monosomy 21 in a neonate who had multiple congenital anomalies, including an abnormal face, a small thorax with widely spaced hypoplastic nipples and nail hypoplasia, lung hypoplasia with severe scoliosis and cardiac abnormalities. Chromosomal analysis revealed a 45, XY, -21.

• Journal of Genetic Medicine
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• v.14 no.2
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• pp.62-66
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• 2017

Interchromosomal insertion of Y chromosome heterochromatin in an autosome was identified in a fetus and a family. A fetal karyotype was analyzed as 46,XX,dup(7)(?q22q21.1) in a referred amniocentesis at 16 weeks of gestation for advanced maternal age. In the familial karyotype analyses for identification of der(7), the mother, the first daughter and the maternal grandmother showed the same der(7) as the fetus's. CBG-banding was positive at 7q22 region of der(7) that indicated inserted material was originated from heterochromatin. The origin of heterochromatic insertion region in der(7) of the fetus and the mother was found in Yq12 region by fluorescent in situ hybridization with a DYZ1 probe. In the specific analysis of Y chromosomal heterochromatic region of ins(7;Y) of the mother, 15 sequence tagged sites from Yp11.3 region including SRY to Yq11.223 region was not detected. Final karyotypes of the mother, the first daughter and the maternal grandmother were reported as 46,XX,der(7)ins(7;Y)(q21.3;q12q12). All female carriers of ins(7;Y) in the family showed normal phenotype and the mother and the maternal grandmother were fertile. A healthy girl was born at term. We report a rare case of familial interchromosomal insertion of Y chromosome heterochromatin detected only in female family members with normal phenotype that was diagnosed prenatally.

• Journal of Genetic Medicine
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• v.9 no.2
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• pp.101-103
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• 2012

Paracentric inversion of chromosome 18 is a rare cytogenetic abnormality. The vast majority of paracentric inversions are harmless and the offspring of paracentric inversion carriers have only slightly elevated risks for unbalanced karyotypes. However, various clinical phenotypes are seen due to breakpoint variation or recombination. We report a prenatally detected case of familial paracentric inversion of chromosome 18, inv(18)(q21.1q22), with normal clinical features.

• Journal of Genetic Medicine
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• v.8 no.2
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• pp.119-124
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• 2011

Purpose: Supernumerary marker chromosome (SMC) could be associated with various phenotypic abnormalities based on the chromosomal origin of SMCs. The present study aimed to determine the genomic contents of SMCs using chromosomal microarray and to analyze molecular cytogenetic characterizations and clinical phenotypes in patients with SMCs. Materials and Methods: Among patients with SMCs detected in routine chromosomal analysis, SMCs originating from chromosome 15 were excluded from the present study. CGH-based oligonucleotide chromosomal microarray was performed in 4 patients. Results: The chromosomal origins of SMCs were identified in 3 patients. Case 1 had a SMC of 16.1 Mb in 1q21.1-q23.3. Case 2 showed 21 Mb gain in 19p13.11-q13.12. Case 3 had a 4.5 Mb-sized SMC rearranged from 2 regions of 2.5 Mb in 22q11.1-q11.21 and 2.0 Mb in 22q11.22-q11.23. Conclusion: Case 1 presented a wide range of phenotypic abnormalities including the phenotype of 1q21.1 duplication syndrome. In case 2, Asperger-like symptoms are apparently related to 19p12-q13.11, hearing problems and strabismus to 19p13.11 and other features to 19q13.12. Compared with cat-eye syndrome type I and 22q11.2 microduplication syndrome, anal atresia in case 3 is likely related to 22q11.1-q11.21 while other features are related to 22q11.22-q11.23. Analyzing SMCs using high-resolution chromosomal microarray can help identify specific gene contents and to offer proper genetic counseling by determining genotype-phenotype correlations.

• Journal of Genetic Medicine
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• v.18 no.2
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• pp.110-116
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• 2021

Microdeletions of chromosome 22q11.2 are one of the most common microdeletions occurring in humans, and is known to be associated with a wide range of highly variable features. These deletions occur within a cluster of low copy repeats (LCRs) in 22q11.2, referred to as LCR22 A-H. DiGeorge (DGS)/velocardiofacial syndrome is the most prevalent form of a 22q11.2 deletions, caused by mainly proximal deletions between LCR22 A and D. As deletions of distal portion to the DGS deleted regions has been extensively studied, the recurrent distal 22q11.2 microdeletions distinct from DGS has been suggested as several clinical entities according to the various in size and position of the deletions on LCRs. We report a case of long-term follow-up of a female diagnosed with a 22q11.2 distal deletion syndrome, identified a deletion of 1.9 Mb at 22q11.21q11.23 (chr22: 21,798,906-23,653,963) using single nucleotide polymorphism array. This region was categorized as distal deletion type of 22q11.2, involving LCR22 D-F. She was born as a preterm, low birth weight to healthy non-consanguineous Korean parents. She showed developmental delay, growth retardation, dysmorphic facial features, and mild skeletal deformities. The patient underwent a growth hormone administration due to growth impairment without catch-up growth. While a height gain was noted, she had become overweight and was subsequently diagnosed with pre-diabetes. Our case could help broaden the genetic and clinical spectrum of 22q11.2 distal deletions.