• Journal of Genetic Medicine
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• 제12권1호
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• pp.6-11
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• 2015

Intellectual disability (ID) is the most common disability among people under the age of 20 years. In the absence of obvious non-genetic causes of ID, the majority of cases of severe ID are thought to have a genetic cause. The advent of technologies such as array comparative genomic hybridization, single nucleotide polymorphism genotyping arrays, and massively parallel sequencing has shown that de novo copy number variations and single nucleotide variations affecting coding regions are major causes of severe ID. This article reviews the genetic causes of ID along with diagnostic approaches for this disability.

• 한국수정란이식학회지
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• 제11권2호
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• pp.145-150
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• 1996

This study was conducted to detect the Y-specific DNA in the blood of the female calf in bovine heterosexual production. Genomic DNAs of the freemartin were isolated from the blood and amplified with Y-chromosome specific DNA primer(l4lbp). In order to estimate the lower limit for the detection of XY cells, blood from a hull was diluted in cow blood to 0.01%. DNA sequencing on the PCR products was shown the same sequences as Y chromosome DNA of the normal cows. The Y specific DNA hand by PCR was detected all blood of female calf suspected to have bovine freemar tin syndrom and the karyotyping with freemartin blood was identified as XX / XY chimerism. Therefore, the PGR methods used in this study was very useful technique for the detection of freemartin in Ranwoo and Holstein.

• Journal of Genetic Medicine
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• 제11권2호
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• pp.43-48
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• 2014

Chorionic villus sampling has gained importance as a tool for early cytogenetic diagnosis with a shift toward first trimester screening. First trimester screening using nuchal translucency and biomarkers is effective for screening. Chorionic villus sampling generally is performed at 10-12 weeks by either the transcervical or transabdominal approach. There are two methods of analysis; the direct method and the culture method. While the direct method may prevent maternal cell contamination, the culture method may be more representative of the true fetal karyotype. There is a concern for mosaicism which occurs in approximately 1% of cases, and mosaic results require genetic counseling and follow-up amniocentesis or fetal blood sampling. In terms of complications, procedure-related pregnancy loss rates may be the same as those for amniocentesis when undertaken in experienced centers. When the procedure is performed after 9 weeks gestation, the risk of limb reduction is not greater than the risk in the general population. At present, chorionic villus sampling is the gold standard method for early fetal karyotyping; however, we anticipate that improvements in noninvasive prenatal testing methods, such as cell free fetal DNA testing, will reduce the need for invasive procedures in the near future.

• Journal of Genetic Medicine
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• 제14권1호
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• pp.34-37
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• 2017

5p deletion syndrome, also known as Cri-du-Chat syndrome, is a chromosomal abnormality caused by a deletion in the short arm of chromosome 5. Clinical features of 5p deletion syndrome are difficult to identify prenatally by ultrasound examination, thus most cases of 5p deletion syndrome have been diagnosed postnatally. Here, we report eight cases of 5p deletion syndrome diagnosed prenatally, but were unable to find common prenatal ultrasound findings among these cases. However, we found that several cases of 5p deletion syndrome were confirmed prenatally when karyotyping was performed on the basis of abnormal findings in a prenatal ultrasound scan. Hence, it is necessary to carefully perform prenatal ultrasonography for detection of rarer chromosomal abnormalities as well as common aneuploidy.

• Journal of Genetic Medicine
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• 제15권2호
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• pp.49-54
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• 2018

Nuchal translucency is an important indicator of an aneuploid fetus in prenatal diagnostics. Previously, only the presence of aneuploid could be confirmed by conventional karyotyping of fetuses with thick nuchal translucency. With the development of genetic diagnostic techniques, however, it has been reported that subtle variations not detectable by conventional karyo-typing might occur in cases of pathologic clinical syndrome in euploid fetuses. One of the newer, high-resolution genetic methods in the prenatal setting is chromosomal microarray. The possible association between nuchal translucency thickness with normal karyotype and submicroscopic chromosomal abnormalities detectable by microarray has been studied. How and when to apply microarray in clinical practice, however, is still debated. This article reviews the current studies on the clinical application of microarray in cases of increased nuchal translucency with normal karyotype for prenatal diagnosis.

• Clinical and Experimental Pediatrics
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• 제56권6호
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• pp.247-253
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• 2013

Purpose: In children with acute leukemia, bone marrow genetic abnormalities (GA) have prognostic significance, and may be the basis for minimal residual disease monitoring. Since April 2007, we have used a multiplex reverse transcriptase-polymerase chain reaction tool (HemaVision) to detect of GA. Methods: In this study, we reviewed the results of HemaVision screening in 270 children with acute leukemia, newly diagnosed at The Catholic University of Korea from April 2007 to December 2011, and compared the results with those of fluorescence in situ hybridization (FISH), and G-band karyotyping. Results: Among the 270 children (153 males, 117 females), 187 acute lymphoblastic leukemia and 74 acute myeloid leukemia patients were identified. Overall, GA was detected in 230 patients (85.2%). HemaVision, FISH, and G-band karyotyping identified GA in 125 (46.3%), 126 (46.7%), and 215 patients (79.6%), respectively. TEL-AML1 (20.9%, 39/187) and AML1-ETO (27%, 20/74) were the most common GA in ALL and AML, respectively. Overall sensitivity of HemaVision was 98.4%, with false-negative results in 2 instances: 1 each for TEL-AML1 and MLL-AF4. An aggregate of diseases-specific FISH showed 100% sensitivity in detection of GA covered by HemaVision for actual probes utilized. G-band karyotype revealed GA other than those covered by HemaVison screening in 133 patients (49.3%). Except for hyperdiplody and hypodiploidy, recurrent GA as defined by the World Health Organizationthat were not screened by HemaVision, were absent in the karyotype. Conclusion: HemaVision, supported by an aggregate of FISH tests for important translocations, may allow for accurate diagnosis of GA in Korean children with acute leukemia.

• Clinical and Experimental Reproductive Medicine
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• 제26권1호
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• pp.43-54
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• 1999

Klinefelter's syndrome is a very important disease in gynecologic endocrinologic fields, because the patients with this karyotype complain of infertility, azospermia and ambiguous genitalia. Y chromosome is an important chromosome which determine genetic sex and the structure of gonad and genitalia. In this study, to elucidate the cytogenetic characteristics and clinical features of Klinefelter's syndrome and Y chromosomal abnormalities in Korea, we studied 303 cases of Klinefelter's syndrome and 11 cases of Y chromosomal abnormalities which were diagnosed by chromosomal analysis at the Cytogenetic Laboratory, Institute of Reproductive Medicine and Population, Seoul National University for 12 years from January 1984 to December 1996. The results of this study showed as follows: 1. In a total of 9275 cases, there were 303 cases (3.3%) of Klinefelter's syndromes, 11 cases (0.1%) of Y chromosomal abnormalities. 2. In 102 cases of patients showed typical clinical features of Klinefelter's syndrome, 101 cases (99%) of them were diagnosed to Klinefelter's syndrome in karyotyping. 3. In 303 cases of Klinefelter's syndrome, there were 277 cases (91.4%) of 47,XXY complement, 16 cases (5.3%) of mosaicism, 2 cases (0.7%) of 48,XXXY, 5 cases (1.7%) of 48,XXYY and 3 cases (1.0%) of 49,XXXXY. 4. In 303 cases of Klinefelter's syndrome, 284 cases (93.7%) of them were diagnosed after puberty and only 19 cases (6.3%) of them were diagnosed before puberty. 5. In 303 cases of Klinefelter's syndrome, there were 146 cases (48.2%) of patients with infertility-associated chief complaints, 101 cases (33.3%) of patients with typical clinical features of Klinefelter's syndrome, 22 cases (7.3%) of patients with ambiguous genitalia. 6. In patients with Klinefelter's syndrome, 48,XXYY and 49,XXXXY had serious symptoms such as mental retardation, developmental delay, Down syndrome-like features, congenital anomalies, but 48,XXYY and other mosaicisms had infertility-associated symptoms or ambiguous genitalia. 7. The 8 cases of polysomy Y (XYY complement) showed several serious symptoms such as Down syndrome-like features, mental retardation, fragile X syndrome-like feature, congenital anomalies, ambiguous genitalia which could be detected before puberty.

• 한국가축번식학회지
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• 제20권3호
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• pp.323-331
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• 1996

포유동물에 있어서 조기 성 판정기술은 축산에 있어서의 성별 육종프로그램이나 인간의 X-염색체 관련 열성유전병의 산전진단 등 여러 분야에 응용될 수 있다. 초기배에 대한 성 판정은 성염색체에 존재하는 특이한 염기서열을 증폭시키는 polymerase chain reaction (PCR)과 X와 Y 염색체에 대한 특이적 probe를 이용하는 fluorescent in situ hybridization (FISH)에 의하여 수행될 수 있다. 1992년과 93년, 2개년도에 걸쳐 본 연구실에서 돼지의 3.3 kb 웅성특이 DNA 절편(pEM39)을 cloning하였다. 본 연구는 pEM39가 성특이 DNA-probe로 이용될 수 있는지를 조사하기 위해 PCR과 FISH를 이용하였다. 돼지 난자는 도축장에서 구입한 돼지 난소로부터 채취되었고, 체외배양후 체외수정되었다. 한편 처녀발생나자를 negative control로 이용하였다. 2 세포기의 수정란을 선발한 후 PCR을 통하여 DNA를 분석한 결과, 10개의 수정란 중 6개는 자성, 다른 4개는 웅성으로 판정되었으며, FISH를 수행한 결과, done된 웅성특이 DNA 단편은 돼지 간조직과 초기배에서 웅성특이성을 보였다. 또한 FISH와 karyotyping을 수행한 결과 clone된 웅성특이 DNA 단편이 Y 염색체 q-arm의 heterochromatic region에 위치함을 알 수 있었다. 이러한 결과로 보아 clone된 웅성특이 DNA 단편이 초기배의 성을 조기판정하는데 있어 유용하리라 사료되며, PCR에 의한 초기배의 성 판정에 있어 신뢰할만할 지표가 될 수 있을 것이다.

• 농업과학연구
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• 제38권2호
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• pp.269-275
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• 2011

The objective of this study was to develop a rapid and reliable PCR method for sexing of morula or blastocyst stage bovine embryo. BOV97M and bovine 1.715 satellite DNA sequences were selected for amplification of male and bovine specific DNA, respectively. But the unbalanced number of copies of these two repetitive sequences required some modification of PCR method. Karyotyping of blastomeres were carried for the confirmation of sex determination in bovine embryos. The coincidence rate of sex between biopsied-single blastomere and matched blastocyst was 80.0%. When in vivo- and in vitro- derived embryos were compared, 61.8% and 56.7% were male in in vitro- and in vivo-derived embryos, respectively. In vivo-derived embryos showed better hatching rate than in vitro-derived embryos following biopsy of blastomeres. In conclusion, rapid and effective PCR could be applied to sexing of bovine preimplantation embryos using single blastomere. The sensitivity of this assay may eliminate the need for biopsy of more than one nucleated blastomere and reduce trauma to the embryos derived from biopsy procedure.

• Journal of mucopolysaccharidosis and rare diseases
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• 제3권1호
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• pp.28-32
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• 2017

Lipoid congenital adrenal hyperplasia (LCAH) is the severe form of congenital adrenal hyperplasia and is characterized by adrenal insufficiency with hyperpigmentation and female external genitalia irrespective of genetic sex. The steroidogenic acute regulatory protein (StAR) is required for the transport of cholesterol into the mitochondria for steroidogenesis, and defects in the StAR gene account for the majority of LCAH cases. In this report, we present a two-day-old hyperpigmented infant with phenotypical female genitalia. With consideration of the clinical and laboratory findings, the infant was suspected of having adrenal insufficiency due to LCAH and treated with glucocorticoid, mineralocorticoid, and sodium chloride. Karyotyping revealed 46, XY. Upon pelvis ultrasonography, adrenal hyperplasia with abdominal masses (thought to be the testicles) was reported. Molecular analysis with targeted exome sequencing revealed the homozygote mutation of c.772C>T ($p.Q258^*$) in exon 7 of the StAR gene. The early detection and treatment of adrenal insufficiency in infants with hyperpigmentation can prevent clinically apparent adrenal crises. During follow-up, the patient had a good clinical condition and maintained normal electrolyte and adrenocorticotropic hormone levels with medication.