• 대한의생명과학회지
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• 제17권2호
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• pp.129-134
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• 2011

Mosaicism is the presence of two or more chromosomally distinct cell lines, each seen in two or more cells. Chromosomal mosaicism presents one of the most difficult problems in prenatal cytogenetic diagnosis, requiring the differentiation of true mosaicism from pseudomosaicism. To overcome associated problems we investigated 24 cases (amniotic fluid 13 cases, abortus tissue 3 cases, peripheral blood 8 cases) in which mosaicism has been found in cytogenetic analysis. 5 cases (38.5%) of 13 amniotic fluid cells in which mosaicisms showed single cell pseudomosaicism. Chromosomal true mosaicism is found in about 0.28% (8/2,826) of amniotic fluid cell cultures. The 24 cases involved 12 cases (50%) with sex chromosomal abnormalities, 7 cases (29.2%) with autosomal structural defects, 3 cases (12.5%) with autosomal abnormalities, 2 cases (8.3%) with a supernumerary marker. Mosaicism detected in amniotic fluid may represent the true mosaicism or may pseudomosaicism. If the same chromosome abnormality is seen in more than one cell and in two different cultures, it is considered a true mosaicism, whereas single-cell abnormalities from a single culture are regarded as pseudomosaicism. In this study, we describe a mosaicism in chromosome analysis, its diagnostic problems and clinical significance.

• 한국발생생물학회지:발생과생식
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• 제22권2호
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• pp.199-203
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• 2018

Although trisomy 16 is commonly detected in spontaneous abortions and accounts for over 30% of cases of autosomal trisomy detected after spontaneous abortion, trisomy 16 mosaicism is rarely detected by amniocentesis in the second trimester. Here, we report a case of level III trisomy 16 mosaicism (47,XX,+16[8]/46,XX[31]) diagnosed by cytogenetic analysis of independently cultured amniotic fluid cells. The female baby was delivered at full term with low birth weight and intrauterine growth retardation, and interestingly, her karyotype was normal (46,XX). Given the difficulty in predicting the outcomes of fetuses with this mosaicism, it is recommended to inform the possibility of mosaicisms including this trisomy 16 mosaicism during prenatal genetic diagnosis and genetic counseling for parents.

• Journal of Genetic Medicine
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• 제3권1호
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• pp.21-24
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• 1999

To study the X chromesome mosaicism in the cytogenetically pure 45,X Turner syndrome patients, we applied PCR technique using DNAs extracted from archived cytogenetic slides. We amplified the DNAs using nested primers targeted to a highly polymorphic short tandem repeat(STR) of the human androgen receptor gene(HUMARA) for the detection of X chromosome mosaicism. This assay is a very sensitive and useful method which can be applied to the DNAs extracted from archived cytogenetic slides to detect X mosaicism. We have tested 50 normal Korean females to determine whether the HUMARA locus is highly polymorphic among Koreans. 85% of Korean population showed heterozygosity in the HUMARA locus. We analysed the 24 DNAs extracted from archived slides of patients and abortuses with Turner syndrome in cytogenetic analysis. We observed the heterozygosities of 50% from pure 45,X patients, 83% from the patients with mosaic Turner syndrome and 8.3% from the abortuses of pure 45,X. Using the PCR technique of the HUMARA locus in the archived cytogenetic slides, we detected X chromosome mosaicism which could not be detected in cytogenetic analysis.

• Clinical and Experimental Pediatrics
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• 제55권10호
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• pp.393-396
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• 2012

Trisomy 14 mosaicism is a rare chromosome disorder characterized by delayed development, failure to thrive, and facial dysmorphism. Only approximately 30 trisomy 14 mosaicism cases have been reported in the literature because trisomy 14 is associated with early spontaneous abortion. We report a case of a 17-month-old girl with abnormal skin pigmentation, delayed development, facial dysmorphism, and failure to thrive with the 47,XX,+14/46,XX chromosome complement.

• Journal of Genetic Medicine
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• 제10권1호
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• pp.52-56
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• 2013

Mosaic trisomy 14 syndrome is a well-known but unusual chromosomal abnormality with a distinct and recognizable phenotype. Array comparative genomic hybridization (CGH) analysis has recently become a widely used method for detecting DNA copy number changes, in place of traditional karyotype analysis. However, the array CGH shows a limitation for detecting the low-level mosaicism. Here, we report the detailed clinical and cytogenetic findings of patient with low-frequency mosaic trisomy 14, initially considered normal based on usual cut-off levels of array CGH, but confirmed by G-banding karyotyping. Our patient had global developmental delay, short stature, congenital heart disease, craniofacial dysmorphic features, and dark skin patches over her whole body. Estimated mosaicism proportion was 23.3% by G-banding karyotyping and 18.0% by array CGH.

• Journal of Genetic Medicine
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• 제10권2호
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• pp.117-119
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• 2013

Double trisomy mosaicism of two different cell lines is extremely rare, particularly those that involve constitutional trisomy 8. We report a case of 47,XXX/47,XX,+8 in a 12-year-old female presenting with several skeletal anomalies. She exhibited distinct phenotypic features such as tall stature, deviation of the left middle finger, webbing of both thumbs and flexion deformities of the both third and fifth distal intermediate phalanges. A mild impulse-control disorder was observed, without mental retardation. Chromosomal and fluorescence in situ hybridization analysis demonstrated double trisomy mosaicism both on lymphocytes and buccal epithelial cells.

• Clinical and Experimental Reproductive Medicine
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• 제19권1호
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• pp.95-101
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• 1992

During the years 1983 to 1991, cytogenetic analysis was performed on 19 women with Turner syndrome in order to find out the incidence of symptoms and signs according to the classification of chromosome abnormalities. 1. All of them showed short stature and the mean height in 7 adults was $140.71{\pm}5.26cm$. 2. Among the 19 patients with Turner syndrome, 7 (36.8%) had 45, XO karyotype, 7 (36.8%) had 46, Xi (Xq), and remained 5 (26.3%) had mosaicism. 3. Five patients with mosaicism had 45, X/46, XX (2), 45, X/46, Xi (Xq) (2) and 45, X/47, XXX (1), respectively. 4. Patients with 45, XO and 46, Xi (Xq) had amenorrhea, whereas only 33% (1/3) of patients with mosaicism had amenorrhea. Total incidence of amenorrhea was 84.6% (11/13). 5. Abnormal external genitalia was detected in 63.6% of patients. The incidence of abnormality in patients with mosaicism was lower than that of other groups. 6. OMPC and deafness were detected in 3 of 19 patients. 7. Two cases of cardiovascular abnormalities were found in patients with 45, XO. This study suggests that gnenetic counselling according to the classification of chromosomal abnormalities could be needed in patients with Turner syndrome.

• Clinical and Experimental Pediatrics
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• 제48권12호
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• pp.1317-1323
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• 2005

목 적 : 성염색체이상증후군은 사춘기 이후 이차 성징의 결여로 그 증상이 뚜렷해지므로 사춘기 이전의 진단은 쉽지 않다. 본 연구는 성염색체이상증후군의 빈도, 진단시 연령, 그리고 임상적 특징을 조사하여 그 의의를 알아보고자 한다. 방 법 : 1981년 2월부터 2001년 8월까지 20년 동안 경북대학교병원 소아과 염색체검사실에 의뢰된 염색체검사 중 성염색체 이상증후군으로 진단된 115례 환자의 임상적 특징, 진단시 연령 그리고 핵형 분석을 후향적인 방법으로 조사하였다. 결 과 : 성염색체이상증후군의 종류와 빈도는 Klinefelter 증후군은 52%, Turner 증후군은 42%, XXX 증후군은 3%, 혼합 성선이형성은 3%였다. Klinefelter 증후군은 47,XXY가 97%, mosaicism이 3%였고, Turner 증후군은 45,X가 67%, mosaicism이 23%, X 염색체의 구조적 이상은 10%였다. XXX 증후군은 47,XXX가 67%, mosaicism은 33%였고, 혼합 성선이형성은 모두 45,X/46,XY였다. 성염색체이상증후군의 81%가 사춘기 이후에 진단되었다. 신생아기에 Klinefelter 증후군과 Turner 증후군으로 진단받은 경우는 표현형이 정상이거나 경한 선천성기형만을 보였다. Turner 증후군과 Klinefelter 증후군의 mosaicism이나 구조적 이상군에서 전형적인 45,X나 47,XXY보다 신체상 증상 발현이 경미할 것으로 생각되었으나 본 연구에서는 통계학적으로 유의한 차이는 보이지 않았다. 결 론 : 성염색체이상증후군은 사춘기 이전에는 그 증상이 뚜렷하지 않으므로 환아에 대한 주의 깊은 관찰과 관심으로 조기에 진단하여 정상적인 정신성적발달과 성장발육 및 성생활을 유지하도록 부모와 환아의 질환에 대한 인지도를 높여야 할 것으로 사료된다. 특히 핵형 분석시 Turner 증후군은 X염색체의 다양한 구조 이상 또는 mosaicism의 빈도가 높기 때문에 핵형 분석시 이를 염두에 두어야 한다.

• Clinical and Experimental Pediatrics
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• 제46권4호
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• pp.397-399
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• 2003

저자들은 특이한 얼굴, 근 긴장도 증가, 정신 지체와 혈액학적으로 일시적인 적혈구 이형성증(dyserythropoiesis)의 소견을 동반한 MDS 의증의 소견과 혈소판 감소증, 호산구 증가증을 동반하는 부분 21-monosomy 증후군 1례를 신생아기부터 8세까지 추적 관찰하고 보고한다. 이와 같은 예는 우리나라에서 보고되는 첫 증례라고 사료되어 간단한 문헌 고찰과 함께 보고하는 바이다.

• Journal of Genetic Medicine
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• 제12권2호
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• pp.118-122
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• 2015

Noninvasive prenatal test (NIPT) is a novel screening method for the diagnosis of fetal chromosomal aneuploidies. NIPT is based on technology that detects cell-free fetal DNA in maternal plasma and analyzes it with massively parallel sequencing technology to determine whether the fetus is at risk of trisomy 21, trisomy 18, trisomy 13 or sex chromosome abnormalities (SCAs). NIPT has been reported to have sensitivity of 99% and a false positive rate of less than 1% for detecting trisomy 21 and trisomy 18. Although extension of the application of NIPT to other SCAs has been attempted, there are concerns in extending NIPT to SCAs because of maternal or fetal mosaicism, undetected maternal SCAs, and multiple pregnancies. Recently, we assessed a pregnancy with the rare Turner syndrome mosaicism 45, X/47, XXX, which was reported as 45, X with NIPT. We present the case here and briefly review the current literatures on NIPT in testing for fetal monosomy X. To the best of our knowledge, this is the first report of the 45, X/47, XXX mosaicism in Korea to be reported as 45, X by NIPT with whole genome sequencing. This case report will provide valuable information for counseling women who want to undergo NIPT.