• 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.

• Journal of Genetic Medicine
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• 제17권1호
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• pp.21-26
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• 2020

Purpose: To evaluate the additive value of prenatal chromosomal microarray analysis (CMA) in assessing increased nuchal translucency (NT) (≥3.5 mm) with normal karyotype and the possibility of detecting clinically significant genomic imbalance, based on specific indications. Materials and Methods: Invasive samples from 494 pregnancies with NT ≥3.5 mm, obtained from the Research Center of Fertility & Genetics of Hamchoon Women's Clinic between January 2019 and February 2020, were included in this study and CMA was performed in addition to a standard karyotype. Results: In total, 494 cases were subjected to both karyotype and CMA analyses. Among these, 199 cases of aneuploidy were excluded. CMA was performed on the remaining 295 cases (59.7%), which showed normal (231/295, 78.3%) or non-significant copy number variation (CNV), such as benign CNV or variants of uncertain clinical significance likely benign (53/295, 18.0%). Clinically significant CNVs were detected in 11 cases (11/295, 3.7%). Conclusion: Prenatal CMA resulted in a 3% to 4% higher CNV diagnosis rate in fetuses exhibiting increased NT (≥3.5 mm) without other ultrasound detected anomalies and normal karyotype. Therefore, we suggest using high resolution, non- targeting CMA to provide valuable additional information for prenatal diagnosis. Further, we recommend that a genetics specialist should be consulted to interpret the information appropriately and provide counseling and follow-up services after prenatal CMA.

• Journal of Genetic Medicine
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• 제11권1호
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• pp.16-21
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• 2014

A 31-year-old woman, who was pregnant with twins, underwent chorionic villus sampling because of increased nuchal translucency in one of the fetuses. Cytogenetic analysis showed a normal karyotype in the fetus with increased nuchal translucency. However, the other fetus, with normal nuchal translucency, had a derivative X chromosome (der(X)). For further analysis, fluorescence in situ hybridization (FISH) and additional molecular studies including fragile X analysis were performed. FISH analysis confirmed that the Y chromosome was the origin of extra segment of the der(X). The X-chromosome breakpoint was determined to be at Xq27 by FMR1 CGG repeat analysis, and the Y-chromosome breakpoint was determined to be at Yq11.23 by the Y chromosome microdeletion study. To predict the fetal outcome, the X-inactivation pattern was examined, and it revealed non-random X inactivation of the der(X). To the best of our knowledge, the identification of an unbalanced Xq;Yq translocation at prenatal diagnosis has never been reported. This study was performed to identify precise breakpoints and the X-inactivation pattern as well as to provide the parents with appropriate genetic counseling.

• Journal of Genetic Medicine
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• 제14권1호
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• pp.1-7
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• 2017

Purpose: The aim of this study was to assess the diagnostic efficacy of noninvasive prenatal screening for trisomy 18 by assessing the levels of unmethylated-maspin (U-maspin) and fetal nuchal translucency (NT) thickness during the first trimester of pregnancy. Materials and Methods: A nested case-control study was conducted using maternal plasma samples collected from 65 pregnant women carrying 11 fetuses with trisomy 18 and 54 normal fetuses. We compared the U-maspin levels, NT thicknesses, or a combination of both in the first trimester between the case and control groups. Results: U-maspin levels and NT thickness were significantly elevated in the first trimester in pregnant women carrying fetuses with trisomy 18 when compared to those carrying normal fetuses (27.2 vs. 6.6 copies/mL, P<0.001 for U-maspin; 5.9 vs. 2.0 mm, P<0.001 for NT). The sensitivities of the U-maspin levels and NT thickness in prenatal screening for fetal trisomy 18 were 90.9% and 90.9%, respectively, with a specificity of 98.1%. The combined U-maspin levels and NT thickness had a sensitivity of 100% in prenatal screening for fetal trisomy 18, with a specificity of 98.1%. Conclusion: A combination of U-maspin levels and NT thickness is highly efficacious for noninvasive prenatal screening of fetal trisomy 18 in the first trimester of pregnancy.

• Journal of Genetic Medicine
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• 제2권1호
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• pp.7-10
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• 1998

The present report describes a case that showed a normal fetal karyotype in an antenatal genetic study but an abnormal placental karyotype of 46,XX,r (15) on postnatal examination. The pregnancy was complicated by fetal nuchal translucency in the first trimester and intrauterine growth restriction in the second and third trimesters. A 1780 gm female baby was born after 40 weeks of gestation, but died of respiratory distress and sepsis on the 10th day of life. Our case was unique in that the placental chromosomal aberration was a structural abnormality instead of a numerical aberration that is seen in most reported cases of confined placental mosaicism.

• Journal of Genetic Medicine
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• 제11권2호
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• pp.56-62
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• 2014

Purpose: To assess the outcomes of increased fetal nuchal translucency (NT), to aid in prenatal counseling and management in our practice. Materials and Methods: We retrospectively reviewed the medical records of patients who underwent first trimester fetal karyotyping using chorionic villi sampling (CVS) and second trimester level II sonography for a fetal NT thickness ${\geq}3.0mm$ between 11 weeks and 13 weeks 6 days' gestation, at Gyeongsang National University Hospital. Pediatric medical records and a telephone interview were used to follow-up live-born children. Exclusion criteria included incomplete data and CVS for other indications. Results: Seventy cases met the inclusion criteria (median NT thickness, 4.7 mm; range, 3.0-16.1 mm). Twenty-nine cases (41.4%) were aneuploid. The prevalence of chromosomal defects increased with NT thickness: NT 3.0-3.4 mm, 16.7%; NT 3.5-4.4 mm, 27.3%; NT 4.5-5.4 mm, 66.7%; NT 5.5-6.4 mm, 37.5%; NT ${\geq}6.5mm$, 62.5%. The most common karyotype abnormality was trisomy 18 (n=12), followed by trisomy 21 (n=9). In chromosomally normal fetuses (n=41), fetal death occurred in 2 cases (4.9%), and structural malformations were found in 11 cases (26.8%). In chromosomally and anatomically normal fetuses (n=28), one child had neurodevelopmental delay (3.6%). Twenty-eight infants who had a prenatal increased NT were alive and well at follow-up (40%). Conclusion: Outcomes of increased fetal NT might help inform prenatal counseling and management. The high prevalence of chromosomal defects associated with increased fetal NT implies that CVS should be performed in the first trimester, particularly considering the stress associated with an uncertain diagnosis.

• 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.

• 대한방사선기술학회지:방사선기술과학
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• 제39권4호
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• pp.549-555
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• 2016

본 연구는 다운증후군 위험도의 예측을 위해 통합선별검사를 실시한 산모를 대상으로, 각 표지자의 유의성에 대한 평가를 하였다. 초음파로 측정한 NT 영상, 산모혈청 PAPP-A, AFP, uE3, hCG, 인히빈 A의 상관성을 후향적으로 분석하였다. 그 결과 NT, uE3, hCG, 인히빈 A와 유의한 상관관계를 보였다(p<.001). ROC분석에서 인히빈 A의 AUC가 0.851로 다운증후군의 가장 큰 예측인자로 분석되었으며. cut-off value 1.33 MoM(민감도 87.5%, 특이도 71.5%)으로 결정되었다. 결론적으로 통합선별검사에서 인히빈 A가 다운증후군을 예측하는 가장 유용한 인자로 나타났다. 이에 각 표지자(parameter)들의 cut-off value를 바탕으로 통합선별검사의 단점을 보완한다면 다운증후군 선별의 독립적인 지표로 사용될 수 있을 것으로 사료된다.

• Journal of Genetic Medicine
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• 제15권2호
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• pp.79-86
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• 2018

Purpose: This study aimed to evaluate the clinical usefulness of non-invasive prenatal testing (NIPT) as an alternative testing of invasive diagnostic testing in pregnancies with ultrasound abnormalities. Materials and Methods: This was a retrospective study of pregnant women with abnormal ultrasound findings before 24 weeks of gestation between April 2016 and March 2017. Abnormal ultrasound findings included isolated increased nuchal translucency, structural anomalies, and soft markers. The NIPT or diagnostic test was conducted and NIPT detected trisomy 21 (T21), T18, T13 and sex chromosomal abnormalities. We analyzed the false positive and residual risks of NIPT based on the ultrasound findings. Results: During the study period, 824 pregnant women had abnormal ultrasound findings. Among the study population, 139 patients (16.9%) underwent NIPT. When NIPT was solely performed in the patients with abnormal ultrasound findings, overall false positive risk was 2.2% and this study found residual risks of NIPT. However, the discordant results of NIPT differed according to the type of abnormal ultrasound findings. Discordant results were significant in the group with structural anomalies with 4.4% false positive rate. However, no discordant results were found in the group with single soft markers. Conclusion: This study found different efficacy of NIPT according to the ultrasound findings. The results emphasize the importance of individualized counseling for prenatal screening or diagnostic test based on the type of abnormal ultrasound.

• Journal of Genetic Medicine
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• 제8권1호
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• pp.35-43
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• 2011

목적: 본원에서 최근 10년간 시행한 융모막 융모생검의 적응증에 따른 결과 및 합병증을 조사하고 현재 사용하고 있는 융모막 융모생검의 효용성을 분석해보고자 한다. 대상 및 방법: 2000년 4월부터 2010년 4월까지 최근 10년간 분당차병원 및 강남차병원에서 융모막 융모생검을 시행한 511례의 진료기록 및 검사 결과를 검토하였다. 각각의 환자에 해당되는 모든 적응증을 조사하고 중복을 허용하여 분석하였다. 태아 염색체 검사는 직접법과 배양법을 통하여 시행하였다. 결과: 각각의 적응증을 살펴보면 태아의 비후된 목덜미 두께를 포함한 비정상 초음파 소견이 294례(294/635, 46.3%)로 가장 높았다. 각각의 적응증에 따른 태아 염색체 이상의 양성예측도는 부모 중에 염색체 이상이 있는 경우가 66.7%(14/21)로 가장 높았다. 융모막 융모생검 상 모자이시즘은 3.1% (16/509)였고, 그 중에서 양수검사로 확인된 진모자이시즘은 2례, 태반에 국한된 모자이시즘은 11례였다. 융모막 융모생검 이후 4주 이내에 임신 종결된 경우는 6례로 태아손실률은 1.2% (6/511)였다. 결론: 융모막 융모생검은 산전 유전진단을 하는데 있어서 적합하고 신뢰할 수 있는 시술이다. 융모막 융모생검 결과 모자이시즘을 보이는 경우 반드시 양수검사를 통하여 진모자이시즘인지 태반에 국한된 모자이시즘인지 확인이 필요하다.