You Jung Han

Disease specific characteristics of fetal epigenetic markers for non-invasive prenatal testing of trisomy 21.

BackgroundNon-invasive prenatal testing of trisomy 21 (T21) is being actively investigated using fetal-specific epigenetic markers (EPs) that are present in maternal plasma. Recently, 12 EPs on chromosome 21 were identified based on tissue-specific epigenetic characteristics between placenta and blood, and demonstrated excellent clinical performance in the non-invasive detection of fetal T21. However, the disease-specific epigenetic characteristics of the EPs have not been established. Therefore, we validated the disease-specific epigenetic characteristics of these EPs for use in non-invasive detection of fetal T21.MethodsWe performed a high-resolution tiling array analysis of human chromosome 21 using a methyl-CpG binding domain-based protein (MBD) method with whole blood samples from non-pregnant normal women, whole blood samples from pregnant normal women, placenta samples of normal fetuses, and placenta samples of T21 fetuses. Tiling array results were validated by bisulfite direct sequencing and qPCR.ResultsAmong 12 EPs, only four EPs were confirmed to be hypermethylated in normal placenta and hypomethylated in blood. One of these four showed a severe discrepancy in the methylation patterns of T21 placenta samples, and another was located within a region of copy number variations. Thus, two EPs were confirmed to be potential fetal-specific markers based on their disease-specific epigenetic characteristics. The array results of these EPs were consisted with the results obtained by bisulfite direct sequencing and qPCR. Moreover, the two EPs were detected in maternal plasma.ConclusionsWe validated that two EPs have the potential to be fetal-specific EPs which is consistent with their disease-specific epigenetic characteristics. The findings of this study suggest that disease-specific epigenetic characteristics should be considered in the development of fetal-specific EPs for non-invasive prenatal testing of T21.

Non-Invasive Epigenetic Detection of Fetal Trisomy 21 in First Trimester Maternal Plasma

Background Down syndrome (DS) is the most common known aneuploidy, caused by an extra copy of all or part of chromosome 21. Fetal-specific epigenetic markers have been investigated for non-invasive prenatal detection of fetal DS. The phosphodiesterases gene, PDE9A, located on chromosome 21q22.3, is completely methylated in blood (M-PDE9A) and unmethylated in the placenta (U-PDE9A). Therefore, we estimated the accuracy of non-invasive fetal DS detection during the first trimester of pregnancy using this tissue-specific epigenetic characteristic of PDE9A. Methodology/Principal Findings A nested, case-control study was conducted using maternal plasma samples collected from 108 pregnant women carrying 18 DS and 90 normal fetuses (each case was matched with 5 controls according to gestational weeks at blood sampling). All pregnancies were singletons at or before 12 weeks of gestation between October 2008 and May 2009. The maternal plasma levels of M-PDE9A and U-PDE9A were measured by quantitative methylation-specific polymerase chain reaction. M-PDE9A and U-PDE9A levels were obtained in all samples and did not differ between male and female fetuses. M-PDE9A levels did not differ between the DS cases and controls (1854.3 vs 2004.5 copies/mL; P = 0.928). U-PDE9A levels were significantly elevated in women with DS fetuses compared with controls (356.8 vs 194.7 copies/mL, P<0.001). The sensitivities of U-PDE9A level and the unmethylation index of PDE9A for non-invasive fetal DS detection were 77.8% and 83.3%, respectively, with a 5% false-positive rate. In the risk assessment for fetal DS, the adjusted odds ratios of U-PDE9A level and UI were 46.2 [95% confidence interval: 7.8–151.6] and 63.7 [95% confidence interval: 23.2–206.7], respectively. Conclusions Our findings suggest that U-PDE9A level and the unmethylation index of PDE9A may be useful biomarkers for non-invasive fetal DS detection during the first trimester of pregnancy, regardless of fetal gender.

Gestational weight gain is an important risk factor for excessive fetal growth

Objective To estimate the odds ratio of prepregnant body mass index (BMI), gestational weight gain (GWG), and gestational diabetes mellitus (GDM) for excessive fetal growth, which we define as large for gestational age (LGA). Methods We included 16,297 women who delivered a live-born singleton baby at term. We fit logistic regressions to estimate the odds ratios of variables, including maternal age, parity, prepregnant BMI ≥23, GWG ≥15 kg, and GDM, for LGA. We classified GWG into four categories (<10, 10-14.9, 15-19.9, and ≥20 kg) and BMI into four categories (underweight, normal, overweight, and obese). After adjusting for age and parity, we analyzed the odds ratios of prepregnant BMI according to GWG between non-GDM and GDM women for LGA. Results The odds ratios of GWG ≥15 kg and prepregnancy BMI ≥23 for LGA were 2.40 (95% confidence interval [CI], 2.16-2.67) and 2.24 (95% CI, 1.99-2.51), respectively. The odd ratio of GDM was 1.37 (95% CI, 1.09-1.71). The risk of GDM women with normal/-overweight BMI and GWG <15 kg for LGA was not significantly greater than those of the reference group. The odd ratios of GDM women with overweight/obese BMI and GWG 15 to 19.9 kg were 3.95 (95% CI, 1.26-12.38) and 9.70 (95% CI, 3.79-24.87), respectively. Conclusion GWG ≥15 kg might be a more important risk factor for LGA than either prepregnancy BMI ≥23 or GDM. Risk for LGA was highest in obese GDM women with GWG ≥15 kg.

Cell-Free Fetal DNA and Cell-Free Total DNA Levels in Spontaneous Abortion with Fetal Chromosomal Aneuploidy

Background Cell-free fetal DNA and cell-free total DNA in maternal circulation have been proposed as potential markers for noninvasive monitoring of the placental condition during the pregnancy. However, the correlation of and change in cell-free fetal DNA and cell-free total DNA in spontaneous abortion (SA) with fetal chromosomal aneuploidy have not yet been reported. Therefore, we investigated cell-free fetal DNA and cell-free total DNA levels in SA women with fetal chromosomal aneuploidy. Methodology/Principal Findings A nested case-control study was conducted with maternal plasma collected from 268 women in their first trimester of pregnancy. Subjects included 41 SA with normal fetal karyotype, 26 SA with fetal chromosomal aneuploidy, and 201 normal controls. The unmethylated PDE9A gene was used to measure the maternal plasma levels of cell-free fetal DNA. The GAPDH gene was used to measure the maternal plasma levels of cell-free total DNA. The diagnostic accuracy was measured using receiver-operating characteristic (ROC) curves. Levels of cell-free fetal DNA and cell-free total DNA were significantly higher in both SA women with normal fetal karyotype and SA women with fetal chromosomal aneuploidy in comparison with the normal controls (P<0.001 in both). The correlation between cell-free fetal DNA and cell-free total DNA levels was stronger in the normal controls (r = 0.843, P<0.001) than in SA women with normal karyotype (r = 0.465, P = 0.002) and SA women with fetal chromosomal aneuploidy (r = 0.412, P = 0.037). The area under the ROC curve for cell-free fetal DNA and cell-free total DNA was 0.898 (95% CI, 0.852–0.945) and 0.939 (95% CI, 0.903–0.975), respectively. Conclusions Significantly high levels of cell-free fetal DNA and cell-free total DNA were found in SA women with fetal chromosomal aneuploidy. Our findings suggest that cell-free fetal DNA and cell-free total DNA may be useful biomarkers for the prediction of SA with fetal chromosomal aneuploidy, regardless of fetal gender.

MicroRNAs as potential biomarkers for noninvasive detection of fetal trisomy 21

PurposeThe objective of this study was to discover a panel of microRNAs (miRNAs) as potential biomarkers for noninvasive prenatal testing (NIPT) of trisomy 21 (T21) and to predict the biological functions of identified biomarkers using bioinformatics tools.MethodsUsing microarray-based genome-wide expression profiling, we compared the expression levels of miRNAs in whole blood samples from non-pregnant women, whole blood samples from pregnant women with euploid or T21 fetuses, and placenta samples from euploid or T21 fetuses. We analyzed the differentially expressed miRNAs according to disease and tissue type (P value <0.05 and two-fold expression change). To predict functions of target genes of miRNAs, the functional annotation tools were used.ResultsWe identified 299 miRNAs which reasonably separate the whole blood from the placenta. Among the identified miRNAs, 150 miRNAs were up-regulated in the placenta, and 149 miRNAs were down-regulated. Most of the up-regulated miRNAs in the placenta were members of the mir-498, mir-379, and mir-127 clusters. Among the up-regulated miRNAs in the placenta, mir-1973 and mir-3196 were expressed at higher levels in the T21 placenta than in the euploid placenta. The two miRNAs potentially regulate 203 target genes that are involved in development of brain, central nervous system, and nervous system. The genes are significantly associated with T21-related disorder such as congenital abnormalities, mental disorders, and nervous system diseases.ConclusionsOur study indicates placenta-specific miRNAs that may be potential biomarkers for NIPT of fetal T21 and provides new insights into the molecular mechanisms of T21 via regulation of miRNAs.

Simple high-throughput analytical method using ultra-performance liquid chromatography coupled with tandem mass spectrometry to quantify total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol in urine

Abstract Background: Since the urinary concentration of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) is a reliable biomarker of exposure to tobacco smoke, we developed a relatively simple high-throughput chromatographic method to quantify total urinary NNAL concentrations in the general population. Methods: The high-throughput analytical method was developed using ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) to identify and quantify total urinary NNAL concentrations in 10 non-smokers and 15 otherwise healthy smokers. Results: Loss of nitric oxide at m/z 30 was found to be the predominant mass transitioned, and therefore was used as the SIM transition to quantify both NNAL and NNAL-methyl-d3 in urine. The analytical method did not require sample derivatization. Standard curves for total NNAL concentrations were linear between 20 and 1500 pg/mL, with coefficients of determination >0.95. Precision and accuracy ranged from 2.2% to 8.6% (CV) and from –5.6% to 10.9% (percent error), respectively. The lowest limit of quantification was 6.7 pg/mL, and 2.0 pg/mL the lowest limit of detection (LLOD). Total urinary NNAL concentrations in non-smoker subjects were <LLOD, whereas in smokers varied between <LLOD to 112.1 pg/mL. Conclusions: An UPLC-MS/MS analytical method to quantify total urinary NNAL concentrations in smokers that does not require sample derivatization is presented herein. The method could be useful in clarifying the toxicities associated with human exposure to cigarette smoking. However, quantification might be adversely affected by co-eluting interfering compounds or selective ion suppression or enhancement as a result of having only one ion transition to monitor NNAL and NNAL-methyl-d3 in urine.

Fetal Loss rate after mid-trimester amniocentesis

Fetal loss rate after mid-trimester amniocentesis You Jung Han, Yun Young Kim, Si Won Lee, Min Hyung Kim, Jin Hoon Chung, Hyun Kyong Ahn, Jung Yeol Han, Moon Young Kim, Jae Hyug Yang, So Yeon Park, Hyun Mee Ryu Department of Obstetrics and Gynecology, Cheil General Hospital and Womens Healthcare Center, Kwandong University College of Medicine, Seoul, Korea; Laboratory of Medical Genetics, Medical Research Institute, Cheil General Hospital and Womens Healthcare Center, Seoul, Korea

Pregnancy outcomes after exposure to phendimetrazine in first trimester of pregnancy

1 PREGNANCY OUTCOMES AFTER EXPOSURE TO PHENDIMETRAZINE IN FIRST TRIMESTER OF PREGNANCY Min-Young Lee, MD, June-Seek Choi, MD, Jung-Yeol Han, MD, Hyun-Kyeong Ahn, MD, Jae-Hyug Yang, MD, Moon-Young Kim, MD, Hyun-Mee Ryu, MD, Min-Hyoung Kim, MD, Jin-Hoon Chung, MD, Kyu-Hong Choi, MD, Si-Won Lee, MD, You-Jung Han, MD, Jae-Ra Lee, MD, Hye-Woen Park, MD Department of Obstetrics and Gynecology, Cheil General Hospital and Women’s Healthcare Center, Kwandong University College of Medicine; The Korean Motherisk Program, Seoul, Korea

Prenatal Genetic Test

유전자 검사는 생명과학의 발달과 더불어 질병 진단 및 연구의 중요한 수단으로 일반화되고있으나, 태아에 대한 유전자 검사는 자기결정권이 없는 태아를 대상으로 하기 때문에 또 다른 윤리적, 사회적 문제가 있을 수 있으므로 특별한 주의를 기울여야 한다. 따라서 태아 유전자 검사를 시행하기 전에 유전 상담이 충분히 이루어져서 부모에게 병의 진단, 자연경과, 가능한 치료를 이해시키며, 질환의 유전방식과 가족의 재발 위험도를 평가하고 그에 따른 가능한 선택을 제시하여 가족들이 질환에 대해 최선의 결정을 할 수 있게 도움을 주어야 한다. 뿐만 아니라 태아 유전자 검사에 대한 현행법의 합리적인 법률 개정도 뒷받침되어야 한다. 【Genetic testing has been generalized for the diagnosis of diseases and is an important method of research with advances in the life sciences. In particular, we should give better attention to the genetic test for a fetus. Because the fetus has no autonomy, ethical and social issues can arise. Therefore, appropriate genetic counseling is needed for parents to be informed with the characteristics, natural progress, and possible treatment of a genetic disease, prior to the prenatal genetic test. Physicians should also inform parents how a particular genetic risk factor relates with the likelihood of a disease, in order to assist the parents in making the best decision. Furthermore, the current law for prenatal genetic testing should be approached rationally.】

Monocentric Derivative Y Chromosome with Duplication of the SRY Gene in an Azoospermic Male

Structural abnormalities of the Y chromosome affect normal testicular differentiation and spermatogenesis. The present case showed a rare monocentric derivative Y chromosome with partial duplication of Yp including the SRY gene and deletion of Yq12 heterochromatin. The karyotype was 46,X,der(Y) (pter q11.23::p11.2 pter).ish der(Y)(DYZ3+,DYZ1-, → → SRY++), confirmed through a FISH study. Even though the patient possessed an abnormal Y chromosome, testicular biopsy showed normal testicular volumes in the proband, with gonadal hormonal levels in the normal range but bilateral varicocele and hypospermatogenesis. We speculate that the abnormal Y chromosome arose from sister chromatids during Y chromosome recombination or intra chromosomal NAHR (non-allelic homologous recombination) during meiosis in the patient s father or in the very early stages of embryogenesis. The ’ derivative Y chromosome might interfere in the meiotic stage of spermatogenesis, leading to the developmental arrest of germ cells. The present case illustrates that the infertility phenotype can have various causes. Also, it emphasizes the importance of accurate and various genetic analyses and could aid in male infertility treatment.