ABSTRACT
Originating but free from chromosomal DNA, extrachromosomal circular DNAs (eccDNAs) are organized in circular form and have long been found in unicellular and multicellular eukaryotes. Their biogenesis and function are poorly understood as they are characterized by sequence homology with linear DNA, for which few detection methods are available. Recent advances in high-throughput sequencing technologies have revealed that eccDNAs play crucial roles in tumor formation, evolution, and drug resistance as well as aging, genomic diversity, and other biological processes, bringing it back to the research hotspot. Several mechanisms of eccDNA formation have been proposed, including the breakage-fusion-bridge (BFB) and translocation-deletion-amplification models. Gynecologic tumors and disorders of embryonic and fetal development are major threats to human reproductive health. The roles of eccDNAs in these pathological processes have been partially elucidated since the first discovery of eccDNA in pig sperm and the double minutes in ovarian cancer ascites. The present review summarized the research history, biogenesis, and currently available detection and analytical methods for eccDNAs and clarified their functions in gynecologic tumors and reproduction. We also proposed the application of eccDNAs as drug targets and liquid biopsy markers for prenatal diagnosis and the early detection, prognosis, and treatment of gynecologic tumors. This review lays theoretical foundations for future investigations into the complex regulatory networks of eccDNAs in vital physiological and pathological processes.
Subject(s)
Male , Female , Animals , Humans , Swine , DNA, Circular/genetics , Genital Neoplasms, Female , Semen , DNA , ReproductionABSTRACT
ObjectiveTo explore the prenatal diagnostic methods of 18q deletion syndrome and improve understanding on the value of non-invasive prenatal testing （NIPT） in prenatal diagnosis of 18q deletion syndrome. Methods18q deletion syndrome was detected by conventional methods such as serological screening， ultrasonic imaging examination， chromosome karyotype analyses of both amniotic fluid cells and parental peripheral blood， and molecular biological techniques including NIPT， chromosomal microarray analysis （CMA） and copy number variation sequencing （CNV-Seq）. Genetic counseling was conducted based on these examination results. ResultsNIPT identified a 24 MB deletion on the chromosome 18 which contained 17 genes including BCL2 by karyotype analysis of amniotic fluid cells and CMA. Further ultrasonic imaging examination confirmed the diagnosis of 18q deletion syndrome and karyotype analysis of parental peripheral blood revealed a de novo deletion mutation. ConclusionsInterventional prenatal diagnosis is an integral standard for the diagnosis of 18q deletion syndrome. NIPT， as an important screening test in middle pregnancy， can indicate the early possible chromosome segment deletion and reduce the time and economic cost when no abnormality is found in ultrasonic imaging.
ABSTRACT
Objective To explore the clinical significance of non-invasive prenatal testing(NIPT)for fetal chromosomal abnormalities in the cases of twin pregnancy and its relationship with age and other related factors.Methods A total of 3733 women with twin pregnancy of 12-26+6 weeks who voluntarily underwent NIPT in the Ningbo Women and Children's Hospital from January 2018 to December 2022 were selected.The results of NIPT and amniocentesis were compared and all the participants were followed up.The detection rate of chromosomal abnormalities by NIPT was calculated,and its correlations with age,gestational weeks,chorionicity,and pregnancy type were analyzed.Results Among the 3733 cases,71 cases of fetal chromosome abnormality were indicated by NIPT,including 13 cases of trisomy 21,19 cases of trisomy 18,5 cases of trisomy 13,18 cases of sex chromosome abnormality,and 16 cases of chromosome microdeletion/duplication(excluding 21,18,13,and sex chromosomes),among which 34 cases were true positive and 37 cases were false positive.The overall sensitivity,specificity,and positive predictive value(PPV)of NIPT for chromosomal abnormalities in the cases of twin pregnancy were 100%,98.99%,and 47.89%(34/71),respectively.NIPT showed the sensitivity,specificity,and PPV of 100%,99.78%,and 78.38%(29/37)for trisomy 21,18,and 13,100%,99.56%,and 16.67%(3/18)for sex chromosome abnormalities,and 100%,99.62%,and 12.5%(2/16)for chromosome microdeletion/duplication,respectively.In the age group of ≥40 years,the NIPT for chromosomal abnormalities showed the PPV of 66.67%,the sensitivity of 100%,and the misdiagnosis rate of 30%。However,the NIPT for trisomy 21,18,and 13 showed the PPV of 100%,the misdiagnosis rate of 0,and the sensitivity and specificity of 100%.In terms of grouping based on gestational weeks,the NIPT for chromosomal abnormalities showed the highest PPV(51.28%)in the women with twin pregnancy for 14-17+6 weeks,followed by that(50.00%)in the women with twin pregnancy for 22-26+6 weeks;the NIPT for trisomy 21,18,and 13 showed the highest PPV of 94.74% in the gestation group of 14-17+6 weeks,followed by that(83.33%)in the gestation group of 18-21+6 weeks.The rate of dichorionic diamniotic twins was higher in assisted pregnancies than in natural pregnancies,and NIPT showed the same detection efficiency for dichorionic diamniotic twins and monochorionic diamniotic twins and the same detection efficiency for different pregnancy types.Conclusions NIPT has high accuracy in the diagnosis of twin pregnancy and high sensitivity and high specificity for different ages and gestational weeks,especially for trisomy 21,18,and 13.NIPT is suitable for assisted pregnancy and natural pregnancy,and it is of high value in clinical application.However,extensive application needs a large population-based study.
Subject(s)
Pregnancy , Child , Female , Humans , Adult , Down Syndrome/genetics , Pregnancy, Twin , Prenatal Diagnosis , Trisomy , Chromosome AberrationsABSTRACT
Objective:To develop a self-made plasma quality control material for non-invasive prenatal testing (NIPT) and evaluate its performance.Methods:139 NIPT-negative maternal plasmas stored in the genetic department of Shaoxing maternal and child health hospital from January 1, 2019 to June 30, 2021 were divided into male groups (19 cases) and female groups (120 cases) according to the neonatal gender. 9360 cases from September 2020 to September 2021 were enrolled as clinical validation cases.First step, 200 μl plasma from a 47 years-old non-pregnant healthy women was used as a matrix. Different amounts (0.1, 0.2, 0.5, 2.5, and 5 μl) of positive DNA from fetal chromosome aneuploidy (T21, T18, T13) detection kit were added. The appropriate volume of positive DNA was 0.5 μl according to the test results. Second step,Plasma in male and female group was treated as matrix. 0.5 μl positive DNA was added per 205 μl. Plasma matrix from female group showed good repeatability and the sensitivity was 100%.Third step, evaluate the self-made plasma quality control material, including storage stability, matrix uniformity and repeatability, and the effect of different batch numbers of positive DNA, by calculating Z score and the CV of fetal DNA concentration (FF).Results:Plasma matrix from female group showed good repeatability and the sensitivity was 100%, while the sensitivity of male group was only 84%. The CV of FF in female matrix was 3.9% in the repetitive experiments. After adding 0.5 μl positive DNA, the mean FF of self-made positive plasma quality control was 5.63%±0.42%, Z values>6, and the CV was 7% after storage of three months. Considering the concentration variation of positive DNA in different lots, 1 μl of positive DNA should be added when the FF of positive DNA is lower than 10%.Used in 9360 clinical cases from September 2020 to September 2021, all positive plasma quality control materials showed positive results, and the positive predictive value of trisomy 21 was 100%.Conclusions:The NIPT self-made positive plasma quality control material has been successfully developed in this study. The preliminary experimental results show that it has good repeatability and stability, which is suitable for clinical application.
ABSTRACT
Objective:To explore the application value of non-invasive prenatal testing (NIPT) technology in twin pregnancy.Methods:A total of 339 twin pregnant women who underwent NIPT at Dalian Municipal Women and Children′s Medical Center(Group), Dalian Jinpu New District Maternity and Child Health Hospital, and Dalian Lvshunkou District People′s Hospital from July 1, 2019 to June 30, 2021 were continuously retrospectively included. The clinical characteristics and test results of pregnant women with high-risk and low-risk were analyzed.Results:Among 339 pregnant women, 336 were successfully tested, with a success rate of 99.12%(336/339); 6 pregnant women were at high risk of NIPT, with a positive screening rate of 1.77%(6/339), including 1 case of high risk of trisomy 13, 2 cases of high risk of trisomy 18, and 3 cases of high risk of Trisomy 21; the results of amniocentesis for 2 high-risk pregnant women were not abnormal.Conclusions:NIPT technology is non-invasive, safe and efficient, and is suitable for large-scale prenatal screening. However, the detection accuracy of pregnant women with twin pregnancy needs to be improved.
ABSTRACT
@#There are a number of novel prenatal cytoogenetic analysis tests for obstetricians and gynecologists on detecting aneuploidies. In the recent years, screening of pregnant patients with non-invasive prenatal testing (NIPT) is one. As the spread of genomic medicine and preventive obstetrics continue, it is prudent for obstetricians and gynecologists to accept and optimize new screening modalities, whenever available. Chromosomal abnormalities are common. Worldwide, one out of 150 live births may involve chromosomal abnormalities. The American College of Obstetrics and Gynecologists (ACOG) and American College of Medical Genetics recommend invasive and non ? invasive prenatal testing (NIPT)3. The invasive testing, however, carries risk for procedure ? related miscarriage. 4This favors NIPT which avoids the risk. The current state of NIPT in the Philippines, is it was only in January 2018, were a NIPT workshop was conducted by the Society of Maternal Fetal Medicine.6 First, due to the minimal studies on personalized and precision medicine on prenatal testing, hence the strong move to conduct this study. In an extensive literature search review in Herdin, a local database and archives of Philippine Obstetrics and Gynecology, none specified researches on non ? invasive prenatal testing. Second, in our country alone, there is no provision for national prenatal tests. In our institution, it was already introduced but with no uptake yet. Because of this gap, scantiness and non - uptake on NIPT locally, hence the conduct of this study. The study aimed to investigate on the obstetricians and gynecologists (OB-GYNs) knowledge, attitude towards and practices (KAP) about NIPT. Majority of the OBGYNs were knowledgeable, had positive attitude and were practicing NIPT. Strikingly, a fourth of the respondents were not comfortable in explaining NIPT. The researcher recommends that there is a need to conduct this study on a larger scale cross - sectional survey and multiple studies due to the paucity of data.
Subject(s)
Pregnancy , Female , Prenatal Diagnosis , Genetic Testing , Mass Screening , DNAABSTRACT
Objective@#To assess the value of non-invasive prenatal testing (NIPT) for the identification of fetal chromosomal aneuploidies.@*Methods@#For 9470 pregnant women with a moderate-to-high risk by conventional serological screening or advanced maternal age, peripheral venous blood samples were collected and, following extraction of free fetal DNA, subjected to large-scale parallel sequencing on a Illumina Hiseq2000 platform. Those with a high risk by NIPT were validated by invasive prenatal diagnosis.@*Results@#Out of the 9470 samples, 194 cases (2.0%) were positive by NIPT testing. These included 50 trisomy 21, 11 trisomy 18, 17 trisomy 13, 44 other autosomal aneuploidies, 55 sex chromosomal aneuploidies, and 17 chromosomal copy number variations. As validated by amniotic fluid or umbilical blood chromosomal karyotyping analysis, NIPT has a false positive rate of 2.0%, 18.2%, 41.2%, 97.7%, 81.8%, 94.1%, respectively. The test has a sensitivity of 100% and a specificity of 98.79%.@*Conclusion@#For common chromosomal aneuploidies such as trisomy 21 and trisomy 18, NIPT has a good sensitivity and specificity, therefore has good value for clinical application.
ABSTRACT
Objective • To understand the cognition, attitude, willingness and demand for non-invasive prenatal testing (NIPT) of pregnant women. Methods • A total of 852 pregnant women were enrolled, including 318 pregnant women with low risk of Down syndrome screened in Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, and 534 pregnant women with high risk of Down syndrome screened in several hospitals in Shanghai who further went to Xinhua Hospital, Shanghai Jiao Tong University School of Medicine for NIPT to confirm the diagnosis of Down syndrome screening. The information about the cognition, attitude, willingness and demand for NIPT was collected by a standard questionnaire. Results • A total of 760 questionnaires were collected, of which 728 ones were valid, with an effective questionnaire rate of 85.45%. The proportion of pregnant women with ideal cognition level was 51.24%. However, 83.10% of pregnant women held a positive attitude towards the promotion of NIPT. There were 79.54% of pregnant women considering it necessary to provide genetic counseling before NIPT. Conclusion • It is of great significance to strengthen the prenatal propaganda and education and pre-test genetic counseling so as to improve the cognitive level of pregnant women and make rational use of NIPT.
ABSTRACT
Objective To assess the clinical value of high throughput seuencing (HTS) in noninvasive prenatal testing (NIPT). Methods The results of NIPT of 2 256 cases of women with singleton pregnancy were retrospectively reviewed. Free fetal DNA in maternal peripheral blood was sequenced using HTS, and bioinformatic analysis techniques. Prenatal diagnosis was performed through amniocentesis when NIPT indicated high risks. High risk results from non-invasive screening of fetal chromosomal and prenatal diagnosis were compared. Results All of the 2, 256 specimens were successfully analyzed and 35 cases were found with fetal chromosomal high risks, with an overall detection rate of 0.58％, including 13 cases with high risk for trisomy 21, 1 with trisomy 18, 1 with trisomy 13, 15 with sex chromosome abnormality and 5 with other chromosomal structures abnormality. All the 34 cases had further prenatal diagnosis except 1 case of pregnant woman with high-risk 13-trisomy who took abortion directly and refused further examination. Among 12 cases with high risk for 21-trisomy, 1 with 18-trisomy, 5 with sex chromosome abnormalities and 1 with the deletion of chromosome, 3 were confirmed by traditional karyotyping and/or single nucleotide polymorphism microarray (SNP-array) technology. The coincidence rate of abnormally high risk results of NIPT detection in fetal chromosomal and prenatal diagnosis were 92.85％, 100％, 33.33％ and 20％respectively. Conclusion There is a relatively high positive coincidence rate when compared HTS for screening of high risk for trisomy 21, 18, 13 aneuploidy and prenatal diagnosis and HTS is reliable. While when it comes to the screening of sex chromosome and other chromosomal structures abnormality, HTS still need to be improved and optimized.
ABSTRACT
OBJECTIVE: To explore the clinical value of non-invasive prenatal testing(NIPT)for screening fetal chromosomal copy number variations(CNVs) and microdeletion/microduplication syndromes(MDs).METHODS: Retrospective analysis was made in the 10 005 women who received NIPT during the first trimester(15-20+ 6 weeks)from January,2012 to July,2017,at First People's Hospital of Yunnan Province,Department of Genetic Diagnosis Center.Among them 32 pregnant women were indicated fetal CNVs,25 of 32 pregnant women selected interventional prenatal diagnosis.Statistical analysis was made on the amniotic fluid/cord blood chromosome G band karyotype and high-throughput sequencing(NGS)genome copy number analysis was made,and relevant CNVs were searched and analyzed in the corresponding database;the consistency of CNVs found in NIPT with interventional prenatal diagnosis was statistically analyzed.RESULTS: During the second trimester(15-20+ 6 weeks),in the 10 005 pregnant women who received NIPT testing 32 cases were shown to have high risks of fetal CNVs,and the screening positive rate was 0.32%(32/10 005).In 25 high risk pregnant women who accepted invasive prenatal diagnosis via informed choice,14 women wereconfirmed as fetal CNVs,the positive predictive value(PPV)of NIPT being 56%(14/25),including 9 cases of microdeletion and 5 cases of microduplication.The sizes were between 587.75 kb and 36.05 Mb.The size and the start and end positions of CNVs found by NIPT were similar to those of fetal DNA samples detected by NGS.Among 14 cases of fetal CNVs,11 cases were identified as MDs,3 cases as unknown clinical significance.In 11 cases of MDs,8 cases were observed fetal chromosome structure abnormalities by karyotype analysis,10 cases were confirmed as de novo abbreviations,and 2 cases as originated from paternal same MD.After genetic counseling,10 pregnant women in 11 cases of MDs chose informed terminations,and one case chose continuing pregnancy.CONCLUSION: As a high-precision screening method,NIPT is expected to be an effective mean to screen for fetal CNVs,which can be used to detect highrisk chromosome microdeletion and microduplication CNVs of larger segments.High risk cases of fetal CNVs found by NIPT require invasive prenatal diagnosis for validation.
ABSTRACT
Objective To assess the positive predictive value (PPV) of fetal sex chromosome aneuploidy (SCA) identified by non-invasive prenatal testing (NIPT) and investigate families' acceptance of SCA fetus. Methods All suspected SCA cases screened by NIPT from singletons were reviewed in Prenatal Diagnosis Center of Shanghai First Maternity and Infant Hospital from April 1, 2015 to October 31, 2017. Maternal age, NIPT indications, prenatal diagnosis protocols, testing results and their pregnancy determinations were analyzed. Results NIPT was provided to 35827 singletons and 86 suspected SCA cases were identified out of 35823 successful ones, giving a positive detection rate of 0.24％. The average maternal age was (31.5±5.0) years. After genetic counseling, 20 patients declined prenatal diagnosis,the rest 66 cases proceeded with aminiocentesis and fetal chromosomal testing, of which 32 were cytogenetically diagnosed as SCA with the PPV of 48.5％ . The SCA fetus consisted of 25 sex chromosome trisomies (seven cases of 47,XXX, three cases of 47,XYY and 15 cases of 47,XXY), one monosomy X (45,X), three mosacisms (47,XXY/48,XXYY, 47,XXX/45,X, 45,X/46,XX, one for each) and three microdeletions/microduplications. Besides, two false positive NIPT cases were proved to be low level of maternal mosacism (45,X/46,XX, 5％ and 10％ for each). After genetic counseling, 17 out of 20 who declined prenatal diagnosis and 9 out of 32 who diagnosed fetal SCAs continued their pregnancies, with a combined proportion of continued pregnancy of 50％. Thirty-four pregnancies were also continued after exclusion of SCA. Interestingly, the proportion of continued pregnancy among those sex chromosomal trisomy fetuses was only 32％(8/25). Conclusions As a safe and rapid prenatal testing for common autosomal aneuploidies, NIPT could also identify some types of SCA, but with relatively low PPV. More long-term researches are required to determine its sensitivity and specificity. For some types of SCA with mild phenotypes, some family would continue the pregnancy. Therefore, limitations of NIPT should be appropriately explained during both pre- and post-testing counseling.
ABSTRACT
Objective To explore the efficiency and the clinical application value of non-invasive prenatal genetic testing for fetal chromosomal aneuploidy.Methods A total of 1 865 pregnant women treated in Guangdong Women and Children Hospital from January 201 1 to January 2013 were selected.Inclusion criteria:advanced age,prenatal screening for high risk,and fetal abnormality indicated by color ultrasonography,agreeing with non-invasive prenatal genetic testing.After non-invasive prenatal genetic testing, the pregnant women with positive result underwent cell culture and chromosomal karyotyping.Following the situations after deliv-ery were designed as the final criteria for definite diagnosis of fetal chromosomal aneuploidy.Results A total of 1 865 pregnant women underwent non-invasive prenatal genetic testing,of which 21 pregnant women were found with positive result,including 14 pregnant women with trisomy 21,5 pregnant women with trisomy 18,2 pregnant women with trisomy 13.The results of chromo-somal karyotyping after amniocentesis or umbilical cord blood puncture were designed as golden standard.Among the women with trisomy 21,one woman refused the prenatal diagnosis,self induced labor and could not be confirmed karyotype.No false positive case was found among the women with trisomy 18 and 13.No missed diagnosis was found among the pregnant women with negative result during follow-up after delivery.Through statistical analysis of non-invasive prenatal fetal genetic testing,the sensitivity for the trisomy 21 was 100%,and the accuracy was 92.9%.The sensitivity and accuracy for the trisomy 18 and 13 were 100%.Conclu-sion Non-invasive prenatal genetic testing can improve the diagnostic efficacy before delivery,reduce the birth of ill infants,and it is a quick,safe,easy-accepted and reliable prenatal diagnostic method,which is worthy to be popularized and an inexorable trend of development in the future.
ABSTRACT
Non-invasive prenatal testing using next generation sequencing technology with cell free fetal DNA from the blood of pregnant women has been rapidly adopted as a screening test for the detection of disorders involving chromosomal aneuploidy, especially Down syndrome. However as part of a prenatal recommendation in high-risk group, this laboratory assessment should be accompanied by informed counseling at both pre-test and post-test stages. In low-risk group and multifetal pregnancies, only conventional maternal serum screening tests in the first trimester and/or second trimester in addition to measurement of nuchal translucency should be recommended, until this potential tool has been incorporated into current screening strategic modalities on the basis ofsufficient published data.