scholarly journals NIPT technique based on the use of long chimeric DNA reads

2020 ◽  
Author(s):  
Vera Belova ◽  
Daria Plakhina ◽  
Sergey Evfratov ◽  
Kirill Tsukanov ◽  
Gennady Khvorykh ◽  
...  
Keyword(s):  
Pregnant Women ◽  
High Performance ◽  
High Throughput Sequencing ◽  
Prenatal Testing ◽  
First Trimester ◽  
Extracellular Dna ◽  
Non Invasive ◽  
Trimester Screening ◽  
Sensitivity Specificity ◽  
Analytical Approaches

Abstract Background: Non-invasive prenatal testing for aneuploidy on chromosomes 21, 18 and 13 is actively used in clinical practice around the world. One of the limitations of the wider implementation of this test is the high cost of the analysis itself, as the high throughput sequencing is still relatively expensive. At the same time, there is a trend of increase of the length of reads yielded by sequencers. Since extracellular DNA is short, in the order of 140-160 bp, it is not possible to effectively use long reads.Results: The authors used high-performance sequencing of cfDNA libraries that went through additional stages of enzymatic fragmentation and random ligation of the resulting products to create long chimeric reads. The authors used a controlled set of samples to analyze a set of cfDNA samples of pregnant women with a high risk of fetus aneuploidy according to the results of the first trimester screening and confirmed by invasive karyotyping of the fetus using laboratory and analytical approaches developed by the authors. They evaluated the sensitivity, specificity, PPV and NPV of the results.Conclusions: The authors developed a technique for constructing long chimeric reads from short cfDNA fragments and validated the test using a control set of extracellular DNA samples obtained from pregnant women. The obtained sensitivity and specificity parameters of the NIPT developed by the authors corresponded to the approaches proposed earlier (99, 93% and 99.14% for 21 trisomy; 100% and 98.34% for 18 trisomy; 100% and 99.17% for 13 trisomy, respectively).

scholarly journals NIPT Technique Based on the Use of Long Chimeric DNA Reads

Genes ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 590
Author(s):  
Vera Belova ◽  
Daria Plakhina ◽  
Sergey Evfratov ◽  
Kirill Tsukanov ◽  
Gennady Khvorykh ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Predictive Value ◽  
High Performance ◽  
High Throughput Sequencing ◽  
Prenatal Testing ◽  
First Trimester ◽  
Extracellular Dna ◽  
Trimester Screening ◽  
Sensitivity Specificity ◽  
Analytical Approaches

Non-invasive prenatal testing (NIPT) for aneuploidy on Chromosomes 21 (T21), 18 (T18) and 13 (T13) is actively used in clinical practice around the world. One of the limitations of the wider implementation of this test is the high cost of the analysis itself, as high-throughput sequencing is still relatively expensive. At the same time, there is an increasing trend in the length of reads yielded by sequencers. Since extracellular DNA is short, in the order of 140–160 bp, it is not possible to effectively use long reads. The authors used high-performance sequencing of cell-free DNA (cfDNA) libraries that went through additional stages of enzymatic fragmentation and random ligation of the resulting products to create long chimeric reads. The authors used a controlled set of samples to analyze a set of cfDNA samples from pregnant women with a high risk of fetus aneuploidy according to the results of the first trimester screening and confirmed by invasive karyotyping of the fetus using laboratory and analytical approaches developed by the authors. They evaluated the sensitivity, specificity, PPV (positive predictive value), and NPV (negative predictive value) of the results. The authors developed a technique for constructing long chimeric reads from short cfDNA fragments and validated the test using a control set of extracellular DNA samples obtained from pregnant women. The obtained sensitivity and specificity parameters of the NIPT developed by the authors corresponded to the approaches proposed earlier (99.93% and 99.14% for T21; 100% and 98.34% for T18; 100% and 99.17% for T13, respectively).

Use of endocervical trophoblasts in noninvasive prenatal testing for common aneuploidies

2020 ◽  
Vol 19 (4) ◽  
pp. 75-80
Author(s):  
E.V. Musatova ◽  
◽  
M.V. Kapustina ◽  
M.E. Minzhenkova ◽  
Zh.G. Markova ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Prenatal Testing ◽  
First Trimester ◽  
Dna Probes ◽  
Fish Analysis ◽  
Trophoblast Cells ◽  
Noninvasive Prenatal Testing ◽  
Chorionic Villi ◽  
Trimester Screening ◽  
Reliable Methods

The article presents an experience of isolation of trophoblast cells from cervical samples of pregnant women and demonstrates a possibility of determining aneuploid cells in cervical samples using FISH analysis. Objective. To study methods of effective isolation and reliable detection of trophoblasts for genetic pathology analysis. Patients and methods. The participants of the study were three pregnant women, who according to the findings of the combined first trimester screening test were referred to the group with a high risk for fetal aneuploidy. The terms of gestation varied from 12 to 14 wks. Immunocytochemical detection of trophoblast cells was performed with FITC-labelled HLA-G antibodies. FISH was performed with the use of locus-specific DNA probes on chromosomes 13/21 and a DNA probe on chromosome 18 centromere. The chromosome set of a fetus was verified by the results of standard cytogenetic analysis of semi-direct chromosome preparations from cytotrophoblast cells obtained by chorionic villi biopsy. Results. HLA-G-positive cells were found in all examined cytological specimens. FISH analysis with the use of DNA probes on chronomomes, whose trisomies are compatible with live birth, detected aneuploid cells in all three cases. Conclusion. The use of cervical trophoblasts for noninvasive collection of information about the genetic status of the developing fetus at present needs further study of effective and reliable methods of their isolation, detection and analysis. Key words: aneuploidy, throphoblast cells, NIPT, prenatal diagnosis, HLA-G

The impact of non-invasive prenatal testing on anxiety in women considered at high or low risk for aneuploidy after combined first trimester screening

2017 ◽  
Vol 37 (10) ◽  
pp. 975-982 ◽  
Author(s):  
Zara Richmond ◽  
Ron Fleischer ◽  
Maya Chopra ◽  
Jason Pinner ◽  
Mario D'Souza ◽  
...  
Keyword(s):  
Prenatal Testing ◽  
First Trimester ◽  
Low Risk ◽  
First Trimester Screening ◽  
Non Invasive ◽  
Trimester Screening ◽  
The Impact

scholarly journals Noninvasive prenatal testing in megacity

2021 ◽  
Vol 2 (2) ◽  
pp. 75-83
Author(s):  
Anton S. Olenev ◽  
Ekaterina N. Songolova ◽  
Alfina A. Yakshibaeva
Keyword(s):  
Prenatal Diagnosis ◽  
Chromosomal Abnormalities ◽  
False Negative ◽  
Prenatal Testing ◽  
First Trimester ◽  
Extracellular Dna ◽  
Prenatal Diagnostics ◽  
Individual Risk ◽  
Negative Results ◽  
Trimester Screening

Introduction. The article presents an analysis of the use of non-invasive prenatal testing for chromosomal abnormalities in the fetal extracellular DNA in the blood of pregnant women in Moscow. Materials and methods. When processing materials and research results, authors considered all available clinical data: findings of an ultrasound examination, medical history and results of additional laboratory tests. Results. The article presents results of invasive prenatal diagnostics and pregnancy outcomes in patients with high NIPT risks. Discussion. Authors analyzed diagnostic capabilities of NIPT, its limitations, false-positive and false- negative results, and described 3 cases of prenatal diagnosis of fetal aneuploidy identified in patients who are in the «gray zone» of risk based on the results of combined screening of the first trimester of pregnancy. Conclusion. Prenatal diagnosis of the described aneuploidy is difficult due to individual risk of developing chromosomal abnormalities of the fetus based on the results of combined first-trimester screening in the range of 1:101-1: 2500 and lack of indications for invasive prenatal diagnostics.

scholarly journals First Quarter Screening for Aneuploidy

2020 ◽  
Vol 71 (1) ◽  
pp. 313-319
Author(s):  
Florina Nela Osvar ◽  
Adrian Ratiu ◽  
Florica Voita-Mekeres ◽  
Gabriel Mihai Mekeres ◽  
Florin Gheorghe Voita ◽  
...  
Keyword(s):  
Chromosomal Abnormalities ◽  
Test Group ◽  
First Trimester ◽  
Study Groups ◽  
Screening Methods ◽  
Non Invasive ◽  
Prenatal Test ◽  
Trimester Screening ◽  
Sensitivity Specificity ◽  
A Prospective Study

The objective of this paper is to evaluate the rate of detection of chromosomal abnormalities through the non-invasive prenatal test (NIPT) and its contribution to reducing the number of invasive tests. We conducted a prospective study on a batch of 3,000 single-pregnancy pregnancies highlighted in the first trimester. The patients were divided into two study groups, the first group, which we will call the TPNI (Non-Invasive Prenatal Test) group. First trimester screening was performed by non-invasive prenatal test at 10 weeks, and ultrasound between 11-13 +/- 6 days according to the criteria of the Fetal Medicine Foundation (FMF. London, UK). The sensitivity, specificity and accuracy of the two screening methods are almost similar, using NITP screening we obtain a rate of approximately 20% lower false-positive results, and we also perform a smaller number of invasive tests.

scholarly journals New screen on the block: non-invasive prenatal testing for fetal chromosomal abnormalities

2017 ◽  
Vol 9 (4) ◽  
pp. 248 ◽  
Author(s):  
Sara Filoche ◽  
Beverley Lawton ◽  
Angela Beard ◽  
Anthony Dowell ◽  
Peter Stone
Keyword(s):  
False Positive ◽  
Chromosomal Abnormalities ◽  
False Positive Rate ◽  
Prenatal Testing ◽  
Diagnostic Procedures ◽  
First Trimester ◽  
Maternal Blood ◽  
Non Invasive ◽  
Positive Rate ◽  
Trimester Screening

ABSTRACT Non-invasive prenatal testing (NIPT) is a new screen for fetal chromosomal abnormalities. It is a screening test based on technology that involves the analysis of feto-placental DNA that is present in maternal blood. This DNA is then analysed for abnormalities of specific chromosomes (eg 13, 18, 21, X, Y). NIPT has a much higher screening capability for chromosomal abnormalities than current combined first trimester screening, with ~99% sensitivity for trisomy 21 (Down syndrome) and at least a 10-fold higher positive predictive value. The low false-positive rate (1–3%) is one of the most advertised advantages of NIPT. In practice, this could lead to a significant reduction in the number of false-positive tests and the need for invasive diagnostic procedures. NIPT is now suitable for singleton and twin pregnancies and can be performed from ~10 weeks in a pregnancy. NIPT is not currently publicly funded in most countries. However, the increasing availability of NIPT commercially will likely lead to an increase in demand for this as a screening option. Given the high numbers of women who visit a general practitioner (GP) in their first trimester, GPs are well-placed to also offer NIPT as a screening option. A GP’s role in facilitating access to this service will likely be crucial in ensuring equity in access to this technology, and it is important to ensure that they are well supported to do so.

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