scholarly journals Adaptable Model Parameters in Non-Invasive Prenatal Testing Lead to More Stable Predictions

2019 ◽  
Vol 20 (14) ◽  
pp. 3414 ◽  
Author(s):  
Gazdarica ◽  
Budis ◽  
Duris ◽  
Turna ◽  
Szemes
Keyword(s):  
Real World ◽  
Prenatal Testing ◽  
Maternal Plasma ◽  
Shotgun Sequencing ◽  
Massively Parallel ◽  
Model Parameters ◽  
Actual Number ◽  
Threshold Levels ◽  
Non Invasive ◽  
Control Set

Recent advances in massively parallel shotgun sequencing opened up new options for affordable non-invasive prenatal testing (NIPT) for fetus aneuploidy from DNA material extracted from maternal plasma. Tests typically compare chromosomal distributions of a tested sample with a control set of healthy samples with unaffected fetuses. Deviations above certain threshold levels are concluded as positive findings. The main problem with this approach is that the variance of the control set is dependent on the number of sequenced fragments. The higher the amount, the more precise the estimation of actual chromosomal proportions is. Testing a sample with a highly different number of sequenced reads as used in training may thus lead to over- or under-estimation of their variance, and so lead to false predictions. We propose the calculation of a variance for each tested sample adaptively, based on the actual number of its sequenced fragments. We demonstrate how it leads to more stable predictions, mainly in real-world diagnostics with the highly divergent inter-sample coverage.

Non-invasive prenatal testing for fetal aneuploidy by massively parallel DNA sequencing of maternal plasma: the future has arrived today/Nicht-invasiver Pränatal-Test auf fetale Aneuploidie mittels massiv-paralleler DNA-Sequenzanalyse im mütterlichen Plasma: in der Zukunft angekommen

2012 ◽  
Vol 36 (5) ◽  
Author(s):  
Amy Swanson ◽  
Christin Coffeen ◽  
Amy J. Sehnert
Keyword(s):  
Massively Parallel Sequencing ◽  
Prenatal Testing ◽  
The United States ◽  
Maternal Blood ◽  
Maternal Plasma ◽  
Massively Parallel ◽  
Clinical Implementation ◽  
Maternal Cell ◽  
Non Invasive ◽  
Fetal Aneuploidy

AbstractAfter decades of research, non-invasive prenatal testing (NIPT) using maternal blood to determine fetal chromosome status has found its way from the research laboratory into clinical practice, triggering a long-awaited paradigm shift in prenatal care. A variety of methods using sequencing of maternal cell-free DNA (cfDNA) have now been studied, primarily demonstrating their ability to detect the most common fetal aneuploidy, trisomy 21 (T21). The focus of this article is on massively parallel sequencing (MPS) with optimized sequence tag mapping and chromosome quantification, which accurately detects T21 as well as multiple other aneuploidies across the genome. The power of this technique resides in its high precision and reduction of variation within and between sequencing runs. Using MPS, classification of aneuploidy status for a given sample can be reliably assigned from the genetic information alone without the need to factor in other maternal pre-test risk or other clinical variables. Performance of this method has been prospectively demonstrated in a rigorous, blinded, multi-center study in the United States. The findings suggest that MPS can be incorporated into existing prenatal screening algorithms to reduce unnecessary invasive procedures. This technology and key considerations for clinical implementation are discussed.

scholarly journals The fragmentation patterns of maternal plasma cell‐free DNA and its applications in non‐invasive prenatal testing

2020 ◽  
Vol 40 (8) ◽  
pp. 911-917 ◽  
Author(s):  
Min Pan ◽  
Pingsheng Chen ◽  
Jiafeng Lu ◽  
Zhiyu Liu ◽  
Erteng Jia ◽  
...  
Keyword(s):  
Plasma Cell ◽  
Prenatal Testing ◽  
Maternal Plasma ◽  
Cell Free Dna ◽  
Non Invasive ◽  
Free Dna ◽  
Fragmentation Patterns

scholarly journals Noninvasive prenatal testing for chromosome aneuploidies and subchromosomal microdeletions/microduplications in a cohort of 42,910 single pregnancies with different clinical features

2019 ◽  
Vol 13 (1) ◽  
Author(s):  
Yibo Chen ◽  
Qi Yu ◽  
Xiongying Mao ◽  
Wei Lei ◽  
Miaonan He ◽  
...  
Keyword(s):  
Clinical Features ◽  
Sex Chromosome ◽  
Prenatal Testing ◽  
Maternal Plasma ◽  
Trisomy 13 ◽  
Noninvasive Prenatal Testing ◽  
Detection Rates ◽  
Non Invasive ◽  
Cell Free Fetal Dna ◽  
Sex Chromosome Aneuploidies

Abstract Background Since the discovery of cell-free DNA (cfDNA) in maternal plasma, it has opened up new approaches for non-invasive prenatal testing. With the development of whole-genome sequencing, small subchromosomal deletions and duplications could be found by NIPT. This study is to review the efficacy of NIPT as a screening test for aneuploidies and CNVs in 42,910 single pregnancies. Methods A total of 42,910 single pregnancies with different clinical features were recruited. The cell-free fetal DNA was directly sequenced. Each of the chromosome aneuploidies and the subchromosomal microdeletions/microduplications of PPV were analyzed. Results A total of 534 pregnancies (1.24%) were abnormal results detected by NIPT, and 403 pregnancies had underwent prenatal diagnosis. The positive predictive value (PPV) for trisomy 21(T21), trisomy 18 (T18), trisomy 13 (T13), sex chromosome aneuploidies (SCAs), and other chromosome aneuploidy was 79.23%, 54.84%, 13.79%, 33.04%, and 9.38% respectively. The PPV for CNVs was 28.99%. The PPV for CNVs ≤ 5 Mb is 20.83%, for within 5–10 Mb 50.00%, for > 10 Mb 27.27% respectively. PPVs of NIPT according to pregnancies characteristics are also different. Conclusion Our data have potential significance in demonstrating the usefulness of NIPT profiling not only for common whole chromosome aneuploidies but also for CNVs. However, this newest method is still in its infancy for CNVs. There is still a need for clinical validation studies with accurate detection rates and false positive rates in clinical practice.

Non-invasive prenatal testing (NIPT): limitations on the way to become diagnosis

Diagnosis ◽  
2015 ◽  
Vol 2 (3) ◽  
pp. 141-158 ◽  
Author(s):  
Ioanna Kotsopoulou ◽  
Panagiota Tsoplou ◽  
Konstantinos Mavrommatis ◽  
Christos Kroupis
Keyword(s):  
Prenatal Testing ◽  
Maternal Plasma ◽  
Screening Tests ◽  
Positive Finding ◽  
Non Invasive ◽  
Cell Free Fetal Dna ◽  
The Future ◽  
The Moment ◽  
Next Generation Sequencing Ngs ◽  
Near Future

AbstractWith the discovery of existing circulating cell-free fetal DNA (ccffDNA) in maternal plasma and the advent of next-generation sequencing (NGS) technology, there is substantial hope that prenatal diagnosis will become a predominately non-invasive process in the future. At the moment, non-invasive prenatal testing (NIPT) is available for high-risk pregnancies with significant better sensitivity and specificity than the other existing non-invasive methods (biochemical and ultrasonographical). Mainly it is performed by NGS methods in a few commercial labs worldwide. However, it is expected that many other labs will offer analogous services in the future in this fast-growing field with a multiplicity of in-house methods (e.g., epigenetic, etc.). Due to various limitations of the available methods and technologies that are explained in detail in this manuscript, NIPT has not become diagnostic yet and women may still need to undergo risky invasive procedures to verify a positive finding or to secure (or even expand) a negative one. Efforts have already started to make the NIPT technologies more accurate (even at the level of a complete fetal genome) and cheaper and thus more affordable, in order to become diagnostic screening tests for all pregnancies in the near future.

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