scholarly journals Incidental Findings of Copy Number Variants by SNP-Based Noninvasive Prenatal Testing: Implications for Maternal Health

2022 ◽  
Vol 226 (1) ◽  
pp. S57
Author(s):  
Georgina Goldring ◽  
Wendy DiNonno ◽  
Wenbo Xu ◽  
Lynn Pais ◽  
Samantha Leonard ◽  
...  
Diagnostics ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 569
Author(s):  
Michaela Hyblova ◽  
Maria Harsanyova ◽  
Diana Nikulenkov-Grochova ◽  
Jitka Kadlecova ◽  
Marcel Kucharik ◽  
...  

Detection of copy number variants as an integral part of noninvasive prenatal testing is increasingly used in clinical practice worldwide. We performed validation on plasma samples from 34 pregnant women with known aberrations using cell-free DNA sequencing to evaluate the sensitivity for copy number variants (CNV) detection using an in-house CNV fraction-based detection algorithm. The sensitivity for CNVs smaller than 3 megabases (Mb), larger than 3Mb, and overall was 78.57%, 100%, and 90.6%, respectively. Regarding the fetal fraction, detection sensitivity in the group with a fetal fraction of less than 10% was 57.14%, whereas there was 100% sensitivity in the group with fetal fraction exceeding 10%. The assay is also capable of indicating whether the origin of an aberration is exclusively fetal or fetomaternal/maternal. This validation demonstrated that a CNV fraction-based algorithm was applicable and feasible in clinical settings as a supplement to testing for common trisomies 21, 18, and 13.


2021 ◽  
Author(s):  
Jing He ◽  
Xuan Feng ◽  
Xing Wang ◽  
Qinghua Zhang ◽  
Lei Zheng ◽  
...  

Abstract Background: Noninvasive prenatal testing (NIPT) is based on second-generation genomic sequencing technology to scan cell-free fetal DNA originating from the placenta in maternal plasma. As the depth of sequencing increases, it can be used to focus on chromosomal aneuploidies, copy number variants (CNVs), and monogenic diseases. It can significantly improve the accuracy of prenatal screening and reduces the number of invasive testing.Methods: In this study, we retrospectively analyzed 16128 naturally conceived singleton pregnancies who underwent expanded NIPT to calculate the true positive rate (TPR) of chromosomal aneuploidies and CNVs, and analyzed the potential influence of maternal sex chromosome abnormalities (SCAs) and maternal CNVs on expanded NIPT results.Results: After invasive prenatal diagnosis and follow-up, 103 pregnancies were found to be true-positive, including 73 cases of chromosomal abnormalities and 30 cases of CNVs. The TPR of T21 was 84.62%, T18 was 50.00%, T13 was 22.22%, SCA was 34.06%, and CNVs was 40.28%. In addition, we found that the positive rate of aneuploidies increased with maternal age and that maternal SCAs accounted for 13.33% of the 60 false positive cases of SCAs.Conclusion: Expanded NIPT showed high sensitivity and specificity in detecting diseases of chromosomal abnormalities. It also shows good performance in detecting CNVs, but maternal SCAs and CNVs confused some NIPT results, indicating it is still necessary to study the potential maternal influence on expanded NIPT results and to report related clinical validation studies.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yunsheng Ge ◽  
Jia Li ◽  
Jianlong Zhuang ◽  
Jian Zhang ◽  
Yanru Huang ◽  
...  

Abstract Background Noninvasive prenatal testing (NIPT) has been wildly used to screen for common aneuplodies. In recent years, the test has been expanded to detect rare autosomal aneuploidies (RATs) and copy number variations (CNVs). This study was performed to investigate the performance of expanded noninvasive prenatal testing (expanded NIPT) in screening for common trisomies, sex chromosomal aneuploidies (SCAs), rare autosomal aneuploidies (RATs), and copy number variations (CNVs) and parental willingness for invasive prenatal diagnosis in a Chinese prenatal diagnosis center. Methods A total of 24,702 pregnant women were retrospectively analyzed at the Women and Children’s Hospital from January 2013 to April 2019, among which expanded NIPT had been successfully conducted in 24,702 pregnant women. The high-risk expanded NIPT results were validated by karyotype analysis and chromosomal microarray analysis. All the tested pregnant women were followed up for pregnancy outcomes. Results Of the 24,702 cases, successful follow-up was conducted in 98.77% (401/446) of cases with common trisomies and SCAs, 91.95% (80/87) of RAT and CNV cases, and 76.25% (18,429/24,169) of cases with low-risk screening results. The sensitivity of expanded NIPT was 100% (95% confidence interval[CI], 97.38–100%), 96.67%(95%CI, 82.78–99.92%), and 100%(95%CI, 66.37–100.00%), and the specificity was 99.92%(95%CI, 99.87–99.96%), 99.96%(95%CI, 99.91–99.98%), and 99.88% (95%CI, 99.82–99.93%) for the detection of trisomies 21, 18, and 13, respectively. Expanded NIPT detected 45,X, 47,XXX, 47,XXY, XYY syndrome, RATs, and CNVs with positive predictive values of 25.49%, 75%, 94.12%, 76.19%, 6.45%, and 50%, respectively. The women carrying fetuses with Trisomy 21/Trisomy 18/Trisomy 13 underwent invasive prenatal diagnosis and terminated their pregnancies at higher rates than those at high risk for SCAs, RATs, and CNVs. Conclusions Our study demonstrates that the expanded NIPT detects fetal trisomies 21, 18, and 13 with high sensitivity and specificity. The accuracy of detecting SCAs, RATs, and CNVs is still relatively poor and needs to be improved. With a high-risk expanded NIPT result, the women at high risk for common trisomies are more likely to undergo invasive prenatal diagnosis procedures and terminate their pregnancies than those with unusual chromosome abnormalities.


2016 ◽  
Vol 47 (1) ◽  
pp. 53-57 ◽  
Author(s):  
R. Li ◽  
J. Wan ◽  
Y. Zhang ◽  
F. Fu ◽  
Y. Ou ◽  
...  

2016 ◽  
Vol 13 (4) ◽  
pp. 303-314 ◽  
Author(s):  
Liis Leitsalu ◽  
Helene Alavere ◽  
Sébastien Jacquemont ◽  
Anneli Kolk ◽  
Anne M Maillard ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Qingwen Zhu ◽  
Jing Wang ◽  
Xiaoning Xu ◽  
Shiying Zhou ◽  
Zhengli Liao ◽  
...  

Noninvasive Prenatal Testing (NIPT) has advanced the detection of fetal chromosomal aneuploidy by analyzing cell-free DNA in peripheral maternal blood. The statistic Z-test that it utilizes, which measures the deviation of each chromosome dosage from its negative control, is now widely accepted in clinical practice. However, when a chromosome has loss and gain regions which offset each other in the z-score calculation, merely using the Z-test for the result tends to be erroneous. To improve the performance of NIPT in this aspect, a novel graphic-aided algorithm (gNIPT) that requires no extra experiment procedures is reported in this study. In addition to the Z-test, this method provides a detailed analysis of each chromosome by dividing each chromosome into multiple 2 Mb size windows, calculating the z-score and copy number variation of each window, and visualizing the z-scores for each chromosome in a line chart. Data from 13537 singleton pregnancy women were analyzed and compared using both the normal NIPT (nNIPT) analysis and the gNIPT method. The gNIPT method had significantly improved the overall positive predictive value (PPV) of nNIPT (88.14% vs. 68.00%, p=0.0041) and the PPV for trisomy 21 (T21) detection (93.02% vs. 71.43%, p=0.0037). There were no significant differences between gNIPT and nNIPT in PPV for trisomy 18 (T18) detection (88.89% vs. 63.64%, p=0.1974) and in PPV for trisomy 13 (T13) detection (57.14% vs. 50.00%, p=0.8004). One false-negative T18 case in nNIPT was detected by gNIPT, which demonstrates the potency of gNIPT in discerning chromosomes that have variation in multiple regions with an offsetting effect in z-score calculation. The gNIPT was also able to detect copy number variation (CNV) in chromosomes, and one case with pathogenic CNV was detected during the study. With no additional test requirement, gNIPT presents a reasonable solution in improving the accuracy of normal NIPT.


2020 ◽  
Vol 8 (12) ◽  
pp. 2561-2567
Author(s):  
Lotte Hatt ◽  
Ripudaman Singh ◽  
Rikke Christensen ◽  
Katarina Ravn ◽  
Inga B Christensen ◽  
...  

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