Expanded noninvasive prenatal testing for fetal aneuploidy and copy number variations and parental willingness for invasive diagnosis in a cohort of 18,516 cases.
Ge Y, Li J, Zhuang J, et al. BMC Med Genomics. 2021;14(1):106. Published 2021 Apr 14. doi:10.1186/s12920-021-00955-6. Open Access: Learn more
Tags: Clinical Experience / Clinical Utility, 2021, China, RAAs, CNVs
- Retrospective analysis of 24,702 cases of expanded NIPT.
- PPVS were 6.45% for RATs and 50% for CNVs.
Performance of a Paired-End Sequencing-Based Noninvasive Prenatal Screening Test in the Detection of Genome-Wide Fetal Chromosomal Anomalies.
Pertile MD, Flowers N, Vavrek D, et al. Clin Chem. 2021;67(9):1210-1219. doi:10.1093/clinchem/hvab067. Open Access: Learn more
Tags: Laboratory Experience / Laboratory Performance, 2021, Australia, RAAs, CNVs
- Study of GW-NIPT in 2335 frozen plasma samples to detect GW chromosomal anomalies including common trisomies, SCAs, RAAs, and partial deletions and duplications.
- “Genome-wide screening analysis including known mosaics correctly classified 27/28 RAAs and 20/27 partial deletions/duplications with a specificity of 99.80% for both anomalies, and an overall genome-wide specificity for all anomalies of 99.34%.”
- ”With an overall genome-wide clinical specificity for any anomaly of 99.34%, this genome-wide screen allows for detection of a broad range of chromosomal anomalies while retaining a clinical specificity far superior to the ~5% false-positive rate of serum screening.”
Diagnostic testing after positive results on cell free DNA screening: CVS or Amnio?
Mardy AH, Norton ME. Prenat Diagn. 2021;41(10):1249-1254. doi:10.1002/pd.6021.
Tags: Review / Meta-Analysis, 2021, International, RAAs
- Review of the literature to provide recommendations on chorionic villus sampling (CVS) versus amniocentesis after a positive NIPT result for autosomal aneuploidies, monosomy X, and multiple aneuploidies.
- “Conclusion: Clinicians should consider rates of CPM, imprinting, ultrasound findings and maternal factors when considering whether to recommend amnio or CVS after an abnormal cfDNA result.”
Cell-free fetal DNA testing and its correlation with prenatal indications.
Wang JW, Lyu YN, Qiao B, et al. BMC Pregnancy Childbirth. 2021;21(1):585. Published 2021 Aug 24. doi:10.1186/s12884-021-04044-5. Open Access: Learn more
Tags: Clinical Experience / Clinical Utility, 2021, China, RAAs, CNVs
- Retrospective analysis of pregnant women with high-risk indications.
- 189 (1.32%) positive NIPT results were identified and 113/189 (59.79%) were confirmed by invasive diagnostic testing. Abnormal serum screening was the most common indication, followed by advanced maternal age.
- PPVs were 91.84% for T21, 68.75% for T18, 37.50% for T13, 66.67% for SCAs, 14.29% for other autosomal aneuploidy abnormalities, and 6.45% for CNVs.
Outcomes of pregnancies with trisomy 16 mosaicism detected by NIPT: a series of case reports.
Peng H, Yang J, Wang D, Guo F, Hou Y, Yin A. Mol Cytogenet. 2021;14(1):44. Published 2021 Sep 20. doi:10.1186/s13039-021-00559-w. Open Access: Learn more
Tags: Case Report / Case Series, 2021, China, RAAs
- “NIPT detected 12 cases of T16 and 2 cases of T16 mosaicism. Prenatal diagnosis confirmed 5 true positive cases and 9 false positive cases. Among the 5 true positive cases, 3 cases had ultrasound abnormalities. All of the 9 false positive cases continued their pregnancies. The newborns who were from these 9 false positive cases except 1 case (case 7) had low birth weights (< 2.5 kg) and there were also 2 premature deliveries.”
- “Conclusion: NIPT serves as a fast and early prenatal screening method, giving clues to chromosome abnormalities and providing guidance for managing pregnancy. Confined placental mosaicism in 16 pregnancies may be at higher risk for preterm delivery.”
Case Report: Paternal Uniparental Isodisomy and Heterodisomy of Chromosome 16 With a Normal Phenotype.
Zhang X, Liu L, Liu Y, Pan X. Front Pediatr. 2021;9:732645. Published 2021 Oct 22. doi:10.3389/fped.2021.732645. Open Access: Learn more
Tags: Case Report / Case Series, 2021, China, RAAs
- Case report of a pregnancy with an NIPT result positive for trisomy 16. CMA of amniocytes revealed paternal UPD 16.
Confined placental mosaicism of trisomy 6 detected through genome-wide NIPT was associated with placental abruption.
Nishiyama M, Wada S, Hasegawa F, et al. Clin Case Rep. 2021;9(12):e05155. Published 2021 Dec 5. doi:10.1002/ccr3.5155. Open Access: Learn more
Tags: Case Report, 2021, Japan, RAAs
- Case report of a pregnancy with a NIPT result positive for trisomy 6 and placental abruption.
Prenatal Identification of Confined Placental Mosaicism in Pregnant Women with Fetal Growth Restriction.
Miyagami K, Shirato N, Izumi M, et al. Reprod Sci. 2022;29(3):896-903. doi:10.1007/s43032-021-00772-3.
Tags: Clinical Experience / Clinical Utility, 2021, Japan, RAAs
- “cfDNA analyses of maternal plasma detected suspected CPM cases with chromosomal aneuploidy or copy number variations in 5 of 40 cases (12.5%). For 4 cases in which the entire placenta consisted of cells with chromosomal abnormalities, fetal growth was severely restricted. CPM can be screened by cfDNA analysis in maternal plasma, accounting for approximately 10% of the causes of moderate or severe FGR [fetal growth restriction], and the higher the proportion of abnormal karyotype cells in the placenta, the more severe the placental dysfunction and FGR.”
Expanding the application of non-invasive prenatal testing in the detection of foetal chromosomal copy number variations.
Wang C, Tang J, Tong K, et al. BMC Med Genomics. 2021;14(1):292. Published 2021 Dec 11. doi:10.1186/s12920-021-01131-6. Open Access: Learn more
Tags: Clinical Experience / Clinical Utility, 2021, China, RAAs, CNVs
- Study of 39,002 women who had NIPT. 473 pregnancies (1.213%) were screen positive for clinically significant fetal chromosome abnormalities by NIPT.
- PPVs for T21, T18, T13, SCA, RATs, and microdeletion/microduplication syndrome cases were 88.89%, 53.33%, 20.00%, 40.22%, 4.88%, and 49.02%, respectively.
- PPVs of CNVs of <5 Mb, 5–10 Mb, and >10 Mb were 54.55%, 38.46%, and 40.00%, respectively.
Three years of clinical experience with a genome-wide cfDNA screening test for aneuploidies and copy-number variants
[published correction appears in Genet Med. 2021 May 6;:]. Soster E, Boomer T, Hicks S, et al. Genet Med. 2021;23(7):1349-1355. doi:10.1038/s41436-021-01135-8. Open Access: Learn more
Tags: Laboratory Performance / Laboratory Experience, Clinical Experience / Clinical Utility, 2021, United States, RAAs, CNVs
- This publication is a retrospective analysis of over 55,000 samples submitted for Expanded NIPT to the laboratory, with diagnostic outcomes available in over 40% of screen positive cases. The publication reports on testing indications, demographics, results, and performance. The authors noted that indications shifted during the 3-year period, with a decrease in referrals for ‘ultrasound findings’ (22.0% to 12.0%) and an increase in referrals of ‘no known high-risk indication’ (3.0% to 16.6%). Of the screen positive results, they reported that 25% would have been missed with NIPT limited to the common aneuploidies. They concluded that, although a broader patient population is using Expanded NIPT, the positivity rates and genome-wide events have remained stable at approximately 5% and 25%, respectively.