Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Dec 16;13(12):2389.
doi: 10.3390/genes13122389.

Clinical, Cytogenetic and Molecular Cytogenetic Outcomes of Cell-Free DNA Testing for Rare Chromosomal Anomalies

Affiliations

Clinical, Cytogenetic and Molecular Cytogenetic Outcomes of Cell-Free DNA Testing for Rare Chromosomal Anomalies

Seher Basaran et al. Genes (Basel). .

Abstract

The scope of cell-free DNA (cfDNA) testing was expanded to the genome, which allowed screening for rare chromosome anomalies (RCAs). Since the efficiency of the test for RCAs remains below the common aneuploidies, there is a debate on the usage of expanded tests. This study focuses on the confirmatory and follow-up data of cases with positive cfDNA testing for RCAs and cases with screen-negative results in a series of 912 consecutive cases that underwent invasive testing following cfDNA testing. Chorion villus sampling (CVS), amniocentesis (AS), fetal blood sampling, and term placenta samples were investigated using classical cytogenetic and molecular cytogenetic techniques. Out of 593 screen-positive results, 504 (85%) were for common aneuploidies, 40 (6.7%) for rare autosomal trisomies (RATs), and 49 (8.3%) for structural chromosome anomalies (SAs). Of the screen-positives for RATs, 20 cases were evaluated only in fetal tissue, and confined placental mosaicism (CPM) could not be excluded. Among cases with definitive results (n = 20), the rates of true positives, placental mosaics, and false positives were 35%, 45%, and 10%, respectively. Among screen-positives for SAs, 32.7% were true positives. The confirmation rate was higher for duplications than deletions (58.3% vs. 29.4%). The rate of chromosomal abnormality was 10.9% in the group of 256 screen-negatives with pathological ultrasound findings. This study provides further data to assess the efficiency of expanded cfDNA testing for RATs and SAs. The test efficiency for cfDNA seems to be higher for duplications than for deletions, which is evidence of the role of expert ultrasound in identifying pregnancies at increased risk for chromosome anomalies, even in pregnancies with screen-negatives. Furthermore, we discussed the efficiency of CVS vs. AC in screen-positives for RATs.

Keywords: NIPT; cell-free DNA; mosaicism; positive predictive values; rare chromosomal anomalies.

PubMed Disclaimer

Conflict of interest statement

The authors declare that they have no conflict of interest. None of the authors are affiliated with any commercial company providing cfDNA tests in Turkey.

Similar articles

Cited by

References

    1. Gregg A.R., Gross S.J., Best R.G., Monaghan K.G., Bajaj K., Skotko B.G., Thompson B.H., Watson M.S. ACMG statement on noninvasive prenatal screening for fetal aneuploidy. Genet. Med. 2013;15:395–398. doi: 10.1038/gim.2013.29. - DOI - PubMed
    1. Hill M., Wright D., Daley R., Lewis C., McKay F., Mason S., Lench N., Howarth A., Boustred C., Lo K., et al. Evaluation of non-invasive prenatal testing (NIPT) for aneuploidy in an NHS setting: A reliable accurate prenatal non-invasive diagnosis (RAPID) protocol. BMC Pregnancy Childbirth. 2014;14:229. doi: 10.1186/1471-2393-14-229. - DOI - PMC - PubMed
    1. Dondorp W., Wert G.d., Bombard Y., Bianchi D.W., Bergmann C., Borry P., Chitty L.S., Fellmann F., Forzano F., Hall A., et al. Non-invasive prenatal testing for aneuploidy and beyond: Challenges of responsible innovation in prenatal screening. Summary and recommendations. Eur. J. Hum. Genet. 2015;23:1438–1450. doi: 10.1038/ejhg.2015.57. - DOI - PMC - PubMed
    1. Kozlowski P., Burkhardt T., Gembruch U., Gonser M., Kähler C., Kagan K.-O., von Kaisenberg C., Klaritsch P., Merz E., Steiner H., et al. DEGUM, ÖGUM, SGUM and FMF Germany Recommendations for the Implementation of First-Trimester Screening, Detailed Ultrasound, Cell-Free DNA Screening and Diagnostic Procedures. Ultraschall Med. 2019;40:176–193. doi: 10.1055/a-0631-8898. - DOI - PubMed
    1. Gadsbøll K., Petersen O.B., Gatinois V., Strange H., Jacobsson B., Wapner R., Vermeesch J.R., NIPT-map Study Group. Vogel I. Current use of noninvasive prenatal testing in Europe, Australia and the USA: A graphical presentation. Acta Obstet. Gynecol. Scand. 2020;99:722–730. doi: 10.1111/aogs.13841. - DOI - PubMed

Substances