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Raymond Y, Fernando S, Menezes M, Mol BW, McLennan A, da Silva Costa F, Hardy T, Rolnik DL. Placental, maternal, fetal, and technical origins of false-positive cell-free DNA screening results. Am J Obstet Gynecol 2024; 230:381-389. [PMID: 38008147 DOI: 10.1016/j.ajog.2023.11.1240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 11/05/2023] [Accepted: 11/16/2023] [Indexed: 11/28/2023]
Abstract
The introduction of noninvasive prenatal testing has resulted in substantial reductions to previously accepted false-positive rates of prenatal screening. Despite this, the possibility of false-positive results remains a challenging consideration in clinical practice, particularly considering the increasing uptake of genome-wide noninvasive prenatal testing, and the subsequent increased proportion of high-risk results attributable to various biological events besides fetal aneuploidy. Confined placental mosaicism, whereby chromosome anomalies exclusively affect the placenta, is perhaps the most widely accepted cause of false-positive noninvasive prenatal testing. There remains, however, a substantial degree of ambiguity in the literature pertaining to the clinical ramifications of confined placental mosaicism and its potential association with placental insufficiency, and consequentially adverse pregnancy outcomes including fetal growth restriction. Other causes of false-positive noninvasive prenatal testing include vanishing twin syndrome, in which the cell-free DNA from a demised aneuploidy-affected twin triggers a high-risk result, technical failures, and maternal origins of abnormal cell-free DNA such as uterine fibroids or unrecognized mosaicisms. Most concerningly, maternal malignancies are also a documented cause of false-positive screening results. In this review, we compile what is currently known about the various causes of false-positive noninvasive prenatal testing.
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Affiliation(s)
- Yvette Raymond
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia.
| | - Shavi Fernando
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia; Monash Women's, Monash Health, Melbourne, Australia; Monash Obstetrics, Melbourne, Australia
| | - Melody Menezes
- Monash Ultrasound for Women, Melbourne, Australia; Department of Paediatrics, The University of Melbourne, Melbourne, Australia; Monash IVF Group, Melbourne, Australia
| | - Ben W Mol
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia; Monash Women's, Monash Health, Melbourne, Australia; Centre for Women's Health Research, The University of Aberdeen, Aberdeen, UK
| | - Andrew McLennan
- Sydney Ultrasound for Women, Sydney, Australia; Discipline of Obstetrics, Gynaecology and Neonatology, The University of Sydney, Sydney, Australia
| | - Fabricio da Silva Costa
- Maternal Fetal Medicine Unit, Gold Coast University Hospital, Queensland, Australia; School of Medicine and Dentistry, Griffith University, Gold Coast, Queensland, Australia
| | - Tristan Hardy
- Monash IVF Group, Melbourne, Australia; Repromed Adelaide, Dulwich, Australia
| | - Daniel L Rolnik
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia; Monash Women's, Monash Health, Melbourne, Australia; Monash Ultrasound for Women, Melbourne, Australia
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Scott F, Smet ME, Elhindi J, Mogra R, Sunderland L, Ferreira A, Menezes M, Meagher S, McLennan A. Late first-trimester ultrasound findings can alter management after high-risk NIPT result. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2023; 62:497-503. [PMID: 37247395 DOI: 10.1002/uog.26272] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 05/14/2023] [Accepted: 05/17/2023] [Indexed: 05/31/2023]
Abstract
OBJECTIVE To evaluate the impact of detailed late first-trimester ultrasound (LFTU) on the positive predictive value (PPV) of a high-risk non-invasive prenatal test (NIPT) result for various chromosomal abnormalities. METHODS This was a retrospective study of all cases undergoing invasive prenatal testing from three tertiary providers of obstetric ultrasound over 4 years, each using NIPT as a first-line screening test. Data were collected from pre-NIPT ultrasound, NIPT, LFTU, placental serology and later ultrasound examinations. Prenatal testing for chromosomal abnormalities was performed by microarray, initially using array comparative genomic hybridization and then single nucleotide polymorphism (SNP) array for the last 2 years. Uniparental disomy testing was performed by SNP array during all 4 years. The majority of NIPT tests were analyzed using the Illumina platform, initially confined to the assessment of the common autosomal trisomies, sex chromosome aneuploidies and rare autosomal trisomies (RAT), then extending to genome-wide analysis for the last 2 years. RESULTS Amniocentesis or chorionic villus sampling (CVS) was performed on 2657 patients, 1352 (51%) of whom had undergone prior NIPT, with 612 (45%) of these returning a high-risk result and meeting the inclusion criteria for the study. LFTU findings significantly affected the PPV of the NIPT result for trisomies 13 (T13), 18 (T18) and 21 (T21), monosomy X (MX) and RAT but not for the other sex chromosomal abnormalities or segmental imbalances (> 7 Mb). Abnormal LFTU increased the PPV close to 100% for T13, T18, T21, MX and RAT. The magnitude of the change in PPV was highest for the most severe chromosomal abnormalities. When LFTU was normal, the incidence of confined placental mosaicism (CPM) was highest in those with a high-risk NIPT result for T13, followed by T18 and T21. After normal LFTU, the PPV for T21, T18, T13 and MX decreased to 68%, 57%, 5% and 25%, respectively. CONCLUSIONS LFTU after a high-risk NIPT result can alter the PPV for many chromosomal abnormalities, assisting counseling regarding invasive prenatal testing and pregnancy management. The high PPVs of NIPT for T21 and T18 are not sufficiently modified by normal LFTU findings to alter management. These at-risk patients should be offered CVS for earlier diagnosis, particularly given the low rate of CPM associated with these aneuploidies. Patients with a high-risk NIPT result for T13 and normal LFTU findings often wait for amniocentesis or avoid invasive testing altogether given the low PPV and higher rate of CPM in this context. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.
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Affiliation(s)
- F Scott
- Sydney Ultrasound for Women, Sydney, Australia
- School of Women's and Children's Health, University of New South Wales, Sydney, Australia
| | - M-E Smet
- Sydney Ultrasound for Women, Sydney, Australia
- Maternal-Fetal Medicine Department, Westmead Hospital, Sydney, Australia
| | - J Elhindi
- Maternal-Fetal Medicine Department, Westmead Hospital, Sydney, Australia
| | - R Mogra
- Sydney Ultrasound for Women, Sydney, Australia
- Department of Obstetrics and Gynaecology, Royal Prince Alfred Hospital, Sydney, Australia
| | - L Sunderland
- Department of Obstetrics and Gynaecology, Royal Prince Alfred Hospital, Sydney, Australia
| | - A Ferreira
- Sydney Ultrasound for Women, Sydney, Australia
- School of Women's and Children's Health, University of New South Wales, Sydney, Australia
| | - M Menezes
- Monash Ultrasound for Women, Melbourne, Australia
| | - S Meagher
- Monash Ultrasound for Women, Melbourne, Australia
| | - A McLennan
- Sydney Ultrasound for Women, Sydney, Australia
- School of Women's and Children's Health, University of Sydney, Sydney, Australia
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Rogers R, Mardy A. Chorionic Villous Testing Versus Amniocentesis After Abnormal Noninvasive Prenatal Testing. Clin Obstet Gynecol 2023; 66:595-606. [PMID: 37650670 DOI: 10.1097/grf.0000000000000801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
In the setting of a normal first-trimester ultrasound, an amniocentesis may be a better option than chorionic villous sampling for invasive diagnostic testing after a cell-free DNA high risk for trisomy 13, given the high rates of confined placental mosaicism. In unaffected fetuses, other evaluations should be considered depending on the cell-free DNA results, including maternal karyotyping for monosomy X, uniparental disomy testing for chromosomes with imprinted genes, serial growth scans for trisomy 16, and a workup for maternal malignancy for multiple aneuploidies or autosomal monosomy.
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Affiliation(s)
- Rosemary Rogers
- Department of Women's Health, Dell Medical School-UT Health Austin, Austin, Texas
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Hui L, Ellis K, Mayen D, Pertile MD, Reimers R, Sun L, Vermeesch J, Vora NL, Chitty LS. Position statement from the International Society for Prenatal Diagnosis on the use of non-invasive prenatal testing for the detection of fetal chromosomal conditions in singleton pregnancies. Prenat Diagn 2023; 43:814-828. [PMID: 37076973 DOI: 10.1002/pd.6357] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 04/15/2023] [Indexed: 04/21/2023]
Abstract
Key points
What is already known about this topic?
In 2015, the International Society for Prenatal Diagnosis (ISPD) published its first position statement on the use of non‐invasive prenatal testing (NIPT) to screen for aneuploidy. Widespread uptake across the globe and subsequent published research has shed new light on test performance and implementation issues.
What does this study add?
This new position statement replaces the 2015 statement with updated information on the current technologies, clinical experience, and implementation practices.
As an international organization, ISPD recognizes that there are important population‐specific considerations in the organization of prenatal screening and diagnosis. These opinions are designed to apply to high income settings where prenatal screening for aneuploidy is an established part of antenatal care.
This position statement is not a clinical practice guideline but represents the consensus opinion of the current ISPD Board based on the current state of knowledge and clinical practice.
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Affiliation(s)
- Lisa Hui
- Department of Obstetrics and Gynaecology, University of Melbourne, Parkville, Victoria, Australia
- Reproductive Epidemiology Group, Murdoch Children's Research Institute, Parkville, Victoria, Australia
- Department of Perinatal Medicine, Mercy Hospital for Women, Heidelberg, Victoria, Australia
- Department of Obstetrics and Gynaecology, Northern Health, Epping, Victoria, Australia
| | - Katie Ellis
- Illumina ANZ, Sydney, New South Wales, Australia
| | - Dora Mayen
- Genetics Clinic, Hospital Angeles Lomas, Estado de Mexico, Mexico
| | - Mark D Pertile
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Rebecca Reimers
- San Diego Perinatal Center, Rady Children's Hospital, San Diego, California, USA
- Scripps Research Institute, La Jolla, California, USA
| | - Luming Sun
- Department of Fetal Medicine & Prenatal Diagnosis Center, Shanghai Key Laboratory of Maternal Fetal Medicine, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, Shanghai, China
| | | | - Neeta L Vora
- Department of Obstetrics and Gynecology, University of North Carolina at Chapel Hill, Division of Maternal Fetal Medicine, Chapel Hill, North Carolina, USA
| | - Lyn S Chitty
- Great Ormond Street NHS Foundation Trust, London, UK
- UCL Great Ormond Street Institute of Child Health, London, UK
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Bussolaro S, Raymond YC, Acreman ML, Guido M, Da Silva Costa F, Rolnik DL, Fantasia I. The accuracy of prenatal cell-free DNA screening for sex chromosome abnormalities: A systematic review and meta-analysis. Am J Obstet Gynecol MFM 2023; 5:100844. [PMID: 36572107 DOI: 10.1016/j.ajogmf.2022.100844] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 11/26/2022] [Accepted: 12/20/2022] [Indexed: 12/26/2022]
Abstract
OBJECTIVE Although cell-free DNA screening for sex chromosome abnormalities is increasingly used in clinical practice, its diagnostic accuracy and clinical utility remain unclear. This systematic review and meta-analysis aimed to determine the performance of cell-free DNA in the detection of sex chromosome abnormalities. DATA SOURCES Medline and PubMed, Embase, and Web of Science were searched from inception to January 2022 for articles relating to cell-free DNA screening for sex chromosome abnormalities. STUDY ELIGIBILITY CRITERIA Original articles, randomized control trials, conference abstracts, cohort and case-control studies, and case series with more than 10 cases with diagnostic confirmation were considered for inclusion. METHODS Quality assessment of each included publication was performed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. The positive predictive value was calculated as the proportion of true positive cases among those who tested positive and underwent diagnostic testing. Sensitivity and specificity were pooled, and a summary receiver operating characteristic curve was produced using bivariate models that included studies that had diagnostic confirmation for high- and low-risk women. RESULTS The search identified 7553 results. Of these, 380 proceeded to the full-text screening, of which 94 articles were included in the meta-analysis with a total of 1,531,240 women tested. All studies reported a confirmatory genetic test. The pooled positive predictive value was 49.4% (95% confidence interval, 45.8-53.1). The pooled positive predictive value was 32.0% (95% confidence interval, 27.0%-37.3%) for monosomy X, 67.6% (95% confidence interval, 62.5%-72.5%) for XXY, 57.5% (95% confidence interval, 51.7%-63.1%) for XXX, and 70.9% (95% confidence interval, 63.9%-77.1%) for XYY. The pooled sensitivity and specificity of cell-free DNA for sex chromosome abnormalities were 94.1% (95% confidence interval, 90.8%-96.3%) and 99.5% (95% confidence interval, 99.0%-99.7%), respectively, with an area under the summary receiver operating characteristic curve of 0.934 (95% confidence interval, 0.907-0.989). CONCLUSION Although the sensitivity and specificity of cell-free DNA for sex chromosome abnormalities are high, the positive predictive value was approximately 50%. The positive predictive value was higher for sex chromosome abnormalities with a supernumerary Y chromosome and lower for monosomy X. Clinicians should inform couples about these findings when offering cell-free DNA for sex chromosome abnormalities.
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Affiliation(s)
- Sofia Bussolaro
- Department of Medicine, Surgery, and Health Sciences, University of Trieste, Trieste, Italy (Dr Bussolaro)
| | - Yvette C Raymond
- Department of Obstetrics and Gynaecology, Monash University, Clayton, Australia (Ms Raymond and Dr Rolnik)
| | - Melissa L Acreman
- Department of Obstetrics and Gynaecology, Ipswich Hospital, Queensland, Australia (Dr Acreman)
| | - Maurizio Guido
- Obstetrics and Gynaecology Unit, San Salvatore Hospital, L'Aquila, Italy (XX Guido and Dr Fantasia); Department of Life, Health, and Environmental Sciences, University of L'Aquila, L'Aquila, Italy (XX Guido)
| | - Fabricio Da Silva Costa
- Maternal Fetal Medicine Unit, Gold Coast University Hospital, Gold Coast, Queensland, Australia (Dr Da Silva Costa); School of Medicine, Griffith University, Gold Coast, Queensland, Australia (Dr Da Silva Costa)
| | - Daniel L Rolnik
- Department of Obstetrics and Gynaecology, Monash University, Clayton, Australia (Ms Raymond and Dr Rolnik); Monash Women's, Monash Health, Clayton, Australia (Dr Rolnik)
| | - Ilaria Fantasia
- Obstetrics and Gynaecology Unit, San Salvatore Hospital, L'Aquila, Italy (XX Guido and Dr Fantasia).
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Bedei I, Gehrke T, Gloning KP, Meyer-Wittkopf M, Willner D, Krapp M, Scharf A, Degenhardt J, Heling KS, Kozlowski P, Trautmann K, Jahns KM, Geipel A, Baumüller JE, Wilhelm L, Gottschalk I, Schröer A, Graf A, Wolter A, Schenk J, Weber A, Van den Veyver IB, Axt-Fliedner R. Multicenter clinical experience with non-invasive cell-free DNA screening for monosomy X and related X-chromosome variants. Prenat Diagn 2023; 43:192-206. [PMID: 36726284 DOI: 10.1002/pd.6320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 01/13/2023] [Accepted: 01/16/2023] [Indexed: 02/03/2023]
Abstract
OBJECTIVE We aimed to investigate how the presence of fetal anomalies and different X chromosome variants influences Cell-free DNA (cfDNA) screening results for monosomy X. METHODS From a multicenter retrospective survey on 673 pregnancies with prenatally suspected or confirmed Turner syndrome, we analyzed the subgroup for which prenatal cfDNA screening and karyotype results were available. A cfDNA screening result was defined as true positive (TP) when confirmatory testing showed 45,X or an X-chromosome variant. RESULTS We had cfDNA results, karyotype, and phenotype data for 55 pregnancies. cfDNA results were high risk for monosomy X in 48/55, of which 23 were TP and 25 were false positive (FP). 32/48 high-risk cfDNA cases did not show fetal anomalies. Of these, 7 were TP. All were X-chromosome variants. All 16 fetuses with high-risk cfDNA result and ultrasound anomalies were TP. Of fetuses with abnormalities, those with 45,X more often had fetal hydrops/cystic hygroma, whereas those with "variant" karyotypes had different anomalies. CONCLUSION Both, 45,X or X-chromosome variants can be detected after a high-risk cfDNA result for monosomy X. When there are fetal anomalies, the result is more likely a TP. In the absence of fetal anomalies, it is most often an FP or X-chromosome variant.
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Affiliation(s)
- Ivonne Bedei
- Department of Prenatal Medicine and Fetal Therapy, Justus-Liebig University, Giessen, Germany
| | - Tascha Gehrke
- Department of Prenatal Medicine and Fetal Therapy, Justus-Liebig University, Giessen, Germany
| | | | | | - Daria Willner
- Center for Prenatal Medicine and Human Genetics, Hamburg, Germany
| | - Martin Krapp
- Center for Prenatal Medicine on Elbe Hamburg, Hamburg, Germany
| | | | | | - Kai-Sven Heling
- Center for Prenatal Diagnosis and Human Genetics, Berlin, Germany
| | - Peter Kozlowski
- Prenatal Medicine and Genetics Düsseldorf, Praenatal.de, Duesseldorf, Germany
| | | | - Kai M Jahns
- Department of Internal Medicine, Johannes Gutenberg University, Mainz, Germany
| | - Annegret Geipel
- Obstetrics and Prenatal Medicine, University Hospital Bonn, Bonn, Germany
| | | | | | - Ingo Gottschalk
- Division of Prenatal Medicine, Department of Obstetrics and Gynecology, University of Cologne, Cologne, Germany
| | | | - Alexander Graf
- Department of Prenatal Medicine and Fetal Therapy, Justus-Liebig University, Giessen, Germany
| | - Aline Wolter
- Department of Prenatal Medicine and Fetal Therapy, Justus-Liebig University, Giessen, Germany
| | - Johanna Schenk
- Department of Prenatal Medicine and Fetal Therapy, Justus-Liebig University, Giessen, Germany
| | - Axel Weber
- Department of Human Genetics, Justus-Liebig University, Giessen, Germany
| | - Ignatia B Van den Veyver
- Departments of Obstetrics and Gynecology and Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Texas Children's Hospital, Houston, Texas, USA
| | - Roland Axt-Fliedner
- Department of Prenatal Medicine and Fetal Therapy, Justus-Liebig University, Giessen, Germany
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Mardy AH, Norton ME. Diagnostic testing after positive results on cell free DNA screening: CVS or Amnio? Prenat Diagn 2021; 41:1249-1254. [PMID: 34386984 DOI: 10.1002/pd.6021] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 06/03/2021] [Accepted: 07/06/2021] [Indexed: 12/16/2022]
Abstract
OBJECTIVE The positive predictive values of cell free DNA (cfDNA) and rates of confined placental mosaicism (CPM), imprinting and other factors vary by chromosome. METHODS We sought to review the literature for each of these features for each chromosome and provide recommendations on chorionic villus sampling (CVS) versus amniocentesis after an abnormal cfDNA result. RESULTS For chromosomes with high rates of CPM (trisomy 13, monosomy X and rare autosomal trisomies [RATs]), an amniocentesis should be considered if the first trimester ultrasound is normal. For monosomy X on cfDNA with an unaffected fetus, maternal karyotyping should be considered after normal fetal diagnostic testing. In cfDNA cases with a trisomy involving a chromosome with imprinted genes (6, 7, 11, 14, 15 and 20), CVS should be considered, followed by amniocentesis if abnormal. If the fetus is unaffected, methylation studies should be considered given the risk of uniparental disomy. A third trimester growth ultrasound should be considered for patients with a positive cfDNA screen for a RAT and an unaffected fetus, especially in the case of trisomy 16. For patients with multiple aneuploidy results on cfDNA, a work-up for maternal malignancy should be considered. CONCLUSIONS Clinicians should consider rates of CPM, imprinting, ultrasound findings and maternal factors when considering whether to recommend amniocentesis or CVS after an abnormal cfDNA result.
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Affiliation(s)
- Anne H Mardy
- Division of Maternal Fetal Medicine, University of California, San Francisco, California, USA
| | - Mary E Norton
- Division of Maternal Fetal Medicine, University of California, San Francisco, California, USA
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Bedei I, Wolter A, Weber A, Signore F, Axt-Fliedner R. Chances and Challenges of New Genetic Screening Technologies (NIPT) in Prenatal Medicine from a Clinical Perspective: A Narrative Review. Genes (Basel) 2021; 12:501. [PMID: 33805390 PMCID: PMC8065512 DOI: 10.3390/genes12040501] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 03/23/2021] [Accepted: 03/25/2021] [Indexed: 12/26/2022] Open
Abstract
In 1959, 63 years after the death of John Langdon Down, Jérôme Lejeune discovered trisomy 21 as the genetic reason for Down syndrome. Screening for Down syndrome has been applied since the 1960s by using maternal age as the risk parameter. Since then, several advances have been made. First trimester screening, combining maternal age, maternal serum parameters and ultrasound findings, emerged in the 1990s with a detection rate (DR) of around 90-95% and a false positive rate (FPR) of around 5%, also looking for trisomy 13 and 18. With the development of high-resolution ultrasound, around 50% of fetal anomalies are now detected in the first trimester. Non-invasive prenatal testing (NIPT) for trisomy 21, 13 and 18 is a highly efficient screening method and has been applied as a first-line or a contingent screening approach all over the world since 2012, in some countries without a systematic screening program. Concomitant with the rise in technology, the possibility of screening for other genetic conditions by analysis of cfDNA, such as sex chromosome anomalies (SCAs), rare autosomal anomalies (RATs) and microdeletions and duplications, is offered by different providers to an often not preselected population of pregnant women. Most of the research in the field is done by commercial providers, and some of the tests are on the market without validated data on test performance. This raises difficulties in the counseling process and makes it nearly impossible to obtain informed consent. In parallel with the advent of new screening technologies, an expansion of diagnostic methods has begun to be applied after invasive procedures. The karyotype has been the gold standard for decades. Chromosomal microarrays (CMAs) able to detect deletions and duplications on a submicroscopic level have replaced the conventional karyotyping in many countries. Sequencing methods such as whole exome sequencing (WES) and whole genome sequencing (WGS) tremendously amplify the diagnostic yield in fetuses with ultrasound anomalies.
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Affiliation(s)
- Ivonne Bedei
- Department of Prenatal Medicine and Fetal Therapy, Justus Liebig University Giessen, 35392 Giessen, Germany; (A.W.); (R.A.-F.)
| | - Aline Wolter
- Department of Prenatal Medicine and Fetal Therapy, Justus Liebig University Giessen, 35392 Giessen, Germany; (A.W.); (R.A.-F.)
| | - Axel Weber
- Institute of Human Genetics, Justus Liebig University Giessen, 35392 Giessen, Germany;
| | - Fabrizio Signore
- Department of Obstetrics and Gynecology, Opedale S. Eugenio, 00144 Rome, Italy;
| | - Roland Axt-Fliedner
- Department of Prenatal Medicine and Fetal Therapy, Justus Liebig University Giessen, 35392 Giessen, Germany; (A.W.); (R.A.-F.)
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