1
|
Faieta M, Falcone R, Duca S, Corsetti E, Giannico R, Gigante L, Diano L, Calugi G, Spinella F, Pizzuti F. Test performance and clinical utility of expanded non-invasive prenatal test: Experience on 71,883 unselected routine cases from one single center. Prenat Diagn 2024; 44:936-945. [PMID: 38686956 DOI: 10.1002/pd.6580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 02/29/2024] [Accepted: 04/08/2024] [Indexed: 05/02/2024]
Abstract
OBJECTIVE The balance between benefits and risks of discordant outcomes makes the Genome-Wide Non-Invasive Prenatal Test (GW-NIPT) controversial. This study aims to evaluate performance and clinical utility in a wide cohort of unselected clinical cases from a single center when a standardized protocol is applied and integrated with a secondary algorithm for data interpretation. METHOD In 2 years, over 70,000 pregnant patients underwent GW-NIPT for fetal common trisomies, sex chromosome aneuploidies, rare autosomal aneuploidies, segmental abnormalities (CNVs ≥ 7 Mb) and microdeletions (CNVs < 7 Mb). All samples were uniformly processed with Veriseq NIPT Solution v2 and analyzed using all data metrics along with a home-made algorithm for sequencing data analysis. Results were retrospectively reviewed for clinical outcomes. RESULTS Among 71,883 eligible cases including twin pregnancies, 1011 (1.4%) received a positive result and 781 were confirmed by invasive prenatal diagnosis. Clinical sensitivity ranged from 99.65% for common trisomy (T21, T18, T13) to 83.33% for microdeletions, while specificity remained high (99.98%) for each class of fetal abnormalities detected. CONCLUSIONS Integrating a standardized protocol with an internal algorithm allowed discordant results to be reduced, yielding high accuracy. Observed reliability in detecting genome-wide chromosomal conditions reinforced the expanded NIPT utility in clinical practice.
Collapse
Affiliation(s)
- Monica Faieta
- Department of NIPT, Eurofins Genoma Group, Rome, Italy
| | - Rossella Falcone
- Department of NIPT, Eurofins Genoma Group, Rome, Italy
- Department of Genetic Counselling, Eurofins Genoma Group, Rome, Italy
| | - Sara Duca
- Department of NIPT, Eurofins Genoma Group, Rome, Italy
| | | | | | - Laura Gigante
- Department of Genetic Counselling, Eurofins Genoma Group, Rome, Italy
| | - Laura Diano
- Department of Genetic Counselling, Eurofins Genoma Group, Rome, Italy
| | - Graziella Calugi
- Department of Research and Development, Eurofins Genoma Group, Rome, Italy
| | - Francesca Spinella
- Department of Research and Development, Eurofins Genoma Group, Rome, Italy
| | | |
Collapse
|
2
|
De Falco A, Gambale A, Pinelli M, Suero T, De Falco L, Iolascon A, Martone S. Trisomy 21 with Maternally Inherited Balanced Translocation (15q;22q) in a Female Fetus: A Rare Case of Probable Interchromosomal Effect. Cells 2024; 13:1078. [PMID: 38994932 PMCID: PMC11240558 DOI: 10.3390/cells13131078] [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: 05/20/2024] [Revised: 06/05/2024] [Accepted: 06/19/2024] [Indexed: 07/13/2024] Open
Abstract
Chromosomal rearrangements can interfere with the disjunction and segregation of other chromosome pairs not involved in the rearrangements, promoting the occurrence of numerical abnormalities in resulting gametes and predisposition to trisomy in offspring. This phenomenon of interference is known as the interchromosomal effect (ICE). Here we report a prenatal case potentially generated by ICE. The first-trimester screening ultrasound of the pregnant woman was normal, but the NIPT indicated a high risk for three copies of chromosome 21, thus suspecting trisomy 21 (T21). After a comprehensive clinical evaluation and genetic counseling, the couple decided to undergo amniocentesis. The prenatal karyotype confirmed T21 but also showed a balanced translocation between the long arm of chromosome 15 (q22) and the long arm of chromosome 22. The parents' karyotypes also showed that the mother had the 15;22 translocation. We reviewed T21 screening methods, and we performed a literature review on ICE, a generally overlooked phenomenon. We observed that ours is the first report of a prenatal case potentially due to ICE derived from the mother. The recurrence risk of aneuploidy in the offspring of translocated individuals is likely slightly increased, but it is not possible to estimate to what extent. In addition to supporting observations, there are still open questions such as, how frequent is ICE? How much is the aneuploidy risk altered by ICE?
Collapse
Affiliation(s)
- Alessandro De Falco
- U.O.C. Genetica Medica, A.O.U. Federico II, 80131 Naples, Italy
- Department of Molecular Medicine and Medical Biotechnology, University Federico II, 80131 Naples, Italy
| | - Antonella Gambale
- U.O.C. Genetica Medica, A.O.U. Federico II, 80131 Naples, Italy
- Department of Molecular Medicine and Medical Biotechnology, University Federico II, 80131 Naples, Italy
| | - Michele Pinelli
- U.O.C. Genetica Medica, A.O.U. Federico II, 80131 Naples, Italy
- Department of Molecular Medicine and Medical Biotechnology, University Federico II, 80131 Naples, Italy
| | - Teresa Suero
- AMES-Centro Polidiagnostico Strumentale, Srl, 80013 Naples, Italy
| | - Luigia De Falco
- AMES-Centro Polidiagnostico Strumentale, Srl, 80013 Naples, Italy
| | - Achille Iolascon
- U.O.C. Genetica Medica, A.O.U. Federico II, 80131 Naples, Italy
- Department of Molecular Medicine and Medical Biotechnology, University Federico II, 80131 Naples, Italy
- CEINGE Biotecnologie Avanzate, 80145 Naples, Italy
| | - Stefania Martone
- U.O.C. Genetica Medica, A.O.U. Federico II, 80131 Naples, Italy
- Department of Molecular Medicine and Medical Biotechnology, University Federico II, 80131 Naples, Italy
| |
Collapse
|
3
|
Li Y, Yang X, Zhang Y, Lou H, Wu M, Liu F, Chang W, Zhao X. The detection efficacy of noninvasive prenatal genetic testing (NIPT) for sex chromosome abnormalities and copy number variation and its differentiation in pregnant women of different ages. Heliyon 2024; 10:e24155. [PMID: 38293423 PMCID: PMC10826137 DOI: 10.1016/j.heliyon.2024.e24155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Revised: 11/15/2023] [Accepted: 01/04/2024] [Indexed: 02/01/2024] Open
Abstract
Objective To analyze the efficacy of noninvasive prenatal genetic testing (NIPT) in detecting fetal sex chromosome abnormalities and copy number variation (CNV), compare the efficacy between NIPT and serological screening alone, and further analyze the fetal sex chromosome abnormalities and CNV differentiation in pregnant women of different ages, so as to provide a reference for the prevention and control of fetal birth defects. Methods Clinical data from 22,692 pregnant women admitted to our hospital from January 2013 to December 2022 were retrospectively analyzed. All participants underwent serological screening and NIPT screening to compare fetal chromosomal abnormalities between the two screening modalities. 145 women whose fetus were diagnosed as sex chromosome abnormalities and 36 women whose fetus were diagnosed as CNV abnormalities based on NIPT screening were selected for prenatal diagnosis by amniocentesis or karyotyping. Taking prenatal diagnosis as the standard, the four-grid table method was used to detect the positive predictive value of NIPT screening for fetal sex chromosomal abnormalities and CNV. According to the age, pregnant women were divided into 18-30 years old (n = 9844), 31-35 years old (n = 7612), >35 years old (n = 5236), and then the detection rates of sexual fetal chromosomal abnormalities, CNV and total chromosomal abnormalities were compared in pregnant women. Results Among the 22,692 pregnant women in this study, the high-risk proportion of serologic screening with 4.38% was higher than that of NIPT screening with 1.93% (P < 0.05). Among the 145 women with fetal sex chromosome abnormalities screened by NIPT, 122 cases of fetal sex chromosome abnormalities were diagnosed prenatally, including 45, X/47, XXX/47, XYY/47, XXY. The positive predictive values of NIPT screening were 25.00%, 58.82%, 85.71%, and 85.71%, respectively, with an overall predictive value of 44.26%. The positive predictive value of fetal sex chromosome abnormalities in NIPT screening was higher than that of serological screening (P < 0.05). Among the 36 pregnant women with fetal CNV, NIPT screening showed that CNVs≤10 Mb and CNVs>10 Mb were 33.33% and 66.67%, respectively. There were 12 cases of prenatal diagnosis of fetal CNV, among which the NIPT-screened positive predictive values of fetal copy number deletion, duplicate, deletion and duplicate were 50.00%, 57.14% and 100.00%, respectively, with an overall predictive value of 58.33%. The positive predictive value of CNV in NIPT screening was higher than that of serological screening without statistically significant difference (P > 0.05). The results of NIPT screening showed that the detection rate of fetal sex chromosome abnormalities and total abnormalities of pregnant women over 35 years of age was significantly higher than that of pregnant women aged 18-30 and 31-35 years (P < 0.05). Conclusion NIPT screening could greatly improve the detection efficacy of fetal sex chromosome abnormalities, CNV and other chromosome abnormalities, and decline the false positive rate. However, the positive predictive value of NIPT screening was relatively low, and further prenatal testing and genetic counseling are still required. In addition, NIPT screening for fetal sex chromosome abnormalities, and the detection rate of total abnormalities in pregnant women older than 35 years old were increased significantly, and pregnancy at an advanced age may be one of the risk factors for fetal chromosomal abnormalities.
Collapse
Affiliation(s)
- Yimei Li
- Department of Gynecology and Obstetrics, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, 450000, Henan, PR China
| | - Xiaofeng Yang
- Department of Gynecology and Obstetrics, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, 450000, Henan, PR China
| | - Ying Zhang
- Department of Gynecology and Obstetrics, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, 450000, Henan, PR China
| | - Huan Lou
- Department of Gynecology and Obstetrics, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, 450000, Henan, PR China
| | - Mingli Wu
- Department of Gynecology and Obstetrics, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, 450000, Henan, PR China
| | - Fang Liu
- Department of Gynecology and Obstetrics, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, 450000, Henan, PR China
| | - Wenjing Chang
- Department of Gynecology and Obstetrics, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, 450000, Henan, PR China
| | - Xueling Zhao
- Department of Gynecology and Obstetrics, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, 450000, Henan, PR China
| |
Collapse
|
4
|
Mahalingam S, Devanboo A, Pradhan A, Suravaparu A, Sai Kiranmai T, Venkataswamy E, Ramprasad VL, Kadam P. True Fetal Trisomy 22 Detected Using Genome-Wide Noninvasive Prenatal Testing. J Obstet Gynaecol India 2023; 73:180-182. [PMID: 37073230 PMCID: PMC10105796 DOI: 10.1007/s13224-022-01730-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 10/30/2022] [Indexed: 01/14/2023] Open
Affiliation(s)
| | | | | | | | - T. Sai Kiranmai
- Sai Diagnostics and Fetal Medicine Center, Anantapuramu, India
| | | | | | | |
Collapse
|
5
|
De Falco L, Vitiello G, Savarese G, Suero T, Ruggiero R, Savarese P, Ianniello M, Petrillo N, Bruno M, Legnante A, Passaretti FF, Ardisia C, Di Spiezio Sardo A, Fico A. A Case Report of a Feto-Placental Mosaicism Involving a Segmental Aneuploidy: A Challenge for Genome Wide Screening by Non-Invasive Prenatal Testing of Cell-Free DNA in Maternal Plasma. Genes (Basel) 2023; 14:668. [PMID: 36980940 PMCID: PMC10048202 DOI: 10.3390/genes14030668] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 02/28/2023] [Accepted: 03/04/2023] [Indexed: 03/11/2023] Open
Abstract
Non-invasive prenatal testing (NIPT) using cell-free DNA can detect fetal chromosomal anomalies with high clinical sensitivity and specificity. In approximately 0.1% of clinical cases, the NIPT result and a subsequent diagnostic karyotype are discordant. Here we report a case of a 32-year-old pregnant patient with a 44.1 Mb duplication on the short arm of chromosome 4 detected by NIPT at 12 weeks' gestation. Amniocentesis was carried out at 18 weeks' gestation, followed by conventional and molecular cytogenetic analysis on cells from the amniotic fluid. SNP array analysis found a de novo deletion of 1.2 Mb at chromosome 4, and this deletion was found to be near the critical region of the Wolf-Hirschhorn syndrome. A normal 46,XY karyotype was identified by G-banding analysis. The patient underwent an elective termination and molecular investigations on tissues from the fetus, and the placenta confirmed the presence of type VI true fetal mosaicism. It is important that a patient receives counselling following a high-risk call on NIPT, with appropriate diagnostic analysis advised before any decisions regarding the pregnancy are taken. This case highlights the importance of genetic counselling following a high-risk call on NIPT, especially in light of the increasing capabilities of NIPT detection of sub-chromosomal deletions and duplications.
Collapse
Affiliation(s)
- Luigia De Falco
- AMES, Centro Polidiagnostico Strumentale, 80013 Naples, Italy
- Fondazione Genetica per la Vita Onlus, Via Cuma, 80132 Naples, Italy
| | - Giuseppina Vitiello
- Department of Molecular Medicine and Medical Biotechnologies, Federico II University Hospital, Via Pansini 5, 80131 Naples, Italy
| | - Giovanni Savarese
- AMES, Centro Polidiagnostico Strumentale, 80013 Naples, Italy
- Fondazione Genetica per la Vita Onlus, Via Cuma, 80132 Naples, Italy
| | - Teresa Suero
- AMES, Centro Polidiagnostico Strumentale, 80013 Naples, Italy
- Fondazione Genetica per la Vita Onlus, Via Cuma, 80132 Naples, Italy
| | - Raffaella Ruggiero
- AMES, Centro Polidiagnostico Strumentale, 80013 Naples, Italy
- Fondazione Genetica per la Vita Onlus, Via Cuma, 80132 Naples, Italy
| | - Pasquale Savarese
- AMES, Centro Polidiagnostico Strumentale, 80013 Naples, Italy
- Fondazione Genetica per la Vita Onlus, Via Cuma, 80132 Naples, Italy
| | - Monica Ianniello
- AMES, Centro Polidiagnostico Strumentale, 80013 Naples, Italy
- Fondazione Genetica per la Vita Onlus, Via Cuma, 80132 Naples, Italy
| | - Nadia Petrillo
- AMES, Centro Polidiagnostico Strumentale, 80013 Naples, Italy
- Fondazione Genetica per la Vita Onlus, Via Cuma, 80132 Naples, Italy
| | - Mariasole Bruno
- AMES, Centro Polidiagnostico Strumentale, 80013 Naples, Italy
- Fondazione Genetica per la Vita Onlus, Via Cuma, 80132 Naples, Italy
| | - Antonietta Legnante
- Department of Public Health, University of Naples “Federico II”, 80145 Naples, Italy
| | - Francesco Fioravanti Passaretti
- Department of Molecular Medicine and Medical Biotechnologies, Federico II University Hospital, Via Pansini 5, 80131 Naples, Italy
| | - Carmela Ardisia
- CRR Genetica Medica, Azienda Ospedaliera s. Maria della Misericordia, 06156 Perugia, Italy
| | | | - Antonio Fico
- AMES, Centro Polidiagnostico Strumentale, 80013 Naples, Italy
- Fondazione Genetica per la Vita Onlus, Via Cuma, 80132 Naples, Italy
| |
Collapse
|
6
|
Raymond YC, Acreman ML, Bussolaro S, Mol BW, Fernando S, Menezes M, Da Silva Costa F, Fantasia I, Rolnik DL. The accuracy of cell-free DNA screening for fetal segmental copy number variants: A systematic review and meta-analysis. BJOG 2023; 130:549-559. [PMID: 36655363 DOI: 10.1111/1471-0528.17386] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 11/17/2022] [Accepted: 11/29/2022] [Indexed: 01/20/2023]
Abstract
BACKGROUND The performance of cell-free DNA (cfDNA) screening for microscopic copy number variants (CNVs) is unclear. OBJECTIVES This was a systematic review and meta-analysis to investigate the sensitivity, specificity and positive predictive value (PPV) of cfDNA screening for CNVs. SEARCH STRATEGY Articles published in EMBASE, PubMed or Web of Science before November 2022 were screened for inclusion. This protocol was registered with PROSPERO (23 March 2021, CRD42021250849) prior to initiation. SELECTION CRITERIA Articles published in English, detailing diagnostic outcomes for at least 10 high-risk CNV results with cfDNA were considered for inclusion. DATA COLLECTION AND ANALYSIS The PPV was calculated and pooled with random-effects models for double-arcsine transformed proportions, using cases with diagnostic confirmation. Overall sensitivity, specificity and a summary receiver-operating characteristics (ROC) curve were calculated using bivariate models. The risk of bias was assessed using QUADAS-2. MAIN RESULTS In all, 63 articles were included in the final analysis, detailing 1 591 459 cfDNA results. The pooled PPV was 37.5% (95% confidence interval [CI] 30.6-44.8), with substantial statistical heterogeneity (I2 = 93.9%). Bivariate meta-analysis estimated sensitivity and specificity to be 77.4% (95% CI 65.7-86.0) and 99.4% (95% CI 98.0-99.8), respectively, with an area under the summary ROC curve of 0.947 (95% CI 0.776-0.984). CONCLUSIONS Approximately one-third of women who screen high-risk for CNVs with cfDNA will have an affected fetus. This value is of importance for screening counselling.
Collapse
Affiliation(s)
- Yvette C Raymond
- Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia
| | - Melissa L Acreman
- Department of Obstetrics and Gynaecology, Ipswich Hospital, Ipswich, Queensland, Australia
| | - Sofia Bussolaro
- Department of Medicine, Surgery and Health Sciences, University of Trieste, Trieste, Italy
| | - Ben W Mol
- Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia.,Aberdeen Centre for Women's Health Research, University of Aberdeen, Aberdeen, UK
| | - Shavi Fernando
- Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia.,Monash Women's, Monash Health, Clayton, Victoria, Australia
| | - Melody Menezes
- Monash Ultrasound for Women, Melbourne, Victoria, Australia.,Department of Paediatrics, The University of Melbourne, Melbourne, Victoria, Australia
| | - Fabricio Da Silva Costa
- Maternal Fetal Medicine Unit, Gold Coast University Hospital, Gold Coast, Queensland, Australia.,School of Medicine, Griffith University, Gold Coast, Queensland, Australia
| | - Ilaria Fantasia
- Obstetrics & Gynaecology Unit, San Salvatore Hospital, L'Aquila, Italy
| | - Daniel Lorber Rolnik
- Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia.,Monash Women's, Monash Health, Clayton, Victoria, Australia
| |
Collapse
|
7
|
Noninvasive Prenatal Screening for Trisomy 21 in Patients with a Vanishing Twin. Genes (Basel) 2022; 13:genes13112027. [DOI: 10.3390/genes13112027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 10/23/2022] [Accepted: 10/31/2022] [Indexed: 11/06/2022] Open
Abstract
A vanishing twin (VT) occurs in up to 30% of early diagnosed twin pregnancies and is associated with an increased risk of fetal aneuploidy. Here, we describe our experience in a large VT population of 847 patients that underwent noninvasive prenatal testing (NIPT) for common fetal trisomies over a three-year period. All patients underwent an ultrasound examination prior to NIPT. Two comparison populations were included, namely, the singleton (n = 105,560) and the viable multiple gestation pregnancy samples (n = 9691) collected over the same period. All NIPT samples in the VT population received a result, of which 14 were high-risk for trisomy 21 (1.6%), nine for trisomy 18 (1.1%), and six for trisomy 13 (0.7%). Diagnostic testing confirmed the presence of trisomy 21 in 6/12 samples, giving a positive predictive value of 50%. One trisomy 18 case and no trisomy 13 cases were confirmed. The time between fetal demise and NIPT sampling did not appear to affect the number of true- or false-positive cases. In conclusion, NIPT is an effective screening method for trisomy 21 in the surviving fetus(es) in VT pregnancies. For trisomies 18 and 13, a positive NIPT should be interpreted carefully and ultrasound monitoring is preferrable over invasive diagnostic testing.
Collapse
|
8
|
Perrot A, Horn R. Health professionals and scientists' views on genome-wide NIPT in the French public health system: Critical analysis of the ethical issues raised by prenatal genomics. PLoS One 2022; 17:e0277010. [PMID: 36318580 PMCID: PMC9624390 DOI: 10.1371/journal.pone.0277010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 10/16/2022] [Indexed: 11/06/2022] Open
Abstract
In France, since January 2020, laboratories have started to make available genome-wide Non-Invasive Prenatal Testing (GW-NIPT) beyond the three common trisomies (T21, T13 and T18) at the same cost as standard NIPT. With the possible margins for interpretation of the legal framework and in the absence of clear and updated guidelines, health professionals are left with questions about which type of screening offer may be clinically responsible, morally appropriate, and, at the same time, respectful of women’s values and ability to make autonomous choices. The aim of this study is to provide an analysis and understanding of the challenging dimensions of clinical practices in the context of evolving scientific knowledge and techniques in prenatal genomics. In this article, we develop a critical analysis of the arguments and concerns that emerge around the offer of expanded NIPT and are discussed by health professionals and scientists. To achieve this, we conducted qualitative semi-structured interviews with 17 health professionals and scientists from September 2021 to February 2022 and a comprehensive literature review (regulatory, scientific, medical, institutional sources). The results of our empirical research highlight the importance of addressing ethical issues related to the differing quality of counselling, the complexity of achieving informed consent, and the avoidance of harm to pregnant women in the feedback of findings beyond T21, T18 and T13. If there is an increase in the provision of GW-NIPT within the French public health system, it will be essential to promote medical practices that respect reproductive choices of women, support their autonomous decision and their understanding of the limitations and uncertainties associated with GW screening. Further research is required to provide an insight into women’s perceptions in order to refine our analysis from the patients’ perspective.
Collapse
Affiliation(s)
- Adeline Perrot
- Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom
- * E-mail:
| | - Ruth Horn
- Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom
- Ethik der Medizin, Medizinische Fakultät, Universität Augsburg, Augsburg, Germany
| |
Collapse
|
9
|
Kleinfinger P, Brechard M, Luscan A, Trost D, Boughalem A, Mylene Valduga, Serero DR S, Costa JM, Lohmann L. Case Report: How whole-genome sequencing-based cell-free DNA prenatal testing can help identify a marker mhromosome. Front Genet 2022; 13:926290. [PMID: 36226188 PMCID: PMC9549001 DOI: 10.3389/fgene.2022.926290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 09/08/2022] [Indexed: 11/30/2022] Open
Abstract
A supernumerary marker chromosome (SMC) is a structurally abnormal chromosome that cannot be characterized by conventional banding cytogenetics. Marker chromosomes are present in 0.075% of prenatal cases. They are associated with variable phenotypes, ranging from normal to severely abnormal, and the prognosis is largely dependent on the results of further cytogenomic analysis. Here, we report the identification and characterization of a marker chromosome following prenatal screening in a 39-year-old pregnant patient. The patient had a normal first trimester ultrasound but was high-risk for fetal chromosome anomalies based on the results of maternal serum parameters. Chorionic villus sampling was performed, and analysis of chorionic villi revealed the presence of two identical marker chromosomes. In the interest of a rapid identification of the markers, we performed noninvasive prenatal testing (NIPT) together with chorionic villus sampling. A pericentromeric 29 Mb duplication of chromosome 20: dup (20) (p13q11.21) was identified and thereafter confirmed by targeted metaphasic FISH. Whole-genome sequencing-based NIPT was instrumental in rapid characterization of the SMCs and allowed us to obviate the need for multiple expensive and time-consuming FISH analyses.
Collapse
|
10
|
Mossfield T, Soster E, Menezes M, Agenbag G, Dubois ML, Gekas J, Hardy T, Jurkowska M, Kleinfinger P, Loggenberg K, Marchili P, Sirica R. Multisite assessment of the impact of cell-free DNA-based screening for rare autosomal aneuploidies on pregnancy management and outcomes. Front Genet 2022; 13:975987. [PMID: 36105088 PMCID: PMC9465083 DOI: 10.3389/fgene.2022.975987] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 07/21/2022] [Indexed: 11/24/2022] Open
Abstract
Cell-free (cf) DNA screening is a noninvasive prenatal screening approach that is typically used to screen for common fetal trisomies, with optional screening for sex chromosomal aneuploidies and fetal sex. Genome-wide cfDNA screening can screen for a wide variety of additional anomalies, including rare autosomal aneuploidies (RAAs) and copy number variants. Here, we describe a multi-cohort, global retrospective study that looked at the clinical outcomes of cases with a high-risk cfDNA screening result for a RAA. Our study cohort included a total of 109 cases from five different sites, with diagnostic outcome information available for 68% (74/109) of patients. Based on confirmatory diagnostic testing, we found a concordance rate of 20.3% for presence of a RAA (15/74) in our study population. Pregnancy outcome was also available for 77% (84/109) of cases in our cohort. Many of the patients experienced adverse pregnancy outcomes, including intrauterine fetal demise, fetal growth restriction, and preterm birth. These adverse outcomes were observed both in patients with fetal or placental confirmation of the presence of a RAA, as well as patients that did not undergo fetal and/or placental diagnostic testing. In addition, we have proposed some suggestions for pregnancy management and counseling considerations for situations where a RAA is noted on a cfDNA screen. In conclusion, our study has shown that genome-wide cfDNA screening for the presence of rare autosomal aneuploidies can be beneficial for both patients and their healthcare practitioners. This can provide a possible explanation for an adverse pregnancy outcome or result in a change in pregnancy management, such as increased monitoring for adverse outcomes.
Collapse
Affiliation(s)
| | - Erica Soster
- Labcorp Women’s Health and Genetics, Laboratory Corporation of America, San Diego, CA, United States
| | - Melody Menezes
- Monash IVF Genetics, Monash IVF Group, Richmond, VIC, Australia
| | | | | | - Jean Gekas
- CHU de Quebec Research and Mother and Child Center, Department of Medical Genetics, University Hospital of Quebec, Laval University, Quebec City, QC, Canada
| | - Tristan Hardy
- Monash IVF Genetics, Monash IVF Group, Richmond, VIC, Australia
| | | | | | | | | | - Roberto Sirica
- AMES, Centro Polidiagnostico Strumentale, Srl, Naples, Italy
| | | |
Collapse
|
11
|
Mayo S, Gómez-Manjón I, Atencia G, Moreno-Izquierdo A, Escribano D, Fernández-Martínez FJ. Noninvasive prenatal testing: How far can we reach detecting fetal copy number variations. Eur J Obstet Gynecol Reprod Biol 2022; 272:150-155. [PMID: 35313136 DOI: 10.1016/j.ejogrb.2022.03.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 02/14/2022] [Accepted: 03/11/2022] [Indexed: 11/27/2022]
Abstract
Non-invasive prenatal testing (NIPT) is currently the best screening test for fetal chromosome abnormalities with the highest sensitivity and specificity and can be done from 10 weeks gestation. We report a detection of 44.7 Mb duplication at 11p15.5-p11.2 by NIPT with a fetal fraction (FF) of only 3%. This chromosome abnormality was confirmed after amniocentesis by karyotyping and array comparative genomic hybridization (aCGH) on cultured fetal cells. Further parental investigation showed that the fetal chromosome abnormality was inherited from the mother who was a carrier of a balanced translocation 46,XX,t(11;X)(p11.2;q28). This case highlights the importance of expanded NIPT in the detection of fetal segmental aneuploidy. NIPT together with complementary studies can lead to the detection of parental chromosome rearrangement despite a low FF, which can impact the couple's reproductive plans. We also reviewed other cases with chromosome rearrangement, detected by NIPT, derived from a parental reciprocal translocation.
Collapse
Affiliation(s)
- Sonia Mayo
- Genetics and Inheritance Research Group, Instituto de Investigación Sanitaria Hospital, 12 de Octubre (imas12), 28041 Madrid, Spain.
| | - Irene Gómez-Manjón
- Genetics and Inheritance Research Group, Instituto de Investigación Sanitaria Hospital, 12 de Octubre (imas12), 28041 Madrid, Spain; Department of Genetics, Hospital Universitario, 12 de Octubre, 28041 Madrid, Spain
| | - Gabriela Atencia
- Genetics and Inheritance Research Group, Instituto de Investigación Sanitaria Hospital, 12 de Octubre (imas12), 28041 Madrid, Spain
| | - Ana Moreno-Izquierdo
- Genetics and Inheritance Research Group, Instituto de Investigación Sanitaria Hospital, 12 de Octubre (imas12), 28041 Madrid, Spain; Department of Genetics, Hospital Universitario, 12 de Octubre, 28041 Madrid, Spain
| | - David Escribano
- Fetal Medicine Unit, Department of Obstetrics and Gynaecology, Hospital Universitario, 12 de Octubre, 28041 Madrid, Spain
| | - Fco Javier Fernández-Martínez
- Genetics and Inheritance Research Group, Instituto de Investigación Sanitaria Hospital, 12 de Octubre (imas12), 28041 Madrid, Spain; Department of Genetics, Hospital Universitario, 12 de Octubre, 28041 Madrid, Spain
| |
Collapse
|
12
|
Dap M, Caffin L, Perdriolle-Galet E, Bonnet C, Morel O. Is Cell-free fetal DNA testing a safe option for women in a high-risk population after combined first-trimester testing? J Gynecol Obstet Hum Reprod 2022; 51:102329. [PMID: 35114410 DOI: 10.1016/j.jogoh.2022.102329] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 01/23/2022] [Accepted: 01/30/2022] [Indexed: 11/16/2022]
Abstract
OBJECTIVES Our study aimed to examine the relevance of cell-free fetal DNA (cfDNA) testing on the screening of chromosomal defects and the issue of pregnancies in patients with a risk over 1:50 after the first-trimester combined test. METHODS This is a retrospective monocentric study. We included all consecutive patients with a singleton pregnancy between January 2015 and December 2020 attending our fetal medicine centre because the estimated risk for trisomy 21 after the first-trimester combined screening was over 1:50. The patients could either choose to have invasive testing or cell-free DNA testing. We collected data about the patient, the tests results (cfDNA, karyotype) and the pregnancy outcome (born alive, medical termination, miscarriage or intrauterine fetal death). RESULTS We included 98 patients with an estimated risk for trisomy 21 over 1:50. We found a total of 14 major chromosomal abnormalities (14/98; 14.3%), of which: thirteen trisomies 21 and one triploidy 69, XXY. A cfDNA testing was chosen by 34 (34/98; 34.7%) patients. Among the pathological results of invasive testing, 5 (5/64; 7.8%) couldn't be targeted by cfDNA testing. Two of them were placental mosaicism, one a triploidy 69, XXY, and two defects inherited from a parent and considered benign. There was no miscarriage linked to an invasive test in the population study. CONCLUSION In our monocentric cohort, a third of the patients choose cfDNA in a case of a risk over 1:50 after combined testing. Even if this cohort is too small to draw definitive conclusions, cfDNA could be safe in a high-risk population after combined testing. None of the chromosomal abnormalities found at the karyotype and non-detectable by cfDNA was a loss of information that impacted pregnancy follow-up. Further study could explore the input of Genome-Wide cfDNA and chromosomal micro-array in this population.
Collapse
Affiliation(s)
- Matthieu Dap
- Obstetrics and fetal medicine Unit, CHRU of Nancy, Nancy, France; Department of fetopathology and placental pathology, CHRU of Nancy, Nancy, France.
| | - Lucie Caffin
- Obstetrics and fetal medicine Unit, CHRU of Nancy, Nancy, France
| | | | - Céline Bonnet
- Department of Genetics, CHRU de Nancy, Vandœuvre-lès-Nancy, France
| | - Olivier Morel
- Obstetrics and fetal medicine Unit, CHRU of Nancy, Nancy, France; Inserm, Diagnostic and Interventional Adaptive Imaging, University of Lorraine, Nancy, France
| |
Collapse
|
13
|
Harasim T, Neuhann T, Behnecke A, Stampfer M, Holinski-Feder E, Abicht A. Initial Clinical Experience with NIPT for Rare Autosomal Aneuploidies and Large Copy Number Variations. J Clin Med 2022; 11:jcm11020372. [PMID: 35054066 PMCID: PMC8777675 DOI: 10.3390/jcm11020372] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 01/07/2022] [Accepted: 01/10/2022] [Indexed: 02/04/2023] Open
Abstract
OBJECTIVE Amniocentesis, chorionic villi sampling and first trimester combined testing are able to screen for common trisomies 13, 18, and 21 and other atypical chromosomal anomalies (ACA). The most frequent atypical aberrations reported are rare autosomal aneuploidies (RAA) and copy number variations (CNV), which are deletions or duplications of various sizes. We evaluated the clinical outcome of non-invasive prenatal testing (NIPT) results positive for RAA and large CNVs to determine the clinical significance of these abnormal results. METHODS Genome-wide NIPT was performed on 3664 eligible patient samples at a single genetics center. For patients with positive NIPT reports, the prescribing physician was asked retrospectively to provide clinical follow-up information using a standardized questionnaire. RESULTS RAAs and CNVs (>7 Mb) were detected in 0.5%, and 0.2% of tested cases, respectively. Follow up on pregnancies with an NIPT-positive result for RAA revealed signs of placental insufficiency or intra-uterine death in 50% of the cases and normal outcome at the time of birth in the other 50% of cases. We showed that CNV testing by NIPT allows for the detection of unbalanced translocations and relevant maternal health conditions. CONCLUSION NIPT for aneuploidies of all autosomes and large CNVs of at least 7 Mb has a low "non-reportable"-rate (<0.2%) and allows the detection of additional conditions of clinical significance.
Collapse
|
14
|
Gug C, Mozos I, Ratiu A, Tudor A, Gorduza EV, Caba L, Gug M, Cojocariu C, Furau C, Furau G, Vaida MA, Stoicanescu D. Genetic Counseling and Management: The First Study to Report NIPT Findings in a Romanian Population. MEDICINA (KAUNAS, LITHUANIA) 2022; 58:medicina58010079. [PMID: 35056387 PMCID: PMC8777823 DOI: 10.3390/medicina58010079] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 12/18/2021] [Accepted: 12/30/2021] [Indexed: 04/25/2023]
Abstract
Background and Objectives: Non-invasive prenatal testing (NIPT) has been confirmed as the most accurate screening test for trisomies 21, 18, 13, sex chromosomes aneuploidies and several microdeletions. This study aimed to assess the accuracy of cell free DNA testing based on low-level whole-genome sequencing to screen for these chromosomal abnormalities and to evaluate the clinical performance of NIPT. Materials and Methods: 380 consecutive cases from a single genetic center, from Western Romania were included in this retrospective study. Cell-free nucleic acid extraction from maternal blood, DNA sequencing and analysis of sequenced regions were performed by BGI Hong Kong and Invitae USA to determine the risk of specific fetal chromosomal abnormalities. In high-risk cases the results were checked by direct analysis of fetal cells obtained by invasive methods: 6 chorionic villus sampling and 10 amniocenteses followed by combinations of QF-PCR, karyotyping and aCGH. Results: NIPT results indicated low risk in 95.76% of cases and high risk in 4.23%. Seven aneuploidies and one microdeletion were confirmed, the other results were found to be a false-positive. A gestational age of up to 22 weeks had no influence on fetal fraction. There were no significant differences in fetal fraction across the high and low risk groups. Conclusions: This is the first study in Romania to report the NIPT results. The confirmation rate was higher for autosomal aneuploidies compared to sex chromosome aneuploidies and microdeletions. All cases at risk for trisomy 21 were confirmed. Only one large fetal microdeletion detected by NIPT has been confirmed. False positive NIPT results, not confirmed by invasive methods, led to the decision to continue the pregnancy. The main limitation of the study is the small number of patients included. NIPT can be used as a screening method for all pregnancies, but in high-risk cases, an invasive confirmation test was performed.
Collapse
Affiliation(s)
- Cristina Gug
- Department of Microscopic Morphology, “Victor Babeş” University of Medicine and Pharmacy, 300041 Timisoara, Romania; (C.G.); (D.S.)
| | - Ioana Mozos
- Department of Functional Sciences, Discipline of Pathophysiology, “Victor Babes” University of Medicine and Pharmacy, 300173 Timisoara, Romania
- Center for Translational Research and Systems Medicine, “Victor Babes” University of Medicine and Pharmacy, 300173 Timisoara, Romania
- Correspondence: ; Tel.: +40-745610004
| | - Adrian Ratiu
- Department of Obstetrics and Gynecology II, “Victor Babes” University of Medicine and Pharmacy, 300041 Timisoara, Romania;
- Obstetrics-Gynecology Clinic IV, Municipal Emergency Clinical Hospital, 300231 Timisoara, Romania
| | - Anca Tudor
- Department of Functional Sciences, Discipline of Medical Informatics and Biostatistics, “Victor Babes” University of Medicine and Pharmacy, 300041 Timisoara, Romania;
| | - Eusebiu Vlad Gorduza
- Department of Medical Genetics, Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania; (E.V.G.); (L.C.)
| | - Lavinia Caba
- Department of Medical Genetics, Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania; (E.V.G.); (L.C.)
| | - Miruna Gug
- Faculty of Medicine, “Victor Babeş” University of Medicine and Pharmacy, 300041 Timisoara, Romania; (M.G.); (C.C.)
| | - Catalina Cojocariu
- Faculty of Medicine, “Victor Babeş” University of Medicine and Pharmacy, 300041 Timisoara, Romania; (M.G.); (C.C.)
| | - Cristian Furau
- Life Sciences Department, Faculty of Medicine, “Vasile Goldis“ Western University of Arad, 310414 Arad, Romania;
| | - Gheorghe Furau
- General Medicine Department, Faculty of Medicine, “Vasile Goldis“ Western University of Arad, 310414 Arad, Romania;
| | - Monica Adriana Vaida
- Department of Anatomy and Embryology, “Victor Babes” University of Medicine and Pharmacy, 300041 Timisoara, Romania;
| | - Dorina Stoicanescu
- Department of Microscopic Morphology, “Victor Babeş” University of Medicine and Pharmacy, 300041 Timisoara, Romania; (C.G.); (D.S.)
| |
Collapse
|
15
|
Christiaens L, Chitty LS, Langlois S. Current controversies in prenatal diagnosis: Expanded NIPT that includes conditions other than trisomies 13, 18, and 21 should be offered. Prenat Diagn 2021; 41:1316-1323. [PMID: 33829520 DOI: 10.1002/pd.5943] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 03/06/2021] [Accepted: 03/22/2021] [Indexed: 11/11/2022]
Abstract
Non-invasive prenatal testing (NIPT) based on analysis of cell free DNA circulating in the maternal plasma has been available clinically to screen for chromosomal abnormalities since 2011. There is significant evidence to suggest that NIPT has revolutionised prenatal screening for the common trisomies 13, 18, and 21. However, the evidence in favour of its extended use to screen for conditions other than these trisomies remains a topic of debate with no national or international organisation supporting clinical implementation for these indications. In the debate presented here - "Expanded NIPT that includes conditions other than trisomies 13, 18, and 21 should be offered" - we will see the pros and cons of screening for a wider range of chromosomal problems. The discussion presented swung the vote from 65% in favour and 35% against before the arguments were voiced to 41% in favour and 59% against. This significant swing in the vote indicates that the majority of our community feel more evidence is required before clinical implementation of extended NIPT.
Collapse
Affiliation(s)
- Lieve Christiaens
- Illumina Inc., San Diego, California, USA.,University Hospital of Utrecht, Utrecht, Netherlands
| | - Lyn S Chitty
- Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.,The UCL Great Ormond Street Institute of Child Health, London, UK
| | - Sylvie Langlois
- Department of Medical Genetics, University of British Columbia, Vancouver, Canada
| |
Collapse
|
16
|
Colley E, Devall AJ, Williams H, Hamilton S, Smith P, Morgan NV, Quenby S, Coomarasamy A, Allen S. Cell-Free DNA in the Investigation of Miscarriage. J Clin Med 2020; 9:jcm9113428. [PMID: 33114508 PMCID: PMC7693881 DOI: 10.3390/jcm9113428] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 10/20/2020] [Accepted: 10/22/2020] [Indexed: 11/16/2022] Open
Abstract
Approximately one in four pregnancies result in pregnancy loss, and ~50% of these miscarriages are caused by chromosomal abnormalities. Genetic investigations are recommended after three consecutive miscarriages on products of conception (POC) tissue. Cell-free DNA (cfDNA) has been utilised for prenatal screening, but very little work has been carried out in nonviable pregnancies. We investigated the use of cfDNA from maternal blood to identify chromosomal abnormalities in miscarriage. One hundred and two blood samples from women experiencing a first trimester miscarriage were collected and stored. The mean gestational age was 7.1 weeks (range: 5–11 weeks). In this research, samples without a genetic test result from POC were not analysed. CfDNA was extracted and analysed using a modified commercial genome-wide non-invasive prenatal test. No results were provided to the patient. In 57 samples, cytogenetic results from POC analysis were available. Chromosomal abnormalities were identified in 47% (27/57) of POC analyses, and cfDNA analysis correctly identified 59% (16/27) of these. In total, 75% (43/57) of results were correctly identified. The average cfDNA fetal fraction was 6% (2–19%). In conclusion, cfDNA can be used to detect chromosomal abnormalities in miscarriages where the ‘fetal fraction’ is high enough; however, more studies are required to identify variables that can affect the overall results.
Collapse
Affiliation(s)
- Emily Colley
- Tommy’s National Centre for Miscarriage Research, Birmingham Women’s and Children’s Hospital, Birmingham B15 2TG, UK; (A.J.D.); (H.W.); (P.S.); (A.C.)
- Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
- West Midlands Regional Genetics Laboratory, Birmingham Women’s and Children’s Hospital, Birmingham B15 2TG, UK; (S.H.); (S.A.)
- Correspondence:
| | - Adam J. Devall
- Tommy’s National Centre for Miscarriage Research, Birmingham Women’s and Children’s Hospital, Birmingham B15 2TG, UK; (A.J.D.); (H.W.); (P.S.); (A.C.)
- Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Helen Williams
- Tommy’s National Centre for Miscarriage Research, Birmingham Women’s and Children’s Hospital, Birmingham B15 2TG, UK; (A.J.D.); (H.W.); (P.S.); (A.C.)
- Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Edgbaston B15 2TT, UK
| | - Susan Hamilton
- West Midlands Regional Genetics Laboratory, Birmingham Women’s and Children’s Hospital, Birmingham B15 2TG, UK; (S.H.); (S.A.)
| | - Paul Smith
- Tommy’s National Centre for Miscarriage Research, Birmingham Women’s and Children’s Hospital, Birmingham B15 2TG, UK; (A.J.D.); (H.W.); (P.S.); (A.C.)
- Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Neil V. Morgan
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK;
| | - Siobhan Quenby
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry CV4 7HL, UK;
- Tommy’s National Centre for Miscarriage Research, University Hospitals Coventry & Warwickshire NHS Trust, Coventry CV2 2DX, UK
| | - Arri Coomarasamy
- Tommy’s National Centre for Miscarriage Research, Birmingham Women’s and Children’s Hospital, Birmingham B15 2TG, UK; (A.J.D.); (H.W.); (P.S.); (A.C.)
- Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Stephanie Allen
- West Midlands Regional Genetics Laboratory, Birmingham Women’s and Children’s Hospital, Birmingham B15 2TG, UK; (S.H.); (S.A.)
| |
Collapse
|