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Das S, Sharma C, Yadav T, Dubey K, Shekhar S, Singh P, Singh K, Gothwal M, Jhirwal M, Shekhawat DS. Absent or hypoplastic nasal bone: What to tell the prospective parents? Birth Defects Res 2024; 116:e2348. [PMID: 38801241 DOI: 10.1002/bdr2.2348] [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: 09/18/2023] [Revised: 02/23/2024] [Accepted: 04/22/2024] [Indexed: 05/29/2024]
Abstract
BACKGROUND Absent or hypoplastic nasal bone (AHNB) on first or second-trimester ultrasonography (USG) is an important soft marker of Down syndrome. However, due to its varied incidence in euploid and aneuploid fetuses, there is always a dilemma of whether to go for invasive fetal testing for isolated AHNB. This study aims to assess outcomes specifically within the context of Indian ethnicity women. MATERIALS AND METHODS This was a prospective observational study. All patients who reported with AHNB in the first- or second-trimester USG were included. Genetic counseling was done, and noninvasive and invasive testing was offered. Chromosomal anomalies were meticulously recorded, and pregnancy was monitored. RESULTS The incidence of AHNB in our study was 1.16% (47/4051). Out of 47 women with AHNB, the isolated condition was seen in 32 (0.78%) cases, while AHNB with structural anomalies was seen in nine cases (0.22%). Thirty-nine women opted for invasive testing. Six out of 47 had aneuploidy (12.7%), while two euploid cases (4.25%) developed nonimmune hydrops. The prevalence of Down syndrome in fetuses with AHNB was 8.5% (4/47) and 0.42% (17/4004) in fetuses with nasal bone present. This difference was statistically significant (p = .001). CONCLUSION The results indicate that isolated AHNB cases should be followed by a comprehensive anomaly scan rather than immediately recommending invasive testing. However, invasive testing is required when AHNB is associated with other soft markers or abnormalities. As chromosomal microarray is more sensitive than standard karyotype in detecting chromosomal aberrations, it should be chosen over karyotype.
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Affiliation(s)
- Shreya Das
- Department of Obstetrics & Gynecology, All India Institute of Medical Sciences, Jodhpur, India
| | - Charu Sharma
- Department of Obstetrics & Gynecology, All India Institute of Medical Sciences, Jodhpur, India
| | - Taruna Yadav
- Department of Diagnostic and Interventional Radiology, All India Institute of Medical Sciences, Jodhpur, India
| | - Kalika Dubey
- Department of Obstetrics & Gynecology, All India Institute of Medical Sciences, Jodhpur, India
| | - Shashank Shekhar
- Department of Obstetrics & Gynecology, All India Institute of Medical Sciences, Jodhpur, India
| | - Pratibha Singh
- Department of Obstetrics & Gynecology, All India Institute of Medical Sciences, Jodhpur, India
| | - Kuldeep Singh
- Department of Pediatrics, All India Institute of Medical Sciences, Jodhpur, India
| | - Meenakshi Gothwal
- Department of Obstetrics & Gynecology, All India Institute of Medical Sciences, Jodhpur, India
| | - Manisha Jhirwal
- Department of Obstetrics & Gynecology, All India Institute of Medical Sciences, Jodhpur, India
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Xia Z, Zhou R, Xu Y, Li Y, Tan J, Luo C, Meng L, Huang M, Qiao F, Hu P, Mao P, Wu Y, Xu Z, Wang Y. Residual risk of clinically significant copy number variations in fetuses with nasal bone absence or hypoplasia after excluding non-invasive prenatal screening-detectable findings. Clin Chim Acta 2024; 553:117744. [PMID: 38158003 DOI: 10.1016/j.cca.2023.117744] [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: 10/17/2023] [Revised: 12/05/2023] [Accepted: 12/21/2023] [Indexed: 01/03/2024]
Abstract
BACKGROUND It remains controversial whether prenatal screening or diagnostic testing should be offered to fetuses with nasal bone (NB) absence or hypoplasia, and there are no studies comparing the yield of chromosomal microarray analysis (CMA) to non-invasive prenatal screening (NIPS). The aim of this study was to evaluate the residual risk of clinically significant copy number variations (CNVs) in fetuses with NB absence or hypoplasia after excluding theoretically NIPS-detectable abnormalities, and to assess their clinical outcomes. METHODS This prospective study encompassed 400 fetuses with NB absence or hypoplasia undergoing CMA testing between 2015 and 2022. Clinically significant CMA findings were categorized into three subgroups, including three-NIPS-detectable (trisomies 21, 18 and 13), five-NIPS-detectable (trisomies 21, 18 and 13 and sex chromosome aneuploidies) and genome-wide NIPS-detectable (variants over 7 Mb). We calculated the theoretical residual risk and compared it with the results of a control cohort of low-risk pregnancies. We further evaluated their clinical outcomes. RESULTS The overall diagnostic yield in our cohort was 7.8% (31/400). The detection rate of clinically significant CMA findings in fetuses with non-isolated NB absence or hypoplasia was significantly higher than that in fetuses with isolated NB absence or hypoplasia (20.0% vs. 6.6%, P =.005). The theoretical residual risks in all NIPS models were significantly higher when compared with the control cohort. The normal infant rate in fetuses with normal CMA results was 97.9% (323/330), and a significant higher incidence was observed in fetuses with isolated NB absence or hypoplasia compared with non-isolated NB absence or hypoplasia (98.4% vs. 91.7%, P =.028). CONCLUSIONS The residual risk of clinically significant CNVs in fetuses with NB absence or hypoplasia following the exclusion of theoretically NIPS-detectable findings was higher than that in low-risk pregnancies. This risk should be considered in genetic counseling to make a more comprehensive and precise choice regarding prenatal genetic testing.
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Affiliation(s)
- Zhengyi Xia
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu Province, China
| | - Ran Zhou
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu Province, China
| | - Yiyun Xu
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu Province, China
| | - Yiming Li
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu Province, China
| | - Jianxin Tan
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu Province, China
| | - Chunyu Luo
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu Province, China
| | - Lulu Meng
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu Province, China
| | - Mingtao Huang
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu Province, China
| | - Fengchang Qiao
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu Province, China
| | - Ping Hu
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu Province, China
| | - Pengyuan Mao
- Department of Public Health, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu Province, China
| | - Yun Wu
- Department of Ultrasonography, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu Province, China.
| | - Zhengfeng Xu
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu Province, China.
| | - Yan Wang
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu Province, China.
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Li H, Yao Y, Zhang C, Qin Y, Zeng L, Song J, Lu L, Wang W, Liu L. Prenatal diagnosis and outcomes in 320 fetuses with nasal bone anomalies. Front Genet 2023; 14:1170720. [PMID: 37693318 PMCID: PMC10483397 DOI: 10.3389/fgene.2023.1170720] [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: 02/21/2023] [Accepted: 08/15/2023] [Indexed: 09/12/2023] Open
Abstract
Object: To investigate the chromosome abnormalities associated with absent or hypoplastic fetal nasal bone. Methods: Patients with fetal nasal bone anomalies (NBA) referred to our center for prenatal diagnosis between 2017 and 2021 were retrospectively evaluated. All these patients underwent chromosomal microarray and/or karyotyping and received genetic counseling before and after testing. Results: Among 320 fetuses with NBA, chromosomal abnormalities were diagnosed in 89 (27.8%) cases, including 53 cases of trisomy 21, which was the most common type of chromosomal aneuploidy, accounting for 59.6% of all detected abnormalities. In addition to aneuploidies, 29 cases of copy number variants (CNVs) were detected. In cases of isolated NBA with low-risk screening results and without other risk factors, the incidence of fetal chromosomal aneuploidies and pathogenic CNVs is 5.3% (7 in 132 cases). Conclusion: This study suggests that parents of fetuses should be informed about the possibility of fetal aneuploidy and pathogenic CNVs and that discussion with the parents is also recommended, providing data support and reference for clinical counseling.
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Affiliation(s)
- Hui Li
- Medical Genetic Center, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yanyi Yao
- Medical Genetic Center, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chengcheng Zhang
- Medical Genetic Center, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yayun Qin
- Medical Genetic Center, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ling Zeng
- Medical Genetic Center, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jieping Song
- Medical Genetic Center, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Li Lu
- Department of Ultrasonography, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Wei Wang
- Department of Pediatric Respiratory, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Lijun Liu
- Medical Genetic Center, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Zhang S, Xu Y, Lu D, Fu D, Zhao Y. Combined use of karyotyping and copy number variation sequencing technology in prenatal diagnosis. PeerJ 2022; 10:e14400. [PMID: 36523456 PMCID: PMC9745786 DOI: 10.7717/peerj.14400] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 10/25/2022] [Indexed: 12/12/2022] Open
Abstract
Background Karyotyping and genome copy number variation sequencing (CNV-seq) are two techniques frequently used in prenatal diagnosis. This study aimed to explore the diagnostic potential of using a combination of these two methods in order to provide a more accurate clinical basis for prenatal diagnosis. Methods We selected 822 pregnant women undergoing amniocentesis and separated them into six groups according to different risk indicators. Karyotyping and CNV-seq were performed simultaneously to compare the diagnostic performance of the two methods. Results Among the different amniocentesis indicators, abnormal fetal ultrasounds accounted for 39.29% of the total number of examinees and made up the largest group. The abnormal detection rate of non-invasive prenatal testing (NIPT) high risk was 37.93% and significantly higher than the other five groups (P < 0.05). The abnormal detection rate of mixed indicators was significantly higher than the history of the adverse reproductive outcomes group (P = 0.0151). The two methods combined found a total of 119 abnormal cases (14.48%). Karyotyping detected 57 cases (6.93%) of abnormal karyotypes, 30 numerical aberrations, and 27 structural aberrations. CNV-seq identified 99 cases (12.04%) with altered CNVs, 30 cases of chromosome aneuploidies, and 69 structural aberrations (28 pathogenic, eight that were likely pathogenic, and 33 microdeletion/duplication variants of uncertain significance (VUS)). Thirty-seven cases were found abnormal by both methods, 20 cases were detected abnormally by karyotyping (mainly mutual translocation and mostly balanced), and 62 cases of microdeletion/duplication were detected by CNV-seq. Steroid sulfatase gene (STS) deletion was identified at chromosome Xp22.31 in three cases. Postnatal follow-up confirmed that babies manifested skin abnormalities one week after birth. Six fetuses had Xp22.31 duplications ranging from 1.5 Kb to 1.7 Mb that were detected by CNV-seq. Follow-up showed that five babies presented no abnormalities during follow-up, except for one terminated pregnancy due to a history of adverse reproductive outcomes. Conclusion The combination of using CNV-seq and karyotyping significantly improved the detection rate of fetal pathogenic chromosomal abnormalities. CNV-seq is an effective complement to karyotyping and improves the accuracy of prenatal diagnosis.
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Affiliation(s)
- Suhua Zhang
- Department of Gynaecology and Obstetrics, Clinical Medical College of Yangzhou University, Northern Jiangsu People’s Hospital, Yang Zhou, Jiangsu Province, China
| | - Yuexin Xu
- Department of Gynaecology and Obstetrics, Clinical Medical College of Yangzhou University, Northern Jiangsu People’s Hospital, Yang Zhou, Jiangsu Province, China
| | - Dan Lu
- Department of Gynaecology and Obstetrics, Clinical Medical College of Yangzhou University, Northern Jiangsu People’s Hospital, Yang Zhou, Jiangsu Province, China
| | - Dan Fu
- Department of Gynaecology and Obstetrics, Clinical Medical College of Yangzhou University, Northern Jiangsu People’s Hospital, Yang Zhou, Jiangsu Province, China
| | - Yan Zhao
- Medical Research Center, Clinical Medical College of Yangzhou University, Northern Jiangsu People’s Hospital, Yang Zhou, Jiangsu Province, China
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Shi X, Lu J, Li L, Wei R, Wu J. Prenatal chromosomal microarray analysis in foetuses with isolated absent or hypoplastic nasal bone. Ann Med 2022; 54:1297-1302. [PMID: 35506821 PMCID: PMC9090372 DOI: 10.1080/07853890.2022.2070271] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
OBJECTIVES To evaluate the efficiency of chromosomal microarray analysis (CMA) in the prenatal diagnosis of foetuses with isolated absent or hypoplastic nasal bone (NB) in the first and second trimester. METHODS From January 2015 to April 2021, foetuses with isolated absent or hypoplastic NB who received invasive prenatal diagnosis were enrolled. The results of CMA were analysed. RESULTS There were 221 foetuses, including 166 cases with isolated absent NB and 55 cases with isolated hypoplastic NB. Twenty-four foetuses (10.9%, 24/221) had an ultrasonic diagnosis in the first trimester and 197 (89.1%, 197/221) had a ultrasonic diagnosis in the second trimester. The overall diagnostic yield of CMA was 9.0% (20/221). Aneuploidies were detected in 13 (5.9%, 13/221) foetuses, including 10 Down syndrome, 2 Klinefelter's syndrome and 1 trisomy 18. Pathogenic copy number variations (CNVs) were detected in seven foetuses (3.2%, 7/221). In addition, variants of unknown significance (VOUS) were detected in four foetuses. The foetuses with isolated absent NB had a higher detection rate of chromosome abnormality than the isolated hypoplastic NB, but the difference was not significant in the statistical analysis (10.2% vs. 5.5%, χ2 =0.642, p = .423). No significant difference was observed in the detection rate between the first trimester and the second trimester (16.6% vs. 8.1%, χ2 = 1.002, p = .317, Chi-square test). CONCLUSION CMA can increase the diagnostic yield of chromosome abnormality, especially pathogenic CNVs for foetuses with isolated absent or hypoplastic NB. CMA should be recommended when isolated absent or hypoplastic NB is suspected antenatally.7.
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Affiliation(s)
- Xiaomei Shi
- Genetic Medical Center, Guangdong Women and Children Hospital, Guangzhou, China
| | - Jian Lu
- Genetic Medical Center, Guangdong Women and Children Hospital, Guangzhou, China
| | - Ling Li
- Genetic Medical Center, Guangdong Women and Children Hospital, Guangzhou, China
| | - Ran Wei
- Genetic Medical Center, Guangdong Women and Children Hospital, Guangzhou, China
| | - Jing Wu
- Genetic Medical Center, Guangdong Women and Children Hospital, Guangzhou, China
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Moczulska H, Serafin M, Wojda K, Borowiec M, Sieroszewski P. Fetal Nasal Bone Hypoplasia in the Second Trimester as a Marker of Multiple Genetic Syndromes. J Clin Med 2022; 11:jcm11061513. [PMID: 35329839 PMCID: PMC8954562 DOI: 10.3390/jcm11061513] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 03/06/2022] [Accepted: 03/08/2022] [Indexed: 01/01/2023] Open
Abstract
Nasal bone hypoplasia is associated with a trisomy of chromosome 21, 18 or 13. Nasal bone hypoplasia can also be seen in other, rarer genetic syndromes. The aim of the study was to evaluate the potential of nasal bone hypoplasia, in the second trimester of pregnancy, as a marker of fetal facial dysmorphism, associated with pathogenic copy number variation (CNV). This retrospective analysis of the invasive tests results in fetuses with nasal bone hypoplasia, after excluding those with trisomy 21, 18 and 13. In total, 60 cases with nasal bone hypoplasia were analyzed. Chromosomal aberrations were found in 7.1% of cases of isolated nasal bone hypoplasia, and in 57% of cases of nasal bone hypoplasia with additional malformations. Additionally, in four of nine cases with non-isolated nasal bone hypoplasia but normal CMA results, a monogenic disease was diagnosed. Non-isolated hypoplastic nasal bone appears to be an effective objective marker of fetal facial dysmorphism, associated with pathogenic CNVs or monogenic diseases. In isolated cases, chromosomal microarray testing can be of additional value if invasive testing is performed, e.g., for aneuploidy testing after appropriate counseling.
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Affiliation(s)
- Hanna Moczulska
- Department of Clinical Genetics, Medical University of Lodz, 90-419 Lodz, Poland; (M.S.); (M.B.)
- Correspondence: ; Tel.: +48-42-201-44-92
| | - Marcin Serafin
- Department of Clinical Genetics, Medical University of Lodz, 90-419 Lodz, Poland; (M.S.); (M.B.)
| | - Katarzyna Wojda
- Department of Fetal Medicine and Gynecology, Medical University of Lodz, 90-419 Lodz, Poland; (K.W.); (P.S.)
| | - Maciej Borowiec
- Department of Clinical Genetics, Medical University of Lodz, 90-419 Lodz, Poland; (M.S.); (M.B.)
| | - Piotr Sieroszewski
- Department of Fetal Medicine and Gynecology, Medical University of Lodz, 90-419 Lodz, Poland; (K.W.); (P.S.)
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Mastromoro G, Guadagnolo D, Khaleghi Hashemian N, Marchionni E, Traversa A, Pizzuti A. Molecular Approaches in Fetal Malformations, Dynamic Anomalies and Soft Markers: Diagnostic Rates and Challenges-Systematic Review of the Literature and Meta-Analysis. Diagnostics (Basel) 2022; 12:575. [PMID: 35328129 PMCID: PMC8947110 DOI: 10.3390/diagnostics12030575] [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: 01/18/2022] [Revised: 02/11/2022] [Accepted: 02/21/2022] [Indexed: 02/06/2023] Open
Abstract
Fetal malformations occur in 2-3% of pregnancies. They require invasive procedures for cytogenetics and molecular testing. "Structural anomalies" include non-transient anatomic alterations. "Soft markers" are often transient minor ultrasound findings. Anomalies not fitting these definitions are categorized as "dynamic". This meta-analysis aims to evaluate the diagnostic yield and the rates of variants of uncertain significance (VUSs) in fetuses undergoing molecular testing (chromosomal microarray (CMA), exome sequencing (ES), genome sequencing (WGS)) due to ultrasound findings. The CMA diagnostic yield was 2.15% in single soft markers (vs. 0.79% baseline risk), 3.44% in multiple soft markers, 3.66% in single structural anomalies and 8.57% in multiple structural anomalies. Rates for specific subcategories vary significantly. ES showed a diagnostic rate of 19.47%, reaching 27.47% in multiple structural anomalies. WGS data did not allow meta-analysis. In fetal structural anomalies, CMA is a first-tier test, but should be integrated with karyotype and parental segregations. In this class of fetuses, ES presents a very high incremental yield, with a significant VUSs burden, so we encourage its use in selected cases. Soft markers present heterogeneous CMA results from each other, some of them with risks comparable to structural anomalies, and would benefit from molecular analysis. The diagnostic rate of multiple soft markers poses a solid indication to CMA.
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Affiliation(s)
- Gioia Mastromoro
- Department of Experimental Medicine, Policlinico Umberto I Hospital, Sapienza University of Rome, 00161 Rome, Italy; (D.G.); (N.K.H.); (E.M.); (A.T.); (A.P.)
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Mellis R, Oprych K, Scotchman E, Hill M, Chitty LS. Diagnostic yield of exome sequencing for prenatal diagnosis of fetal structural anomalies: A systematic review and meta-analysis. Prenat Diagn 2022; 42:662-685. [PMID: 35170059 PMCID: PMC9325531 DOI: 10.1002/pd.6115] [Citation(s) in RCA: 77] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 02/08/2022] [Accepted: 02/10/2022] [Indexed: 11/10/2022]
Abstract
Objectives We conducted a systematic review and meta‐analysis to determine the diagnostic yield of exome sequencing (ES) for prenatal diagnosis of fetal structural anomalies, where karyotype/chromosomal microarray (CMA) is normal. Methods Following electronic searches of four databases, we included studies with ≥10 structurally abnormal fetuses undergoing ES or whole genome sequencing. The incremental diagnostic yield of ES over CMA/karyotype was calculated and pooled in a meta‐analysis. Sub‐group analyses investigated effects of case selection and fetal phenotype on diagnostic yield. Results We identified 72 reports from 66 studies, representing 4350 fetuses. The pooled incremental yield of ES was 31% (95% confidence interval (CI) 26%–36%, p < 0.0001). Diagnostic yield was significantly higher for cases pre‐selected for likelihood of monogenic aetiology compared to unselected cases (42% vs. 15%, p < 0.0001). Diagnostic yield differed significantly between phenotypic sub‐groups, ranging from 53% (95% CI 42%–63%, p < 0.0001) for isolated skeletal abnormalities, to 2% (95% CI 0%–5%, p = 0.04) for isolated increased nuchal translucency. Conclusion Prenatal ES provides a diagnosis in an additional 31% of structurally abnormal fetuses when CMA/karyotype is non‐diagnostic. The expected diagnostic yield depends on the body system(s) affected and can be optimised by pre‐selection of cases following multi‐disciplinary review to determine that a monogenic cause is likely.
What's already known about this topic?
Prenatal exome sequencing (ES) increases genetic diagnoses in fetuses with structural abnormalities and a normal karyotype and chromosomal microarray. Published diagnostic yields from ES are varied and may be influenced by study size, case selection and fetal phenotype.
What does this study add?
This study provides a comprehensive systematic review of the literature to date and investigates the diagnostic yield of ES for a range of isolated system anomalies, to support clinical decision‐making on how to offer prenatal ES.
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Affiliation(s)
- Rhiannon Mellis
- North Thames Genomic Laboratory HubGreat Ormond Street Hospital for Children NHS Foundation TrustLondonUK
- Genetics and Genomic MedicineUCL Great Ormond Street Institute of Child HealthLondonUK
| | | | - Elizabeth Scotchman
- North Thames Genomic Laboratory HubGreat Ormond Street Hospital for Children NHS Foundation TrustLondonUK
| | - Melissa Hill
- North Thames Genomic Laboratory HubGreat Ormond Street Hospital for Children NHS Foundation TrustLondonUK
- Genetics and Genomic MedicineUCL Great Ormond Street Institute of Child HealthLondonUK
| | - Lyn S Chitty
- North Thames Genomic Laboratory HubGreat Ormond Street Hospital for Children NHS Foundation TrustLondonUK
- Genetics and Genomic MedicineUCL Great Ormond Street Institute of Child HealthLondonUK
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