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Tsai P, Shinar S. Agenesis of the corpus callosum: What to tell expecting parents? Prenat Diagn 2023; 43:1527-1535. [PMID: 37794643 DOI: 10.1002/pd.6447] [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: 04/08/2023] [Revised: 09/09/2023] [Accepted: 09/14/2023] [Indexed: 10/06/2023]
Abstract
Agenesis of the corpus callosum (ACC) is one of the most common brain malformations, with an incidence estimated to range from 0.5 to 70 in 10,000 among the general population. Prenatal diagnosis is made via ultrasound; however, fetal MRI is useful to confirm or exclude the presence of associated cerebral abnormalities-mostly cortical malformations-that may affect postnatal prognosis. When no additional central nervous system (CNS) or extra CNS anomalies are identified and no genetic cause is found, an isolated ACC is diagnosed. Overall, in cases of ACC, an underlying genetic cause can be identified in up to 12.5% with chromosomal microarray (CMA) and up to 47% with whole exome sequencing (WES). In cases where ACC is the only anomaly detected, the yield of WES is 30%. Postnatal outcomes are variable and depend on whether the condition is isolated or not. In truly isolated ACC, outcomes range from normal in 65% of cases through mild to severe neurodevelopmental impairments in 35% of cases. An interdisciplinary team of medical experts is key in guiding parents toward informed decision-making in pregnancies complicated by ACC. Considering current and expected advancements in genetic testing and imaging technologies in upcoming years, we herein summarize current recommendations for the management and prenatal counseling of expecting parents of fetuses with ACC. Our review pertains primarily to expecting parents of fetuses with complete ACC.
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Affiliation(s)
- Pascale Tsai
- Michael G. DeGroote School of Medicine, Waterloo Regional Campus, McMaster University, Hamilton, Ontario, Canada
| | - Shiri Shinar
- Fetal Medicine Unit, Ontario Fetal Center, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
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Lannoo L, van Straaten K, Breckpot J, Brison N, De Catte L, Dimitriadou E, Legius E, Peeters H, Parijs I, Tsuiko O, Vancoillie L, Vermeesch JR, Van Buggenhout G, Van Den Bogaert K, Van Calsteren K, Devriendt K. Rare autosomal trisomies detected by non-invasive prenatal testing: an overview of current knowledge. Eur J Hum Genet 2022; 30:1323-1330. [PMID: 35896702 PMCID: PMC9712527 DOI: 10.1038/s41431-022-01147-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Revised: 06/15/2022] [Accepted: 06/30/2022] [Indexed: 12/16/2022] Open
Abstract
Non-invasive prenatal testing has been introduced for the detection of Trisomy 13, 18, and 21. Using genome-wide screening also other "rare" autosomal trisomies (RATs) can be detected with a frequency about half the frequency of the common trisomies in the large population-based studies. Large prospective studies and clear clinical guidelines are lacking to provide adequate counseling and management to those who are confronted with a RAT as a healthcare professional or patient. In this review we reviewed the current knowledge of the most common RATs. We compiled clinical relevant parameters such as incidence, meiotic or mitotic origin, the risk of fetal (mosaic) aneuploidy, clinical manifestations of fetal mosaicism for a RAT, the effect of confined placental mosaicism on placental function and the risk of uniparental disomy (UPD). Finally, we identified gaps in the knowledge on RATs and highlight areas of future research. This overview may serve as a first guide for prenatal management for each of these RATs.
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Affiliation(s)
- Lore Lannoo
- Department of Obstetrics and Gynaecology, Division Woman and Child, University Hospitals Leuven, Leuven, Belgium
| | | | - Jeroen Breckpot
- Department of Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Nathalie Brison
- Department of Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Luc De Catte
- Department of Obstetrics and Gynaecology, Division Woman and Child, University Hospitals Leuven, Leuven, Belgium
| | | | - Eric Legius
- Department of Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Hilde Peeters
- Department of Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Ilse Parijs
- Department of Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Olga Tsuiko
- Department of Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Leen Vancoillie
- Department of Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | | | | | | | - Kristel Van Calsteren
- Department of Obstetrics and Gynaecology, Division Woman and Child, University Hospitals Leuven, Leuven, Belgium
| | - Koenraad Devriendt
- Department of Human Genetics, University Hospitals Leuven, Leuven, Belgium.
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Huang H, Cai M, Liu L, Xu L, Lin N. Effectiveness of Chromosomal Microarray Analysis for Prenatal Diagnosis of Fetal Echogenic Intracardiac Focus: A Single-Center Experience. Int J Gen Med 2021; 14:1991-1997. [PMID: 34045891 PMCID: PMC8149271 DOI: 10.2147/ijgm.s311800] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 05/05/2021] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Echogenic intracardiac focus (EIF) is a common ultrasound finding during pregnancy. However, the correlation between fetal EIF and cardiac abnormality remains in dispute until now. The study aimed to examine the association of fetal EIF with chromosomal abnormality by means of chromosomal microarray analysis (CMA). MATERIALS AND METHODS A total of 192 pregnant women with fetal EIF undergoing amniocentesis or umbilical cord blood puncture were recruited and assigned into groups A (8 cases with isolated EIF alone), B (75 cases with EIF and other cardiac malformations) and C (109 cases with EIF and extracardiac malformations). All fetuses underwent karyotyping analysis and CMA simultaneously. The detection of chromosomal abnormality and copy number variations (CNVs) were compared. RESULTS Chromosomal karyotyping identified 5 fetuses with chromosomal abnormality, including 3 cases with trisomy 21, one fetus with Turner's syndrome, and one fetus with chromosome 8 mosaicism, while CMA detected 6 additional fetuses with CNVs, including 2 fetuses with pathogenic CNVs and 4 fetuses with variants of uncertain significance (VOUS). There was no significant difference among groups A (0), B (5.33%) and C (6.42%) in terms of the prevalence of chromosomal abnormality (P> 0.05). Among the 4 fetuses with VOUS, pregnancy continued in 2 fetuses, and pregnancy was terminated in other 2 fetuses. CONCLUSION An isolated EIF may not correlate with chromosomal abnormality. However, CMA is recommended in fetuses with CMA complicated by other abnormal cardiac ultrasound findings, which facilitates the prediction of fetal outcomes during the genetic counseling and precision assessment of prognosis.
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Affiliation(s)
- Hailong Huang
- Fujian Maternity and Child Health Hospital, Affiliated Hospital of Fujian Medical University, Fujian Key Laboratory for Prenatal Diagnosis and Birth Defect, Fuzhou City, Fujian Province, 350001, People’s Republic of China
| | - Meiying Cai
- Fujian Maternity and Child Health Hospital, Affiliated Hospital of Fujian Medical University, Fujian Key Laboratory for Prenatal Diagnosis and Birth Defect, Fuzhou City, Fujian Province, 350001, People’s Republic of China
| | - Linyu Liu
- Fujian Maternity and Child Health Hospital, Affiliated Hospital of Fujian Medical University, Fujian Key Laboratory for Prenatal Diagnosis and Birth Defect, Fuzhou City, Fujian Province, 350001, People’s Republic of China
- School of Clinical Medicine, Fujian Medical University, Fuzhou City, Fujian Province, 350122, People’s Republic of China
| | - Liangpu Xu
- Fujian Maternity and Child Health Hospital, Affiliated Hospital of Fujian Medical University, Fujian Key Laboratory for Prenatal Diagnosis and Birth Defect, Fuzhou City, Fujian Province, 350001, People’s Republic of China
| | - Na Lin
- Fujian Maternity and Child Health Hospital, Affiliated Hospital of Fujian Medical University, Fujian Key Laboratory for Prenatal Diagnosis and Birth Defect, Fuzhou City, Fujian Province, 350001, People’s Republic of China
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Levy B, Hoffmann ER, McCoy RC, Grati FR. Chromosomal mosaicism: Origins and clinical implications in preimplantation and prenatal diagnosis. Prenat Diagn 2021; 41:631-641. [PMID: 33720449 DOI: 10.1002/pd.5931] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 03/03/2021] [Accepted: 03/06/2021] [Indexed: 12/18/2022]
Abstract
The diagnosis of chromosomal mosaicism in the preimplantation and prenatal stage is fraught with uncertainty and multiple factors need to be considered in order to gauge the likely impact. The clinical effects of chromosomal mosaicism are directly linked to the type of the imbalance (size, gene content, and copy number), the timing of the initial event leading to mosaicism during embryogenesis/fetal development, the distribution of the abnormal cells throughout the various tissues within the body as well as the ratio of normal/abnormal cells within each of those tissues. Additional factors such as assay noise and culture artifacts also have an impact on the significance and management of mosaic cases. Genetic counseling is an important part of educating patients about the likelihood of having a liveborn with a chromosome abnormality and these risks differ according to the time of ascertainment and the tissue where the mosaic cells were initially discovered. Each situation needs to be assessed on a case-by-case basis and counseled accordingly. This review will discuss the clinical impact of finding mosaicism through: embryo biopsy, chorionic villus sampling, amniocentesis, and noninvasive prenatal testing using cell-free DNA.
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Affiliation(s)
- Brynn Levy
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, New York, USA
| | - Eva R Hoffmann
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Rajiv C McCoy
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Francesca R Grati
- Research and Development, Cytogenetics and Medical Genetics Unit, TOMA Advanced Biomedical Assays, S.p.A. (Impact Lab), Busto Arsizio, Varese, Italy
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Ma N, Xi H, Chen J, Peng Y, Jia Z, Yang S, Hu J, Pang J, Zhang Y, Hu R, Wang H, Liu J. Integrated CNV-seq, karyotyping and SNP-array analyses for effective prenatal diagnosis of chromosomal mosaicism. BMC Med Genomics 2021; 14:56. [PMID: 33632221 PMCID: PMC7905897 DOI: 10.1186/s12920-021-00899-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 02/09/2021] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Emerging studies suggest that low-coverage massively parallel copy number variation sequencing (CNV-seq) more sensitive than chromosomal microarray analysis (CMA) for detecting low-level mosaicism. However, a retrospective back-to-back comparison evaluating accuracy, efficacy, and incremental yield of CNV-seq compared with CMA is warranted. METHODS A total of 72 mosaicism cases identified by karyotyping or CMA were recruited to the study. There were 67 mosaic samples co-analysed by CMA and CNV-seq, comprising 40 with sex chromosome aneuploidy, 22 with autosomal aneuploidy and 5 with large cryptic genomic rearrangements. RESULTS Of the 67 positive mosaic cases, the levels of mosaicism defined by CNV-seq ranged from 6 to 92% compared to the ratio from 3 to 90% by karyotyping and 20% to 72% by CMA. CNV-seq not only identified all 43 chromosomal aneuploidies or large cryptic genomic rearrangements detected by CMA, but also provided a 34.88% (15/43) increased yield compared with CMA. The improved yield of mosaicism detection by CNV-seq was largely due to the ability to detect low level mosaicism below 20%. CONCLUSION In the context of prenatal diagnosis, CNV-seq identified additional and clinically significant mosaicism with enhanced resolution and increased sensitivity. This study provides strong evidence for applying CNV-seq as an alternative to CMA for detection of aneuploidy and mosaic variants.
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Affiliation(s)
- Na Ma
- Department of Medical Genetics, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, Hunan, China
| | - Hui Xi
- Department of Medical Genetics, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, Hunan, China
| | - Jing Chen
- Department of Medical Genetics, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, Hunan, China
| | - Ying Peng
- Department of Medical Genetics, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, Hunan, China
| | - Zhengjun Jia
- Department of Medical Genetics, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, Hunan, China
| | - Shuting Yang
- Department of Medical Genetics, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, Hunan, China
| | - Jiancheng Hu
- Department of Medical Genetics, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, Hunan, China
| | - Jialun Pang
- Department of Medical Genetics, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, Hunan, China
| | - Yanan Zhang
- Department of Medical Genetics, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, Hunan, China
| | - Rong Hu
- Department of Medical Genetics, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, Hunan, China
| | - Hua Wang
- Department of Medical Genetics, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, Hunan, China.
- National Health Commission Key Laboratory of Birth Defects Research, Prevention and Treatment, Changsha, 410008, Hunan, China.
| | - Jing Liu
- Department of Medical Genetics, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, Hunan, China.
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Zhang Y, Zhong M, Zheng D. Chromosomal mosaicism detected by karyotyping and chromosomal microarray analysis in prenatal diagnosis. J Cell Mol Med 2020; 25:358-366. [PMID: 33201576 PMCID: PMC7810963 DOI: 10.1111/jcmm.16080] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 10/18/2020] [Accepted: 10/25/2020] [Indexed: 01/02/2023] Open
Abstract
To investigate the incidence and clinical significance of chromosomal mosaicism (CM) in prenatal diagnosis by G‐banding karyotyping and chromosomal microarray analysis (CMA). This is a single‐centre retrospective study of invasive prenatal diagnosis for CM. From 5758 karyotyping results and 6066 CMA results, 104 foetal cases with CM were selected and analysed further. In total, 50% (52/104) of foetal cases with CM were affected by ultrasound‐detectable phenotypes. Regardless of whether they were singleton or twin pregnancies, isolated structural defects in one system (51.35%, 19/37 in singletons; 86.67%, 13/15 in twins) and a single soft marker (18.92%, 7/37 in singletons; 13.33%, 2/15 in twins) were the most common ultrasound anomalies. Mosaic autosomal trisomy (19.23%, 20/104) was the most frequent type, and its rate was higher in phenotypic foetuses (28.85%, 15/52) than in non‐phenotypic foetuses (9.62%, 5/52). There was no difference in mosaic fractions between phenotypic and non‐phenotypic foetuses based on specimen sources or overall classification. Discordant mosaic results were observed in 16 cases (15.38%, 16/104) from different specimens or different testing methods. Genetic counselling and clinical management regarding CM in prenatal diagnosis remain challenging due to the variable phenotypes and unclear significance. Greater caution should be used in prenatal counselling, and more comprehensive assays involving serial ultrasound examinations, different specimens or testing methods verifications and follow‐up should be applied.
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Affiliation(s)
- Yi Zhang
- Department of Obstetrics and Gynecology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Mei Zhong
- Department of Obstetrics and Gynecology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Dezhong Zheng
- Department of Cardiology, Third Affiliated Hospital of Southern Medical University, Southern Medical University, Guangzhou, China
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