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Objective: We aimed to investigate the value of exome sequencing (ES) in fetuses with callosal anomalies (CA) with or without other structural anomalies, but with normal findings by karyotyping and chromosome microarray analysis (CMA)., Methods: Cases with CA with or without other structural anomalies were screened for eligibility. Fetuses with abnormal karyotyping or CMA results were excluded. We performed ES on DNA samples from eligible fetus-parental trios and identified diagnostic genetic variants based on the ultrasonographic features., Results: A total of 50 eligible fetus-parental trios were successfully analyzed by ES. We found 17 likely pathogenic or pathogenic variants in 14 genes from 17 fetuses, with a total proportion of diagnostic genetic variants equal to 34.0% (17/50). Of the 17 cases with a diagnosis, 10 (29.4%, 10/35) were isolated and 7 (43.8%, 7/15) were non-isolated. Pregnancy outcome data showed that 70.0% (7/10) of the surviving isolated CA fetuses with negative ES results had a good prognosis in early childhood., Conclusions: Our study used ES prenatally for CA and showed that ES can be used diagnostically to define the molecular defects that underlie unexplained CA. Most subjects with isolated CA with negative results for genetic causes will have a favorable prognosis in early childhood., (© 2022 John Wiley & Sons Ltd.)

Objective: In this study, we report the indications for prenatal cytogenetic diagnosis of triploid cases, in an attempt to identify clues to early diagnosis., Study Design: This was a retrospective analysis of prenatal cases of triploidy during a 9-year period at mainland China. Clinical data were reviewed for these cases, including maternal demographics, indications for invasive testing, fetal ultrasound findings, and pregnancy outcomes., Results: A total of 22 singleton pregnancies affected with triploid fetuses were detected. The fetal karyotype included 69,XXX (72.7%) and 69,XXY (27.3%). Eighteen cases were identified by the first trimester screening program. One case was missed by maternal cell-free DNA testing, but detected by second trimester anatomy scan. Three cases escaped the first trimester screening and were detected by second trimester anatomy scan., Conclusions: The present study demonstrates that most triploid cases can be diagnosed prenatally during the first trimester. The early asymmetrical fetal growth restriction, structural anomalies, and extremely high risk serum screening result for trisomy 21 or 18 should alert the physicians to the investigation of triploidy., Key Message: Ultrasound-based first-trimester screening plays a major role in early diagnosis of fetal triploidy. Future replacement of routine first-trimester screening by cell-DNA testing might miss the chance of early diagnosis and management of triploid pregnancies.

The genetic diagnosis of congenital heart defects (CHDs) is challenging because of genetic and phenotypic heterogeneity. The aim of our study was to evaluate the clinical value of whole exome sequencing (WES) in the prenatal diagnosis of CHDs in a large cohort. Trio-based WES was performed in 260 fetuses with CHDs negative for karyotype and chromosome microarray analysis results. WES produced a diagnostic yield of 10% (26/260) in the entire cohort. Relative high diagnostic rate was observed in cases with cardiac rhabdomyoma (60%), complex CHDs (16.7%), septal defect (14.0%), and conotruncal defect (9.9%). There was no significant difference between the diagnostic yields in simple and complex CHDs groups (9.9% vs 16.7%), and in non-isolated and isolated CHDs groups (15.7% vs 7.9%). The diagnostic yields in cases with CHDs with soft markers, CHDs with fetal growth restriction, and CHDs with other structural anomalies (syndromic CHDs) were 0 (0/13), 50% (1/2) and 18.2% (10/55), respectively. Variants of unknown significance were detected in 16 (6.2%) fetuses, and secondary findings in 7 (2.7%) cases. Variants in 14 candidate genes were identified. Our study demonstrates an incremental diagnostic yield by trio-based WES in the prenatal diagnosis of CHDs after routine tests, not as high as expected., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Thalassemia is a great health burden in mainland China. Carrier screening and prenatal diagnosis (PND) are essential for its prevention. The aim of this study was to describe the trend in the timing of PND for thalassemia in at-risk families in mainland China. All women who were at-risk for thalassemia and received PND at a mainland Chinese tertiary obstetric center between 2011 and 2019 were included. Information required for the survey was obtained from the database of the institute. In total, 4045 women underwent PND for thalassemia, including 1720 for β-thalassemia (β-thal) and 2325 for α-thalassemia (α-thal). The median gestational age for the PND procedure was 13 weeks. The number of PNDs performed increased year by year over this period. For both β-thal and α-thal, the proportion of women undergoing early PND also increased along with the time span. A total of 428 cases was diagnosed prenatally to be affected with β-thal major (β-TM) and 769 were affected with Hb Bart's disease. Most of the β-TM pregnancies and all of the Hb Bart's disease pregnancies were terminated. With the implementation of effective screening measures, births of affected infants have been dramatically avoided, and early PND has become the main approach, thus allowing the possibility of obtaining results at an earlier stage of pregnancy.

Objective: The aim of this study is to review our institution's experience with fetal cardiac rhabdomyoma, and to document the prenatal genetic testing for tuberous sclerosis complex (TSC) and clinical outcome of the affected pregnancies., Study Design: During a four-year period, patients with fetal cardiac rhabdomyoma were detected by echocardiography in the second trimester of pregnancy. Molecular genetic analysis was conducted on fetuses to screen for variants of TSC1/TSC2 genes. We reviewed medical records of these affected pregnancies, including maternal demographics, sonographic findings, genotyping results and pregnancy outcomes., Results: Eleven cases with fetal cardiac rhabdomyoma were studied during the study period. A pathogenic variant of TSC1/TSC2 genes was detected in all cases, including two with an inherited variant and nine with a de novo variant. Out of these eleven cases diagnosed prenatally, eight pregnancies were terminated and three continued till term., Conclusions: Cardiac rhabdomyoma is the prenatal sign of TSC. A molecular investigation of TSC1/TSC2 genes should be recommended for fetuses with a rhabdomyoma and the parents, and the prognostic counselling should include TSC and its consequences., (Copyright © 2020 Elsevier B.V. All rights reserved.)

A female of Chinese origin carried the codon 43 (G>T) ( HBB : c.130G > T) and codons 71/72 (+A) ( HBB : c.216_217insA) mutations of the β-globin gene in cis , identified during prenatal thalassemia screening. The double in cis mutations were inherited from her mother. Both of the two carriers behave as a traditional heterozygote for β-thalassemia (β-thal) with microcytosis and a high Hb A 2 level. This case report indicates that the possibility of multiple mutations in cis in a fetus with thalassemia trait has to be considered in a prenatal screening program.

Objective: To estimate cost efficacy of first-trimester screening strategies based on nuchal translucency (NT) and maternal blood cell-free DNA (cfDNA) testing in women with advanced maternal age (AMA)., Materials and Methods: This was a retrospective population-based analysis of all pregnant women with AMA booked for combined first-trimester screening (cFTS) in China over a 3-year period. The assumed screening strategies were the following: cFTS (Strategy 1), cfDNA testing as a first-tier investigation replacing biomarkers after NT measurement (Strategy 2), and cfDNA testing combined with dating ultrasound for all women (Strategy 3). The direct costs were compared between strategies., Results: Strategy 1 was completed in 6443 women with AMA. The respective detection rates were 94.5% and 90.9% for trisomies 21 and 18, with a total screen-positive rate of 13.5%. Such a policy resulted in 871 invasive tests and a total cost of $747,870 or a cost of $116 per person tested. Strategy 2 would result in a total cost of $1,812,570, or a cost of $281 per person tested, with increased detection rates for trisomies 21 and 18, and a decreased number of invasive tests compared with strategy 1. The total cost of Strategy 3 would be $1,675,430, or a cost of $260 per person tested with the least number of invasive tests., Conclusion: The cfDNA modalities have the advantages of higher detection rate for common trisomies and lower screening-positive rate. However, the cost of cfDNA testing needs to decrease significantly if it is to replace the current cFTS practice in a population of AMA on a purely cost effectiveness basis., (Copyright © 2018. Published by Elsevier B.V.)

Objective: To present the experience on prenatal diagnosis of Wolf-Hirschhorn syndrome (WHS) to further delineate the fetal presentation of this syndrome., Study Design: This was a retrospective analysis of ten pregnancies with fetal WHS identified by chromosomal microarray (CMA). Clinical data were reviewed for these cases, including maternal demographics, indications for invasive testing, sonographic findings, CMA results and pregnancy outcomes., Results: Three cases were diagnosed at the first trimester because of an increased NT or cystic hygroma. The remaining seven cases were identified at late gestation for abnormal ultrasound findings. CMA revealed 4p deletions to be terminal in all of the ten cases. Deletion sizes ranged from 2.05 to 19.02 Mb., Conclusion: Prenatal findings such as increased NT, severe and early onset intrauterine growth retardation, and renal dysplasia or oligohydramnios should warrant the diagnosis of WHS and invasive testing using CMA., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Objective: To explore the genetic etiology of fetuses with ventricular septal defects (VSD) using chromosomal microarray analysis (CMA)., Methods: A total of 248 fetuses were divided into isolated VSD group, VSD with other cardiac and/or great vessels malformation group, VSD with extra-cardiac anomalies group (including malformation and sonographic soft markers), and VSD with both cardiac and extra-cardiac anomalies group. Standard karyotyping was carried out for all fetuses, and CMA was performed for 6 fetuses with an abnormal karyotype and a proportion of fetuses with a normal karyotype. All cases were followed up, and neonates were followed up until 1 year of age., Results: Chromosomal abnormalities were identified in 60 (24.2%) of the 248 fetuses. For 6 of the fetuses subjected to further CMA analysis, the origin of abnormal chromosomes were clarified, among which 2 have overlapped with the critical region of Wolf-Hirschhorn syndrome. Candidate genes for VSD included WHSC1, LBX1, LDB3 and BBS10. For 143 fetuses with a normal karyotype, CMA has identified pathogenic copy number variations (CNVs) in 11 cases (7.7%). These included 9 well-known microdeletion or microduplication syndromes, including 22q11.2 microdeletion, 17p11.2 microdeletion (Smith-Magenis syndrome), 17p13.3 microdeletion (Miller-Dieker syndrome), 1p36 microdeletion, 1q21.1 microduplication and 4q deletion. Candidate genes for VSD included TBX1, LZTR1, FAT1, AKAP10, SKI, PRDM26, GJA5, ERCC4 and YWHAE. For 48.7% of the fetuses with benign CNVs, spontaneously closure has occurred within the first year of life., Conclusion: CMA may increase the detection rate of submicroscopic imbalances by 7.7%. No significant correlation between different groups of VSD and the pathogenic CNVs was observed. Whole-genome CMA should be recommended to the fetuses with VSD but a normal karyotype. Nearly half of VSDs with benign CNVs may close spontaneously within the first year of life.

Objective: We describe the changes over a 4-year period in the number of diagnostic testing after the introduction of non-invasive prenatal testing (NIPT)., Methods: The rate of NIPT as an indication in women who received amniocentesis, and the number of amniocentesis required for detection of one case with major aneuploidy were compared between a 1-year baseline period before the introduction of NIPT, and the 3 years following NIPT introduction., Results: A total of 7536 amniocentesis procedures were performed over the 4-year study period. During the baseline period of the year 2011, the number of invasive testing required for detection of one common trisomy was 57. During the first 2 years that NIPT was offered, NIPT averaged 1.7 percent of the total indications for amniocentesis, and the required number of invasive testing decreased to 30. With the increase of the percentage of NIPT during the 3rd year, the required number of invasive testing further decreased to 26., Conclusion: After the clinical introduction of NIPT, invasive prenatal diagnostic testing had not decreased at a Chinese prenatal diagnostic unit, but a remarkably improved detection rate of major aneuploidies in diagnostic procedures was observed.

Objective: To report the strategy of first-trimester aneuploidy screening in pregnancies at risk for homozygous α(0)-thalassemian., Methods: Women at risk of homozygous α(0)-thalassemia were given an ultrasound examination at 11-14 weeks' gestation to exclude an affected pregnancy. Fetal cardiothoracic ratio (CTR) and nuchal translucence (NT) were measured. If cardiomegaly was found, chorionic villus sampling (CVS) was offered for α-thalassemia; otherwise the first-trimester combined screening test was performed on the pregnancy. The invasive testing for karyotyping was only followed in those cases with a positive aneuploidy screening test., Results: In total, 69 of 288 pregnancies were found to be affected by homozygous α(0)-thalassemia using ultrasound, and the findings were confirmed by invasive testing. In the remaining 219 pregnancies, invasive testing was not performed for α-thalassemia because of a normal fetal CTR, and the women received the first-trimester combined screening. Nine CVS procedures were performed for karyotyping because of a positive aneuploidy screening. Totally three pregnancies with aneuploidy were diagnosed and terminated., Conclusions: Our strategy can selectively detect aneuploidy pregnancies not affected by homozygous α-thalassemia, and, meanwhile, save on the cost of unnecessary aneuploidy screening or karyotyping in pregnancies with an affected fetus of homozygous α(0)-thalassemia.

Objective: To assess the value of whole-genome high-resolution chromosome microarray analysis (CMA) for the investigation of fetuses with ultrasound abnormalities., Methods: Whole genome high-resolution CytoScanHD array from Affymetrix was employed to investigate 651 fetuses with structural abnormalities detected by ultrasound, for whom standard G-banded chromosome analysis has revealed a normal karyotype. The fetuses were divided into a single malformation group (n=264) and a multiple malformations group (n=387). In total there were 130 chorionic villus samples, 192 amniotic fluid samples and 329 cord blood samples. Extraction of fetal DNA and CMA experiment have followed the standard guidelines from the manufacturers. All copy number variations (CNVs) detected by CMA were confirmed by fluorescence in situ hybridization (FISH) or real-time polymerase chain reaction (RT-PCR)., Results: CMA analysis has detected genomic CNVs in 475 (73%) cases. Clinically significant CNVs were found in 11.5% (75/651) of fetuses, including two uniparental disomies (UPD) and two cryptic mosaicisms. Variations of unknown significance (VOUS) was found in 2.0% (13/651) of tested fetuses., Conclusion: Above results have suggested that whole-genome and high-resolution CMA is valuable for the analysis of fetuses with structural abnormalities detected by ultrasound, which can increase the detection rate by approximately 11%. CMA using single nucleotide polymorphism (SNP) array has the ability to detect UPD and low-level mosaicisms. Sufficient communication between technicians and genetic counselors, parental testing and comparison the results with in-house and relevant online databases can significantly reduce the rate of VOUS.

MECP2 duplication results in a well-recognised syndrome in 100% of affected male children; this syndrome is characterised by severe neurodevelopmental disabilities and recurrent infections. However, no sonographic findings have been reported for affected foetuses, and prenatal molecular diagnosis has not been possible for this disease due to lack of prenatal clinical presentation. In this study, we identified a small duplication comprising the MECP2 and L1CAM genes in the Xq28 region in a patient from a family with severe X-linked mental retardation and in a prenatal foetus with brain structural abnormalities. Using high-resolution chromosome microarray analysis (CMA) to screen 108 foetuses with congenital structural abnormalities, we identified additional three foetuses with the MECP2 duplication. Our study indicates that ventriculomegaly, hydrocephalus, agenesis of the corpus callosum, choroid plexus cysts, foetal growth restriction and hydronephrosis might be common ultrasound findings in prenatal foetuses with the MECP2 duplication and provides the first set of prenatal cases with MECP2 duplication, the ultrasonographic phenotype described in these patients will help to recognise the foetuses with possible MECP2 duplication and prompt the appropriate molecular testing., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Introduction: CHARGE syndrome is an autosomal dominant genetic disorder with known pattern of features. The aim of the study was to present the fetal features of CHARGE syndrome to gain awareness that the antenatal characteristics can be very nonspecific. Case Presentation: This was a retrospective study of 13 cases with CHARGE syndrome diagnosed by prenatal or postnatal genetic testing and physical examination. Two (15.4%; 2/13) had normal ultrasound scans during pregnancy. One (7.7%; 1/13) with first-trimester cystic hygroma presented intrauterine fetal demise at 16 weeks gestation. The remaining 10 (76.9%; 10/13) cases had abnormal ultrasound features in utero; among these, 1 had an increased nuchal translucency in the first trimester, 5 had second-trimester abnormal ultrasounds including micrognathia, cardiac defects, and facial defects, and 4 third-trimester abnormal ultrasounds including micrognathia, isolated fetal growth restriction, and polyhydramnios. Among the 11 cases with abnormal prenatal ultrasound scans, no fetus could reach the diagnostic criteria of CHARGE syndrome if only based on the results of ultrasound. However, the diagnosis was made in all cases when CHD7 defects were detected. Discussion/Conclusion: The CHARGE syndrome presents non-specific abnormal ultrasound markers in utero. Exome sequencing in the genetic workup will aid in prenatal diagnosis of this syndrome. [ABSTRACT FROM AUTHOR]

To analyze the risk for genetic aberrations and pregnancy outcomes in pregnancies with isolated polyhydramnios. This was a retrospective study of singleton pregnancies complicated by isolated polyhydramnios that underwent genetic amniocentesis between 2016 and 2021. Clinical and laboratory data were collected and reviewed for these cases, including maternal demographics, prenatal sonographic findings, chromosomal microarray results, and pregnancy outcomes. A total of 94 singleton pregnancies were included. Three (3.2%) cases with chromosomal abnormalities were detected, including 2 case of trisomy 21 and 1 of 22q21.1 microdeletion. One case was diagnosed as Prader-Willi syndrome caused by maternal uniparental disomy of chromosome 15. Perinatal death occurred in 1 case with severe polyhydramnios, and was retrospectively diagnosed as Bartter syndrome. Of the 90 infants survived, two were identified to have single gene disorders after birth by whole exome sequencing. We first attempted to determine the value of exome sequencing in pregnancies with isolated polyhydramnios. Our results warrant more studies to evaluate advanced genetic testing technologies used in such pregnancies. [ABSTRACT FROM AUTHOR]

To present the prenatal features and postnatal outcomes of pregnancies with fetal nemaline myopathy (NM). This was a retrospective study of nine cases with NM diagnosed by prenatal or postnatal clinical features and confirmed by genetic testing. Clinical and laboratory data were collected and reviewed for these cases, including maternal demographics, prenatal sonographic findings, exome sequencing (ES) results, and pregnancy outcomes. All of the nine cases were detected to have NM-causing variants, involving NEB gene in 2 cases, ACTA1 in 3 cases, KLHL40 in 3 cases, and TPM2 in 1 case. Almost all (8/9) had normal first-trimester ultrasound scans except one who had an increased nuchal translucency. Seven (7/9) cases had second-trimester abnormal ultrasounds with fetal akinesia and/or extremity anomalies. Two (2/9) had only third-trimester abnormal ultrasounds with fetal akinesia and polyhydramnios, with one combined with fetal growth restriction. Four pregnancies with a positive prenatal ES were terminated, while five having not receiving prenatal ES continued to term. Only one infant survived 1 year old, and four passed away within 12 months. Prenatal ultrasound can detect clues that lead to the diagnosis of NM, such as reduced or absent fetal movements, polyhydramnios and extremity anomalies. [ABSTRACT FROM AUTHOR]

Congenital diaphragmatic hernia (CDH) is a birth defect that can be caused by genetic syndromes. In this study, a case of CDH diagnosed in the first trimester of pregnancy was reported. Exome sequencing (ES) was used to determine the genetic cause of the CDH, and a variant in the ARID2 gene associated with Coffin-Siris syndrome (CSS) type 6 was identified. The study highlights the importance of early diagnosis of CDH and suggests that genetic testing, including ES, should be considered in the evaluation of fetuses with CDH. However, ES is not recommended as a routine test in early pregnancy. [Extracted from the article]

A global survey indicates that genetic syndromes affect approximately 8% of the population, but most genetic diagnoses can only be performed after babies are born. Abnormal facial characteristics have been identified in various genetic diseases; however, current facial identification technologies cannot be applied to prenatal diagnosis. We developed Pgds-ResNet, a fully automated prenatal screening algorithm based on deep neural networks, to detect high-risk fetuses affected by a variety of genetic diseases. In screening for Trisomy 21, Trisomy 18, Trisomy 13, and rare genetic diseases, Pgds-ResNet achieved sensitivities of 0.83, 0.92, 0.75, and 0.96, and specificities of 0.94, 0.93, 0.95, and 0.92, respectively. As shown in heatmaps, the abnormalities detected by Pgds-ResNet are consistent with clinical reports. In a comparative experiment, the performance of Pgds-ResNet is comparable to that of experienced sonographers. This fetal genetic screening technology offers an opportunity for early risk assessment and presents a non-invasive, affordable, and complementary method to identify high-risk fetuses affected by genetic diseases. Additionally, it has the capability to screen for certain rare genetic conditions, thereby enhancing the clinic's detection rate. [ABSTRACT FROM AUTHOR]

PPP2R1A-related neurodevelopmental disorder (NDD) is expressed with autosomal dominant inheritance and is typically caused by a pathogenic de novo PPP2R1A mutation. It is characterized by the predominant features of hypotonia, developmental delay, moderate-to-severe intellectual disability, agenesis of corpus callosum (ACC), ventriculomegaly, and dysmorphic features; however, none of these anomalies have been diagnosed prenatally. We report on the prenatal diagnosis of PPP2R1A-related NDD in two fetuses by whole exome sequencing. Fetus 1 had partial ACC and severe lateral ventriculomegaly; the pathogenic heterozygous c.544C > T (p. Arg182Trp) de novo missense variant in PPP2R1A was detected. Fetus 2 had severe enlargement of the lateral and third ventricles and macrocephaly; they showed a heterozygous likely pathogenic mutation in PPP2R1A gene (c.547C > T, p. Arg183Trp). Both variants were de novo. This was the first study to use trio WES to prenatally analyze fetuses with PPP2R1A variants. Prenatal diagnosis will not only expand the fetal phenotype of this rare genetic condition but also allow for an appropriate counseling of prospective parents regarding pregnancy outcomes. [ABSTRACT FROM AUTHOR]

Objective: SHOX haploinsufficiency have been commonly found in isolated short stature (ISS) and Léri–Weill dyschondrosteosis (LWD) patients. However, few publications have described the genetic analysis and clinical characteristics of fetuses with SHOX haploinsufficiency. Methods: Chromosomal microarray (CMA) were applied in 14,051 fetuses and sequentially whole exome sequence (WES) in 1340 fetuses who underwent prenatal diagnosis during 2016–2021. The analysis and summary of molecular genetics, sonographic characteristics, and follow-up results were performed in fetuses with SHOX haploinsufficiency without other genetic etiologies. A comparison was made between three groups according to prenatal diagnostic indications. Results: 8 (0.06%) fetuses of SHOX haploinsufficiency were all detected by CMA, of which 5 (62.5%) were detected with short long bones by ultrasound scan, and 4 were inherited from their previously undiagnosed parents. No pathogenic SHOX variants were found by WES. The detection rate of SHOX haploinsufficiency was obviously higher in the short long bone group (2.6%, 5/191) than the other abnormality group (0.03%, 1/3919) or no ultrasound abnormality group (0.02%, 2/9941). Three of the fetuses were liveborn with normal growth up to the age of four and four were terminated. Conclusion: The phenotype of fetuses with SHOX haploinsufficiency is highly varied. Over 1/3 of the cases exhibited no phenotype and nearly 2/3 with short long bones, in the absence of Madelung deformity during fetal development. SHOX haploinsufficiency should be considered in all antenatal presentations, especially in the case of isolated short long bones. CMA can provide effective detection. [ABSTRACT FROM AUTHOR]

The aim of this study was to present prenatal ultrasound findings, molecular testing results and pregnancy outcomes of cases with 22q11.2 deletion (del22q11.2) diagnosed prenatally. A total of 76 foetuses were included. All cases were diagnosed by using chromosomal microarray analysis. Data on prenatal diagnosis, ultrasound findings, pregnancy outcomes and inheritance of del22q11.2 were reviewed. Congenital heart defects (CHDs) were the most common indications (47/76, 61.8%) for prenatal testing and were isolated in 52.6% (40/76). The constitution of CHDs comprised predominantly of conotruncal defects (61.7%; 29/47). Other cardiac anomalies were encountered in 38.3% (18/47) of cases. Extracardiac findings, including unilateral multicystic dysplastic kidney, clubfoot, increased nuchal translucency, intrauterine growth retardation and polyhydramnios, were found in 31.6% (24/76) of cases, and were combined with CHDs in 7 cases. Twelve cases had normal sonographic scans at the time of prenatal diagnosis. Foetal CHDs, especially conotruncal defects, are the most predictive association with del22q11.2. The information about del22q11.2 should also be part of the contents in comprehensive pre-test counselling even for those who are referred for diagnostic testing with foetal extracardiac findings. What is already known on this subject? 22q11.2 deletion (del22q11.2) is the most common microdeletion syndrome in humans. At present, the main indications for prenatal testing for del22q11.2 are pregnancies of abnormal sonographic findings, especially foetal congenital heart defects. What do the results of this study add? Many extracardiac malformations, including some lethal or mildly non-specific ones, could be associated with foetal del22q11.2. There were also del22q11.2 foetuses had normal sonographic scans at the time of prenatal diagnosis. What are the implications of these findings for clinical practice and/or further research? The information about del22q11.2 should also be part of the contents in comprehensive pre-test counselling even for those who are referred for diagnostic testing with indications other than foetal cardiac anomalies. [ABSTRACT FROM AUTHOR]

Introduction Kabuki syndrome (KS) is a multiple congenital anomaly syndrome with characterized facial features. The aim of study was to report on prenatal sonographic findings associated with KS in six Chinese families. Case Presentation During the study period, 7 families of KS were diagnosed. Variants of KMT2D were detected in 4 cases, and variants of KDM6A in 3 cases. For cases with KMT2D variants, cleft palate was the only finding on second trimester ultrasound in 2 cases. One case presented with polyhydramnios in late third trimester. One case showed ventricular septal defect and renal anomaly at 22 weeks gestation. For cases with KDM6A variants, one was detected at 22 weeks to have coarctation of the aorta. One presented with third-trimester intrauterine growth restriction. The other with hypoplastic left heart had a maternal KDM6A variant c.1227_1228del. Further family study showed that this variant was also present in the healthy maternal mother, but not in the healthy maternal father and two maternal brothers. The two female carriers were healthy. Discussion/Conclusion Although there is no specific ultrasound feature which has both a high sensitivity and high positive predictive value for KS, this disorder should be considered as a differential diagnosis in fetuses with congenital anomalies including polyhydramnios with normal karyotyping/microarray analysis. [ABSTRACT FROM AUTHOR]

Background: There are few studies on the detection rate by chromosomal microarray analysis (CMA) of the prenatal diagnosis of talipes equinovarus (TE) compared to conventional karyotyping. We aimed to explore the molecular etiology of fetal TE and examine the detection rate by CMA, which provides more information for the clinical screening and genetic counseling of TE. Methods: In this retrospective study, pregnancies diagnosed with fetal TE were enrolled and clinical data for all cases were retrieved from our medical record database, including demographic data for pregnancies, ultrasound findings, karyotype/CMA results, and pregnant and perinatal outcomes. Results: Among the 164 patients, 17 (10.4%) clinically significant variants were detected by CMA. In 148 singleton pregnancies, the diagnostic rate of clinically significant variants was significantly higher in the non-isolated TE group than in the isolated TE group (10/37, 27.0% vs. 6/111, 5.4%, P < 0.001). In twin pregnancies, 1 (6.3%) pathogenic copy number variant was present in the other 16 twin pregnancies. Conclusions: This study demonstrates that CMA is useful for the prenatal genetic diagnosis of fetal TE. Fetal TE with the associated structural malformation correlates with a higher probability of clinically significant variants. This data may aid prenatal diagnosis and genetic counseling for fetal TE. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study is to evaluate the impact of the utility of maternal cell-free DNA (cfDNA) on the number of chorionic villus sampling (CVS) at a mainland Chinese maternal hospital.Methods: This was a retrospective cohort study conducted in consecutive singleton pregnancies that underwent CVS between the 11th and 14th gestational weeks at a Chinese maternal hospital during a nine-year period. The indications, complications and prenatal diagnosis results were evaluated.Results: This study consisted of 5108 CVS procedures, including 2000 performed for fetal karyotyping, and 3108 performed for fetal single-gene genotyping. During the period with the introduction of cfDNA, the proportion of the number of CVS procedures for the indication of positive serum screening declined significantly, and abnormal ultrasound was the main indication for CVS performed for fetal karyotyping. Thalassemia was always the main indication for CVS, accounting for 50.5% of all CVS cases.Conclusions: cfDNA has changed the spectrum of CVS indications. CVS is now the invasive procedure performed for patients with a fetus having a very high risk of fetal genetic defects, including fetuses having major abnormal ultrasound or having a risk of single-gene disorder inherited from their parents. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the utility of a chromosomal microarray (CMA) in fetuses with isolated fetal growth restriction (FGR) and explore risk factors for the prediction of chromosomal aberration and perinatal adverse outcomes. Method: This study included 271 fetuses of estimated fetal weight less than the 3rd percentile without other structural malformation. Early-onset and late-onset FGR were defined as gestational weeks less than 32 weeks and more than 32 weeks respectively. These patients underwent quantitative fluorescent polymerase chain reaction (QF-PCR) and CMA as the first-line genetic detection strategy. Chromosomal anomalies were compared after stratified analysis by the early-onset and the late-onset FGR, including the absence or presence of ultrasound soft markers, abnormal amniotic fluid, abnormal umbilical Doppler, and gestational disorders. The follow-up time was within 1 year after birth. Logistic regression was used to seek risk predictors of chromosomal aberration and perinatal adverse outcomes for isolated FGR. Results: The CMA identified clinically significant variants in 18/271 (6.6%) fetuses, and variants of unknown significance (VOUS) in 15/271 (5.5%) fetuses. Stratified analysis showed that there was a higher incidence of clinically significant variants in fetuses with the early-onset FGR compared with late-onset FGR (8.7%, 17/195 vs. 1.3%, 1/76, p < 0.05). Regression analysis showed that early gestational age (GA) at diagnosis of FGR was the major risk factor for chromosomal aberration (OR = 0.846). By variable regression analysis, early GA at diagnosis and decreased estimated fetal weight (EFW) percentile of suspicion of FGR, asymmetrical FGR, abnormal amniotic fluid, and severe preeclampsia could all increase the risk of adverse outcomes of isolated FGR including intra-uterine fetal death (IUFD), termination of pregnancy (TOP), and preterm birth in pregnancies with FGR. Conclusion: This study emphasized the value of microarrays for unbalanced genomic variants in fetuses with isolated FGR, especially since the gestational age of nullipara was less than 32 weeks. Perinatal adverse outcomes of isolated FGR were influenced by multiple factors including GA and estimated fetal weight (EFW) percentile of suspicion of FGR, asymmetrical FGR, abnormal amniotic fluid, and severe preeclampsia. [ABSTRACT FROM AUTHOR]

Transaldolase (TALDO) deficiency is a rare autosomal recessive disorder caused by variants in the TALDO1 gene that commonly results in multisystem dysfunction. Herein, we reported compound heterozygous variants in a Chinese prenatal case with TALDO deficiency using whole-exome sequencing (WES) for trios and Sanger sequencing. The heterozygous variants were located on the TALDO1 gene: NM_006755.2:c.574C > T(Chr11:g.763456C > T), a missense variant in exon 5 paternally inherited; NM_006755.2:c.462-2A > G(Chr11:g.763342A > G), a splicing aberration in intron 4 maternally inherited. The qualitative analysis of urinary polyols in neonatal urine indicated that xylitol + arabitol and ribitol in the proband's urine were significantly increased. These findings expand the variation spectrum of the TALDO1 gene, provide solid evidence for the counseling of the family in regard to future pregnancies, strongly support the application of WES in prenatal diagnosis, and further prove that effective postpartum treatments could improve prognosis. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the prognosis of fetuses with a prenatal diagnosis of micrognathia in the first trimester.Study Design: Over a 3-year period, patients with fetal micrognathia were detected at the time of nuchal translucency screening. The medical records of these pregnancies were reviewed, including maternal demographics, sonographic findings, genetic testing results and pregnancy outcomes.Results: Forty-three cases of first-trimester micrognathia were included in this study. Chromosomal abnormalities were detected in seven cases. Of the fetuses with a normal array, further investigation of monogenic disorders with whole-exome sequencing was undertaken in 13 cases. Monogenic syndromes were identified in eight cases, including six with de-novo dominant alleles and two with recessive conditions. Whole-exome sequencing was refused in 23 cases; among these, other additional anomalies were found on anatomic ultrasound in 10 cases.Conclusion: This study demonstrated that caution should be adopted when finding an apparently isolated micrognathia in early gestation, even with a normal array. A diagnosis of genetic syndrome or multiple anomalies on subsequent scans is most likely, and will affect the final prognosis. [ABSTRACT FROM AUTHOR]

Objective: Only a small number of reports have been made on the prenatal ultrasound findings observed in 1p36 deletion syndrome. We explored prenatal diagnosis of 1p36 deletion by ultrasound as well as chromosomal microarray (CMA), and delineated the fetal presentation of this syndrome.Study Design: This was a retrospective analysis of 10 new prenatal cases of 1p36 deletion identified by CMA at a single Chinese medical center. Clinical data were reviewed for these cases, including maternal demographics, indications for invasive testing, sonographic findings, CMA results and pregnancy outcomes.Results: One case was diagnosed because of a positive cell-free DNA (cfDNA) testing result for terminal 1p deletion, and the remaining nine cases were identified because of an abnormal ultrasound findings, including early miscarriage, structural abnormalities and fetal growth restriction. CMA revealed 1p36 deletions to be terminal in six cases, and interstitial in four cases. Deletion sizes ranged from 1.7 to 42.7 Mb.Conclusions: Prenatal findings such as cardiac malformations, especially Ebstein anomaly, and fetal growth retardation should warrant the diagnosis of 1p36 deletion and invasive genetic testing using CMA. [ABSTRACT FROM AUTHOR]

Objective: To evaluate whether cell-free DNA (cfDNA) testing could replace an invasive procedure in pregnancies with isolated fetal omphalocele.Study design: This was a retrospective study of all pregnancies with sonographically detected fetal omphalocele at three tertiary referral centers between 2012 and 2016. Invasive diagnostic testing was performed for genetic investigations using conventional karyotyping or chromosomal microarray. cfDNA testing was assumed to be offered to patients with isolated fetal omphalocele for screening for common aneuploidies.Results: Invasive genetic testing was performed in a total of 107 pregnancies with a fetal omphalocele. Abnormal karyotype was found in 66% (31/47) of nonisolated omphalocele cases and in 1.7% (1/60) of isolated omphalocele cases. No pathogenic copy number variations (CNVs) were detected in 59 cases with isolated omphalocele and normal karyotype. If cfDNA screening was used in cases with isolated omphalocele, the affected fetus with trisomy 18 would be detected, and no rare chromosomal aberrations or submicroscopic pathogenic CNVs would be missed.Conclusions: cfDNA testing could be recommended for prenatal genetic evaluation in pregnancies with isolated fetal omphalocele after thorough pretest counseling.Key Message: A very low percentage of aneuploidies and rare chromosomal/subchromosomal abnormalities are found in prenatal cases of isolated omphalocele. It seems that for pregnancies with isolated omphalocele, cfDNA testing represents an alternative for patients who choose to continue the pregnancies and are reluctant to undertake invasive diagnostic testing. [ABSTRACT FROM AUTHOR]

Objective: To report the experience with first-trimester prenatal detection of pregnancies complicated by trisomy 18. Study design: Proven cases of trisomy 18 identified between 11 and 14 weeks of gestation were retrospectively reviewed. Information on maternal demographics, prenatal sonographic findings, indications for prenatal diagnosis and chromosomal analysis results was obtained by reviewing medical records. Results: During the 7-year period from January 2011 to December 2017, 89 cases of full trisomy 18 had first-trimester indications for prenatal diagnosis at Guangzhou Women and Children's Medical Center. Eighty-five (95.5%) had abnormal sonographic findings in the first trimester. The most common finding was increased nuchal translucency (55.1%), followed by cystic hygroma (18.0%), omphalocele (14.6%), and fetalis hydrops (11.2%). Four cases (4.5%) were not associated with any abnormal first-trimester sonographic finding, and were diagnosed because of routine positive screening results for trisomy 18. A single case was diagnosed because of a positive cell-free DNA (cfDNA) result. Conclusion: These results demonstrate that a large number of fetuses with trisomy 18 have abnormal sonographic findings in the first trimester, and support the continued utility of first-trimester sonographic examination in the diagnosis of this trisomy even with the availability of cfDNA. [ABSTRACT FROM AUTHOR]

The aim of this study was to analyse the factors associated with fetal pleural effusion over the past five years in a single institute in the South of China. Between January 2011 and May 2016, 129 foetuses with pleural effusion were referred to the Fetal Medicine Unit in Guangzhou's Women and Children's Medical Center. Seventy-nine women accepted an invasive procedure to rule out chromosomal abnormalities, fetal anaemia, intrauterine infections or some of the submicroscopic chromosomal abnormalities. Our results showed that chromosomal anomalies occurred in 15.2% (12/79) of cases including 8 Turner syndrome (45, X) (10.1%), 3 trisomy 21 (3.8%) and 1 trisomy 13 (1.3%). Pathological microdeletion or microduplication syndrome occurred in 3 out of 36 (8.3%) prenatal samples with normal karyotype and structural defects. Eight foetuses (10.1%) affected with haemoglobin Bart's disease showed pleural effusion at second or third trimester. Two cases (2.5%) were found to have an intrauterine infection. In conclusion, fetal pleural effusion has a close correlation with chromosomal abnormality. CMA may increase the detection rate of chromosomal aberrations, especially for micro-deletion or micro-duplication syndromes. In the South of China, Thalassemia must be considered when a fetal pleural effusion is detected.Impact statementWhat is already known on this subject? The aetiology of fetal pleural effusion includes a chromosomal abnormality, a congenital heart disease, congenital infections and a number of genetic syndromes.What do the results of this study add? This is the first retrospective study to analyse the aetiology of fetal pleural effusion in one institute in the South of China.What are the implications of these findings for clinical practice and/or further research? Besides the chromosomal abnormality, micro-deletion and micro-duplication syndromes were also detected in our study. We feel that thalassemia must be considered when fetal pleural effusion is detected in South China. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study is to explore the utility of rapid medical trio exome sequencing (ES) for prenatal diagnosis using the skeletal dysplasia as an exemplar.Method: Pregnant women who were referred for genetic testing because of ultrasound detection of fetal abnormalities suggestive of a skeletal dysplasia were identified prospectively. Fetal samples (amniocytes or cord blood), along with parental blood, were send for rapid copy number variations testing and medical trio ES in parallel.Results: Definitive molecular diagnosis was made in 24/27 (88.9%) cases. Chromosomal abnormality (partial trisomy 18) was detected in one case. Sequencing results had explained the prenatal phenotype enabling definitive diagnoses to be made in 23 cases. There were 16 de novo dominant pathogenic variants, four dominant pathogenic variants inherited maternally or paternally, two recessive conditions with pathogenic variants inherited from unaffected parents, and one X-linked condition. The turnaround time from receipt of samples in the laboratory to reporting sequencing results was within 2 weeks.Conclusion: Medical trio ES can yield very timely and high diagnostic rates in fetuses presenting with suspected skeletal dysplasia. These definite diagnoses aided parental counseling and decision making in most of cases. [ABSTRACT FROM AUTHOR]

Introduction: Congenital diaphragmatic eventration (CDE) is defined as the abnormal elevation of the diaphragm, due to incomplete muscularization of the diaphragm with a thin membranous sheet replacing normal diaphragmatic muscle. Case report: We report a prenatal case with a diaphragmatic mesothelial cyst combined with CDE. Conclusion: A large cystic mass between the thoracic wall and the liver in early pregnancy is highly suggestive of cystic diaphragm. [ABSTRACT FROM AUTHOR]

The 17q12 deletion syndrome is a chromosomal anomaly resulting from the interstitial microdeletion of the long arm of chromosome 17. The aim of this study was to present the experience on prenatal diagnosis of 17q12 deletion to further define the prenatal phenotypes of this syndrome. Eleven pregnancies with foetal 17q12 deletion detected by chromosomal microarray (CMA) were retrospectively included at a single Chinese tertiary medical centre. Clinical data were reviewed for these cases, including the maternal demographics, foetal ultrasound findings, CMA results and pregnancy outcomes. The deletion sizes of 17q12 ranged from 1.42 to 1.94 Mb. The deletion had arisen de novo in 10 cases and inherited from one of the parents in one case. Variable kidney abnormalities were found by ultrasound in all of the cases, with bilateral or unilateral hyperechogenic kidneys being the most common findings. This study indicates that a strikingly high correlation between prenatal hyperechogenic kidneys and 17q12 deletion, and prenatal testing with CMA should be offered to the foetal cases of hyperechogenic kidneys. Impact statement What is already known on this subject? 17q12 deletion syndrome is a cause of renal abnormalities, maturity-onset diabetes of the young and neurodevelopmental disorders. Prenatal diagnosis has been reported in several isolated cases with the use of microarray-based technologic means. What do the results of this study add? The results provide further evidence that a strikingly high correlation between prenatal hyperechogenic kidneys and 17q12 deletion, and genetic testing should be offered to foetal cases with hyperechogenic kidneys. A rare prenatal case of 17q12 deletion with multiple structural malformations and anhydramnios is presented. What are the implications of these findings for clinical practice and/or further research? There should be a high index of suspicion of carriers in parents when 17q12 deletion is confirmed prenatally. An extremely wide phenotype spectrum of this deletion should be emphasised in the prenatal counselling. [ABSTRACT FROM AUTHOR]

Objective: To report the experience on the clinical use of noninvasive cell-free (cf) DNA testing at late pregnancy.Study Design: A cohort of 1539 women with singleton gestations of ≥23 weeks receiving cfDNA testing in a 3-year period were included for this study. Maternal characteristics and data on cfDNA testing, confirming diagnostic testing and pregnancy outcome were reviewed.Results: During the study period, 1539 patients had cfDNA testing although they had a normal first-trimester screening. Of these, 7 cases had a positive result, including 5 for chromosome 21, one for chromosome 18, and one for chromosome 13. The most common indication was soft markers on ultrasound, followed by polyhydramnios. Cytogenetic testing was done for the 5 trisomy 21 positive cases, and confirmed the cfDNA results. Confirmative testing was declined in the two cases with positive cfDNA for trisomy 18/13, and postnatal placental investigation showed confined placental mosaicism with normal karyotype in the cord blood of newborns. There were no confirmed false negatives reported. The cfDNA screening achieved a positive predictive value of 71.4 % and a negative predictive value of 100 % in late pregnancy for common trisomies.Conclusions: There is no gestational age upper limit for cfDNA use in the clinical practice. Most of the time, cfDNA was used in late gestation for reassurance in patients who is at low risk for aneuploidies but had second-trimester soft markers on ultrasound. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate which chromosomal abnormalities in our cohort of foetuses with increased nuchal translucency (NT) in the first trimester of pregnancy could be detected by cell free (cf)DNA screening as well. There were 775 singleton pregnancies referred for cytogenetic testing due to an increased NT (≥3.0 mm). Chromosome aberrations were investigated using karyotyping or chromosomal microarray analysis (CMA). Karyotyping had been chosen for foetal cytogenetic testing by 446 patients, and CMA by 329 patients. Common aneuploidies (trisomies 21, 18, 13 and sex aneuploidies) were detected in 2.2% (99/446) and 1.8% (59/329) cases, respectively. In 329 with CMA testing, clinically significant copy number variations (CNVs) other than common aneuploidies were detected in 2.7% cases; among these, five had a pathogenic microscopic CNV, which could have been detected by karyotyping. There were four cases (1.2%) having a pathogenic submicroscopic CNV, which could have been missed by karyotyping. The total CMA detection rate (23.4%) was not statistically different from that (24.2%) by karyotyping (p > .05). The percentage of chromosomal aberrations, which cfDNA screening would miss in patients with increased NT in the first trimester, might be the same as in those with normal NT. Impact statement What is already known about this topic? First trimester NT is a powerful marker for screening for common aneuploidies. cfDNA screening is more accurate than any standard screening with NT. The need of NT in the era of prenatal screening using cfDNA is debated. What does this study add? An increased NT did not identify any additional aneuploidies that were detected by cfDNA screening. What are the implications of these findings for clinical practice and/or further research? The percentage of chromosomal aberrations which cfDNA screening would miss in patients with increased NT might be the same as in those with normal NT. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the efficacy of the sonographic cardiothoracic ratio (CTR) in early pregnancy for the prediction of fetal haemoglobin (Hb) Bart's disease.Study Design: Over a 1.5-year period at a Chinese tertiary obstetric centre, women at risk of Hb Bart's disease were given the option of a non-invasive approach to exclude an affected pregnancy between 11 weeks and 13 weeks and 6 days of gestation, with a routine rescan after a 2-week interval. The fetal CTR, a sonographic marker, was assessed, and invasive testing followed in cases of fetal cardiomegaly. The diagnosis of fetal Hb Bart's disease was based on DNA analysis from chorionic villus sampling.Results: Of 154 at-risk cases studied, five cases (four at 11 weeks of gestation) were subjected to direct invasive testing because of an unsatisfactory scan. Of the remaining 149 cases, non-invasive ultrasound examinations were performed successfully. Thirty-four (22.8%) affected pregnancies were revealed, including one picked up on rescan. The sensitivity and specificity of the non-invasive approach were 97.1% and 100%, respectively. The need for an invasive test was reduced by 74.7%, and all affected pregnancies except one were diagnosed before 14 weeks of gestation.Conclusion: CTR can differentiate reliably between pregnancies with and without Hb Bart's disease. This non-invasive approach for the exclusion of Hb Bart's disease can be used in early pregnancy. [ABSTRACT FROM AUTHOR]

α-Thalassemia is a common inherited disease in southern China. The severest form is Hb Bart's hydrops fetalis, in which the affected fetuses almost always die in utero or shortly after birth, and the mothers are at high risk for severe morbidity. Therefore, this condition should be controlled, especially prenatally. In this study, we reported on a two-year experience in prenatal control of Hb Bart's hydrops fetalis at a mainland Chinese hospital. Totally, 573 pregnancies at risk for Hb Bart's hydrops fetalis were referred and different prenatal procedures were offered depending on the gestational age at presentation. One hundred fifty-two affected fetuses were diagnosed prenatally; among these, only half presented in early gestation, and were terminated in time. Although our prenatal program has successfully prevented the birth of children with severe thalassemia, it does not show a satisfactory outcome, considering the gestational age when an affected pregnancy is terminated. [ABSTRACT FROM AUTHOR]

Objective: To present the experience on prenatal diagnosis of Miller-Dieker syndrome (MDS)/PAFAH1B1-related lissencephaly to further determine fetal phenotypes of this syndrome.Study Design: This was a retrospective study of ten pregnancies with fetal MDS/PAFAH1B1-related lissencephaly identified by chromosomal microarray (CMA)/exome sequencing (ES). Clinical and laboratory data were collected and reviewed for these cases, including maternal demographics, prenatal sonographic findings, CMA or ES results and pregnancy outcomes.Results: Two cases were diagnosed in the first trimester because of an increased nuchal translucency. The remaining eight cases were identified at late gestation, including four in the second trimester because of fetal cardiac anomalies or ventriculomegaly, and four in the third trimester because of ventriculomegaly. CMA revealed 17p13.3 deletions in nine cases, and ES detected a de novo PAFAH1B1 missense mutation in one case.Conclusion: The prenatal presentation of MDS/PAFAH1B1-related lissencephaly depended on the gestational age when the diagnosis was made. Mild ventriculomegaly was the most common prenatal sonographic sign identified in cases of MDS/PAFAH1B1-related lissencephaly. It is important that fetal MRI and invasive testing with CMA should be considered in fetuses with apparently 'isolated' mild ventriculomegaly. [ABSTRACT FROM AUTHOR]