Prenatal Diagnosis Center Research Articles

Prenatal diagnosis analysis of three cases of Turner syndrome fetuses with complex mosaic small supernumerary marker chromosomes

To explore the value of applying multiple genetic testing techniques for the prenatal diagnosis of Turner syndrome fetuses with complex mosaic small supernumerary marker chromosomes (sSMC). Chromosomal karyotypes of amniotic fluid samples from 5 030 pregnant women who had undergone amniocentesis at the Prenatal Diagnosis Center of the Third Affiliated Hospital of Zhengzhou University from January to December 2022 were retrospectively reviewed. Three fetuses with complex mosaicism fetuses (carrying 2 types of sSMC) were selected as the study subjects. Genetic tests including G-banded chromosomal karyotyping analysis, fluorescence in situ hybridization (FISH), chromosomal microarray analysis (CMA), and copy number variation sequencing (CNV-seq) were used to clarify the origin and mosaic status of the sSMC. This study has been approved by the Medical Ethics Committee of the Third Affiliated Hospital of Zhengzhou University (No. 2023-159-01). G-banded chromosomal analysis of fetus 1 showed a karyotype of 45,X[64]/46,X,+mar1[13]/46,X,+mar2[3]. FISH results showed that 52% of of its cells had contained one X chromosome signal, whilst 48% contained two X chromosome signals. CMA results revealed the fetus had harbored a 32.32 Mb and a 50.93 Mb deletion in Xp22.33p21.1 and Xq22.2q28 regions, respectively, in addition with mosaic deletions of approximately 1.43 copies, 1.78 copies and 1.43 copies in the Xp21.1p11.1, Xq11.1q21.1 and Xq21.2q22.2 regions, respectively. The fetus 2 had a karyotype of 45,X[27]/46,X,+mar1[14]/46,X,+mar2[12]. FISH results indicated that 88% of its cells contained one X chromosomes signal and two Y chromosome signals, and 12% contained signals for one X chromosomes signal and one Y chromosome signal. CNV-seq results revealed a deletion of 7.74 Mb in the Yq11.222q11.23 region and a mosaic duplication of approximately 1.738 copies in the Yp11.31q11.221 region. The fetus 3 had a karyotype of 45,X[60]/46,X,+mar1[11]/46,X,+mar2[6]. FISH results showed that 28% of its cells contained one X chromosome signal, and 72% contained tow X chromosome signals. CNV-seq results revealed deletions of 55.60 Mb and 53.50 Mb in the Xp22.33p11.1 and Xq22.1q28 regions, respectively, along with a mosaic deletion of approximately 1.85 copies in the Xp11.1q13.2 region and a mosaic repeats of approximately 2.66 copies in the Xq13.2q22.1 region. The sSMCs in the 3 fetuses had all originated from sex chromosomes and were of complex mosaic type. After genetic counseling, the three couples had all opted to terminate the pregnancy. The combined use of multiple genetic testing techniques has determined the origin and structure of complex mosaic sSMCs and provided a basis for prenantal diagnosis and genetic counseling.

Prenatal diagnosis, ultrasound findings and pregnancy outcome of 7q11.23 deletion and duplication syndromes: what are the fetal features?

ObjectiveAnalyze the ultrasound findings, single nucleotide polymorphism array (SNP-array) results, and pregnancy outcomes of fetuses with 7q11.23 deletions and duplications in the second and third trimesters. Investigate the prenatal ultrasound characteristics and follow up information of these fetuses.MethodsSeven fetuses were diagnosed with 7q11.23 deletion and six with 7q11.23 duplication via SNP-array at the prenatal diagnosis center of a single Chinese tertiary medical center from January 2017 to May 2024. Maternal demographics, ultrasound findings, SNP-array results, pregnancy outcomes, and follow-up information were comprehensively reviewed and analyzed.ResultsThe copy number variations (CNVs) ranged from 1.43 Mb to 1.78 Mb in cases of 7q11.23 deletions and from 1.42 Mb to 1.68 Mb in cases of 7q11.23 duplications. These CNVs encompassed 29 OMIM-listed genes, including ELN, DNAJC30, GTF2IRD1, and GTF2I. Among the seven cases of 7q11.23 deletion syndrome, six exhibited ultrasound abnormalities. The main clinical phenotypes included three cases of intrauterine growth restriction and four cases of cardiovascular system abnormalities, specifically two cases with ventricular septal defects, one case with aortic narrowing, and one case with supravalvular pulmonary stenosis. One case was particularly notable, exhibiting complex multi-organ structural malformations. Out of six cases of 7q11.23 duplication syndrome, five exhibited ultrasound abnormalities. These included two cases of cardiovascular abnormalities: one case with a widened left ventricle and another case with a shortened fetal humerus length. One case revealed complex multi-organ structural malformations, including hydronephrosis, a microgallbladder, and a cleft lip and palate. All seven cases of 7q11.23 deletions and three cases of 7q11.23 duplications opted for termination of the pregnancy. The remaining three cases of 7q11.23 duplications chose to continue the pregnancy. One case underwent surgical treatment for a ventricular septal defect after birth, and the prognosis was favorable. Another case involved a full-term delivery, this child was followed up at the age of 4 and exhibited a phenotype of poor language expression ability.ConclusionOur study broadened the clinical phenotype spectrum of fetuses with 7q11.23 deletions and duplications. Additionally, it conducted a preliminary evaluation of prenatal ultrasound findings and postnatal clinical phenotypes in follow-up cases. The clinical phenotype of fetuses with 7q11.23 deletion and duplication syndromes involves multiple systems and is relatively complex. Cardiovascular abnormalities and intrauterine growth restriction are the most common clinical manifestations observed in prenatal 7q11.23 deletion syndrome. Fetuses with 7q11.23 duplications exhibit a wide range of clinical phenotypes that lack specificity.

Hypospadias Associated With Fetal Growth Restriction: A Multicentric Descriptive and Prognostic Cohort Study.

To determine the prevalence of genetic and endocrine abnormalities and to assess fetal, neonatal and surgical outcomes in cases of hypospadias associated with fetal growth restriction. A multicentric retrospective study was conducted across five prenatal diagnosis centers in Paris. The cohort encompassed all fetuses diagnosed with the combination of fetal growth restriction < 10th percentile (FGR) and hypospadias from 2013 to 2021. Maternal data, fetal outcome and results of prenatal investigations were collected, along with postnatal data, encompassing endocrinological and genetic assessments, functional aspects and surgical outcomes. Among the 82 patients included in the cohort, there were 14 (17%) terminations of pregnancy and four (5%) in utero deaths, leaving 64 (78%) live neonates, including five (6%) with early neonatal death. Among the 52 (63%) cases where hypospadias and FGR were considered as ultrasound-isolated anomalies, six (12%, [3.2%-20.8%]) exhibited chromosomic, genetic, or endocrinological abnormalities diagnosed half prenatally and half postnatally. Fifty percent of the overall hypospadias were proximal. Most children underwent surgical intervention before reaching 2years of age, with 50% encountering complications and often required reintervention. The association of FGR and hypospadias should not be underestimated as genetic or endocrinological abnormalities were identified even when hypospadias and FGR initially appear isolated. Additionally, the overall prognosis may be worsened using complex and iterative surgical procedures.

Second Trimester Screening Markers of Fetal Chromosomal Abnormalities Other than Common Trisomies: A Case-Control Study

Background: To enhance the efficacy of maternal serum screening (MSS), we conducted an analysis to examine the correlation between certain factors identified during second-trimester screening (STS) and fetal chromosomal abnormalities, excluding the common trisomies (trisomies 13, 18, and 21). Additionally, specific risk factor ranges were established for each category. Methods: A retrospective 1:3 matched case-control study was conducted. Case data were obtained from 311 STS samples of fetal chromosomal abnormalities other than common trisomies, with testing performed in the Prenatal Diagnosis Center of the Maternal and Child Health Care Hospital of Sichuan Province in China between 6 January 2013 and 12 April 2023. A total of 933 controls were matched accordingly. Univariate and multivariable conditional logistic regression analyses were implemented and sensitivity analysis was performed. Results: Multivariable logistic analyses revealed that the independent risk factors for fetal chromosomal abnormalities other than common trisomies were ultrasonographic structural abnormalities (odds ratio (OR) = 3.038; 95% confidence interval (CI), 1.774–5.202; p &lt; 0.001); free β-human chorionic gonadotropin (free β-hCG) as multiples of the median (MoMs) of ≤0.34 (OR = 3.006; 95% CI, 1.803–5.013; p &lt; 0.001), 2.82–3.53 (OR = 1.884; 95% CI, 1.321–2.688; p &lt; 0.001), 3.54–4.67 (OR = 1.949; 95% CI, 1.300–2.923, p = 0.001), and ≥4.68 (OR = 1.730; 95% CI, 1.045–2.866; p = 0.033); and a trisomy 21 (T21) risk of 1/271–1/1000 (OR = 2.434; 95% CI, 1.706–3.472; p &lt; 0.001), 1/101–1/270 (OR = 3.330; 95% CI, 2.300–4.821; p &lt; 0.001), and ≥1/100 (OR = 3.441; 95% CI, 2.178–5.438; p &lt; 0.001). Conclusions: Ultrasonographic structural abnormalities, free β-hCG MoMs, and T21 risk were identified as independent risk factors for fetal chromosomal abnormalities (with the exception of common trisomies) in STS. Our findings thus provide data to support clinical decision-making.

Application of triplet-primer PCR technology for the genetic testing and prenatal diagnosis of patients with Myotonic dystrophy type 1

To explore the application of triplet-primer PCR (TP-PCR) for the genetic testing and prenatal diagnosis in patients with Myotonic dystrophy type 1 (DM1). A total of 60 individuals from 48 pedigrees undergoing genetic testing at the Genetic and Prenatal Diagnosis Center of the First Affiliated Hospital of Zhengzhou University from May 2018 to October 2022 were selected as the study subjects. TP-PCR combined with capillary electrophoresis was applied to determine the number of CTG repeats of the DMPK gene, and prenatal testing was provided to four DM1 pedigrees. This study was approved by the First Affiliated Hospital of Zhengzhou University (Ethics No. KS-2018-KY-36). A total of 52 DM1 patients were detected, mostly with muscle weakness, muscular atrophy and myotonia as the initial symptoms, along with typical myotonic potentials. Some patients also had abnormalities of other systems. The number of abnormal CTG repeats of the DMPK gene was > 50, whilst the number of CTG repeats on the normal allele had ranged from 5 to 18. The number of the most common normal CAG repeats was 6 (30.77%, 16/52). Among the four DM1 pedigrees undergoing prenatal diagnosis, one fetus was healthy, whilst three fetuses were found to have abnormal CTG repeats (> 50 times) and diagnosed with DM1. TP-PCR can diagnose DM1 patients with speed and accuracy. However, this method cannot accurately determine the number of CTG repeats when it exceeds 50.

Array Comparative Genomic Hybridization (aCGH) Results among Patients Referred to Invasive Prenatal Testing after First-Trimester Screening: A Comprehensive Cohort Study.

Introduction: Invasive prenatal testing with chromosomal microarray analysis after first-trimester screening is a relevant option but there is still debate regarding the indications. Therefore, we evaluated the prevalence of numerical chromosomal aberrations detected by classic karyotype and clinically relevant copy number variants (CNVs) in prenatal samples using array comparative genomic hybridization (aCGH) stratified to NT thickness: <the 95th percentile, the 95th percentile-2.9 mm, 3.0-3.4 mm, 3.5-3.9 mm, 4.0-4.5 mm, and >4.5 mm, and by the presence/absence of associated structural anomalies detected by ultrasonography. Materials and Methods: Retrospective cohort study carried out at two tertiary Polish centers for prenatal diagnosis (national healthcare system) in central and south regions from January 2018 to December 2021. A total of 1746 prenatal samples were received. Indications for invasive prenatal testing included high risk of Down syndrome in the first-trimester combined test (n = 1484) and advanced maternal age (n = 69), and, in 193 cases, other reasons, such as parental request, family history of congenital defects, and genetic mutation carrier, were given. DNA was extracted directly from amniotic fluid (n = 1582) cells and chorionic villus samples (n = 164), and examined with classic karyotype and aCGH. Results: Of the entire cohort of 1746 fetuses, classical karyotype revealed numerical chromosomal aberrations in 334 fetuses (19.1%), and aCGH detected CNV in 5% (n = 87). The frequency of numerical chromosomal aberrations increased with NT thickness from 5.9% for fetuses with NT < p95th to 43.3% for those with NT > 4.5 mm. The highest rate of numerical aberrations was observed in fetuses with NT > 4.5 mm having at least one structural anomaly (50.2%). CNVs stratified by NT thickness were detected in 2.9%, 2.9%, 3.5%, 4.3%, 12.2%, and 9.0% of fetuses with NT < 95th percentile, 95th percentile-2.9 mm, 3.0-3.4 mm, 3.5-3.9 mm, 4.0-4.5 mm, and >4.5 mm, respectively. After exclusion of fetuses with structural anomalies and numerical aberrations, aCGH revealed CNVs in 2.0% of fetuses with NT < 95th percentile, 1.5% with NTp95-2.9 mm, 1.3% with NT 3.0-3.4 mm, 5.4% with NT 3.5-3.9 mm, 19.0% with NT 4.0-4.5 mm, and 14.8% with NT > 4.5 mm. Conclusions: In conclusion, our study indicates that performing aCGH in samples referred to invasive prenatal testing after first-trimester screening provides additional clinically valuable information over conventional karyotyping, even in cases with normal NT and anatomy.

Genetic analysis of a Chinese pedigree affected with Branchio-oculo-facial syndrome and a literature review

To explore the genetic etiology of a Chinese pedigree affected with Branchio-oculo-facial syndrome (BOFS) and summarize the prenatal phenotype of BOFS patients. A pedigree with BOFS which had presented at the Genetics and Prenatal Diagnosis Center of the First Affiliated Hospital of Zhengzhou University in December 2021 was selected as the study subject. Clinical data of the pedigree was collected. The fetus was subjected to routine prenatal ultrasound scan. Trio-whole exome sequencing (trio-WES) was carried out for the fetus and its parents, and candidate variant was verified by Sanger sequencing. Relevant literature was searched from the database to summarize the prenatal phenotype of BOFS patients. Ultrasound exam suggested the fetus had cleft lip and palate. Its father had presented with high palatal arch, prematurely grayed hair, occult cleft lip, congenital preauricular fistula, red-green color blindness and unilateral renal agenesis. Its grandfather also had high palatal arch, prematurely gray hair, protruding ears, congenital preauricular fistula and hearing disorders. Trio-WES revealed that the fetus and its father had both harbored a heterozygous c.890-1G>A variant of the TFAP2A gene. The same variant was not found in its mother. Sanger sequencing confirmed that its grandfather had also harbored the same variant. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was rated as likely pathogenic (PVS1+PM2_Supporting). Combined with 36 similar cases retrieved from the literature, the prenatal phenotypes of BOFS patients had included growth restriction (25/37), renal abnormalities (10/37), cleft lip and palate (5/37) and oligohydramnios (5/37). The c.890-1G>A variant of the TFAP2A gene probably underlay the pathogenesis of BOFS in this pedigree. Discovery of the novel variant has enriched the mutational spectrum of the TFAP2A gene. The common prenatal phenotypes of BOFS have included growth restriction, renal abnormalities, cleft lip and palate and oligohydramnios. Delineation of the intrauterine phenotype of BOFS may facilitate its prenatal diagnosis, clinical diagnosis, treatment and genetic counseling.

Réduction embryonnaire pour demande maternelle en cas de grossesse gémellaire : enquête nationale française

IntroductionIn France, embryo reduction is controversial in twin pregnancy, especially when there is no underlying pathology. The objective of this study was to establish the status of this practice in France and to depict the ethical issues around this problematic. Study designA questionnaire drafted by Maternal and Fetal Medicine physicians and family planning teams of the University Hospital from Strasbourg was distributed to the 48 French Multidisciplinary Prenatal Diagnosis Centers, among which 28 answered (58,3%). ResultsEmbryo reduction in twin pregnancy on maternal request has already challenged 71% of the centers; 29% have performed such a reduction. The overall position of the centers to these requests is negative (3.1/10), with very mixed levels of in-team agreement. The main arguments against this practice are that twin pregnancy is not a pathology, that embryo reduction exposes to the risk of loosing the entire pregnancy, the feeling of being held hostage with the alternative of abortion of the whole pregnancy, and the lack of legal framing. On the contrary, the arguments in favor of the reduction are: that the reduction can avoid an abortion, that this type of reduction can be related to a partial abortion, that it responds to women's rights and that mental health is an integral part of women's health. ConclusionThere is no consensus about how to respond to patients requesting for embryo reduction in twin pregnancy. However, the majority of Centers have been confronted with it and it would be necessary to open the debate on this problem and the ethical questions it raises.

Path analysis of COVID-19 cognition, social support, and mental health of pregnant women with interventional prenatal diagnosis during the COVID-19 pandemic based on structural equation modeling.

This study aims to investigate the relationship between Corona Virus Disease 2019 (COVID-19) cognition, social support, and mental health among pregnant women proposed for undergoing interventional prenatal diagnosis in Sichuan Province during the COVID-19 pandemic. A total of 2270 pregnant women (2232 valid) who were proposed to undergo interventional prenatal diagnosis at a tertiary hospital prenatal diagnosis center in Sichuan Province from January to December 2022 were selected by Convenience sampling and surveyed using a self-administered general information questionnaire, social support rating scale, mental health questionnaire (including: Self-Rating Anxiety Scale, Self-Rating Depression Scale), and self-administered COVID-19 cognition questionnaire. Structural equation modeling showed that social support negatively predicted anxiety (β = -0.34, t = -14.98, P < .001) and negatively predicted depressive status (β = -0.21, t = -9.57, P < .001); COVID-19 cognition negatively predicted anxiety (β = -0.76, t = -5.34, P < .001) and depression (β = -0.40, t = -2.99, P < .01); anxiety positively predicted anxiety (β = 0.73, t = 37.34, P < .001). The overall knowledge rate of COVID-19 cognition among 2232 pregnant women who were to undergo interventional prenatal diagnosis was 76.40%. The fit indices of the model were: CMIN/DF = 3.071, GFI = 0.999, AGFI = 0.993, CFI = 0.999, RMSEA = 0.030, NFI = 0.998, and TLI = 0.992, indicating that the model had a good fit and the model was scientifically valid. Pregnant women in Sichuan province who are to undergo prenatal interventional diagnosis have a medium level of COVID-19 awareness, and their level of COVID-19 awareness and social support will directly affect their anxiety and depression level, and their anxiety level will also affect their depression level. We should give more attention to pregnant women, especially those in particular situations such as advanced age, poor maternal history, family history of genetic disease, etc, they should be given adequate care and social support, and multiple channels and types of health education should be provided for the COVID-19 to improve the pregnant women's knowledge of COVID-19, which is important for improving the mental health of pregnant women.

Clinical predictive value of pre-pregnancy tests for unexplained recurrent spontaneous abortion: a retrospective study.

Early prediction and intervention are crucial for the prognosis of unexplained recurrent spontaneous abortion (uRSA). The main purpose of this study is to establish a risk prediction model for uRSA based on routine pre-pregnancy tests, in order to provide clinical physicians with indications of whether the patients are at high risk. This was a retrospective study conducted at the Prenatal Diagnosis Center of Henan Provincial People's Hospital between January 2019 and December 2022. Twelve routine pre-pregnancy tests and four basic personal information characteristics were collected. Pre-pregnancy tests include thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine thyroid (FT4), thyroxine (TT4), total triiodothyronine (TT3), peroxidase antibody (TPO-Ab), thyroid globulin antibody (TG-Ab), 25-hydroxyvitamin D [25-(OH) D], ferritin (Ferr), Homocysteine (Hcy), vitamin B12 (VitB12), folic acid (FA). Basic personal information characteristics include age, body mass index (BMI), smoking history and drinking history. Logistic regression analysis was used to establish a risk prediction model, and receiver operating characteristic (ROC) curve and decision curve analysis (DCA) were employed to evaluate the performance of prediction model. A total of 140 patients in uRSA group and 152 women in the control group were randomly split into a training set (n = 186) and a testing set (n = 106). Chi-square test results for each single characteristic indicated that, FT3 (p = 0.018), FT4 (p = 0.048), 25-(OH) D (p = 0.013) and FA (p = 0.044) were closely related to RSA. TG-Ab and TPO-Ab were also important characteristics according to clinical experience, so we established a risk prediction model for RSA based on the above six characteristics using logistic regression analysis. The prediction accuracy of the model on the testing set was 74.53%, and the area under ROC curve was 0.710. DCA curve indicated that the model had good clinical value. Pre-pregnancy tests such as FT3, FT4, TG-Ab, 25-(OH)D and FA were closely related to uRSA. This study successfully established a risk prediction model for RSA based on routine pre-pregnancy tests.

P-536 Preimplantation Genetic Testing for hereditary breast and ovarian cancer syndrome due to BRCA pathogenic variant : the parisian center experience

Abstract Study question What are the outcomes of Preimplantation genetic testing for monogenic disease (PGT-M) for BRCA pathogenic variants? Summary answer Among couples entering a PGT-M program for BRCA pathogenic variants, 23.5% achieved a live-birth. What is known already BRCA pathogenic variants are associated with an oncologic predisposition with variable penetrance and are accessible to screening and preventive procedures to avoid or early detect the development of cancer. Transmission of BRCAmutations to offspring poses a significant reproductive concern for BRCA mutation carriers. PGT-M offers a solution to prevent this mutation transmission. Despite reproductive challenges related to BRCA status, there are no existing international guidelines for applying PGT-M in these situations. In France, authorization for BRCA related PGT-M is case-specific, considering the personal and familial severity of the disease and submitted to a multidisciplinary prenatal diagnosis center (CPDPN). Study design, size, duration This retrospective observational study, is a single-center analysis of 46 requests for PGT-M related to BRCA pathogenic variants at our PGT center from January 2015 to December 2022. Participants/materials, setting, methods Forty-six couples asked for PGT-M for BRCA pathogenic variant carried by one of the partner. The present study involves the examination of data encompassing referrals, decisions as well as clinical outcomes associated with PGT-M. Main results and the role of chance Forty-six requests for PGT-M due to the risk of hereditary predisposition to breast and ovarian cancer have been received: 36 for a pathogenic variant in the BRCA1 gene and 10 for BRCA2. Nine couples ultimately did not proceed and dropped out. Eight requests were declined, either due to the refusal of the multidisciplinary prenatal diagnosis center (CPDPN) based on family history (n = 4) or alteration of ovarian reserve (n = 4), the 2 latter requests are still under investigation. In total, requests from 27 couples (55%) were considered eligible and feasible. Among them, 17 (63%) underwent at least one PGT-M cycles (5 dropped out before the beginning and 5 are still pending). Overall, 33 ovarian stimulation cycles for in vitro fertilization were initiated, resulting in the retrieval of 192 mature oocytes and the formation of 145 embryos. Of these, 97 were biopsied, and 38 did not carried the BRCA pathogenic variant. A total of 21 fresh or frozen embryo transfers were performed and 8 pregnancies were achieved, leading to 4 deliveries and 5 live births (23.5% of couples who started a PGT-M cycle). Limitations, reasons for caution In the absence of established guidelines, there is variability in information regarding PGT-M among oncogeneticists. Thus, only selected carriers of BRCA pathogenic variants are addressed to our PGT centers. Additionally, women participating in a fresh PGT cycle were selected on several criteria including ovarian reserve parameters. Wider implications of the findings PGT-M provides a viable alternative for couples seeking to prevent the transmission of BRCA mutations. To increase the PGT-M cumulative live birth rate, the transfer of male embryos carrying the variant, assumed to have lower tumor risks, should be considered and discussed with patients. Trial registration number Not applicable

Idiopathic polyhydramnios and postnatal outcomes of children: The role of exome sequencing.

The objective of our study was to evaluate the long-term outcome of children born from a pregnancy complicated by idiopathic polyhydramnios. The secondary objective was to investigate factors associated with adverse outcomes. We conducted a retrospective study in two prenatal diagnosis centers between January 1, 2009 and December 31, 2020. Inclusion criteria were pregnancies with a diagnosis of idiopathic polyhydramnios, defined by a deepest pocket greater than 8cm, no detectable abnormality at ultrasound and a negative amniotic fluid assessment including karyotype, chromosomal microarray, biochemical assays (electrolytes and digestive enzymes), and viruses (parvovirus B19 and cytomegalovirus). One-year outcomes of these children were collected. The primary endpoint was adverse postnatal outcome, defined by at least one of the following criteria: stillbirth, neonatal death, or serious and incurable condition diagnosed in the first year of life. Of the 245 women referred for isolated polyhydramnios, 73 were diagnosed with idiopathic polyhydramnios after prenatal investigations. The mean age at follow-up of children was 28months (95% CI 20-36). An adverse outcome occurred in 25% of cases (18/73), with one stillbirth, two neonatal deaths, and 15 severe conditions diagnosed postnatally, including a rate of monogenic disorders of 8.2% (6/73). Pediatric follow-up was normal for 75% of the children (55/73), including a rate of 9% (5/55) of curable conditions. Repeated amnioreduction was independently associated with an adverse outcome. Pregnant women with polyhydramnios should be informed of the increased risk of 25% of perinatal mortality and serious conditions diagnosed after birth.

Comparison of the performance of NIPT and NIPT-plus for fetal chromosomal aneuploidy and high Z-score increases the positive predictive value.

To evaluate non-invasive prenatal testing (NIPT) and expanded non-invasive prenatal testing (NIPT-plus) for detecting aneuploidies at different sequencing depths and assess Z-score accuracy in predicting trisomies 21, 18, 13, 45X, and 47XXX. Pregnancies with positive NIPT or NIPT-plus results detected at the prenatal diagnosis center of Nanfang Hospital were included in this retrospective study, between January 2017 and December 2022. Invasive prenatal diagnostic results were collected. Logistic regression analyses were used to study the relationship between Z-score and positive predictive value (PPV). Optimal cut-off values were obtained based on receiver operating characteristic analysis, and PPVs were calculated in different groups. We evaluated 1348 pregnant women with positive results, including 930 reported by NIPT and 418 reported by NIPT-plus. NIPT reported significantly more rare chromosomal aneuploidies (RCAs), and NIPT-plus had a significantly higher PPV for trisomy 21 (T21). Logistic regression analyses showed a significant association (P < 0.001) between Z-score and PPVs for T21 and trisomy 18 (T18). A linear relationship was observed between fetal fraction (FF) and Z-values in the true positive cases of T21 and T18.The high Z-score group had significantly higher PPVs than the low Z-score group for T21, T18, trisomy 13, and 47XXX, but not for 45X. The Z-score is helpful in assessing NIPT or NIPT-plus results. Therefore, we suggest including the Z-score and FF in the results. By combining the Z-score, FF, and maternal age, clinicians can interpret NIPT results more accurately and improve personal counsel to reduce patients' anxiety.

Whole-genome sequencing in prenatally detected congenital malformations: prospective cohort study in clinical setting.

To investigate the diagnostic yield of trio whole-genome sequencing (WGS) in fetuses with various congenital malformations referred to a tertiary center for prenatal diagnosis. In this prospective study, 50 pregnancies with different congenital malformations, negative for trisomies and causative copy-number variants, were analyzed further with fetal-parental trio WGS analysis. Parents were eligible for inclusion if they accepted further investigation following the detection of isolated or multiple malformations on prenatal ultrasound. Cases with isolated increased nuchal translucency, gamete donation or multiple pregnancy were excluded. WGS with the Illumina Inc. 30× polymerase-chain-reaction-free short-read sequencing included analysis of single-nucleotide variants, insertions and deletions, structural variants, short tandem repeats and copy-number identification of SMN1 and SMN2 genes. A molecular diagnosis was achieved in 13/50 (26%) cases. Causative sequence variants were identified in 12 genes: FGFR3 (n = 2), ACTA1 (n = 1), CDH2 (n = 1), COL1A2 (n = 1), DHCR7 (n = 1), EYA1 (n = 1), FBXO11 (n = 1), FRAS1 (n = 1), L1CAM (n = 1), OFD1 (n = 1), PDHA1 (n = 1) and SOX9 (n = 1). The phenotypes of the cases were divided into different groups, with the following diagnostic yields: skeletal malformation (4/9 (44%)), multisystem malformation (3/7 (43%)), central nervous system malformation (5/15 (33%)) and thoracic malformation (1/10 (10%)). Additionally, two cases carried variants that were considered potentially clinically relevant, even though they were assessed as variants of uncertain significance, according to the guidelines provided by the American College of Medical Genetics and Genomics. Overall, we identified a causative or potentially clinically relevant variant in 15/50 (30%) cases. We demonstrate a diagnostic yield of 26% with clinical WGS in prenatally detected congenital malformations. This study emphasizes the benefits that WGS can bring to the diagnosis of fetal structural anomalies. It is important to note that causative chromosomal aberrations were excluded from our cohort before WGS. As chromosomal aberrations are a well-known cause of prenatally detected congenital malformations, future studies using WGS as a primary diagnostic test, including assessment of chromosomal aberrations, may show that the detection rate exceeds the diagnostic yield of this study. WGS can add clinically relevant information, explaining the underlying cause of the fetal anomaly, which will provide information concerning the specific prognosis of the condition, as well as estimate the risk of recurrence. A genetic diagnosis can also provide more reproductive choice for future pregnancies. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Prenatal diagnosis of fetal microdeletion and microduplication syndromes among pregnant women with advanced maternal ages

To assess the value of combined chromosomal karyotyping and chromosomal microarray analysis (CMA) and/or copy number variation sequencing (CNV-seq) for the prenatal diagnosis for women with advanced maternal ages, and to explore the challenges of prenatal genetic counseling brought by the types of fetal CNVs and uncertainty of related phenotypes. A retrospective analysis was carried out on 1 841 women with advanced maternal age who underwent interventional prenatal diagnosis at the Prenatal Diagnosis Center of Xiamen University Affiliated Women and Children's Hospital from January 2017 to December 2020. Routine chromosomal karyotyping analysis and CMA/CNV-seq detection were carried out. CMA/CNV-seq had detected pathogenic variants in 2 cases which had failed karyotyping analysis. Two hundred and twenty one fetal chromosomal abnormalities were detected by karyotyping analysis, among which 187 were detected by CMA/CNV-seq. CMA/CNV-seq analysis of 23 cases with balanced chromosome structural aberrations and 10 cases with low proportion mosaicisms (including a marker chromosome) had yielded a negative result. In addition, 26 cases (26/1 841, 1.4%) with pathogenic CNVs were discovered among those with a normal karyotype, of which 13 (50.0%) were recurrent CNVs associated with neurocognitive impairment, with 22q11.21 microdeletions and microduplications being the most common types (26.92%). The combination of karyotyping analysis and CMA/CNV-seq not only increased the rate of prenatal diagnosis, but also complemented with each other, which has facilitated genetic counseling and formulation of prenatal diagnosis strategy for the affected families.

Prenatal ultrasonographic manifestations and genetic diagnosis of nine fetuses with 7q11.23 duplication syndrome

To analyze ultrasonographic manifestations and genetic etiology of nine fetuses with 7q11.23 duplication syndrome. Ultrasonographic finding, pregnancy outcome and follow-up of nine fetuses detected at the Prenatal Diagnosis Center of the Third Affiliated Hospital of Zhengzhou University from January 2017 to December 2021 were retrospectively analyzed. The fetuses were found to harbor a duplication in the 7q11.23 region by chromosomal microarray analysis (CMA). Among these, five had shown ventriculomegaly, including four syndromic and one non-syndromic. For the remainders, one had ventricular septal defect and mild tricuspid regurgitation, one had echogenic intracardiac focus, whilst another two were normal. Five couples had accepted parental verification, and the results confirmed that the 7q11.23 duplication carried by their fetuses were de novo in origin. Following genetic counseling, seven couples had opted to terminate their pregnancies. Two fetuses were delivered at full term, and follow-up had found no abnormalities. Prenatal ultrasonographic manifestations of fetuses with 7q11.23 duplication syndrome are variable. CMA can provide assistance for their diagnosis and genetic counseling.

Prenatal diagnosis and phenotypic analysis of two fetuses harboring heterozygous deletions of SHOX gene

To explore the clinical manifestations of two fetuses harboring heterozygous deletions of the SHOX gene. Two pregnant women who had presented at the Prenatal Diagnosis Center of Nanjing Drum Tower Hospital respectively on June 24, 2022 and July 27, 2022 were selected as the study subjects. In case 1, prenatal ultrasonography had shown short femur and intrauterine growth retardation of the fetus. Case 2 had a history of spontaneous abortions due to structural chromosomal aberrations. Fetus 1 had undergone a test for the FGFR3 gene, and both fetuses were subjected to single nucleotide polymorphism-based microarray (SNP array) analysis. After excluding the influence of FGFR3 gene variant, fetus 1 was found to harbor a heterozygous 883 kb deletion at Xpter or Ypter, whilst fetus 2 was found to harbor a 5.75 Mb deletion in the Xpter region. Both deletions have encompassed the SHOX gene. The origin of the deletion in fetus 1 was unknown, whilst that in fetus 2 was inherited from its mother. Fetus 1 has been delivered at term with a normal phenotype, and fetus 2 was not born yet. The intrauterine and postnatal phenotypes of fetuses may be predicted by combining the ultrasound finding, parental phenotype and results of CMA, and the results can facilitate genetic counseling and decision making over the pregnancy.

Genetic diagnosis and analysis of eight cases with central 22q11.2 deletion syndrome

To explore the pregnancy outcome and postpartum clinical phenotype of LCR22B/C~D central 22q11.2 deletion syndrome. For fetuses diagnosed with central 22q11.2 deletion by chromosomal microarray analysis (CMA) at the Prenatal Diagnosis Center of the Third Affiliated Hospital of Zhengzhou University from January 2019 to April 2022, their prenatal imaging, parental CMA verification, pregnancy outcomes and postpartum clinical phenotype were analyzed. Eight cases of central 22q11.2 deletion syndrome were included, including six cases with LCR22B~D 22q11.2 deletions and two with LCR22C~D 22q11.2 deletions. Among the six cases with LCR22B~D type 22q11.2 deletions, three had shown cardiovascular malformations (right aortic arch, ventricular septal defect, mild tricuspid regurgitation), one had shown urinary defect (right kidney heterotopia). Two cases with LCR22C~D 22q11.2 deletions showed nonspecific ultrasonographic findings, including oligohydramnios with growth restriction and nuchal skin thickening. The CMA verification showed that six cases were inherited from their parents, and five couples had chosen to continue with the pregnancy. Postpartum follow-up showed that the physical and intellectual development of all children were normal. One couple had opted to terminate the pregnancy considering the ectopic fetal right kidney. Two remaining cases had decided to terminate their pregnancies without parental verification. The central 22q11.2 deletion syndrome of the LCR22B/C~D type is different from the classical types. Its genetic information mainly comes from parents. Prenatal imaging has mainly shown cardiovascular and urinary abnormalities. Postnatal growth and intellectual development have been normal. Therefore, the couples should be provided with suffice prenatal genetic counseling.

Analysis of DMD gene variants in a single center

Objective: To investigate the DMD genetic variants of the Chinese population with Duchenne (DMD) and Becker muscular dystrophies (BMD). Methods: A cross-sectional study was conducted on 2 690 unrelated patients with DMD and BMD aged 0-18 who visited the Genetic and Prenatal Diagnosis Center of the First Affiliated Hospital of Zhengzhou University from January 2005 to February 2022. The clinical data, such as gender, age, clinical manifestations, and address, were collected. Multiplex ligation-dependent probe amplification, next generation sequencing panel, Sanger sequencing, and PCR amplification were used to detect the variants of the DMD gene in the patients, whose clinical information and gene detection results were descriptively analyzed. Results: The 2 690 patients included 2 648 males and 42 females, with an age of 6.0 (4.0, 9.0) years. The serum creatine kinase increased in all patients. Pathogenic DMD gene variants were detected in the 2 618 patients, including 1 875 cases (71.6%) large deletions, 231 cases (8.8%) duplications, and 512 cases (19.6%) small variants. Among the deletion variants, the deletion of 3 exons was the most common, accounting for 15.4% (288/1 875); and hotspot deletion involved exons 45 to 50, accounting for 6.3% (119/1 875). Exon 2 was the most common type duplication region, accounting for 13.0% (30/231). Small variants were distributed in all 79 exons of the DMD gene, with no hotspots. In addition, the 46 small variants were previously unreported. Conclusion: Exon deletion is the most common type of DMD gene variant, followed by small variants and exon duplication.

Genetic testing for fetal loss of heterozygosity using single nucleotide polymorphism array and whole-exome sequencing

The study explored the clinical significance of fetal loss of heterozygosity (LOH) identified by single-nucleotide polymorphism array (SNP array). We retrospectively reviewed data from pregnant women who underwent invasive diagnostic procedures at prenatal diagnosis centers in southeastern China from December 2016 to December 2021. SNP array was performed by the Affymetrix CytoScan 750 K array platform. Fetuses with LOH were further identified by parental verification, MS-MLPA, and/or trio whole-exome sequencing (trio-WES). The genetic results, fetal clinical manifestations, and perinatal outcome were analyzed. Of 11,062 fetuses, 106 (0.96%) had LOH exhibiting a neutral copy number, 88 (83.0%) had LOH in a single chromosome, whereas 18 (17.0%) had multiple LOHs on different chromosomes. Sixty-six fetuses had ultrasound anomalies (UAs), most frequently fetal growth restriction (18/66 (27.3%)). Parental SNP array verification was performed in 21 cases and trio-WES in 21 cases. Twelve cases had clinically relevant uniparental disomy, five had pathogenic variants, four had likely pathogenic variants, six had variants of unknown significance, and eight had identity by descent. The rate of adverse pregnancy outcomes in fetuses with LOH and UAs (24/66 (36.4%)) was higher than in those without UAs (6/40 (15.0%)) (p < 0.05). LOH is not uncommon. Molecular genetic testing techniques, including parental SNP array verification, trio-WES, methylation-specific multiplex ligation-dependent probe amplification, regular and systematic ultrasonic monitoring, and placental study, can accurately assess the prognosis and guide the management of the affected pregnancy.