Fetal Phenotype Research Articles

Exome Sequencing in Fetuses With Bilateral Renal Agenesis Identified on Second Trimester Ultrasound: ASingle Referral Center Experience.

To determine the exome sequencing results in fetuses with bilateral renal agenesis (BRA). This was a retrospective study of 14 cases with BRA diagnosed on second trimester anatomy ultrasound. All cases underwent invasive prenatal diagnosis. Genetic investigations were performed by chromosomal microarray analysis and trio exome sequencing. Clinical and laboratory data were collected and reviewed for these cases, including maternal demographics, prenatal sonographic findings, molecular sequencing results, and pregnancy outcomes. Pathogenic and likely pathogenic variants in three genes (FRAS1, PBX1, and KMT2D) were detected by exome sequencing in 6 (6/14) cases. One gene (FRAS1) is inherited in an autosomal recessive (AR) manner and two (PBX1and KMT2D) are autosomal dominant (AD); both AD variants were de novo. Only the FRAS1 variants were detected in more than one case. Variants in five cases were believed to be the cause of BRA, and the variants detected in PBX1 and KMT2D were likely the cause of fetal phenotype suggesting that the two genes can present with BRA. The yield of exome sequencing in our series is one third (4/12) after excluding two families with a previous family history. Fraser syndrome, resulting from FRAS1 variants, is the most common cause of genetic BRA identified in this specific cohort. The determination of genetic etiology will be valuable in the possible choices for pregnancy management and risk assessment of recurrence in future pregnancies.

Prenatal diagnosis of fetal skeletal anomalies via whole-exome sequencing in a tertiary referral center

The accurate prenatal diagnosis of skeletal anomaly (SKA) using prenatal imaging alone remains challenging. We aimed to investigate the efficacy of whole-exome sequencing (WES) in the prenatal molecular genetic diagnosis of skeletal system abnormalities, with or without additional ultrasound anomalies. All fetuses with SKA were subjected to sequential genetic tests, and after excluding fetal chromosomal abnormalities and clinically significant copy number variations (CNVs) consistent with the observed phenotype, the affected fetuses were further subjected to WES. The clinical features of fetal SKA were collected, and the results of molecular genetic testing and perinatal outcomes were analyzed. Following negative routine genetic test results of the 78 fetuses, trio-WES was conducted for 73 fetuses, and fetus-only WES (single WES) was performed for five fetuses due to parental refusal. Fetal skeletal system abnormalities in our cohort were subdivided into seven groups: 39 (50%) had short long bones, 14 (17.9%) had abnormal limb morphology, 4 (5.1%) had polydactyly, 4 (5.1%) had the absence of the radius tibia or tibiofibula, 5 (6.4%) had spine anomalies, 6 (7.7%) had strephenopodia, and 6 (7.7%) had multiple deformities. In total, we identified the molecular diagnoses for 32/78 fetuses with SKAs, and confirmed 41 pathogenic/likely pathogenic variants in 28 genes, including nine novel variants in our cohort. The overall diagnostic rate was 41% (32/78). Our findings demonstrate that WES can greatly improve the genetic diagnostic rate of fetal SKAs following routine genetic testing, which can comprehensively guide perinatal management and help assess the risk of recurrence in future pregnancies. Our data also provide a basis for the association between the SKA phenotype and related genotypes and expand the spectrum of fetal SKA phenotypes and related genes.

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.

A novel frameshift deletion variant of ARSL associated with X-linked recessive chondrodysplasia punctata 1: a case report and literature review of prenatal, confirmed cases

BackgroundX-linked recessive chondrodysplasia punctata 1 (CDPX1) is a rare congenital skeletal dysplasia characterized by stippled epiphyses, nasal hypoplasia, and brachytelephalangy. ARSL (formerly known as ARSE), a member of the sulfatase gene family located on Xp22.3, has been identified as the causative gene for CDPX1. The high clinical and genetic heterogeneity of CDPX1 presents a challenge to prenatal diagnosis.Case presentationA G1P0 woman in her 30s with an unremarkable prenatal course presented in the second trimester. Maternal diseases, tobacco, alcohol, and drug history during pregnancy were denied. Obstetrical ultrasound examination revealed a flattened nose and a flattened midface with echogenic alterations of lumbar spinous process in the fetus. Amniocentesis was performed for genetic testing. A normal karyotype and a negative result of CNV-seq were obtained. However, Whole exome sequencing (WES) in trios revealed a hemizygous ARSL variant [NM_000047.3:c.1108del p.(Trp370Glyfs*35)] in the fetus, which was maternally inherited as confirmed by Sanger sequencing. This variant was absent from the genomAD and HGMD databases. According to the ACMG guidelines, this variant was interpreted as likely pathogenic (PVS1 + PM2_Supporting). The couple decided to terminate the pregnancy. After induction of labour, a severe nasal hypoplasia was noted; and brachytelephalangy was not remarkable. Postmortem digital X-ray imaging revealed symmetrical stippled epiphyses of the vertebrae in all spine regions and enlargement of spinous process of L1-L4 vertebrae.ConclusionA novel frameshift deletion variant of ARSL and the associated fetal phenotype have been identified. This study provides useful information for prenatal diagnosis and genetic counseling of CDPX1.

Prenatal diagnosis and genetic analysis of two fetuses with Wolf-Hirschhorn syndrome

To explore the prenatal ultrasound phenotype and genetic basis of two fetuses with Wolf-Hirschhorn syndrome (WHS). A retrospective analysis was conducted on the ultrasound imaging data of two fetuses suspected for WHS at the Prenatal Diagnostic Center of Qingyuan People's Hospital in July 2017 and August 2019, respectively. Amniotic fluid samples of the two fetuses were subjected to chromosomal karyotyping and chromosomal microarray analysis (CMA). This study was approved by the Qingyuan People's Hospital (Ethics No. IRB-2022-064). Prenatal ultrasound examination of the two fetuses had consistently revealed WHS-associated traits including intrauterine growth restriction (IUGR), craniofacial abnormalities and cardiovascular anomalies. Karyotyping analysis suggested that both fetuses had harbored cryptic chromosomal translocations involving partial deletion of 4p. And parental verification revealed that it was de novo for fetus 1 and paternal for fetus 2. CMA has confirmed that fetus 1 had an approximately 8.7 Mb deletion at 4p16.3p16.1 and a 6.8 Mb duplication at 8p23.1p23.1, whilst fetus 2 had a 20.05 Mb deletion at 4p16.3p15.31 and a 7.66 Mb duplication at 9p24.3p24.1. The karyotype of fetus 1 was determined as 46,XN,der(4)t(4;8)(p16.1;p23.1)dn.arr[hg19]4p16.3p16.1(68345_8721580)×1, 8p23.3p23.1(158048_6933745)×3, and that of fetus 2 was determined as 46,XN,der(4)t(4;9)(p15.3;p24)pat.arr[hg19]4p16.3p15.31(68345_20116061)×1, 9p24.3p24.1(208454_7868292)×3. The 4p deletion is probably the main cause for the WHS phenotype in both fetuses. WHS should be suspected when IUGR, renal anomalies, craniofacial and cardiovascular abnormalities are detected upon prenatal ultrasound screening.

Identification of a novel intronic variant in COL4A2 gene associated with fetal severe cerebral encephalomalacia and subdural hemorrhage

BackgroundGenetic variants in COL4A2 are less common than those of COL4A1 and their fetal clinical phenotype has not been well described to date. We present a fetus from China with an intronic variant in COL4A2 associated with a prenatal diagnosis of severe cerebral encephalomalacia and subdural hemorrhage.MethodsWhole exome sequencing (WES) was applied to screen potential genetic causes. Bioinformatic analysis was performed to predict the pathogenicity of the variant. In in vitro experiment, the minigene assays were performed to assess the variant’s effect.ResultsIn this proband, we observed ventriculomegaly, subdural hemorrhage, and extensive encephalomalacia that initially suggested cerebral hypoxic-ischemic and/or hemorrhagic lesions. WES identified a de novo heterozygous variant c.549 + 5G > A in COL4A2 gene. This novel variant leads to the skipping of exon 8, which induces the loss of 24 native amino acids, resulting in a shortened COL4A2 protein (p.Pro161_Gly184del).ConclusionOur study demonstrated that c.549 + 5G > A in COL4A2 gene is a disease-causing variant by aberrant splicing. This finding enriches the variant spectrum of COL4A2 gene, which not only improves the understanding of the fetal neurological disorders associated with hypoxic-ischemic and hemorrhagic lesions from a clinical perspective but also provides guidance on genetic diagnosis and counseling.

Characterization of the Prenatal Ultrasound Phenotype Associated With 7q11.23 Microduplication Syndrome and Williams-Beuren Syndrome.

This study aimed to characterize the intrauterine phenotype of fetuses with 7q11.23 microduplication syndrome and Williams-Beuren syndrome (WBS) to provide insight into prenatal genotype and phenotype correlations in the 7q11.23 region. Seven fetuses with 7q11.23 microduplication syndrome and sixteen with WBS were diagnosed via array comparative genomic hybridization (array CGH) or copy number variation sequencing (CNV-seq) at our center. Clinical data were also systematically collected and analyzed, including intrauterine phenotype, pregnancy outcome, and inheritance. In our cases, the most common prenatal ultrasound feature of 7q11.23 microduplication syndrome was cardiovascular defects; less frequent features included choroid plexus cysts, anencephaly, bilateral pyelectasis, and cervical lymphatic hygroma. On the other hand, WBS was mainly associated with cardiovascular defects and intrauterine growth retardation. Other clinical phenotypes included hypoechoic frontal horn of the right lateral ventricle, crossed fused renal ectopia, hyperechogenic bowel, hyperechogenic right thoracic cavity, and hyperechogenic hepatic parenchyma/intrahepatic duct wall. Our study describes a series of new ultrasound features identified prenatally in fetuses with 7q11.23 microduplications and microdeletions with the intent of expanding the prenatal phenotype associated with copy number variants in this chromosomal region. Additional studies are needed to clearly delineate specific prenatal features associated with these rare genetic entities.

Molecular diagnostic yield of exome sequencing in a Chinese cohort of 512 fetuses with anomalies

BackgroundCurrently, whole exome sequencing has been performed as a helpful complement in the prenatal setting in case of fetal anomalies. However, data on its clinical utility remain limited in practice. Herein, we reported our data of fetal exome sequencing in a cohort of 512 trios to evaluate its diagnostic yield.MethodsIn this retrospective cohort study, the couples performing prenatal exome sequencing were enrolled. Fetal phenotype was classified according to ultrasound and magnetic resonance imaging findings. Genetic variants were analyzed based on a phenotype-driven followed by genotype-driven approach in all trios.ResultsA total of 97 diagnostic variants in 65 genes were identified in 69 fetuses, with an average detection rate of 13.48%. Skeletal and renal system were the most frequently affected organs referred for whole exome sequencing, with the highest diagnostic rates. Among them, short femur and kidney cyst were the most common phenotype. Fetal growth restriction was the most frequently observed phenotype with a low detection rate (4.3%). Exome sequencing had limited value in isolated increased nuchal translucency and chest anomalies.ConclusionsThis study provides our data on the detection rate of whole exome sequencing in fetal anomalies in a large cohort. It contributes to the expanding of phenotypic and genotypic spectrum.

Novel fetal phenotype of TAF8 deficiency.

TAF8 is part of the transcription factor TFIID complex. TFIID is crucial for recruiting the transcription factor complex containing RNA polymerase II. TAF8 deficiency was recently reported as causing a severe neurodevelopmental disorder in eight patients. We have ascertained three Muslim Arab couples with fetal brain malformations. Clinical, imaging, pathological, biochemical, and molecular analyses were performed. Pre-natal ultrasound performed in four pregnancies revealed massive cerebellar atrophy, microcephaly, cerebral and corpus callosum (CC) anomalies. Pre-natal MRI studies of two of the affected fetuses confirmed microcephaly, small vermis, abnormal sulcation pattern with malformation, and shortening of CC. The fetuses were found to carry a novel likely pathogenic homozygous variant (c.45 + 5 G > A) of TAF8, predicted to affect splicing and presenting autosomal recessive inheritance. Post-mortem examinations confirmed the imaging studies in one fetus. Dysmorphic features including hypertelorism, wide nasal bridge, clinodactyly, and hirsutism were present. Western blotting analysis in fibroblasts of an affected fetus demonstrated a significant reduction of TAF8 protein. We determined high expression levels of TAF8 which progressively diminish in fetal brains of WT mice. We report for the first time the fetal presentation of TAF8 deficiency due to a novel genetic variant, and study TAF8 presence during fetal and neonatal periods in mouse brains. Our study may contribute to understanding the role of TAF8 in the developing human brain.

Prenatal diagnosis of 17q12 copy number variants in fetuses via chromosomal microarray analysis - A retrospective cohort study and literature review

Purpose17q12 copy number variants (CNVs) have variable presentations and incomplete penetrance, challenging prenatal counseling and management. This study aims to investigate the intrauterine phenotype. MethodsWe included 48 fetuses diagnosed with 17q12 microdeletion or microduplication by chromosomal microarray analysis. ResultsFor 17q12 deletion, renal anomalies were found in 35 fetuses (35/37, 94.6 %), with hyperechogenic kidneys (HEK, 28/37, 75.7 %) and multicystic dysplastic kidneys (17/37, 45.9 %) being the most common findings. Duodenal obstruction (DO) was most frequently combined in 17q12 duplication fetuses. In addition, cardiac abnormalities were the first reported prenatal phenotype in 17q12 duplication fetuses. ConclusionOur study shows that HEK and DO are the most predominant presentations of 17q12 deletion and duplication, respectively, and cardiac structural abnormalities may be associated with the latter. Although 17q12 CNVs have incomplete penetrance and variable expressivity and may be mainly involved in neurodevelopmental disorders, their short-term prognosis appears positive.

Oncofetal morphogenesis similar to embryonic gut formation by a subpopulation of DLD-1 human colon cancer cells

Cancer stem cells (CSC) are thought to be responsible for cancer phenotypes and cellular heterogeneity. Here we demonstrate that the human colon cancer cell line DLD1 contains two types of CSC-like cells that undergo distinct morphogenesis in the reconstituted basement membrane gel Matrigel. In our method with cancer cell spheroids, the parent cell line (DLD1-P) developed grape-like budding structures, whereas the other (DLD1-Wm) and its single-cell clones dynamically developed worm-like ones. Gene expression analysis suggested that the former mimicked intestinal crypt-villus morphogenesis, while the latter mimicked embryonic hindgut development. The organoids of DLD1-Wm cells rapidly extended in two opposite directions by expressing dipolar proteolytic activity. The invasive morphogenesis required the expression of MMP-2 and CD133 genes and ROCK activity. These cells also exhibited gastrula-like morphogenesis even in two-dimensional cultures without Matrigel. Moreover, the two DLD1 cell lines showed clear differences in cellular growth, tumor growth and susceptibility to paclitaxel. This study also provides a simple organoid culture method for human cancer cell lines. HT-29 and other cancer cell lines underwent characteristic morphogenesis in direct contact with normal fibroblasts. Such organoid cultures would be useful for investigating the nature of CSCs and for screening anti-cancer drugs. Our results lead to the hypothesis that CSC-like cells with both invasive activity and a fetal phenotype, i. e. oncofetal CSCs, are generated in some types of colon cancers.

Cytogenetically Balanced Reciprocal Translocation Could Hide Molecular Genomic Unbalances: Implications for Foetal Phenotype Correlation.

When an increased nuchal translucency (>3.00 mm) is observed during the echographic examination of a foetus in the first trimester of pregnancy, an increased risk of chromosomopathy is considered, and the pregnant woman is offered the possibility of an invasive investigation. Here, we focused our attention on prenatal diagnosis issues in cases of foetuses with cytogenetically balanced reciprocal translocations. We report the finding of a cytogenetically balanced, de facto genomically unbalanced translocation that poses a challenge in a case of prenatal diagnosis, changing the risk of Down syndrome in a Zellweger syndromic spectrum risk (PEX3 deletion). At term, a healthy baby was born. This case teaches that prenatal diagnosis in cases of foetuses at increased risk of chromosomal abnormality imperatively requires molecular investigation in addition to a morphological karyotype.

Fetal agenesis of corpus callosum: chromosomal copy number abnormalities and postnatal follow-up

ObjectiveAgenesis of the corpus callosum (ACC) is an anomaly that can occur in fetuses during pregnancy. However, there is currently no treatment for fetal ACC. Therefore, we conducted a retrospective analysis of obstetric outcomes of fetal ACC to explore the relationship between fetal ACC phenotypes and chromosomal copy number abnormalities.Methods and resultsAmniotic fluid or umbilical cord blood were extracted from pregnant women with fetal ACC for karyotype analysis and chromosomal microarray analysis (CMA). Among the 48 fetuses with ACC, 22 (45.8%, 22/48) had isolated ACC, and 26 (54.2%, 26/48) had non-isolated ACC. Chromosomal abnormalities were detected via karyotype analysis in four cases. In addition to the four cases of pathogenic copy number variations (CNVs) detected using karyotype analysis, CMA revealed two cases of pathogenic CNVs with 17q12 microduplication and 16p12.2 microdeletion. The obstetric outcomes of 26 patients with non-isolated ACC were followed up, and 17 chose to terminate the pregnancy. In addition, seven of the nine cases with non-isolated ACC showed no obvious abnormality during postnatal follow-up, whereas only one case with normal CMA showed an abnormal phenotype at six months. Of the 22 patients with isolated ACC, six chose to terminate the pregnancy. Postnatal follow-up of 16 isolated ACC cases revealed only one with benign CNV, presenting with intellectual disability.ConclusionPregnant women with fetal ACC should be offered prenatal CMA, particularly non-isolated ACC. Patients with ACC should undergo prolonged postnatal follow-up, and appropriate intervention should be provided if necessary.

Prenatal diagnosis and genetic analysis of small supernumerary marker chromosomes in the eastern chinese han population: A retrospective study of 36 cases.

Small supernumerary marker chromosomes (sSMCs) are additional chromosomes with unclear structures and origins, and their correlations with clinical fetal phenotypes remain incompletely understood, which reduces the accuracy of genetic counseling. We conducted a retrospective analysis of a cohort of 36 cases of sSMCs diagnosed in our center. We performed G-banding and chromosomal microarray analysis (CMA). The resulting karyotypes were compared with case reports in the literature and various databases including OMIM, DECIPHER, ClinVar, ClinGen, ISCA, DGV, and PubMed. Karyotype analysis data revealed that 19 out of 36 fetuses were mosaic. Copy number variants (CNVs) analysis results showed that 27 out of 36 fetuses harbored pathogenic/likely pathogenic variants. Among these 27 cases, 11 fetuses carried sex chromosome-related CNVs, including 4 female cases exhibiting Turner syndrome phenotypes and 7 cases showing Y chromosome deletions. In the remaining 16 fetuses with autosomal CNVs, 9 fetuses carried variants associated with Cat eye syndrome, Emanuel syndrome, Tetrasomy 18p, and 15q11-q13 duplication syndrome. Among these, 22 fetuses were terminated, and the remaining 5 fetuses were delivered and developed normally. Additionally, we identified a few variants with unclear pathogenicity. Cytogenetic analysis is essential for identifying the pathogenicity of sSMCs and increasing the accuracy of genetic counseling.

HDAC1/2/3-mediated downregulation of neurogranin is involved in cognitive impairment in offspring exposed to maternal subclinical hypothyroidism.

Subclinical hypothyroidism (SCH) in pregnancy is the most common form of thyroid dysfunction in pregnancy, which can affect fetal nervous system development and increase the risk of neurodevelopmental disorders after birth. However, the mechanism of the effect of maternal subclinical hypothyroidism on fetal brain development and behavioral phenotypes is still unclear and requires further study. In this study, we constructed a mouse model of maternal subclinical hypothyroidism by exposing dams to drinking water containing 50 ppm propylthiouracil (PTU) during pregnancy and found that its offspring were accompanied by severe cognitive deficits by behavioral testing. Mechanistically, gestational SCH resulted in the upregulation of protein expression and activity of HDAC1/2/3 in the hippocampus of the offspring. ChIP analysis revealed that H3K9ac on the neurogranin (Ng) promoter was reduced in the hippocampus of the offspring of SCH, with a significant reduction in Ng protein, leading to reduced expression levels of synaptic plasticity markers PSD95 (a membrane-associated protein in the postsynaptic density) and SYN (synaptophysin, a specific marker for presynaptic terminals), and impaired synaptic plasticity. In addition, administration of MS-275 (an HDAC1/2/3-specific inhibitor) to SCH offspring alleviated impaired synaptic plasticity and cognitive dysfunction in offspring. Thus, our study suggests that maternal subclinical hypothyroidism may mediate offspring cognitive dysfunction through the HDAC1/2/3-H3K9ac-Ng pathway. Our study contributes to the understanding of the signaling mechanisms underlying maternal subclinical hypothyroidism-mediated cognitive impairment in the offspring.

A DIO2 missense mutation and its impact on fetal response to PRRSV infection

BackgroundPorcine reproductive and respiratory syndrome virus 2 (PRRSV-2) infection during late gestation substantially lowers fetal viability and survival. In a previous genome-wide association study, a single nucleotide polymorphism on chromosome 7 was significantly associated with probability of fetuses being viable in response to maternal PRRSV-2 infection at 21 days post maternal inoculation. The iodothyronine deiodinase 2 (DIO2) gene, located ~ 14 Kilobase downstream of this SNP, was selected as a priority candidate related to fetal susceptibility following maternal PRRSV-2 infection. Our objectives were to identify mutation(s) within the porcine DIO2 gene and to determine if they were associated with fetal outcomes after PRRSV-2 challenge. Sequencing of the DIO2, genotyping identified variants, and association of DIO2 genotypes with fetal phenotypes including DIO2 mRNA levels, viability, survival, viral loads, cortisol and thyroid hormone levels, and growth measurements were conducted.ResultsA missense variant (p.Asn91Ser) was identified in the parental populations from two independent PRRSV-2 challenge trials. This variant was further genotyped to determine association with fetal PRRS outcomes. DIO2 mRNA levels in fetal heart and kidney differed by the genotypes of Asn91Ser substitution with significantly greater DIO2 mRNA expression in heterozygotes compared with wild-type homozygotes (P < 0.001 for heart, P = 0.002 for kidney). While Asn91Ser did not significantly alter fetal viability and growth measurements, interaction effects of the variant with fetal sex or trial were identified for fetal viability or crown rump length, respectively. However, this mutation was not related to dysregulation of the hypothalamic-pituitary-adrenal and thyroid axis, indicated by no differences in circulating cortisol, T4, and T3 levels in fetuses of the opposing genotypes following PRRSV-2 infection.ConclusionsThe present study suggests that a complex relationship among DIO2 genotype, DIO2 expression, fetal sex, and fetal viability may exist during the course of fetal PRRSV infection. Our study also proposes the increase in cortisol levels, indicative of fetal stress response, may lead to fetal complications, such as fetal compromise, fetal death, or premature farrowing, during PRRSV infection.

SERPINA11 related novel serpinopathy - A perinatal lethal disorder.

SERPINA11 is a hitherto poorly characterised gene belonging to Clade A of the SERPIN superfamily, with unknown expression pattern and functional significance. We report a perinatal lethal phenotype in two foetuses from the same family associated with a biallelic loss of function variant in SERPINA11, and provide functional evidence to support its candidature as a Mendelian disorder. The SERPINA11 variant-associated foetal phenotype is characterised by gross and histopathological features of extracellular matrix disruption. Western blot and immunofluorescence analyses revealed SERPINA11 expression in multiple mouse tissues, with pronounced expression in the bronchiolar epithelium. We observed a significant decrease in SERPINA11 immunofluorescence in the affected foetal lung compared with a healthy gestation-matched foetus. Protein expression data from HEK293T cell lines following site-directed mutagenesis support the loss of function nature of the variant. Transcriptome analysis from the affected foetal liver indicated the possibility of reduced SERPINA11 transcript abundance. This novel serpinopathy appears to be a consequence of the loss of inhibition of serine proteases involved in extracellular matrix remodelling, revealing SERPINA11 as a protease inhibitor critical for embryonic development.

Significant improvement of cardiac outflow tract septation defects in a DiGeorge syndrome model after minoxidil treatment

The T-BOX transcription factor TBX1 is essential for the development of the pharyngeal apparatus and it is haploinsufficient in DiGeorge syndrome (DGS), a developmental anomaly associated with congenital heart disease and other abnormalities. The murine model recapitulates the heart phenotype and showed collagen accumulation.We first used a cellular model to study gene expression during cardiogenic differentiation of WT and Tbx1−/− mouse embryonic stem cells. Then we used a mouse model of DGS to test whether interfering with collagen accumulation using an inhibitor of lysyl hydroxylase would modify the cardiac phenotype of the mutant.We found that loss of Tbx1 in a precardiac differentiation model was associated with up regulation of a subset of ECM-related genes, including several collagen genes. In the in vivo model, early prenatal treatment with Minoxidil, a lysyl hydroxylase inhibitor, ameliorated the cardiac outflow tract septation phenotype in Tbx1 mutant fetuses, but it had no effect on septation in WT fetuses. We conclude that TBX1 suppresses a defined subset of ECM-related genes. This function is critical for OFT septation because the inhibition of collagen cross-linking in the mutant reduces significantly the penetrance of septation defects.

Multiparametric prenatal imaging characterization of fetal brain edema in Chiari II malformation might help to select candidates for fetal surgery

ObjectiveTo identify brain edema in fetuses with Chiari II malformation using a multiparametric approach including structural T2-weighted, diffusion tensor imaging (DTI) metrics, and MRI-based radiomics.MethodsA single-center retrospective review of MRI scans obtained in fetuses with Chiari II was performed. Brain edema cases were radiologically identified using the following MR criteria: brain parenchymal T2 prolongation, blurring of lamination, and effacement of external CSF spaces. Fractional anisotropy (FA) values were calculated from regions of interest (ROI), including hemispheric parenchyma, internal capsule, and corticospinal tract, and compared group-wise. After 1:1 age matching and manual single-slice 2D segmentation of the fetal brain parenchyma using ITK-Snap, radiomics features were extracted using pyradiomics. Areas under the curve (AUCs) of the features regarding discriminating subgroups were calculated.ResultsNinety-one fetuses with Chiari II underwent a total of 101 MRI scans at a median gestational age of 24.4 weeks and were included. Fifty scans were visually classified as Chiari II with brain edema group and showed significantly reduced external CSF spaces compared to the nonedema group (9.8 vs. 18.3 mm, p < 0.001). FA values of all used ROIs were elevated in the edema group (p < 0.001 for all ROIs). The 10 most important radiomics features showed an AUC of 0.81 (95%CI: 0.71, 0.91) for discriminating between Chiari II fetuses with and without edema.ConclusionsBrain edema in fetuses with Chiari II is common and radiologically detectable on T2-weighted fetal MRI sequences, and DTI-based FA values and radiomics features provide further evidence of microstructure differences between subgroups with and without edema.Clinical relevance statementA more severe phenotype of fetuses with Chiari II malformation is characterized by prenatal brain edema and more postnatal clinical morbidity and disability. Fetal brain edema is a promising prenatal MR imaging biomarker candidate for optimizing the risk-benefit evaluation of selection for fetal surgery.Key PointsBrain edema of fetuses prenatally diagnosed with Chiari II malformation is a common, so far unknown, association.DTI metrics and radiomics confirm microstructural differences between the brains of Chiari II fetuses with and without edema.Fetal brain edema may explain worse motor outcomes in this Chiari II subgroup, who may substantially benefit from fetal surgery.Graphical

Artificial intelligence-based diagnosis in fetal pathology using external ear shapes.

Here we trained an automatic phenotype assessment tool to recognize syndromic ears in two syndromes in fetuses-=CHARGE and Mandibulo-Facial Dysostosis Guion Almeida type (MFDGA)-versus controls. We trained an automatic model on all profile pictures of children diagnosed with genetically confirmed MFDGA and CHARGE syndromes, and a cohort of control patients, collected from 1981 to 2023 in Necker Hospital (Paris) with a visible external ear. The model consisted in extracting landmarks from photographs of external ears, in applying geometric morphometry methods, and in a classification step using machine learning. The approach was then tested on photographs of two groups of fetuses: controls and fetuses with CHARGE and MFDGA syndromes. The training set contained a total of 1489 ear photographs from 526 children. The validation set contained a total of 51 ear photographs from 51 fetuses. The overall accuracy was 72.6% (58.3%-84.1%, p<0.001), and 76.4%, 74.9%, and 86.2% respectively for CHARGE, control and MFDGA fetuses. The area under the curves were 86.8%, 87.5%, and 90.3% respectively for CHARGE, controls, and MFDGA fetuses. We report the first automatic fetal ear phenotyping model, with satisfactory classification performances. Further validations are required before using this approach as a diagnostic tool.