RNA-seq analysis-based study on the effects of gestational diabetes mellitus on macrosomia.

Background: Both the mother and the infant are negatively impacted by macrosomia. Macrosomia is three times as common in hyperglycemic mothers as in normal mothers. This study sought to determine why hyperglycemic mothers experienced higher macrosomia. Methods: Hematoxylin and Eosin staining was used to detect the placental structure of normal mother(NN), mothers who gave birth to macrosomia(NM), and mothers who gave birth to macrosomia and had hyperglycemia (DM). The gene expressions of different groups were detected by RNA-seq. The differentially expressed genes (DEGs) were screened with DESeq2 R software and verified by qRT-PCR. The STRING database was used to build protein-protein interaction networks of DEGs. The Cytoscape was used to screen the Hub genes of the different group. Results: The NN group's placental weight differed significantly from that of the other groups. The structure of NN group's placenta is different from that of the other group, too. 614 and 3207 DEGs of NM and DM, respectively, were examined in comparison to the NN group. Additionally, 394 DEGs of DM were examined in comparison to NM. qRT-PCR verified the results of RNA-seq. Nucleolar stress appears to be an important factor in macrosomia, according on the results of KEGG and GO analyses. The results revealed 74 overlapped DEGs that acted as links between hyperglycemia and macrosomia, and 10 of these, known as Hub genes, were key players in this process. Additionally, this analysis believes that due of their close connections, non-overlapping Hubs shouldn't be discounted. Conclusion: In diabetic mother, ten Hub genes (RPL36, RPS29, RPL8 and so on) are key factors in the increased macrosomia in hyperglycemia. Hyperglycemia and macrosomia are linked by 74 overlapping DEGs. Additionally, this approach contends that non-overlapping Hubs shouldn't be ignored because of their tight relationships.

Interaction effects of MTHFR C677T and A1298C polymorphisms with maternal glycated haemoglobin levels on adverse birth outcomes.

AIMS: The role of maternal genetic factors in the association between high glycated haemoglobin (HbA1c) levels and adverse birth outcomes remains unclear. MATERIALS AND METHODS: In this study, the maternal HbA1c levels of 5108 normoglycemic pregnant women in China were measured, and A1298C and C677T polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene were genotyped. RESULTS: Elevated HbA1c levels during the second trimester were associated with increased risks of macrosomia, large-for-gestational age (LGA), preterm birth (PTB), and reduced gestational age (p < 0.05). Pregnant women with MTHFR A1298C AA or C677T CT + TT genotypes were susceptible to adverse pregnancy outcomes related to HbA1c levels. Among pregnant women with the A1298C AA genotype, each standard deviation (SD) increase in HbA1c levels increased the risk of PTB by 1.32-times and reduced the gestational age by 0.11 weeks (p < 0.05). For MTHFR C677T CC + TT genotype carriers, higher HbA1c levels were associated with 1.49-, 1.24-, and 1.23-times increased risks of macrosomia, LGA, and PTB, respectively (p < 0.05). A U-shaped curve for PTB risk in relation to HbA1c levels was observed among the C677T CC + TT participants, with a cut-off value of 4.58%. Among subjects with the A1298C AA genotype combined with the C677T CT + TT genotype, each SD increase in HbA1c levels was associated with 1.40 and 1.37-times increased risks of LGA and PTB, respectively. CONCLUSIONS: Our findings highlight the importance of glycaemic control during pregnancy and the potential impact of genetic factors on birth outcomes. However, further large-scale studies are required to confirm these findings.

Methylation analysis by targeted bisulfite sequencing in large for gestational age (LGA) newborns: the LARGAN cohort.

BACKGROUND: In 1990, David Barker proposed that prenatal nutrition is directly linked to adult cardiovascular disease. Since then, the relationship between adult cardiovascular risk, metabolic syndrome and birth weight has been widely documented. Here, we used the TruSeq Methyl Capture EPIC platform to compare the methylation patterns in cord blood from large for gestational age (LGA) vs adequate for gestational age (AGA) newborns from the LARGAN cohort. RESULTS: We found 1672 differentially methylated CpGs (DMCs) with a nominal p < 0.05 and 48 differentially methylated regions (DMRs) with a corrected p < 0.05 between the LGA and AGA groups. A systems biology approach identified several biological processes significantly enriched with genes in association with DMCs with FDR < 0.05, including regulation of transcription, regulation of epinephrine secretion, norepinephrine biosynthesis, receptor transactivation, forebrain regionalization and several terms related to kidney and cardiovascular development. Gene ontology analysis of the genes in association with the 48 DMRs identified several significantly enriched biological processes related to kidney development, including mesonephric duct development and nephron tubule development. Furthermore, our dataset identified several DNA methylation markers enriched in gene networks involved in biological pathways and rare diseases of the cardiovascular system, kidneys, and metabolism. CONCLUSIONS: Our study identified several DMCs/DMRs in association with fetal overgrowth. The use of cord blood as a material for the identification of DNA methylation biomarkers gives us the possibility to perform follow-up studies on the same patients as they grow. These studies will not only help us understand how the methylome responds to continuum postnatal growth but also link early alterations of the DNA methylome with later clinical markers of growth and metabolic fitness.

Germline (epi)genetics reveals high predisposition in females: a 5-year, nationwide, prospective Wilms tumour cohort.

BACKGROUND: Studies suggest that Wilms tumours (WT) are caused by underlying genetic (5%-10%) and epigenetic (2%-29%) mechanisms, yet studies covering both aspects are sparse. METHODS: We performed prospective whole-genome sequencing of germline DNA in Danish children diagnosed with WT from 2016 to 2021, and linked genotypes to deep phenotypes. RESULTS: Of 24 patients (58% female), 3 (13%, all female) harboured pathogenic germline variants in WT risk genes (FBXW7, WT1 and REST). Only one patient had a family history of WT (3 cases), segregating with the REST variant. Epigenetic testing revealed one (4%) additional patient (female) with uniparental disomy of chromosome 11 and Beckwith-Wiedemann syndrome (BWS). We observed a tendency of higher methylation of the BWS-related imprinting centre 1 in patients with WT than in healthy controls. Three patients (13%, all female) with bilateral tumours and/or features of BWS had higher birth weights (4780 g vs 3575 g; p=0.002). We observed more patients with macrosomia (>4250 g, n=5, all female) than expected (OR 9.98 (95% CI 2.56 to 34.66)). Genes involved in early kidney development were enriched in our constrained gene analysis, including both known (WT1, FBXW7) and candidate (CTNND1, FRMD4A) WT predisposition genes. WT predisposing variants, BWS and/or macrosomia (n=8, all female) were more common in female patients than male patients (p=0.01). CONCLUSION: We find that most females (57%) and 33% of all patients with WT had either a genetic or another indicator of WT predisposition. This emphasises the need for scrutiny when diagnosing patients with WT, as early detection of underlying predisposition may impact treatment, follow-up and genetic counselling.

Investigation of a pervasive immune, cardiac, and behavioral phenotype in Beckwith-Wiedemann syndrome: A case report.

Beckwith-Wiedemann syndrome (BWS) is an imprinting disorder caused by genetic and epigenetic changes in the chromosome 11p15 region. The syndrome is characterized by a wide range of features including macrosomia, lateralized overgrowth, abdominal wall defects, and hypoglycemia. BWS presentation is variable across the entire patient population, but certain areas including immunology, cardiology, and behavioral differences are not well characterized. We present a case of a male patient with BWS due to the most common cause of BWS, loss of methylation at imprinting center 2 with a variable phenotype, including classical features (macrosomia, macroglossia, omphalocele, placentomegaly and mild lateralized overgrowth) in addition to uncommon features (immune deficiency, developmental delays, and pulmonary stenosis) not typically seen in BWS. This study defines a patient's clinical presentation and course and highlights the need to consider atypical organ systems in BWS as either an expansion of the phenotype or co-existing conditions to develop personalized care models.

Association of placental PPARα/γ and miR-27b expression with macrosomia in healthy pregnancy.

BACKGROUND: Peroxisomal proliferator-activated receptors (PPARs) and microRNAs (miRNAs) play important roles in the development of fetuses, whereas expression changes of PPARs and three miRNAs (miR-17, miR-27b and miR-34a) and whether these miRNAs regulate PPARs in non-GDM macrosomia placenta is unclear. METHODS: A case-control study was performed to collect information and placental tissues on mothers and newborns of non-GDM macrosomia and normal-birth-weight infants. In vitro HTR8-SVneo cellular model was used to detect the effects of miRNAs on PPARs expression. Quantitative real-time PCR (qRT-PCR) and western blot was applied to examine the expression levels of PPARs, miR-17, miR-27b, and miR-34a in placental tissues and cells. RESULTS: The PPARα/γ mRNA and protein levels were significantly up-regulated and miR-27b was down-regulated in the placenta of macrosomia group compared with in the control group, while no difference was observed in PPARß, miR-17, and miR-34a. After adjusting for confounding factors, low miR-27b and high PPARα/γ mRNA expression still increased the risk of macrosomia. The PPARα/γ protein levels presented a corresponding decrease or increase when cells were transfected with miR-27b mimic or inhibitor. CONCLUSIONS: Placental PPARα/γ and miR-27b expression were associated with non-GDM macrosomia and miR-27b probably promotes the occurrence of non-GDM macrosomia by regulating PPARα/γ protein. IMPACT: Low miR-27b and high PPARα/γ mRNA expression in the placenta were associated with higher risk of macrosomia. In vitro HTR8-SVneo cell experiment supported that miR-27b could negatively regulate the expression of PPARα and PPARγ protein. MiR-27b was probably involved in non-GDM macrosomia through negative regulation of PPARα/γ protein.

Genome-wide placental DNA methylations in fetal overgrowth and associations with leptin, adiponectin and fetal growth factors.

BACKGROUND: Fetal overgrowth "programs" an elevated risk of type 2 diabetes in adulthood. Epigenetic alterations may be a mechanism in programming the vulnerability. We sought to characterize genome-wide alterations in placental gene methylations in fetal overgrowth and the associations with metabolic health biomarkers including leptin, adiponectin and fetal growth factors. RESULTS: Comparing genome-wide placental gene DNA methylations in large-for-gestational-age (LGA, an indicator of fetal overgrowth, n = 30) versus optimal-for-gestational-age (OGA, control, n = 30) infants using the Illumina Infinium Human Methylation-EPIC BeadChip, we identified 543 differential methylation positions (DMPs; 397 hypermethylated, 146 hypomethylated) at false discovery rate < 5% and absolute methylation difference > 0.05 after adjusting for placental cell-type heterogeneity, maternal age, pre-pregnancy BMI and HbA1c levels during pregnancy. Twenty-five DMPs annotated to 20 genes (QSOX1, FCHSD2, LOC101928162, ADGRB3, GCNT1, TAP1, MYO16, NAV1, ATP8A2, LBXCOR1, EN2, INCA1, CAMTA2, SORCS2, SLC4A4, RPA3, UMAD1,USP53, OR2L13 and NR3C2) could explain 80% of the birth weight variations. Pathway analyses did not detect any statistically significant pathways after correcting for multiple tests. We validated a newly discovered differentially (hyper-)methylated gene-visual system homeobox 1 (VSX1) in an independent pyrosequencing study sample (LGA 47, OGA 47). Our data confirmed a hypermethylated gene-cadherin 13 (CDH13) reported in a previous epigenome-wide association study. Adiponectin in cord blood was correlated with its gene methylation in the placenta, while leptin and fetal growth factors (insulin, IGF-1, IGF-2) were not. CONCLUSIONS: Fetal overgrowth may be associated with a large number of altered placental gene methylations. Placental VSX1 and CDH13 genes are hypermethylated in fetal overgrowth. Placental ADIPOQ gene methylations and fetal circulating adiponectin levels were correlated, suggesting the contribution of placenta-originated adiponectin to cord blood adiponectin.

Performance of whole-genome promoter nucleosome profiling of maternal plasma cell-free DNA for prenatal noninvasive prediction of fetal macrosomia: a retrospective nested case-control study in mainland China.

BACKGROUND: Fetal macrosomia is common occurrence in pregnancy, which is associated with several adverse prognosis both of maternal and neonatal. While, the accuracy of prediction of fetal macrosomia is poor. The aim of this study was to develop a reliable noninvasive prediction classifier of fetal macrosomia. METHODS: A total of 3600 samples of routine noninvasive prenatal testing (NIPT) data at 12+ 0-27+ 6 weeks of gestation, which were subjected to low-coverage whole-genome sequencing of maternal plasma cell-free DNA (cfDNA), were collected from three independent hospitals. We identified set of genes with significant differential coverages by comparing the promoter profiling between macrosomia cases and controls. We selected genes to develop classifier for noninvasive predicting, by using support vector machine (SVM) and logistic regression models, respectively. The performance of each classifier was evaluated by area under the curve (AUC) analysis. RESULTS: According to the available follow-up results, 162 fetal macrosomia pregnancies and 648 matched controls were included. A total of 1086 genes with significantly differential promoter profiling were found between pregnancies with macrosomia and controls (p < 0.05). With the AUC as a reference，the classifier based on SVM (CMA-A2) had the best performance, with an AUC of 0.8256 (95% CI: 0.7927-0.8586). CONCLUSIONS: Our study provides that assessing the risk of fetal macrosomia by whole-genome promoter nucleosome profiling of maternal plasma cfDNA based on low-coverage next-generation sequencing is feasible.

Epigenetic and Transcriptomic Programming of HSC Quiescence Signaling in Large for Gestational Age Neonates.

Excessive fetal growth is associated with DNA methylation alterations in human hematopoietic stem and progenitor cells (HSPC), but their functional impact remains elusive. We implemented an integrative analysis combining single-cell epigenomics, single-cell transcriptomics, and in vitro analyses to functionally link DNA methylation changes to putative alterations of HSPC functions. We showed in hematopoietic stem cells (HSC) from large for gestational age neonates that both DNA hypermethylation and chromatin rearrangements target a specific network of transcription factors known to sustain stem cell quiescence. In parallel, we found a decreased expression of key genes regulating HSC differentiation including EGR1, KLF2, SOCS3, and JUNB. Our functional analyses showed that this epigenetic programming was associated with a decreased ability for HSCs to remain quiescent. Taken together, our multimodal approach using single-cell (epi)genomics showed that human fetal overgrowth affects hematopoietic stem cells' quiescence signaling via epigenetic programming.

Downregulation of lncRNA USP2­AS1 in the placentas of pregnant women with non­diabetic fetal macrosomia promotes trophoblast cell proliferation.

Macrosomia is a common perinatal complication, with a series of adverse effects on newborns and pregnant women. However, the effects of long non­coding RNAs (lncRNAs) on non­diabetic fetal macrosomia (NDFMS) remain unclear. The aim of the present study was to investigate whether aberrant lncRNA expression in the placenta is involved in the pathogenesis of NDFMS and to elucidate its biological mechanisms. The expression profile of lncRNAs in the placentas of pregnant women with NDFMS was investigated using an Agilent Human LncRNA Microarray. Differentially expressed lncRNAs were selected for validation using reverse transcription­quantitative polymerase chain reaction (RT­qPCR). Additionally, the function of lncRNA ubiquitin­specific peptidase 2 antisense RNA 1 (USP2­AS1) was investigated using a trophoblast cell line. The results revealed that 763 lncRNAs were upregulated and 129 lncRNAs were downregulated in the placentas of women in the NDFMS group (|FC| ≥2.0). A total of 10 lncRNAs (|FC| ≥4.0, signal value ≥50) were selected for validation using two­stage RT­qPCR, indicating that the expression trends of the 10 differentially expressed lncRNAs in the NDFMS group (n=8 vs. 8 and 48 vs. 48) were consistent with the microarray data. In addition, a significant downregulation in the levels of lncRNA USP2­AS1 was observed in both the microarray data and second­stage verification. The overexpression of lncRNA USP2­AS1 induced G1 phase cell cycle arrest and the number of cells entering S phase was reduced. In addition, the viability of HTR­8/SVneo cells was significantly inhibited when lncRNA USP2­AS1 was overexpressed. Therefore, these findings demonstrated that lncRNAs were significantly differentially expressed in the placentas of pregnant women with NDFMS and that the downregulation of lncRNA USP2­AS1 may be involved in the pathogenesis of NDFMS, by promoting trophoblast cell viability.

Exosomal RNA Expression Profiles and Their Prediction Performance in Patients With Gestational Diabetes Mellitus and Macrosomia.

Introduction: Exosomes are cell-derived vesicles that are present in many biological fluids. Exosomal RNAs in cord blood may allow intercellular communication between mother and fetus. We aimed to establish exosomal RNA expression profiles in cord blood from patients with gestational diabetes mellitus and macrosomia (GDM-M) and evaluate their prediction performance. Methods: We used microarray technology to establish the differential messenger RNA (mRNA), long non-coding RNA (lncRNA), and circular RNA (circRNA) expression profiles in cord blood exosomes from 3 patients with GDM-M compared with 3 patients with GDM and normal neonatal weight, followed by qPCR validation in an additional 40 patients with GDM. Logistic regression, receiver operating characteristic (ROC) curves, and graphical nomogram were applied to evaluate the performance of exosomal RNA (in peripheral blood) in macrosomia prediction. Results: A total of 98 mRNAs, 372 lncRNAs, and 452 circRNAs were differentially expressed in cord blood exosomes from patients with GDM-M. Pathway analysis based on screening data showed that the differential genes were associated with Phosphatidylinositol 3'-kinase (PI3acK)-Akt signaling pathway, Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling pathway, Transforming growth factor (TGF)-beta signaling pathway, insulin resistance, glycerolipid metabolism, fatty acid degradation, and mammalian target of rapamycin (mTOR) signaling pathway. After validation by qPCR, the expressions of GDF3, PROM1, AC006064.4, lnc-HPS6-1:1, and circ_0014635 were significantly increased and the expression of lnc-ZFHX3-7:1 was significantly decreased in cord blood exosomes of an additional 20 patients with GDM-M. The risk prediction performance of the expression of these validated genes (in peripheral blood exosomes) for GDM-related macrosomia was also evaluated. Only GDF3 expression and AC006064.4 expression showed well prediction performance [area under the curve (AUC) = 0.78 and 0.74, respectively]. Excitingly, the model including maternal age, fasting plasma glucose, 2-h plasma glucose, GDF3 expression, and AC006064.4 expression in peripheral blood exosomes had better prediction performance with an AUC of 0.86 (95% CI = 0.75-0.97). Conclusion: These results showed that exosomal RNAs are aberrantly expressed in the cord blood of patients with GDM-M and highlighted the importance of exosomal RNAs in peripheral blood for GDM-M prediction.

Plasmatic circRNAs Panel to Predict the Risk of Macrosomia in Women with Gestational Diabetes Mellitus.

OBJECTIVES: Fetal macrosomia and its associated complications are the most frequent and serious morbidities for infants associated with gestational diabetes mellitus (GDM). In this study, we aimed to determine the expression of circulating circRNAs in humans, which may be promising biomarkers for the diagnosis of GDM or predicting the macrosomia in GDM patients. DESIGN: A multi-stage validation and risk score formula analysis was applied for validation. PARTICIPANTS/MATERIALS, SETTING, METHODS: A total of 26 circRNAs previously reported highly expressed in placenta tissues or umbilical cord blood of GDM patients during the pregnancy were enrolled. We recruited a total of 200 patients with GDM with or without macrosomia, 200 healthy pregnant woman, and 200 healthy volunteers. RESULTS: We discovered that four circRNAs including circRNA_1030, circRNA_23658, circRNA_0009049, and circRNA_32231 were upregulated in plasmatic samples of patients with GDM with or without macrosomia in training set and validation set compared with the healthy pregnant woman and healthy volunteers. Further receiver operating characteristic (ROC) curve analysis in risk score formula indicated a high diagnostic ability and area under ROC curve value (AUC) of 0.950 and 0.815 in training set and validation set for predicting GDM from controls group, for predicting macrosomia from GDM, the AUC was 0.975 and 0.820, respectively. The four circRNAs were further investigated with stable expression in human plasma samples. LIMITATIONS: The study was limited by larger scale of sample validation and the detailed mechanism investigation. CONCLUSION: The circRNA_1030, circRNA_23658, circRNA_0009049, and circRNA_32231 might be the potential biomarkers for predicting the GDM and macrosomia during the perinatal period.

Placental mtDNA copy number and methylation in association with macrosomia in healthy pregnancy.

INTRODUCTION: Fetal growth and development depend on metabolic energy from placental mitochondria. However, the impact of placental mitochondria on the occurrence of macrosomia remains unclear. We aimed to explore the association between macrosomia without gestational diabetes mellitus (non-GDM) and changes in placental mitochondrial DNA (mtDNA) copy number and methylation. METHODS: Fifty-four newborns with macrosomia and 54 normal birthweight controls were enrolled in this study. Placental mtDNA copy number and mRNA expression of nuclear genes related to mitochondrial replication or ATP synthesis-related genes were measured by real-time quantitative polymerase chain reaction (qPCR). Methylation levels of the non-coding regulatory region D-loop and ATP synthesis-related genes were detected by targeted bisulfite sequencing. RESULTS: Newborns with macrosomia had lower placental mtDNA copy number and higher methylation rates of the CpG15 site in the D-loop region (D-CpG15) and CpG6 site in the cytochrome C oxidase III (COX3) gene (COX3-CpG6) than normal birth weight newborns. After adjusting for potential covariates (gestational age, prepregnancy BMI, and infant sex), decreased placental mtDNA copy number (adjusted odds ratio [aOR] = 2.09, 95% confidence interval [CI] 1.03-4.25), elevated methylation rate of D-CpG15 (aOR = 2.06, 95% CI 1.03-4.09) and COX3-CpG6 (aOR = 2.13, 95% CI 1.08-4.20) remained significantly associated with a higher risk of macrosomia. DISCUSSION: Reduced mtDNA copy number and increased methylation levels of specific loci at mtDNA would increase the risk of macrosomia. However, the detailed molecular mechanism needs further identification.

Detection of hypermethylation at H19DMR at amniocentesis in a fetus with overgrowth, distended abdomen and Beckwith-Wiedemann syndrome.

OBJECTIVE: We present detection of hypermethylation at H19 differentially methylated region (DMR) at amniocentesis in a fetus with overgrowth, distended abdomen and Beckwith-Wiedemann syndrome (BWS). CASE REPORT: A 31-year-old, gravida 2, para 1, woman was referred for genetic counseling at 22 weeks of gestation because of fetal overgrowth with fetal biometry equivalent to 24 weeks of gestation and a distended abdomen with an abdominal circumference equivalent to 26 weeks of gestation. She did not undergo any assisted reproductive technology during this pregnancy. Amniocentesis was performed at 23 weeks of gestation. Conventional cytogenetic analysis revealed a karyotype of 46,XX. Array comparative genomic hybridization analysis on the DNA extracted from uncultured amniocytes revealed no genomic imbalance. Methylation analysis on the DNA extracted from amniocytes revealed hypermethylation at H19DMR [imprinting center 1 (IC1)] and normal methylation at KvDMR1 (IC2). The methylation test confirmed the diagnosis of BWS in the fetus. The parents decided to continue the pregnancy. At 36 weeks of gestation, a 4000-g female baby was delivered with macroglossia, ear tags and creases, and an enlarged liver, consistent with the phenotype of BWS. CONCLUSION: Prenatal diagnosis of fetal overgrowth should include a differential diagnosis of BWS, and methylation analysis of H19DMR (IC1) and KvDMR1 (IC2) is useful under such a circumstance.

Risks of Macrosomia Associated with Catechol-O-Methyltransferase Genotypes and Genetic-Epigenetic Interactions among Children with and without Gestational Diabetes Exposure.

Background: Gestational diabetes mellitus (GDM) is a major macrosomia risk factor. Variations in the catechol-O-methyltransferase (COMT; rs4680) genotypes are associated with heightened susceptibility to environmental exposures and nutritional conditions. However, macrosomia risks associated with COMT genetics, epigenetics, and the interaction between genetic and epigenetics among children with and without exposure to GDM are unknown. Methods: Data from women/children pairs (n = 1087) who participated in the Tianjin Gestational Diabetes Birth Cohort were used to examine the odds of being born with macrosomia associated with COMT-genotypes, 55 CpG sites located on the COMT gene, and genetic and epigenetic interactions. Odds of macrosomia associated with COMT genetic, epigenetic, genetic and epigenetic interactions, and moderations with GDM were tested using adjusted logistic regression models. Results: Overall, 16.1% (n = 175) of children were born with macrosomia. Models showed that children with at least one copy of the minor allele (A) had higher odds of macrosomia (odds ratio, 1.82; 95% confidence interval 1.25-2.64) compared with children with the GG-genotype. After false discovery rate corrections, none of the 55 CpG sites located on the COMT gene was associated with odds of macrosomia. The genetic and epigenetic associations were not modified by exposure to GDM. Conclusion: Findings suggest carriers of the COMT GG-genotype had lower odds of macrosomia, and this association was not modified by epigenetics or exposure to GDM.

Epigenetic alteration of Rho guanine nucleotide exchange Factor 11 (ARHGEF11) in cord blood samples in macrosomia exposed to intrauterine hyperglycemia.

Background: Macrosomia at birth is associated with maternal hyperglycemia and leads to subsequent susceptibility to obesity, abnormal glucose metabolism, hypertension, and dyslipidemia in offspring. Epigenetic reprogramming has been reported to be involved in the development of human diseases caused by suboptimal environmental or nutritional factors. The study was aiming to explore epigenetic mechanism influences on macrosomic infants exposed to intrauterine hyperglycemia. We performed a genome-wide analysis of DNA methylation in cord blood from macrosomic infants born to women with gestational diabetes in order to identify genes related to fetal growth or early adipose tissue development.Methods: To analyze the epigenetic patterns in umbilical cord blood in gestational diabetes mellitus (GDM), we collected umbilical cord blood from women with GDM (mean pregestational BMI of 24.4 kg/m2 and mean neonatal birth weight of 4366 g) and normal glucose-tolerant women (mean pregestational BMI of 19.8 kg/m2 and mean neonatal birth weight of 3166 g). Differentially methylated genes in the GDM group were identified using the Infinium HumanMethylation450 BeadChip array.Results: A total of 1251 genes were differentially methylated compared to the controls (p < .01). The methylation microarray data showed that two specific CpG sites (cg12604331 and cg08480098) in the gene body of ARHGEF11 were significantly hypomethylated in the cord blood in macrosomic infants. Altered DNA methylation levels of ARHGEF11 were negatively correlated with glucose levels and neonatal birth weight.Conclusions: Exposure to adverse intrauterine environments can alter fetal development, such as by affecting the nutritional status of the fetus. Such exposure can also result in significant epigenetic modifications, including DNA methylation, which could serve as a potential marker for nutrition and metabolic conditions at the neonatal stage or even in the adult.

Heterozygous recurrent HNF4A variant p.Arg85Trp causes Fanconi renotubular syndrome 4 with maturity onset diabetes of the young, an autosomal dominant phenocopy of Fanconi Bickel syndrome with colobomas.

Heterozygous pathogenic variants in HNF4A cause hyperinsulinism, maturity onset diabetes of the young type 1, and more rarely Fanconi renotubular syndrome. Specifically, the recurrent missense pathogenic variant c.253C>T (p.Arg85Trp) has been associated with a syndromic form of hyperinsulinism with additional features of macrosomia, renal tubular nephropathy, hypophosphatemic rickets, and liver involvement. We present an affected mother, who had been previously diagnosed clinically with the autosomal recessive Fanconi Bickel Syndrome, and her affected son. The son's presentation expands the clinical phenotype to include multiple congenital anomalies, including penile chordee with hypospadias and coloboma. This specific pathogenic variant should be considered in the differential diagnosis of Fanconi Bickel Syndrome when genetics are negative or the family history is suggestive of autosomal dominant inheritance. The inclusion of hyperinsulinism and maturity onset of the diabetes of the young changes the management of this syndrome and the recurrence risk is distinct. Additionally, this family also emphasizes the importance of genetic confirmation of clinical diagnoses, especially in adults who grew up in the premolecular era that are now coming to childbearing age. Finally, the expansion of the phenotype to include multiple congenital anomalies suggests that the full spectrum of HNF4A is likely unknown.

Placental proteome abnormalities in women with gestational diabetes and large-for-gestational-age newborns.

INTRODUCTION: Gestational diabetes mellitus (GDM) is the most frequent metabolic complication during pregnancy and is associated with development of short-term and long-term complications for newborns, with large-for-gestational-age (LGA) being particularly common. Interestingly, the mechanism behind altered fetal growth in GDM is only partially understood. RESEARCH DESIGN AND METHODS: A proteomic approach was used to analyze placental samples obtained from healthy pregnant women (n=5), patients with GDM (n=12) and with GDM and LGA (n=5). Effects of altered proteins on fetal development were tested in vitro in human embryonic stem cells (hESCs). RESULTS: Here, we demonstrate that the placental proteome is altered in pregnant women affected by GDM with LGA, with at least 37 proteins differentially expressed to a higher degree (p<0.05) as compared with those with GDM but without LGA. Among these proteins, 10 are involved in regulating tissue differentiation and/or fetal growth and development, with bone marrow proteoglycan (PRG2) and dipeptidyl peptidase-4 (DPP-4) being highly expressed. Both PRG2 and DPP-4 altered the transcriptome profile of stem cells differentiation markers when tested in vitro in hESCs, suggesting a potential role in the onset of fetal abnormalities. CONCLUSIONS: Our findings suggest that placental dysfunction may be directly responsible for abnormal fetal growth/development during GDM. Once established on a larger population, inhibitors of the pathways involving those altered factors may be tested in conditions such as GDM and LGA, in which therapeutic approaches are still lacking.

The Role of circRNA-SETD2/miR-519a/PTEN Axis in Fetal Birth Weight through Regulating Trophoblast Proliferation.

Abnormal birth weight is the one of the major causes of adulthood diseases such as obesity, metabolic syndrome, cardiovascular disease, type 2 diabetes, and hypertension. Accumulating evidence has suggested that the placental trophoblast is one of the most important reasons that influence birth weight. Our previous study showed that miR-519a are correlated with low fetal birth weight through regulating trophoblast proliferation. To further clarify the detailed mechanisms on how it is regulated, we screened the placental-specific circular RNAs (circRNAs) via microarray assay. The result identified that circ-SETD2 was highly expressed in the placenta of the patients with fetal macrosomia compared with healthy donors. Furthermore, bioinformatic analyses and the luciferase reporter assay revealed that miR-519a possessing the binding sites for both circ-SETD2 and phosphate and tensin homolog was deleted on chromosome 10 (PTEN). Interestingly, upregulation of circ-SETD2 enhanced the proliferation and invasion of the human trophoblast-like cell line HTR8/SVneo cell. A parallel study performed by Western blotting showed that overexpression of circ-SETD2 reduced miR-519a levels and increased PTEN levels in HTR8/SVneo cells. Importantly, the enhancement of HTR8/SVneo cell activity by circ-SETD2 overexpression was nullified when the cells were cotransfected by circ-SETD2 and miR-519a, suggesting the involvement of the circ-SETD2/miR-519a/PTEN axis in trophoblast activity. Taken together, we illustrate the role of circ-SETD2, as an upstream signaling of miR-519a/PTEN, in placenta development via regulating trophoblast proliferation and invasion. These findings improve our understanding of the mechanisms of progression of fetal macrosomia and will guide future development of therapeutic strategies against the disease by targeting the circ-SETD2/miR-519a/PTEN axis.

Noninvasive Fetal Genotyping by Droplet Digital PCR to Identify Maternally Inherited Monogenic Diabetes Variants.

BACKGROUND: Babies of women with heterozygous pathogenic glucokinase (GCK) variants causing mild fasting hyperglycemia are at risk of macrosomia if they do not inherit the variant. Conversely, babies who inherit a pathogenic hepatocyte nuclear factor 4α (HNF4A) diabetes variant are at increased risk of high birth weight. Noninvasive fetal genotyping for maternal pathogenic variants would inform pregnancy management. METHODS: Droplet digital PCR was used to quantify reference and variant alleles in cell-free DNA extracted from blood from 38 pregnant women heterozygous for a GCK or HNF4A variant and to determine fetal fraction by measurement of informative maternal and paternal variants. Droplet numbers positive for the reference/alternate allele together with the fetal fraction were used in a Bayesian analysis to derive probability for the fetal genotype. The babies' genotypes were ascertained postnatally by Sanger sequencing. RESULTS: Droplet digital PCR assays for GCK or HNF4A variants were validated for testing in all 38 pregnancies. Fetal fraction of ≥2% was demonstrated in at least 1 cell-free DNA sample from 33 pregnancies. A threshold of ≥0.95 for calling homozygous reference genotypes and ≤0.05 for heterozygous fetal genotypes allowed correct genotype calls for all 33 pregnancies with no false-positive results. In 30 of 33 pregnancies, a result was obtained from a single blood sample. CONCLUSIONS: This assay can be used to identify pregnancies at risk of macrosomia due to maternal monogenic diabetes variants.