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PubMed2026

Prader-Willi syndrome as a neurogenetic model for psychosis and obsessive-compulsive disorder: A review of clinical, behavioral, and biological insights.

Prader-Willi syndrome (PWS) is a complex neurodevelopmental disorder classically defined by hyperphagia and obesity. However, its profound psychiatric phenotype offers a unique genetic framework for understanding major mental illnesses. This review positions PWS as a potentially informative biological model for psychosis and obsessive-compulsive disorder (OCD), bridging the gap between 15q11-q13 imprinting defects and neural circuit dysfunction. We synthesize evidence demonstrating that psychosis in PWS is not a uniform trait but is disproportionately linked to the maternal uniparental disomy (mUPD) subtype. This genotype-phenotype correlation suggests that overexpression of maternally imprinted genes and loss of paternal expression disrupt cortical excitatory-inhibitory balance, resembling the "schizophrenia-bipolar" genomic architecture. Furthermore, synthesized evidence characterizes the repetitive, ritualistic behaviors in PWS not merely as behavioral challenges, but as a developmentally arrested OCD-spectrum phenotype driven by distinct serotonergic-oxytocinergic imbalances and hypothalamic-limbic dysconnectivity. Mechanistic insights from preclinical models of MAGEL2, SNORD116, and NDN deficiency are integrated with clinical findings to highlight shared neurobiological substrates. Finally, we outline a roadmap for precision psychiatry in PWS, emphasizing the necessity of pharmacogenomics in antipsychotic management and the potential of targeted circuit-based therapeutics. By deconstructing the psychiatric comorbidities of PWS, we provide a framework for translating genomic architecture into mechanistic understanding and targeted treatment for complex neuropsychiatric disorders.

15q11-q13↗
PubMed2024

Prenatal diagnosis of recurrent Kagami-Ogata syndrome inherited from a mother affected by Temple syndrome: a case report and literature review.

BACKGROUND: Kagami-Ogata syndrome (KOS) and Temple syndrome (TS) are two imprinting disorders characterized by the absence or reduced expression of maternal or paternal genes in the chromosome 14q32 region, respectively. We present a rare prenatally diagnosed case of recurrent KOS inherited from a mother affected by TS. CASE PRESENTATION: The woman's two affected pregnancies exhibited recurrent manifestations of prenatal overgrowth, polyhydramnios, and omphalocele, as well as a small bell-shaped thorax with coat-hanger ribs postnatally. Prenatal genetic testing using a single-nucleotide polymorphism array detected a 268.2-kb deletion in the chromosome 14q32 imprinted region inherited from the mother, leading to the diagnosis of KOS. Additionally, the woman carried a de novo deletion in the paternal chromosome 14q32 imprinted region and presented with short stature and small hands and feet, indicating a diagnosis of TS. CONCLUSIONS: Given the rarity of KOS as an imprinting disorder, accurate prenatal diagnosis of this rare imprinting disorder depends on two factors: (1) increasing clinician recognition of the clinical phenotype and related genetic mechanism, and (2) emphasizing the importance of imprinted regions in the CMA workflow for laboratory analysis.

Humans↗
PubMed2025

Adult bi-paternal offspring generated through direct modification of imprinted genes in mammals.

Imprinting abnormalities pose a significant challenge in applications involving embryonic stem cells, induced pluripotent stem cells, and animal cloning, with no universal correction method owing to their complexity and stochastic nature. In this study, we targeted these defects at their source-embryos from same-sex parents-aiming to establish a stable, maintainable imprinting pattern de novo in mammalian cells. Using bi-paternal mouse embryos, which exhibit severe imprinting defects and are typically non-viable, we introduced frameshift mutations, gene deletions, and regulatory edits at 20 key imprinted loci, ultimately achieving the development of fully adult animals, albeit with a relatively low survival rate. The findings provide strong evidence that imprinting abnormalities are a primary barrier to unisexual reproduction in mammals. Moreover, this approach can significantly improve developmental outcomes for embryonic stem cells and cloned animals, opening promising avenues for advancements in regenerative medicine.

Animals↗
PubMed2025

Perinatal Lead (Pb) Exposure Increases Mouse Embryonic Weight and Alters Neuronal Gene Expression.

Acute and chronic exposure to lead (Pb) during pregnancy is linked to adverse health outcomes, including delayed neurodevelopment in offspring. However, the pathways by which Pb exposure influences long-term health remain poorly understood. To address this, we measured the effects of perinatal Pb exposure on gene expression including imprinted genes, X-linked genes, and sexually dimorphic genes. Female mice were given control or Pb acetate dosed (32 ppm) drinking water two weeks prior to timed mating until embryonic day (E)10-12, upon which whole embryos were collected, weighed, and sexed at E13-15. From a subset of embryo heads (n&#x2265;9 per sex per group), we extracted and sequenced RNA. We used linear regression to assess Pb impacts on embryonic weight and gene expression across all mice and stratified by sex. Among the differentially expressed genes, we identified significantly enriched pathways. Pb-exposed embryos weighed more than controls (p=0.007), across both sexes. Collectively, we identified 2,920 differentially expressed genes (FDR<0.05), including 31 imprinted genes and 120 X-linked genes upon Pb exposure. Pb exposure altered expression in gene pathways related to neuronal structure and function as well as sexually dimorphic genes (44 for females; 76 for males). These findings highlight perinatal Pb-linked alterations that may drive later-life health outcomes.

DOHaD↗
PubMed2001

mtDna and the islands of the North Atlantic: estimating the proportions of Norse and Gaelic ancestry.

A total of 1,664 new mtDNA control-region sequences were analyzed in order to estimate Gaelic and Scandinavian matrilineal ancestry in the populations of Iceland, Orkney, the Western Isles, and the Isle of Skye and to investigate other aspects of their genetic history. A relative excess of private lineages in the Icelanders is indicative of isolation, whereas the scarcity of private lineages in Scottish island populations may be explained by recent gene flow and population decline. Differences in the frequencies of lineage clusters are observed between the Scandinavian and the Gaelic source mtDNA pools, and, on a continent-wide basis, such differences between populations seem to be associated with geography. A multidimensional scaling analysis of genetic distances, based on mtDNA lineage-cluster frequencies, groups the North Atlantic islanders with the Gaelic and the Scandinavian populations, whereas populations from the central, southern, and Baltic regions of Europe are arranged in clusters in broad agreement with their geographic locations. This pattern is highly significant, according to a Mantel correlation between genetic and geographic distances (r=.716). Admixture analyses indicate that the ancestral contributions of mtDNA lineages from Scandinavia to the populations of Iceland, Orkney, the Western Isles, and the Isle of Skye are 37.5%, 35.5%, 11.5%, and 12.5%, respectively.

Atlantic Islands↗
PubMed2026

Deoxyribonucleic acid methylation abnormalities at imprinted loci in oligospermic and azoospermic men.

OBJECTIVE: To assess deoxyribonucleic acid (DNA) methylation at imprinted and repetitive genomic regions in ejaculated and testicular sperm from men with oligospermia, azoospermia, and those undergoing vasectomy reversal (VR), compared with fertile controls. DESIGN: Observational case-control study. SUBJECTS: Samples were obtained from 68 men, including 29 infertile men (18 oligospermic [5-15 million/mL], 11 severely oligospermic [<5 million/mL]) and 20 fertile controls with confirmed natural conceptions. Testicular tissue was collected from 11 azoospermic men (7 obstructive azoospermia [OA], 4 nonobstructive azoospermia [NOA]) and 8 men with prior paternity undergoing VR. EXPOSURE: Sperm DNA methylation at four imprinted genes (H19, GTL2, MEST, and LIT1) and one repetitive element (LINE1). MAIN OUTCOME MEASURES: Methylation levels at CpG sites determined by bisulfite pyrosequencing. RESULTS: The H19 was significantly hypomethylated only in severe oligospermia compared with fertile controls, whereas other groups showed nonsignificant trends with overlapping distributions. In contrast, MEST was significantly hypermethylated in oligospermic, azoospermic, and VR groups compared with fertile controls. No significant differences were observed for GTL2, LIT1, or LINE1. CONCLUSION: The DNA methylation abnormalities in sperm are locus-specific and vary across infertility phenotypes. MEST alterations were consistent across groups, whereas H19 changes were limited to severe oligospermia. Similar methylation patterns in testicular sperm from azoospermic and VR groups suggest that epigenetic alterations may reflect the testicular environment or obstruction, or differences between testicular and ejaculated sperm.

Humans↗
PubMed2026

Convergent IGF2 overexpression in pheochromocytoma/paraganglioma: insights from Beckwith-Wiedemann syndrome.

Beckwith-Wiedemann syndrome (BWS) is an imprinting disorder characterized by overgrowth and tumor predisposition, caused by dysregulated expression of genes on chromosome 11p15.5. An association between BWS and pheochromocytoma/paraganglioma (PPGL) has been suggested in isolated case reports over the past fifty years, but the molecular basis for this link remains unclear. We identified four patients with BWS who developed metastatic PPGL and investigated IGF2 pathway activation in these tumors and in PPGL across various genotypes. Pan-cancer transcriptomic analysis of The Cancer Genome Atlas (TCGA) demonstrated that PPGL overexpresses IGF2, with pseudohypoxic tumors exhibiting higher expression compared to other molecular clusters. Loss of heterozygosity and loss of imprinting at 11p15.5 partially explain this overexpression, with PPGL additionally demonstrating globally elevated expression of imprinted genes compared to most other tumor types, suggesting a broader relaxation of genomic imprinting. Cognate receptor profiling revealed that PPGLs are equipped to respond to IGF2 signaling, with high expression of IGF1R and insulin receptor isoform A (IR-A). Immunohistochemistry confirmed IGF2 protein overexpression in both BWS-associated and genotypically diverse sporadic PPGLs. Our results indicate that IGF2 overexpression is a convergent molecular feature of PPGL across genotypes and suggest the IGF2 pathway as a potential diagnostic and therapeutic target.

Humans↗
PubMed2026

Beckwith-Wiedemann spectrum exhibiting a 46,XY karyotype caused by genome-wide paternal uniparental heterodisomy: a case report.

BACKGROUNDS: Patients with genome-wide paternal uniparental disomy (GWpUPD) usually exhibit clinical features of Beckwith-Wiedemann syndrome (BWS) and a 46,XX karyotype, with all chromosomes showing isodisomy. To date, male patients with GWpUPD and a complete 46,XY karyotype, specifically involving heterodisomy, have not been described. RESULTS: We report a male infant exhibiting classical BWS clinical features. DNA methylation analyses showed paternal-specific methylation across multiple imprinted loci, suggesting GWpUPD. Genetic analysis of autosomes and sex chromosomes indicated two distinct paternal genomes in peripheral blood leukocytes, whereas a normal biparental genome was detected in other tissues under chimeric conditions. These findings indicated that the patient had genome-wide paternal uniparental heterodisomy (GWpUPhD). The SNP array revealed the presence of one copy of the X chromosome and one copy of the Y chromosome, the patient is a chimera composed of 46,XY biparental cells (with maternal X) and 46,XY GWpUPhD cells (with paternal X). CONCLUSIONS: This is the first report of a male patient with a GWpUPhD chimera. We propose a potential mechanism of GWpUPhD formation. Our findings expand the molecular spectrum of GWpUPD and provide valuable insights into its pathogenesis in chimeric conditions. Furthermore, the potential for clinical manifestations unique to 46,XY heterodisomy warrants careful long-term follow-up.

Humans↗
PubMed2025

Activation of the imprinted Prader-Willi syndrome locus by CRISPR-based epigenome editing.

Epigenome editing with DNA-targeting technologies such as CRISPR-dCas9 can be used to dissect gene regulatory mechanisms and potentially treat associated disorders. For example, Prader-Willi syndrome (PWS) results from loss of paternally expressed imprinted genes on chromosome 15q11.2-q13.3, although the maternal allele is intact but epigenetically silenced. Using CRISPR repression and activation screens in human induced pluripotent stem cells (iPSCs), we identified genomic elements that control the expression of the PWS gene SNRPN from the paternal and maternal chromosomes. We showed that either targeted transcriptional activation or DNA demethylation can activate the silenced maternal SNRPN and downstream PWS transcripts. However, these two approaches function at unique regions, preferentially activating different transcript variants and involving distinct epigenetic reprogramming mechanisms. Remarkably, transient expression of the targeted demethylase leads to stable, long-term maternal SNRPN expression in PWS iPSCs. This work uncovers targeted epigenetic manipulations to reprogram a disease-associated imprinted locus and suggests possible therapeutic interventions.

Prader-Willi Syndrome↗
PubMed2026

Epigenetic safety of in vitro maturation in PCOS: genome-wide DNA methylation profiling of cord blood from a randomized controlled trial.

BACKGROUND: In vitro maturation (IVM) provides a safer alternative to conventional in vitro fertilization (IVF) for women with polycystic ovary syndrome (PCOS) by mitigating the risk of ovarian hyperstimulation. However, concerns persist regarding whether IVM perturbs epigenetic reprogramming in the offspring. Current evidence is constrained by candidate-gene approaches or a lack of parental controls. This study aimed to evaluate the genome-wide DNA methylation safety of IVM compared with conventional IVF using a rigorous trio-based design. METHODS: This secondary epigenetic analysis was nested within a randomized controlled trial (RCT) (ClinicalTrials.gov: NCT03463772). We included 10 nuclear families (trios), comprising five IVM-conceived and five IVF-conceived singleton offspring alongside their biological parents. Both groups utilized a uniform freeze-only single-blastocyst transfer strategy to minimize hormonal confounding. Genomic DNA from umbilical cord blood (UCB) and parental peripheral blood was analyzed using reduced representation bisulfite sequencing (RRBS). Genome-wide methylation patterns and differentially methylated regions (DMRs) were subsequently compared between the groups. RESULTS: Clinical characteristics were comparable between the IVM and IVF groups. Genome-wide analyses demonstrated high concordance in UCB methylation patterns, revealing no significant differences in global CpG methylation levels or distributions across key genomic features (promoters, CpG islands, and gene bodies). Only three rare DMRs were identified in UCB (representing&#x2009;~&#x2009;0.0001% of the genome), none of which mapped to imprinted or developmentally critical loci. Furthermore, methylation variability remained consistent between the groups. CONCLUSIONS: Our findings provide robust mechanistic evidence supporting the epigenetic safety of IVM. The remarkable stability of the neonatal methylome confirms that specific IVM conditions do not compromise early developmental programming, thereby endorsing IVM as a safe and viable alternative for women with PCOS. TRIAL REGISTRATION: ClinicalTrials.gov registry, NCT03463772. Registered on March 13, 2018.

Humans↗
PubMed2026

Population-scale detection of methylation outliers from long-read genome sequencing.

BACKGROUND: Aberrant DNA methylation can mediate the functional effects of rare genetic variation and contribute to imprinting disorders, repeat expansion diseases, and other pathogenic regulatory mechanisms. Long-read sequencing technologies now enable genome-wide detection of CpG methylation alongside genetic variation from a single assay. However, methods for systematic identification and interpretation of methylation outliers from long-read sequencing data remain limited. METHODS: We developed METAFORA, a computational workflow for detecting methylation outlier regions from PacBio and Oxford Nanopore long-read sequencing data. METAFORA constructs population-level methylation references, segments the genome into correlated CpG blocks, infers technical and biological sources of variation through hidden factor estimation, models uncertainty due to variable depth sequencing, and computes covariate-adjusted methylation outlier scores for individual samples. We applied METAFORA across large long-read sequencing cohorts and integrated methylation outliers with multi-omic data. METAFORA is implemented as a snakemake workflow available at https://github.com/tjense25/METAFORA. RESULTS: METAFORA identified methylation outlier regions associated with rare structural variants, tandem repeat expansions, and imprinting abnormalities. We found outlier regions were enriched for molecular outliers across transcriptomic and chromatin accessibility datasets, supporting their functional relevance in gene regulation. In a representative case, METAFORA identified an imprinting defect affecting the GNAS locus associated with an STX16 deletion. CONCLUSIONS: METAFORA enables scalable detection and interpretation of methylation outliers from long-read sequencing data and provides a framework for integrating epigenetic outliers with genomic and multi-omic analyses. These approaches may improve interpretation of rare regulatory variation and support discovery of clinically relevant epigenetic abnormalities in genomic medicine.

DNA methylation↗
PubMed2026

Mammalian DNA methyltransferases in DNA methylation and imprinted gene expression in extraembryonic ectoderm of post-implantation embryos.

DNA methylation in mammals is mainly catalyzed by three DNA methyltransferases (DNMTs). Conventionally, DNMT1 is considered the primary DNMT protein for maintenance DNA methylation, whereas DNMT3A and DNMT3B function in de novo DNA methylation. In two previous studies, we demonstrated that DNMT3A and DNMT3B maintain genome-wide DNA methylation in embryonic stem (ES) cells and in the epiblast of post-implantation embryos. Interestingly, DNMT3A and DNMT3B also sustain genome-wide DNA methylation in the extraembryonic ectoderm (EXE) of post-implantation embryos, including repeats, genic and intergenic regions. Although DNMT1 plays a major role in maintaining DNA methylation at the imprinting control regions (ICRs) in the imprinted regions, DNMT3A and DNMT3B are required for preserving DNA methylation at the ICRs of a subset of imprinted regions in EXE, similar to the observations in ES cells and epiblast. Surprisingly, de novo DNA methylation mediated by DNMT3A and DNMT3B leads to increased DNA methylation at a large subset of imprinted regions. These results are consistent with what we previously elucidated in the epiblast of post-implantation embryos. Importantly, loss of DNA methylation at the ICR of an imprinted region, resulting from the absence of DNMT1 or two DNMT3 proteins, causes allelic expression switch of the corresponding imprinted genes in that imprinted region. This study provides further evidence that DNMT3A and DNMT3B exert both maintenance and de novo DNA methylation functions across the genome in post-implantation embryos. It also validates some previous findings for DNA methylation-dependent allelic expression switch of imprinted genes.

DNA methylation↗
PubMed2025

Balancing LncRNA H19 and miR-675 Bioconversion as a Key Regulator of Embryonic Myogenesis Under Maternal Obesity.

BACKGROUND: Maternal obesity (MO) impairs fetal skeletal muscle development, but the underlying mechanisms remain poorly defined. The regulatory roles of lncRNA H19 and its first exon derived microRNA675 (miR675) in prenatal muscle development remain to be examined. H19/Igf2 are in the same imprinting cluster with H19 expressed from the maternal allele while Igf2 expresses paternally. H19 contains a G-rich loop, and KH-type splicing regulatory protein (KHSRP) mediates the biogenesis of pre-miRNAs containing G-rich loops, which depends on its phosphorylation by AKT, a key mediator of IGF2 signalling. This study aims to depict the elusive function of these regulators that are affected by MO during embryonic myogenesis. METHODS: Single-cell transcriptomic sequencing and GeoMx spatial RNA sequencing were performed to identify the differentially expressed genes between embryos from MO and control (CT) mice. Both E11.5 and E13.5 embryos were collected and analysed to validate the sequencing data. The roles of H19 and miR657 in myogenesis were further analysed in P19 embryonic cells via CRISPR/dCas9-mediated H19 activation and inhibition. The epigenetic changes of H19 were analysed by methylated DNA immunoprecipitation, and allele-targeted analysis of H19 was performed by crossing C57BL/6J and CAST/EiJ mice. RESULTS: Transcriptomic analysis showed that MO embryos contained less differentiated myocytes (1.34%) than CT embryos (2.86%). Myogenesis-related GO biological processes were down-regulated in the MO embryonic myotome region. MO embryos showed lower expression of myogenic transcription factors such as Myf5, Myod1, Myog, Mef2c and Myh3 (p&#x2009;<&#x2009;0.05). MO altered epigenetic modifications of the H19 genomic cluster, showing a decreased methylation level in H19 imprinting control region (p&#x2009;<&#x2009;0.05) and a diallelic expression pattern of H19, which elevated its expression in MO embryos. Overexpression of H19 inhibited myogenesis in P19 cells, but miR675 promoted myogenesis, suggesting the critical regulatory roles of bioconversion of H19 to miR675. A KHSRP mediates the biogenesis of miR675, a process that relies on its phosphorylation by IGF2/AKT signalling. Knocking-down of KHSRP and inhibition of AKT abolished miR675 biogenesis. MO suppressed IGF2/AKT signalling and blocked KHSRP-dependent miR675 biogenesis in embryos. CONCLUSIONS: We found differential effects of H19 and miR675 on embryonic myogenesis. MO up-regulates H19 but blocks its miR675 bioconversion via suppressing IGF2/AKT/KHSRP signalling axis. Myogenesis in MO embryos was impeded due to the highly accumulated H19 and blocked miR675 biogenesis.

RNA, Long Noncoding↗
PubMed2026

CAR-T Cell Therapy: Manufacturing Platforms and Clinical Consequences.

Chimeric antigen receptor (CAR) T-cell therapy has transformed hematological cancer care, yet variability in efficacy, durability, and safety cannot be explained solely by antigen selection or patient factors. We propose that manufacturing platforms are active biological determinants of outcome. Viral vectors, used in all licensed products, provide stable genomic integration and durable expression but are limited by cost, cargo capacity, and centralized production. Nonviral strategies, including transposons, CRISPR knock-ins, and messenger RNA delivery, enable faster, less-expensive manufacturing with larger payloads, while introducing distinct safety and persistence profiles. This review presents a three-layer mechanistic framework that reframes manufacturing as biology: integration biology determines genomic risk and transgene stability; clonal fitness shapes persistence, dominance, and exhaustion; and epigenomic imprinting, influenced by gene transfer method, cytokines, and culture stress, preconfigures functional trajectories. Clinical observations link platform choice to immune recovery, where prolonged B-cell aplasia and delayed T-cell reconstitution contribute to infection-related nonrelapse mortality, and hematopoietic reserve at apheresis emerges as a practical predictor. Finally, manufacturing is positioned as the key to democratizing cell therapy. Decentralized, nonviral production aligned with regulatory standards may enable equitable access and transition CAR-T therapy from innovation to sustainable global care.

Humans↗
PubMed2026

Combined effects of urine exposure and cryopreservation on sperm quality: an in vitro study of retrograde ejaculation.

Sperm quality influences fertility and offspring health through both genomic inheritance and epigenetic inheritance. Thus, for use in clinical-assisted reproductive technology (ART), spermatozoa must have optimal genomic and epigenetic structures. In patients with retrograde ejaculation, spermatozoa are usually recovered from urine and then cryopreserved for ART. However, the effects of urine exposure and subsequent freeze-thaw cycles on sperm quality remain unclear. This is particularly true for epigenetic changes and their underlying mechanisms. In this study, we examined how different durations of urine exposure (10 min and 40 min) followed by freeze-thaw cycles affected sperm motility, DNA integrity, and methylation levels of imprinting genes (H19-imprinted maternally expressed transcript [ H19 ], mesoderm-specific transcript [ MEST ], and the transposable element Alu [ Alu ]). As the duration of urine exposure increased, sperm motility (median [interquartile range]) decreased from 48.0% (39.0%-52.5%) to 1.0% (1.0%-5.0%), the DNA fragmentation index (DFI; median [interquartile range]) increased from 12.0% (9.3%-19.9%) to 23.5% (13.9%-33.9%), the MEST methylation level (mean &#xb1; standard deviation [s.d.]) increased from 3.8% &#xb1; 1.5% to 11.5 &#xb1; 1.2%, and the H19 methylation level (mean &#xb1; s.d.) decreased from 86.9% &#xb1; 0.9% to 82.1% &#xb1; 0.5%. The freeze-thaw process further reduced sperm motility, while the DFI and methylation levels of MEST and H19 did not significantly change. The Alu methylation level remained stable. These findings demonstrate that urine exposure affects sperm motility, DNA integrity, and methylation levels of some imprinting genes. These effects intensify over time. In contrast, the freeze-thaw process impacts only sperm motility. In clinical practice, minimizing exposure to urine might improve sperm quality.

Humans↗
PubMed2025

FTDC1/2, oocyte-specific cofactors of DNMT1 required for epigenetic regulation and embryonic development.

The unique epigenetic patterns during gametogenesis and embryonic development indicate the existence of specialized methylation machinery. In the present study, we describe the discovery of two oocyte-specific cofactors of DNA methyltransferase 1 (DNMT1), encoded by uncharacterized genes, ferritin domain containing 1 and 2 (Ftdc1 and Ftdc2). Genetic ablation of Ftdc1 or Ftdc2 causes midgestation defects and female infertility. FTDC1 or FTDC2 depletion induces the progressive loss of DNA methylation including imprinted regions in early embryos. This loss correlates with a marked reduction in DNMT1 protein due to increased degradation, likely via the ubiquitin-proteasome pathway. Mechanistically, we find that FTDC1, FTDC2 and DNMT1 form a complex by direct interactions, thereby stabilizing each other. Surprisingly, knockout of Ftdc1 or Ftdc2 displayed stronger DNA demethylation phenotypes and earlier embryonic lethality than the Dnmt1-null mutant, implying their unique functions. These data suggest that FTDC1/2 are crucial players specifically involved in maintaining genomic methylation during embryogenesis, offering new insights into the epigenetic control of mammalian development.

DNA (Cytosine-5-)-Methyltransferase 1↗
PubMed2024

Epigenetic footprints: Investigating placental DNA methylation in the context of prenatal exposure to phenols and phthalates.

BACKGROUND: Endocrine disrupting compounds (EDCs) such as phthalates and phenols can affect placental functioning and fetal health, potentially via epigenetic modifications. We investigated the associations between pregnancy exposure to synthetic phenols and phthalates estimated from repeated urine sampling and genome wide placental DNA methylation. METHODS: The study is based on 387 women with placental DNA methylation assessed with Infinium MethylationEPIC arrays and with 7 phenols, 13 phthalates, and two non-phthalate plasticizer metabolites measured in pools of urine samples collected twice during pregnancy. We conducted an exploratory analysis on individual CpGs (EWAS) and differentially methylated regions (DMRs) as well as a candidate analysis focusing on 20 previously identified CpGs. Sex-stratified analyses were also performed. RESULTS: In the exploratory analysis, when both sexes were studied together no association was observed in the EWAS. In the sex-stratified analysis, 114 individual CpGs (68 in males, 46 in females) were differentially methylated, encompassing 74 genes (36 for males and 38 for females). We additionally identified 28 DMRs in the entire cohort, 40 for females and 42 for males. Associations were mostly positive (for DMRs: 93% positive associations in the entire cohort, 60% in the sex-stratified analysis), with the exception of several associations for bisphenols and DINCH metabolites that were negative. Biomarkers associated with most DMRs were parabens, DEHP, and DiNP metabolite concentrations. Some DMRs encompassed imprinted genes including APC (associated with parabens and DiNP metabolites), GNAS (bisphenols), ZIM2;PEG3;MIMT1 (parabens, monoethyl phthalate), and SGCE;PEG10 (parabens, DINCH metabolites). Terms related to adiposity, lipid and glucose metabolism, and cardiovascular function were among the enriched phenotypes associated with differentially methylated CpGs. The candidate analysis identified one CpG mapping to imprinted LGALS8 gene, negatively associated with ethylparaben. CONCLUSIONS: By combining improved exposure assessment and extensive placental epigenome coverage, we identified several novel genes associated with the exposure, possibly in a sex-specific manner.

Humans↗