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Eggermann T, Monk D, de Nanclares GP, Kagami M, Giabicani E, Riccio A, Tümer Z, Kalish JM, Tauber M, Duis J, Weksberg R, Maher ER, Begemann M, Elbracht M. Imprinting disorders. Nat Rev Dis Primers 2023; 9:33. [PMID: 37386011 DOI: 10.1038/s41572-023-00443-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/19/2023] [Indexed: 07/01/2023]
Abstract
Imprinting disorders (ImpDis) are congenital conditions that are characterized by disturbances of genomic imprinting. The most common individual ImpDis are Prader-Willi syndrome, Angelman syndrome and Beckwith-Wiedemann syndrome. Individual ImpDis have similar clinical features, such as growth disturbances and developmental delay, but the disorders are heterogeneous and the key clinical manifestations are often non-specific, rendering diagnosis difficult. Four types of genomic and imprinting defect (ImpDef) affecting differentially methylated regions (DMRs) can cause ImpDis. These defects affect the monoallelic and parent-of-origin-specific expression of imprinted genes. The regulation within DMRs as well as their functional consequences are mainly unknown, but functional cross-talk between imprinted genes and functional pathways has been identified, giving insight into the pathophysiology of ImpDefs. Treatment of ImpDis is symptomatic. Targeted therapies are lacking owing to the rarity of these disorders; however, personalized treatments are in development. Understanding the underlying mechanisms of ImpDis, and improving diagnosis and treatment of these disorders, requires a multidisciplinary approach with input from patient representatives.
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Affiliation(s)
- Thomas Eggermann
- Institute for Human Genetics and Genomic Medicine, Medical Faculty, RWTH Aachen University, Aachen, Germany.
| | - David Monk
- School of Biological Sciences, University of East Anglia, Norwich, UK
| | - Guiomar Perez de Nanclares
- Rare Diseases Research Group, Molecular (Epi)Genetics Laboratory, Bioaraba Research Health Institute, Araba University Hospital-Txagorritxu, Vitoria-Gasteiz, Spain
| | - Masayo Kagami
- Department of Molecular Endocrinology, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Eloïse Giabicani
- Sorbonne Université, INSERM, Centre de Recherche Saint-Antoine, APHP, Hôpital Armand Trousseau, Endocrinologie Moléculaire et Pathologies d'Empreinte, Paris, France
| | - Andrea Riccio
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Università della Campania Luigi Vanvitelli, Caserta, Italy
- Institute of Genetics and Biophysics A. Buzzati-Traverso, CNR, Naples, Italy
| | - Zeynep Tümer
- Kennedy Center, Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jennifer M Kalish
- Division of Human Genetics and Center for Childhood Cancer Research, Children's Hospital of Philadelphia and the Departments of Pediatrics and Genetics at the Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Maithé Tauber
- Centre de Référence Maladies Rares PRADORT (syndrome de PRADer-Willi et autres Obésités Rares avec Troubles du comportement alimentaire), Hôpital des Enfants, CHU Toulouse, Toulouse, France
- Institut Toulousain des Maladies Infectieuses et Inflammatoires (Infinity) INSERM UMR1291 - CNRS UMR5051 - Université Toulouse III, Toulouse, France
| | - Jessica Duis
- Department of Pediatrics, Children's Hospital Colorado, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Rosanna Weksberg
- Division of Clinical and Metabolic Genetics, Department of Paediatrics and Genetics and Genome Biology Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
- Institute of Medical Sciences and Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Eamonn R Maher
- Department of Medical Genetics, University of Cambridge, Cambridge, UK
| | - Matthias Begemann
- Institute for Human Genetics and Genomic Medicine, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Miriam Elbracht
- Institute for Human Genetics and Genomic Medicine, Medical Faculty, RWTH Aachen University, Aachen, Germany
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Alsharairi NA. Exploring the Diet-Gut Microbiota-Epigenetics Crosstalk Relevant to Neonatal Diabetes. Genes (Basel) 2023; 14:genes14051017. [PMID: 37239377 DOI: 10.3390/genes14051017] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/24/2023] [Accepted: 04/28/2023] [Indexed: 05/28/2023] Open
Abstract
Neonatal diabetes (NDM) is a rare monogenic disorder that presents as hyperglycemia during the first six months of life. The link between early-life gut microbiota dysbiosis and susceptibility to NDM remains uncertain. Experimental studies have demonstrated that gestational diabetes mellitus (GDM) could develop into meconium/gut microbiota dysbiosis in newborns, and thus, it is thought to be a mediator in the pathogenesis of NDM. Epigenetic modifications have been considered as potential mechanisms by which the gut microbiota and susceptibility genes interact with the neonatal immune system. Several epigenome-wide association studies have revealed that GDM is associated with neonatal cord blood and/or placental DNA methylation alterations. However, the mechanisms linking diet in GDM with gut microbiota alterations, which may in turn induce the expression of genes linked to NDM, are yet to be unraveled. Therefore, the focus of this review is to highlight the impacts of diet, gut microbiota, and epigenetic crosstalk on altered gene expression in NDM.
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Affiliation(s)
- Naser A Alsharairi
- Heart, Mind & Body Research Group, Griffith University, Gold Coast, QLD P.O. Box 4222, Australia
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Chao Y, Qin Y, Zou X, Wang X, Hu C, Xia F, Zou C. Promising therapeutic aspects in human genetic imprinting disorders. Clin Epigenetics 2022; 14:146. [PMID: 36371218 PMCID: PMC9655922 DOI: 10.1186/s13148-022-01369-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 11/01/2022] [Indexed: 11/13/2022] Open
Abstract
Genomic imprinting is an epigenetic phenomenon of monoallelic gene expression pattern depending on parental origin. In humans, congenital imprinting disruptions resulting from genetic or epigenetic mechanisms can cause a group of diseases known as genetic imprinting disorders (IDs). Genetic IDs involve several distinct syndromes sharing homologies in terms of genetic etiologies and phenotypic features. However, the molecular pathogenesis of genetic IDs is complex and remains largely uncharacterized, resulting in a lack of effective therapeutic approaches for patients. In this review, we begin with an overview of the genomic and epigenomic molecular basis of human genetic IDs. Notably, we address ethical aspects as a priority of employing emerging techniques for therapeutic applications in human IDs. With a particular focus, we delineate the current field of emerging therapeutics for genetic IDs. We briefly summarize novel symptomatic drugs and highlight the key milestones of new techniques and therapeutic programs as they stand today which can offer highly promising disease-modifying interventions for genetic IDs accompanied by various challenges.
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Affiliation(s)
- Yunqi Chao
- grid.13402.340000 0004 1759 700XDepartment of Endocrinology, The Children’s Hospital, School of Medicine, Zhejiang University, Hangzhou, 310052 Zhejiang China
| | - Yifang Qin
- grid.13402.340000 0004 1759 700XDepartment of Endocrinology, The Children’s Hospital, School of Medicine, Zhejiang University, Hangzhou, 310052 Zhejiang China
| | - Xinyi Zou
- grid.13402.340000 0004 1759 700XZhejiang University City College, Hangzhou, 310015 Zhejiang China
| | - Xiangzhi Wang
- grid.13402.340000 0004 1759 700XDepartment of Endocrinology, The Children’s Hospital, School of Medicine, Zhejiang University, Hangzhou, 310052 Zhejiang China
| | - Chenxi Hu
- grid.13402.340000 0004 1759 700XDepartment of Endocrinology, The Children’s Hospital, School of Medicine, Zhejiang University, Hangzhou, 310052 Zhejiang China
| | - Fangling Xia
- grid.13402.340000 0004 1759 700XDepartment of Endocrinology, The Children’s Hospital, School of Medicine, Zhejiang University, Hangzhou, 310052 Zhejiang China
| | - Chaochun Zou
- grid.13402.340000 0004 1759 700XDepartment of Endocrinology, The Children’s Hospital, School of Medicine, Zhejiang University, Hangzhou, 310052 Zhejiang China
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Han X, He H, Shao L, Cui S, Yu H, Zhang X, Wu Q. Deletion of Meg8-DMR Enhances Migration and Invasion of MLTC-1 Depending on the CTCF Binding Sites. Int J Mol Sci 2022; 23:ijms23158828. [PMID: 35955961 PMCID: PMC9369160 DOI: 10.3390/ijms23158828] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 07/28/2022] [Accepted: 08/05/2022] [Indexed: 11/30/2022] Open
Abstract
The Dlk1-Dio3 imprinted domain on mouse chromosome 12 contains three well-characterized paternally methylated differentially methylated regions (DMRs): IG-DMR, Gtl2-DMR, and Dlk1-DMR. These DMRs control the expression of many genes involved in embryonic development, inherited diseases, and human cancer in this domain. The first maternal methylation DMR discovered in this domain was the Meg8-DMR, the targets and biological function of which are still unknown. Here, using an enhancer-blocking assay, we first dissected the functional parts of the Meg8-DMR and showed that its insulator activity is dependent on the CCCTC-binding factor (CTCF) in MLTC-1. Results from RNA-seq showed that the deletion of the Meg8-DMR and its compartment CTCF binding sites, but not GGCG repeats, lead to the downregulation of numerous genes on chromosome 12, in particular the drastically reduced expression of Dlk1 and Rtl1 in the Dlk1-Dio3 domain, while differentially expressed genes are enriched in the MAPK pathway. In vitro assays revealed that the deletion of the Meg8-DMR and CTCF binding sites enhances cell migration and invasion by decreasing Dlk1 and activating the Notch1-Rhoc-MAPK/ERK pathway. These findings enhance research into gene regulation in the Dlk1-Dio3 domain by indicating that the Meg8-DMR functions as a long-range regulatory element which is dependent on CTCF binding sites and affects multiple genes in this domain.
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Affiliation(s)
- Xiao Han
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Hongjuan He
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Lan Shao
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Shuang Cui
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Haoran Yu
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Ximeijia Zhang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Qiong Wu
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150001, China
- Correspondence: ; Tel./Fax: +86-0451-86416944
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Alhendi ASN, Lim D, McKee S, McEntagart M, Tatton-Brown K, Temple IK, Davies JH, Mackay DJG. Whole-genome analysis as a diagnostic tool for patients referred for diagnosis of Silver-Russell syndrome: a real-world study. J Med Genet 2021; 59:613-622. [PMID: 34135092 DOI: 10.1136/jmedgenet-2021-107699] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 05/06/2021] [Indexed: 02/01/2023]
Abstract
BACKGROUND Silver-Russell syndrome (SRS) is an imprinting disorder characterised by prenatal and postnatal growth restriction, but its clinical features are non-specific and its differential diagnosis is broad. Known molecular causes of SRS include imprinting disturbance, single nucleotide variant (SNV), CNV or UPD affecting several genes; however, up to 40% of individuals with a clinical diagnosis of SRS currently receive no positive molecular diagnosis. METHODS To determine whether whole-genome sequencing (WGS) could uncover pathogenic variants missed by current molecular testing, we analysed data of 72 participants recruited to the 100,000 Genomes Project within the clinical category of SRS. RESULTS In 20 participants (27% of the cohort) we identified genetic variants plausibly accounting for SRS. Coding SNVs were identified in genes including CDKN1C, IGF2, IGF1R and ORC1. Maternal-effect variants were found in mothers of five participants, including two participants with imprinting disturbance and one with multilocus imprinting disorder. Two regions of homozygosity were suggestive of UPD involving imprinted regions implicated in SRS and Temple syndrome, and three plausibly pathogenic CNVs were found, including a paternal deletion of PLAGL1. In 48 participants with no plausible pathogenic variant, unbiased analysis of SNVs detected a potential association with STX4. CONCLUSION WGS analysis can detect UPD, CNV and SNV and is potentially a valuable addition to diagnosis of SRS and related growth-restricting disorders.
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Affiliation(s)
- Ahmed S N Alhendi
- Human Genetics and Genomic Medicine, Faculty of Medicine, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Derek Lim
- Department of Clinical Genetics, Birmingham Women's and Children's Hospital, Birmingham, UK
| | - Shane McKee
- Department of Genetic Medicine, Belfast City Hospital, Belfast, UK
| | - Meriel McEntagart
- Department of Clinical Genetics, St George's Healthcare NHS Trust, London, UK
| | | | - I Karen Temple
- Human Genetics and Genomic Medicine, Faculty of Medicine, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Justin H Davies
- Human Genetics and Genomic Medicine, Faculty of Medicine, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Deborah J G Mackay
- Human Genetics and Genomic Medicine, Faculty of Medicine, University Hospital Southampton NHS Foundation Trust, Southampton, UK .,Wessex Regional Genetics Laboratory, Salisbury NHS Foundation Trust, Salisbury, UK
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Freschi A, Del Prete R, Pignata L, Cecere F, Manfrevola F, Mattia M, Cobellis G, Sparago A, Bartolomei MS, Riccio A, Cerrato F. The number of the CTCF binding sites of the H19/IGF2:IG-DMR correlates with DNA methylation and expression imprinting in a humanized mouse model. Hum Mol Genet 2021; 30:1509-1520. [PMID: 34132339 PMCID: PMC8330897 DOI: 10.1093/hmg/ddab132] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 04/23/2021] [Accepted: 04/26/2021] [Indexed: 01/05/2023] Open
Abstract
The reciprocal parent of origin-specific expression of H19 and IGF2 is controlled by the H19/IGF2:IG-DMR (IC1), whose maternal allele is unmethylated and acts as a CTCF-dependent insulator. In humans, internal IC1 deletions are associated with Beckwith-Wiedemann syndrome (BWS) and Silver-Russell syndrome (SRS), depending on their parental origin. These genetic mutations result in aberrant DNA methylation, deregulation of IGF2/H19 and disease with incomplete penetrance. However, the mechanism linking the microdeletions to altered molecular and clinical phenotypes remains unclear. To address this issue, we have previously generated and characterized two knock-in mouse lines with the human wild-type (hIC1wt) or mutant (hIC1∆2.2) IC1 allele replacing the endogenous mouse IC1 (mIC1). Here, we report an additional knock-in line carrying a mutant hIC1 allele with an internal 1.8 kb deletion (hIC1∆1.8). The phenotype of these mice is different from that of the hIC1∆2.2-carrying mice, partially resembling hIC1wt animals. Indeed, proper H19 and Igf2 imprinting and normal growth phenotype were evident in the mice with maternal transmission of hIC1Δ1.8, while low DNA methylation and non-viable phenotype characterize its paternal transmission. In contrast to hIC1wt, E15.5 embryos that paternally inherit hIC1Δ1.8 displayed variegated hIC1 methylation. In addition, increased Igf2 expression, correlating with increased body weight, was found in one third of these mice. Chromatin immunoprecipitation experiments in mouse embryonic stem cells carrying the three different hIC1 alleles demonstrate that the number of CTCF target sites influences its binding to hIC1, indicating that in the mouse, CTCF binding is key to determining hIC1 methylation and Igf2 expression.
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Affiliation(s)
- Andrea Freschi
- Department of Environmental Biological and Pharmaceutical Sciences and Technologies (DiSTABiF), Università degli Studi della Campania "Luigi Vanvitelli", Caserta 81100, Italy.,Genetics and Epigenetics of Behaviour (GEB), Istituto Italiano di Tecnologia (IIT), Genova 16163, Italy
| | - Rosita Del Prete
- Department of Environmental Biological and Pharmaceutical Sciences and Technologies (DiSTABiF), Università degli Studi della Campania "Luigi Vanvitelli", Caserta 81100, Italy
| | - Laura Pignata
- Department of Environmental Biological and Pharmaceutical Sciences and Technologies (DiSTABiF), Università degli Studi della Campania "Luigi Vanvitelli", Caserta 81100, Italy
| | - Francesco Cecere
- Department of Environmental Biological and Pharmaceutical Sciences and Technologies (DiSTABiF), Università degli Studi della Campania "Luigi Vanvitelli", Caserta 81100, Italy.,Institute of Genetics and Biophysics (IGB) "Adriano Buzzati-Traverso", Consiglio Nazionale delle Ricerche (CNR), Naples 80131, Italy
| | - Francesco Manfrevola
- Department of Experimental Medicine, Università degli Studi della Campania "Luigi Vanvitelli", Naples 80138, Italy
| | - Monica Mattia
- Department of Experimental Medicine, Università degli Studi della Campania "Luigi Vanvitelli", Naples 80138, Italy
| | - Gilda Cobellis
- Department of Experimental Medicine, Università degli Studi della Campania "Luigi Vanvitelli", Naples 80138, Italy
| | - Angela Sparago
- Department of Environmental Biological and Pharmaceutical Sciences and Technologies (DiSTABiF), Università degli Studi della Campania "Luigi Vanvitelli", Caserta 81100, Italy
| | - Marisa S Bartolomei
- Department of Cell and Developmental Biology, Epigenetics Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Andrea Riccio
- Department of Environmental Biological and Pharmaceutical Sciences and Technologies (DiSTABiF), Università degli Studi della Campania "Luigi Vanvitelli", Caserta 81100, Italy.,Institute of Genetics and Biophysics (IGB) "Adriano Buzzati-Traverso", Consiglio Nazionale delle Ricerche (CNR), Naples 80131, Italy
| | - Flavia Cerrato
- Department of Environmental Biological and Pharmaceutical Sciences and Technologies (DiSTABiF), Università degli Studi della Campania "Luigi Vanvitelli", Caserta 81100, Italy
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Eggermann T, Kraft F, Lausberg E, Ergezinger K, Kunstmann E. Paternal 132 bp deletion affecting KCNQ1OT1 in 11p15.5 is associated with growth retardation but does not affect imprinting. J Med Genet 2021; 58:173-176. [PMID: 32447323 DOI: 10.1136/jmedgenet-2020-106868] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 03/24/2020] [Accepted: 03/30/2020] [Indexed: 01/01/2023]
Abstract
BACKGROUND The chromosomal region 11p15.5 harbours two imprinting centres (H19/IGF2:IG-DMR/IC1, KCNQ1OT1:TSS-DMR/IC2). Molecular alterations of the IC2 are associated with Beckwith-Wiedemann syndrome (BWS), whereas only single patients with growth retardation and Silver-Russell syndrome (SRS) features have been reported. CNVs in 11p15.5 account for less than 1% of patients with BWS and SRS, and they mainly consist of duplications of both ICs either affecting the maternal (SRS) or the paternal (BWS) allele. However, this correlation does not apply to smaller CNVs, which are associated with diverse clinical outcomes. METHODS AND RESULTS We identified a family with a 132 bp deletion within the KCNQ1OT1 gene, associated with growth retardation in case of paternal transmission but a normal phenotype when maternally inherited. Comparison of molecular and clinical data with cases from the literature helped to delineate its functional relevance. CONCLUSION Microdeletions within the paternal IC2 affecting the KCNQ1OT1 gene have been described in only five families, and they all include the differentially methylated region KCNQ1OT1:TSS-DMR/IC2 and parts of the KCNQ1 gene. However, these deletions have different impacts on the expression of both genes and the cell-cycle inhibitor CDKN1C. They thereby cause different phenotypes. The 132 bp deletion is the smallest deletion in the IC2 reported so far. It does not affect the IC2 methylation in general and the coding sequence of the KCNQ1 gene. Thus, the deletion is only associated with a growth retardation phenotype when paternally transmitted but not with other clinical features in case of maternal inheritance as observed for larger deletions.
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Affiliation(s)
- Thomas Eggermann
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Nordrhein-Westfalen, Germany
| | - Florian Kraft
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Nordrhein-Westfalen, Germany
| | - Eva Lausberg
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Nordrhein-Westfalen, Germany
| | | | - Erdmute Kunstmann
- Institute of Human Genetics, University of Würzburg, Würzburg, Germany
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Eggermann T, Begemann M, Pfeiffer L. Unusual deletion of the maternal 11p15 allele in Beckwith-Wiedemann syndrome with an impact on both imprinting domains. Clin Epigenetics 2021; 13:30. [PMID: 33541417 PMCID: PMC7863277 DOI: 10.1186/s13148-021-01020-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 01/25/2021] [Indexed: 11/10/2022] Open
Abstract
Background Whereas duplications in 11p15.5 covering both imprinting centers (ICs) and their subordinated genes account for up to 1% of Beckwith–Wiedemann and Silver–Russell syndrome patients (BWS, SRS), the deletions in 11p15.5 reported so far only affect one of the ICs. In these cases, not only the size and gene content had an impact on the phenotype, but also the sex of the contributing parent influences the clinical signs of the deletion carrier. Results We here report on the first case with a heterozygous deletion within the maternal allele affecting genes which are regulated by both ICs in 11p15.5 in a BWS patient, and describe the molecular and clinical consequences in case of its maternal or paternal inheritance. Conclusions The identification of a unique deletion affecting both 11p15.5 imprinting domains in a BWS patient illustrates the complexity of the regulation mechanisms in these key imprinting regions.
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Affiliation(s)
- Thomas Eggermann
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Pauwelsstr. 30, 52074, Aachen, Germany.
| | - Matthias Begemann
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Pauwelsstr. 30, 52074, Aachen, Germany
| | - Lutz Pfeiffer
- MVZ Medicover Humangenetik Berlin Lichtenberg, Berlin, Germany
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Hirakawa K, Matsuzaki H, Tanimoto K. Transient establishment of imprinted DNA methylation of transgenic human IC1 sequence in mouse during the preimplantation period. Hum Mol Genet 2020; 29:3646-3661. [PMID: 33258474 DOI: 10.1093/hmg/ddaa253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 11/14/2020] [Accepted: 11/26/2020] [Indexed: 01/31/2023] Open
Abstract
Monoallelic gene expression at the Igf2/H19 locus is controlled by paternal allele-specific DNA methylation of the imprinting control region (H19 ICR) that is established during spermatogenesis. We demonstrated that the H19 ICR fragment in transgenic mice acquires allele-specific methylation only after fertilization, which is essential for maintaining its allelic methylation during early embryogenesis. We identified a DNA element required for establishing postfertilization methylation within a 118 bp (m118) region. A previously generated knock-in mouse whose endogenous H19 ICR was substituted with the human H19 ICR (hIC1; 4.8 kb) sequence revealed that the hIC1 sequence was partially methylated in sperm, although this methylation was lost by the blastocyst stage, which we assume is due to a lack of an m118-equivalent sequence in the hIC1 transgene. To identify a cis sequence involved in postfertilization methylation within the hIC1 region, we generated three transgenic mouse lines (TgM): one carrying an 8.8 kb hIC1 sequence joined to m118 (hIC1+m118), one with the 8.8 kb hIC1 and one with the 5.8 kb hIC1 sequence joined to m118 (hIC1-3'+m118). We found that the hIC1-3' region was resistant to de novo DNA methylation throughout development. In contrast, the 5' portion of the hIC1 (hIC1-5') in both hIC1+m118 and hIC1 TgM were preferentially methylated on the paternal allele only during preimplantation. As DNA methylation levels were higher in hIC1+m118, the m118 sequence could also induce imprinted methylation of the human sequence. Most importantly, the hIC1-5' sequence appears to possess an activity equivalent to that of m118.
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Affiliation(s)
- Katsuhiko Hirakawa
- Graduate school of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
| | - Hitomi Matsuzaki
- Faculty of Life and Environmental Sciences, Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
| | - Keiji Tanimoto
- Faculty of Life and Environmental Sciences, Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
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Abstract
Abstract
Imprinting disorders are a group of rare diseases with a broad phenotypic spectrum caused by a wide variety of genetic and epigenetic disturbances of imprinted genes or gene clusters. The molecular genetic causes and their respective frequencies vary between the different imprinting disorders so that each has its unique requirements for the diagnostic workflow, making it challenging. To add even more complexity to this field, new molecular genetic causes have been identified over time and new technologies have enhanced the detectability e. g. of mosaic disturbances.
The precise identification of the underlying molecular genetic cause is of utmost importance in regard to recurrence risk in the families, tumour risk, clinical management and conventional and in the future therapeutic managements.
Here we give an overview of the imprinting disorders, their specific requirements for the diagnostic workup and the most common techniques used and point out possible pitfalls.
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Affiliation(s)
- Jasmin Beygo
- Institute of Human Genetics, University Hospital Essen , University of Duisburg-Essen , Essen , Germany
| | - Deniz Kanber
- Institute of Human Genetics, University Hospital Essen , University of Duisburg-Essen , Essen , Germany
| | - Thomas Eggermann
- Institute of Human Genetics, Medical Faculty , RWTH Aachen University , Aachen , Germany
| | - Matthias Begemann
- Institute of Human Genetics, Medical Faculty , RWTH Aachen University , Aachen , Germany
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Brück J, Begemann M, Dey D, Elbracht M, Eggermann T. Molecular characterization of temple syndrome families with 14q32 epimutations. Eur J Med Genet 2020; 63:104077. [PMID: 33010492 DOI: 10.1016/j.ejmg.2020.104077] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 09/07/2020] [Accepted: 09/17/2020] [Indexed: 12/17/2022]
Abstract
Temple Syndrome (TS14) is an imprinting disorder caused by molecular disruptions of the imprinted region in 14q32 (MEG3:TSS-DMR). The frequency of the three known TS14 subtypes (deletions, maternal uniparental disomy (upd(14)mat), loss of methylation (LOM)) is currently in discussion, and within the LOM group, the occurrence of Multilocus Imprinting Disturbances (MLID) has been identified. We present 16 TS14 patients with molecular alterations affecting the MEG3:TSS-DMR, comprising seven patients (43.8%) with LOM, six carriers with upd(14)mat (37.5%), and three cases (18.8%) with a deletion affecting the paternal MEG3:TSS-DMR. We did not find any evidence for MLID in the LOM group, including two cases in which different tissues were available. Whole exome sequencing (WES) in the MEG3:TSS-DMR LOM patients and their parents (Trio WES) did not reveal an obvious pathogenic variant which might cause aberrant methylation at imprinted loci. By summarizing our data with those from the literature, we could show that MLID affecting clinically relevant imprinted loci is rare in TS14 and therefore differs markedly from other imprinting disorders associated with MLID, e.g. Silver-Russell syndrome (SRS) and Beckwith-Wiedemann syndrome (BWS). However, consistent with the clinical overlap with TS14, in SRS patients carrying MLID the MEG3:TSS-DMR is frequently affected. Variants in the known candidate genes for maternal effect variants causing MLID and fetal MLID determinants could not be identified in TS14 patients. Thus, 14q32 epimutations probably have other molecular causes than epimutations in BWS or SRS patients.
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Affiliation(s)
- Johanna Brück
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Matthias Begemann
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Daniela Dey
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Miriam Elbracht
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Thomas Eggermann
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany.
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12
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Eggermann T, Brück J, Knopp C, Fekete G, Kratz C, Tasic V, Kurth I, Elbracht M, Eggermann K, Begemann M. Need for a precise molecular diagnosis in Beckwith-Wiedemann and Silver-Russell syndrome: what has to be considered and why it is important. J Mol Med (Berl) 2020; 98:1447-55. [PMID: 32839827 DOI: 10.1007/s00109-020-01966-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 07/10/2020] [Accepted: 08/17/2020] [Indexed: 12/11/2022]
Abstract
Abstract Molecular diagnostic testing of the 11p15.5-associated imprinting disorders Silver-Russell and Beckwith-Wiedemann syndrome (SRS, BWS) is challenging due to the broad spectrum of molecular defects and their mosaic occurrence. Additionally, the decision on the molecular testing algorithm is hindered by their clinical heterogeneity. However, the precise identification of the type of defect is often a prerequisite for the clinical management and genetic counselling. Four major molecular alterations (epimutations, uniparental disomies, copy number variants, single nucleotide variants) have been identified, but their frequencies vary between SRS and BWS. Due to their molecular aetiology, epimutations in both disorders as well as upd(11)pat in BWS are particular prone to mosaicism which might additionally complicate the interpretation of testing results. We report on our experience of molecular analysis in a total cohort of 1448 patients referred for diagnostic testing of BWS and SRS, comprising a dataset from 737 new patients and from 711 cases from a recent study. Though the majority of positively tested patients showed the expected molecular results, we identified a considerable number of clinically unexpected molecular alterations as well as not yet reported changes and discrepant mosaic distributions. Additionally, the rate of multilocus imprinting disturbances among the patients with epimutations and uniparental diploidies could be further specified. Altogether, these cases show that comprehensive testing strategies have to be applied in diagnostic testing of SRS and BWS. The precise molecular diagnosis is required as the basis for a targeted management (e.g. ECG (electrocardiogram) and tumour surveillance in BWS, growth treatment in SRS). The molecular diagnosis furthermore provides the basis for genetic counselling. However, it has to be considered that recurrence risk calculation is determined by the phenotypic consequences of each molecular alteration and mechanism by which the alteration arose. Key messages The detection rates for the typical molecular defects of Beckwith-Wiedemann syndrome or Silver-Russell syndrome (BWS, SRS) are lower in routine cohorts than in clinically well-characterised ones. A broad spectrum of (unexpected) molecular alterations in both disorders can be identified. Multilocus imprinting disturbances (MLID) are less frequent in SRS than expected. The frequency of MLID and uniparental diploidy in BWS is confirmed. Mosaicism is a diagnostic challenge in BWS and SRS. The precise determination of the molecular defects affecting is the basis for a targeted clinical management and genetic counselling.
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Abstract
Genomic imprinting, a phenomenon in which the two parental alleles are regulated differently, is observed in mammals, marsupials and a few other species, including seed-bearing plants. Dysregulation of genomic imprinting can cause developmental disorders such as Beckwith-Wiedemann syndrome (BWS) and Silver-Russell syndrome (SRS). In this Review, we discuss (1) how various (epi)genetic lesions lead to the dysregulation of clinically relevant imprinted loci, and (2) how such perturbations may contribute to the developmental defects in BWS and SRS. Given that the regulatory mechanisms of most imprinted clusters are well conserved between mice and humans, numerous mouse models of BWS and SRS have been generated. These mouse models are key to understanding how mutations at imprinted loci result in pathological phenotypes in humans, although there are some limitations. This Review focuses on how the biological findings obtained from innovative mouse models explain the clinical features of BWS and SRS.
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Affiliation(s)
- Suhee Chang
- Epigenetics Institute, Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Marisa S Bartolomei
- Epigenetics Institute, Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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Higashimoto K, Watanabe H, Tanoue Y, Tonoki H, Tokutomi T, Hara S, Yatsuki H, Soejima H. Hypomethylation of a centromeric block of ICR1 is sufficient to cause Silver-Russell syndrome. J Med Genet 2020; 58:422-425. [PMID: 32447322 PMCID: PMC8142445 DOI: 10.1136/jmedgenet-2020-106907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 04/08/2020] [Accepted: 04/20/2020] [Indexed: 11/15/2022]
Abstract
Silver-Russell syndrome (SRS) is a representative imprinting disorder. A major cause is the loss of methylation (LOM) of imprinting control region 1 (ICR1) within the IGF2/H19 domain. ICR1 is a gametic differentially methylated region (DMR) consisting of two repeat blocks, with each block including three CTCF target sites (CTSs). ICR1-LOM on the paternal allele allows CTCF to bind to CTSs, resulting in IGF2 repression on the paternal allele and biallelic expression of H19. We analysed 10 differentially methylated sites (DMSs) (ie, seven CTSs and three somatic DMRs within the IGF2/H19 domain, including two IGF2-DMRs and the H19-promoter) in five SRS patients with ICR1-LOM. Four patients showed consistent hypomethylation at all DMSs; however, one exhibited a peculiar LOM pattern, showing LOM at the centromeric region of the IGF2/H19 domain but normal methylation at the telomeric region. This raised important points: there may be a separate regulation of DNA methylation for the two repeat blocks within ICR1; there is independent control of somatic DMRs under each repeat block; sufficient IGF2 repression to cause SRS phenotypes occurs by LOM only in the centromeric block; and the need for simultaneous methylation analysis of several DMSs in both blocks for a correct molecular diagnosis.
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Affiliation(s)
- Ken Higashimoto
- Division of Molecular Genetics & Epigenetics, Department of Biomolecular Sciences, Saga University Faculty of Medicine, Saga, Japan
| | - Hijiri Watanabe
- Department of Pediatrics, Amakusa Medical Center, Amakusa, Japan
| | - Yuka Tanoue
- Division of Molecular Genetics & Epigenetics, Department of Biomolecular Sciences, Saga University Faculty of Medicine, Saga, Japan
| | - Hidefumi Tonoki
- Medical Genetics Center, Department of Pediatrics, Tenshi Hospital, Sapporo, Japan
| | - Tomoharu Tokutomi
- Department of Clinical Genetics, School of Medicine, Iwate Medical University, Morioka, Japan
| | - Satoshi Hara
- Division of Molecular Genetics & Epigenetics, Department of Biomolecular Sciences, Saga University Faculty of Medicine, Saga, Japan
| | - Hitomi Yatsuki
- Division of Molecular Genetics & Epigenetics, Department of Biomolecular Sciences, Saga University Faculty of Medicine, Saga, Japan
| | - Hidenobu Soejima
- Division of Molecular Genetics & Epigenetics, Department of Biomolecular Sciences, Saga University Faculty of Medicine, Saga, Japan
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15
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Rovina D, La Vecchia M, Cortesi A, Fontana L, Pesant M, Maitz S, Tabano S, Bodega B, Miozzo M, Sirchia SM. Profound alterations of the chromatin architecture at chromosome 11p15.5 in cells from Beckwith-Wiedemann and Silver-Russell syndromes patients. Sci Rep 2020; 10:8275. [PMID: 32427849 PMCID: PMC7237657 DOI: 10.1038/s41598-020-65082-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 04/24/2020] [Indexed: 01/12/2023] Open
Abstract
Beckwith-Wiedemann syndrome (BWS) and Silver-Russell syndrome (SRS) are imprinting-related disorders associated with genetic/epigenetic alterations of the 11p15.5 region, which harbours two clusters of imprinted genes (IGs). 11p15.5 IGs are regulated by the methylation status of imprinting control regions ICR1 and ICR2. 3D chromatin structure is thought to play a pivotal role in gene expression control; however, chromatin architecture models are still poorly defined in most cases, particularly for IGs. Our study aimed at elucidating 11p15.5 3D structure, via 3C and 3D FISH analyses of cell lines derived from healthy, BWS or SRS children. We found that, in healthy cells, IGF2/H19 and CDKN1C/KCNQ1OT1 domains fold in complex chromatin conformations, that facilitate the control of IGs mediated by distant enhancers. In patient-derived cell lines, we observed a profound impairment of such a chromatin architecture. Specifically, we identified a cross-talk between IGF2/H19 and CDKN1C/KCNQ1OT1 domains, consisting in in cis, monoallelic interactions, that are present in healthy cells but lost in patient cell lines: an inter-domain association that sees ICR2 move close to IGF2 on one allele, and to H19 on the other. Moreover, an intra-domain association within the CDKN1C/KCNQ1OT1 locus seems to be crucial for maintaining the 3D organization of the region.
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Affiliation(s)
- Davide Rovina
- Medical Genetics, Department of Health Sciences, Università degli Studi di Milano, 20142, Milano, Italy
| | - Marta La Vecchia
- Medical Genetics, Department of Health Sciences, Università degli Studi di Milano, 20142, Milano, Italy
| | - Alice Cortesi
- Genome Biology Unit, Istituto Nazionale di Genetica Molecolare "Romeo ed Enrica Invernizzi" (INGM), 20122, Milano, Italy
| | - Laura Fontana
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122, Milano, Italy.,Medical Genetics, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, 20122, Milano, Italy
| | - Matthieu Pesant
- Genome Biology Unit, Istituto Nazionale di Genetica Molecolare "Romeo ed Enrica Invernizzi" (INGM), 20122, Milano, Italy
| | - Silvia Maitz
- Clinical Pediatric, Genetics Unit, MBBM Foundation, San Gerardo di Monza, 20900, Monza, Italy
| | - Silvia Tabano
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122, Milano, Italy.,Medical Genetics, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, 20122, Milano, Italy
| | - Beatrice Bodega
- Genome Biology Unit, Istituto Nazionale di Genetica Molecolare "Romeo ed Enrica Invernizzi" (INGM), 20122, Milano, Italy
| | - Monica Miozzo
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122, Milano, Italy.,Medical Genetics, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, 20122, Milano, Italy
| | - Silvia M Sirchia
- Medical Genetics, Department of Health Sciences, Università degli Studi di Milano, 20142, Milano, Italy.
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Elbracht M, Mackay D, Begemann M, Kagan KO, Eggermann T. Disturbed genomic imprinting and its relevance for human reproduction: causes and clinical consequences. Hum Reprod Update 2020; 26:197-213. [DOI: 10.1093/humupd/dmz045] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 11/07/2019] [Accepted: 11/15/2019] [Indexed: 12/19/2022] Open
Abstract
Abstract
BACKGROUND
Human reproductive issues affecting fetal and maternal health are caused by numerous exogenous and endogenous factors, of which the latter undoubtedly include genetic changes. Pathogenic variants in either maternal or offspring DNA are associated with effects on the offspring including clinical disorders and nonviable outcomes. Conversely, both fetal and maternal factors can affect maternal health during pregnancy. Recently, it has become evident that mammalian reproduction is influenced by genomic imprinting, an epigenetic phenomenon that regulates the expression of genes according to their parent from whom they are inherited. About 1% of human genes are normally expressed from only the maternally or paternally inherited gene copy. Since numerous imprinted genes are involved in (embryonic) growth and development, disturbance of their balanced expression can adversely affect these processes.
OBJECTIVE AND RATIONALE
This review summarises current our understanding of genomic imprinting in relation to human ontogenesis and pregnancy and its relevance for reproductive medicine.
SEARCH METHODS
Literature databases (Pubmed, Medline) were thoroughly searched for the role of imprinting in human reproductive failure. In particular, the terms ‘multilocus imprinting disturbances, SCMC, NLRP/NALP, imprinting and reproduction’ were used in various combinations.
OUTCOMES
A range of molecular changes to specific groups of imprinted genes are associated with imprinting disorders, i.e. syndromes with recognisable clinical features including distinctive prenatal features. Whereas the majority of affected individuals exhibit alterations at single imprinted loci, some have multi-locus imprinting disturbances (MLID) with less predictable clinical features. Imprinting disturbances are also seen in some nonviable pregnancy outcomes, such as (recurrent) hydatidiform moles, which can therefore be regarded as a severe form of imprinting disorders. There is growing evidence that MLID can be caused by variants in the maternal genome altering the imprinting status of the oocyte and the embryo, i.e. maternal effect mutations. Pregnancies of women carrying maternal affect mutations can have different courses, ranging from miscarriages to birth of children with clinical features of various imprinting disorders.
WIDER IMPLICATIONS
Increasing understanding of imprinting disturbances and their clinical consequences have significant impacts on diagnostics, counselling and management in the context of human reproduction. Defining criteria for identifying pregnancies complicated by imprinting disorders facilitates early diagnosis and personalised management of both the mother and offspring. Identifying the molecular lesions underlying imprinting disturbances (e.g. maternal effect mutations) allows targeted counselling of the family and focused medical care in further pregnancies.
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Affiliation(s)
- Miriam Elbracht
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Deborah Mackay
- Human Genetics and Genomic Medicine, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Matthias Begemann
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Karl Oliver Kagan
- Obstetrics and Gynaecology, University Hospital of Tübingen, Tübingen, Germany
| | - Thomas Eggermann
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany
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17
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Wesseler K, Kraft F, Eggermann T. Molecular and Clinical Opposite Findings in 11p15.5 Associated Imprinting Disorders: Characterization of Basic Mechanisms to Improve Clinical Management. Int J Mol Sci 2019; 20:ijms20174219. [PMID: 31466347 PMCID: PMC6747273 DOI: 10.3390/ijms20174219] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 08/26/2019] [Accepted: 08/26/2019] [Indexed: 12/14/2022] Open
Abstract
Silver-Russell and Beckwith-Wiedemann syndromes (SRS, BWS) are rare congenital human disorders characterized by opposite growth disturbances. With the increasing knowledge on the molecular basis of SRS and BWS, it has become obvious that the disorders mirror opposite alterations at the same genomic loci in 11p15.5. In fact, these changes directly or indirectly affect the expression of IGF2 and CDKN1C and their associated pathways, and thereby, cause growth disturbances as key features of both diseases. The increase of knowledge has become possible with the development and implementation of new and comprehensive assays. Whereas, in the beginning molecular testing was restricted to single chromosomal loci, many tests now address numerous loci in the same run, and the diagnostic implementation of (epi)genome wide assays is only a question of time. These high-throughput approaches will be complemented by the analysis of other omic datasets (e.g., transcriptome, metabolome, proteome), and it can be expected that the integration of these data will massively improve the understanding of the pathobiology of imprinting disorders and their diagnostics. Especially long-read sequencing methods, e.g., nanopore sequencing, allowing direct detection of native DNA modification, will strongly contribute to a better understanding of genomic imprinting in the near future. Thereby, new genomic loci and types of pathogenic variants will be identified, resulting in more precise discrimination into different molecular subgroups. These subgroups serve as the basis for (epi)genotype-phenotype correlations, allowing a more directed prognosis, counseling, and therapy. By deciphering the pathophysiological consequences of SRS and BWS and their molecular disturbances, future therapies will be available targeting the basic cause of the disease and respective pathomechanisms and will complement conventional therapeutic strategies.
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Affiliation(s)
- Katharina Wesseler
- Institute of Human Genetics, University Hospital, Technical University Aachen (RWTH), 52074 Aachen, Germany
| | - Florian Kraft
- Institute of Human Genetics, University Hospital, Technical University Aachen (RWTH), 52074 Aachen, Germany
| | - Thomas Eggermann
- Institute of Human Genetics, University Hospital, Technical University Aachen (RWTH), 52074 Aachen, Germany.
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Monk D, Mackay DJG, Eggermann T, Maher ER, Riccio A. Genomic imprinting disorders: lessons on how genome, epigenome and environment interact. Nat Rev Genet 2019; 20:235-48. [PMID: 30647469 DOI: 10.1038/s41576-018-0092-0] [Citation(s) in RCA: 207] [Impact Index Per Article: 41.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Genomic imprinting, the monoallelic and parent-of-origin-dependent expression of a subset of genes, is required for normal development, and its disruption leads to human disease. Imprinting defects can involve isolated or multilocus epigenetic changes that may have no evident genetic cause, or imprinting disruption can be traced back to alterations of cis-acting elements or trans-acting factors that control the establishment, maintenance and erasure of germline epigenetic imprints. Recent insights into the dynamics of the epigenome, including the effect of environmental factors, suggest that the developmental outcomes and heritability of imprinting disorders are influenced by interactions between the genome, the epigenome and the environment in germ cells and early embryos.
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Neuheuser L, Meyer R, Begemann M, Elbracht M, Eggermann T. Next generation sequencing and imprinting disorders: Current applications and future perspectives: Lessons from Silver-Russell syndrome. Mol Cell Probes 2019; 44:1-7. [DOI: 10.1016/j.mcp.2018.12.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 12/05/2018] [Accepted: 12/22/2018] [Indexed: 12/28/2022]
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Kraft F, Wesseler K, Begemann M, Kurth I, Elbracht M, Eggermann T. Novel familial distal imprinting centre 1 (11p15.5) deletion provides further insights in imprinting regulation. Clin Epigenetics 2019; 11:30. [PMID: 30770769 PMCID: PMC6377752 DOI: 10.1186/s13148-019-0629-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 02/08/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Deletions of the imprinting centre 1 (IC1) in 11p15.5 are rare and their clinical significance is not only influenced by their parental origin but also by their exact genomic localization. In case the maternal IC1 allele is affected, the deletion is associated with the overgrowth disorder Beckwith-Wiedemann syndrome (BWS) and a gain of methylation (GOM) of the IC1. The consequences of deletions of the paternal IC1 allele depend on the localization and probably the binding sites of methylation-specific DNA-binding factors affected by the change. It has been suggested that distal deletions of the paternal allele are associated with a normal IC1 methylation and phenotype, whereas proximal alterations cause a loss of methylation (LOM) and Silver-Russell syndrome (SRS) features. RESULTS In a patient referred for molecular BWS testing and his family, a deletion within the IC1 was identified by MLPA. It was associated with a GOM, corresponding to the transmission of the alteration via the maternal germline. Accordingly, the deletion was also detectable in the maternal grandmother, but here the paternal chromosome 11p15.5 was affected and a IC1 LOM was observed. By nanopore sequencing, the localization of the deletion could be precisely determined. CONCLUSIONS We report for the first time both GOM and LOM of the IC1 in the same family, caused by transmission of a 2.2-kb deletion in 11p15.5. Nanopore sequencing allowed the precise characterization of the change by long-read sequencing and thereby provides further insights in the regulation of imprinting in the IC1.
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Affiliation(s)
- Florian Kraft
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Pauwelsstr. 30, D-52074, Aachen, Germany
| | - Katharina Wesseler
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Pauwelsstr. 30, D-52074, Aachen, Germany
| | - Matthias Begemann
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Pauwelsstr. 30, D-52074, Aachen, Germany
| | - Ingo Kurth
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Pauwelsstr. 30, D-52074, Aachen, Germany
| | - Miriam Elbracht
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Pauwelsstr. 30, D-52074, Aachen, Germany
| | - Thomas Eggermann
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Pauwelsstr. 30, D-52074, Aachen, Germany.
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21
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Valente FM, Sparago A, Freschi A, Hill-Harfe K, Maas SM, Frints SGM, Alders M, Pignata L, Franzese M, Angelini C, Carli D, Mussa A, Gazzin A, Gabbarini F, Acurzio B, Ferrero GB, Bliek J, Williams CA, Riccio A, Cerrato F. Transcription alterations of KCNQ1 associated with imprinted methylation defects in the Beckwith-Wiedemann locus. Genet Med 2019; 21:1808-20. [PMID: 30635621 DOI: 10.1038/s41436-018-0416-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 12/10/2018] [Indexed: 11/18/2022] Open
Abstract
Purpose Beckwith–Wiedemann syndrome (BWS) is a developmental disorder caused by dysregulation of the imprinted gene cluster of chromosome 11p15.5 and often associated with loss of methylation (LOM) of the imprinting center 2 (IC2) located in KCNQ1 intron 10. To unravel the etiological mechanisms underlying these epimutations, we searched for genetic variants associated with IC2 LOM. Methods We looked for cases showing the clinical features of both BWS and long QT syndrome (LQTS), which is often associated with KCNQ1 variants. Pathogenic variants were identified by genomic analysis and targeted sequencing. Functional experiments were performed to link these pathogenic variants to the imprinting defect. Results We found three rare cases in which complete IC2 LOM is associated with maternal transmission of KCNQ1 variants, two of which were demonstrated to affect KCNQ1 transcription upstream of IC2. As a consequence of KCNQ1 haploinsufficiency, these variants also cause LQTS on both maternal and paternal transmission. Conclusion These results are consistent with the hypothesis that, similar to what has been demonstrated in mouse, lack of transcription across IC2 results in failure of methylation establishment in the female germline and BWS later in development, and also suggest a new link between LQTS and BWS that is important for genetic counseling.
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22
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Soellner L, Kraft F, Sauer S, Begemann M, Kurth I, Elbracht M, Eggermann T. Search for cis-acting factors and maternal effect variants in Silver-Russell patients with ICR1 hypomethylation and their mothers. Eur J Hum Genet 2018; 27:42-48. [PMID: 30218098 DOI: 10.1038/s41431-018-0269-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 07/06/2018] [Accepted: 08/09/2018] [Indexed: 11/09/2022] Open
Abstract
Silver-Russell syndrome is an imprinting disorder characterized by severe intrauterine and postnatal growth retardation. The majority of patients show loss of methylation (LOM) of the H19/IGF2 IG-DMR (ICR1) in 11p15.5. In ~10% of these patients aberrant methylation of additional imprinted loci on other chromosomes than 11 can be observed (multilocus imprinting defect - MLID). Recently, genomic variations in the ICR1 have been associated with disturbed methylation of the ICR1. In addition, variants in factors contributing to the life cycle of imprinting are discussed to cause aberrant imprinting, including MLID. These variants can either be identified in the patients with imprinting disorders themselves or in their mothers. We performed comprehensive studies to elucidate the role of both cis-acting variants in 11p15.5 as well as of maternal effect variants in the etiology of ICR1 LOM. Whereas copy number analysis and next generation sequencing in the ICR1 did not provide any evidence for a variant, search for maternal effect variants in 21 mothers of patients with ICR1 LOM identified two carriers of NLRP5 variants. By considering our results as well as those from the literature, we conclude that the causes for epimutations are heterogeneous. MLID might be regarded as an own etiological subgroup, associated with maternal effect variants in NLRP and functionally related genes. In addition, these variants might also contribute to LOM of single imprinted loci. Furthermore, genomic variants in the patients themselves might result in aberrant methylation patterns and need further investigation.
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Affiliation(s)
- Lukas Soellner
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Florian Kraft
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Sabrina Sauer
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany.,Labor Dr. Wisplinghoff, Köln, Germany
| | - Matthias Begemann
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Ingo Kurth
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Miriam Elbracht
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Thomas Eggermann
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany.
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