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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: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [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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Molecular Basis of Beckwith–Wiedemann Syndrome Spectrum with Associated Tumors and Consequences for Clinical Practice. Cancers (Basel) 2022; 14:cancers14133083. [PMID: 35804856 PMCID: PMC9265096 DOI: 10.3390/cancers14133083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 06/19/2022] [Accepted: 06/20/2022] [Indexed: 12/10/2022] Open
Abstract
Simple Summary Beckwith–Wiedemann syndrome (BWS, OMIM 130650) is an inborn overgrowth disorder caused by molecular alterations in chromosome 11p15.5. These molecular changes affect so-called imprinted genes, i.e., genes which underlie a complex regulation which is linked to the parental origin of the gene copy. Thus, either the maternal gene copy is expressed or the paternal, but this balanced regulation is prone to disturbances. In fact, different types of molecular variants have been identified in BWS, resulting in a variable phenotype; thus, it was consented that the syndromic entity was extended to the Beckwith–Wiedemann spectrum (BWSp). Some molecular subgroups of BWSp are associated with an increased embryonic tumor risk and have different likelihoods for specific tumors. Therefore, the precise determination of the molecular subgroup is needed for precise monitoring and treatment, but the molecular diagnostic procedure has several limitations and challenges which have to be considered. Abstract Beckwith–Wiedemann syndrome (BWS, OMIM 130650) is a congenital imprinting condition with a heterogenous clinical presentation of overgrowth and an increased childhood cancer risk (mainly nephroblastoma, hepatoblastoma or neuroblastoma). Due to the varying clinical presentation encompassing classical, clinical BWS without a molecular diagnosis and BWS-related phenotypes with an 11p15.5 molecular anomaly, the syndromic entity was extended to the Beckwith–Wiedemann spectrum (BWSp). The tumor risk of up to 30% depends on the molecular subtype of BWSp with causative genetic or epigenetic alterations in the chromosomal region 11p15.5. The molecular diagnosis of BWSp can be challenging for several reasons, including the range of causative molecular mechanisms which are frequently mosaic. The molecular basis of tumor formation appears to relate to stalled cellular differentiation in certain organs that predisposes persisting embryonic cells to accumulate additional molecular defects, which then results in a range of embryonal tumors. The molecular subtype of BWSp not only influences the overall risk of neoplasia, but also the likelihood of specific embryonal tumors.
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Marwaha S, Knowles JW, Ashley EA. A guide for the diagnosis of rare and undiagnosed disease: beyond the exome. Genome Med 2022; 14:23. [PMID: 35220969 PMCID: PMC8883622 DOI: 10.1186/s13073-022-01026-w] [Citation(s) in RCA: 83] [Impact Index Per Article: 41.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 02/10/2022] [Indexed: 02/07/2023] Open
Abstract
AbstractRare diseases affect 30 million people in the USA and more than 300–400 million worldwide, often causing chronic illness, disability, and premature death. Traditional diagnostic techniques rely heavily on heuristic approaches, coupling clinical experience from prior rare disease presentations with the medical literature. A large number of rare disease patients remain undiagnosed for years and many even die without an accurate diagnosis. In recent years, gene panels, microarrays, and exome sequencing have helped to identify the molecular cause of such rare and undiagnosed diseases. These technologies have allowed diagnoses for a sizable proportion (25–35%) of undiagnosed patients, often with actionable findings. However, a large proportion of these patients remain undiagnosed. In this review, we focus on technologies that can be adopted if exome sequencing is unrevealing. We discuss the benefits of sequencing the whole genome and the additional benefit that may be offered by long-read technology, pan-genome reference, transcriptomics, metabolomics, proteomics, and methyl profiling. We highlight computational methods to help identify regionally distant patients with similar phenotypes or similar genetic mutations. Finally, we describe approaches to automate and accelerate genomic analysis. The strategies discussed here are intended to serve as a guide for clinicians and researchers in the next steps when encountering patients with non-diagnostic exomes.
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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] [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] [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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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; 98:1447-1455. [PMID: 32839827 PMCID: PMC7524824 DOI: 10.1007/s00109-020-01966-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [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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Kraft F, Kurth I. Long-read sequencing to understand genome biology and cell function. Int J Biochem Cell Biol 2020; 126:105799. [PMID: 32629027 DOI: 10.1016/j.biocel.2020.105799] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 06/29/2020] [Accepted: 07/02/2020] [Indexed: 02/08/2023]
Abstract
Determining the sequence of DNA and RNA molecules has a huge impact on the understanding of cell biology and function. Recent advancements in next-generation short-read sequencing (NGS) technologies, drops in cost and a resolution down to the single-cell level shaped our current view on genome structure and function. Third-generation sequencing (TGS) methods further complete the knowledge about these processes based on long reads and the ability to analyze DNA or RNA at single molecule level. Long-read sequencing provides additional possibilities to study genome architecture and the composition of highly complex regions and to determine epigenetic modifications of nucleotide bases at a genome-wide level. We discuss the principles and advancements of long-read sequencing and its applications in genome biology.
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Affiliation(s)
- Florian Kraft
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany.
| | - Ingo Kurth
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany.
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Chang S, Bartolomei MS. Modeling human epigenetic disorders in mice: Beckwith-Wiedemann syndrome and Silver-Russell syndrome. Dis Model Mech 2020; 13:dmm044123. [PMID: 32424032 PMCID: PMC7272347 DOI: 10.1242/dmm.044123] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
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: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [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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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] [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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