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Eggermann T. Human Reproduction and Disturbed Genomic Imprinting. Genes (Basel) 2024; 15:163. [PMID: 38397153 PMCID: PMC10888310 DOI: 10.3390/genes15020163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 01/23/2024] [Accepted: 01/24/2024] [Indexed: 02/25/2024] Open
Abstract
Genomic imprinting is a specific mode of gene regulation which particularly accounts for the factors involved in development. Its disturbance affects the fetus, the course of pregnancy and even the health of the mother. In children, aberrant imprinting signatures are associated with imprinting disorders (ImpDis). These alterations also affect the function of the placenta, which has consequences for the course of the pregnancy. The molecular causes of ImpDis comprise changes at the DNA level and methylation disturbances (imprinting defects/ImpDefs), and there is an increasing number of reports of both pathogenic fetal and maternal DNA variants causing ImpDefs. These ImpDefs can be inherited, but prediction of the pregnancy complications caused is difficult, as they can cause miscarriages, aneuploidies, health issues for the mother and ImpDis in the child. Due to the complexity of imprinting regulation, each pregnancy or patient with suspected altered genomic imprinting requires a specific workup to identify the precise molecular cause and also careful clinical documentation. This review will cover the current knowledge on the molecular causes of aberrant imprinting signatures and illustrate the need to identify this basis as the prerequisite for personalized genetic and reproductive counselling of families.
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Affiliation(s)
- Thomas Eggermann
- Institute for Human Genetics and Genomic Medicine, Medical Faculty, RWTH University Aachen, Pauwelsstr. 3, D-52074 Aachen, Germany
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2
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Epimutation in inherited metabolic disorders: the influence of aberrant transcription in adjacent genes. Hum Genet 2022; 141:1309-1325. [PMID: 35190856 DOI: 10.1007/s00439-021-02414-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 12/08/2021] [Indexed: 12/12/2022]
Abstract
Epigenetic diseases can be produced by a stable alteration, called an epimutation, in DNA methylation, in which epigenome alterations are directly involved in the underlying molecular mechanisms of the disease. This review focuses on the epigenetics of two inherited metabolic diseases, epi-cblC, an inherited metabolic disorder of cobalamin (vitamin B12) metabolism, and alpha-thalassemia type α-ZF, an inherited disorder of α2-globin synthesis, with a particular interest in the role of aberrant antisense transcription of flanking genes in the generation of epimutations in CpG islands of gene promoters. In both disorders, the epimutation is triggered by an aberrant antisense transcription through the promoter, which produces an H3K36me3 histone mark involved in the recruitment of DNA methyltransferases. It results from diverse genetic alterations. In alpha-thalassemia type α-ZF, a deletion removes HBA1 and HBQ1 genes and juxtaposes the antisense LUC7L gene to the HBA2 gene. In epi-cblC, the epimutation in the MMACHC promoter is produced by mutations in the antisense flanking gene PRDX1, which induces a prolonged antisense transcription through the MMACHC promoter. The presence of the epimutation in sperm, its transgenerational inheritance via the mutated PRDX1, and the high expression of PRDX1 in spermatogonia but its nearly undetectable transcription in spermatids and spermatocytes, suggest that the epimutation could be maintained during germline reprogramming and despite removal of aberrant transcription. The epivariation seen in the MMACHC promoter (0.95 × 10-3) is highly frequent compared to epivariations affecting other genes of the Online Catalog of Human Genes and Genetic Disorders in an epigenome-wide dataset of 23,116 individuals. This and the comparison of epigrams of two monozygotic twins suggest that the aberrant transcription could also be influenced by post-zygotic environmental exposures.
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Naveh NSS, Deegan DF, Huhn J, Traxler E, Lan Y, Weksberg R, Ganguly A, Engel N, Kalish JM. The role of CTCF in the organization of the centromeric 11p15 imprinted domain interactome. Nucleic Acids Res 2021; 49:6315-6330. [PMID: 34107024 PMCID: PMC8216465 DOI: 10.1093/nar/gkab475] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 04/22/2021] [Accepted: 05/20/2021] [Indexed: 02/06/2023] Open
Abstract
DNA methylation, chromatin-binding proteins, and DNA looping are common components regulating genomic imprinting which leads to parent-specific monoallelic gene expression. Loss of methylation (LOM) at the human imprinting center 2 (IC2) on chromosome 11p15 is the most common cause of the imprinting overgrowth disorder Beckwith-Wiedemann Syndrome (BWS). Here, we report a familial transmission of a 7.6 kB deletion that ablates the core promoter of KCNQ1. This structural alteration leads to IC2 LOM and causes recurrent BWS. We find that occupancy of the chromatin organizer CTCF is disrupted proximal to the deletion, which causes chromatin architecture changes both in cis and in trans. We also profile the chromatin architecture of IC2 in patients with sporadic BWS caused by isolated LOM to identify conserved features of IC2 regulatory disruption. A strong interaction between CTCF sites around KCNQ1 and CDKN1C likely drive their expression on the maternal allele, while a weaker interaction involving the imprinting control region element may impede this connection and mediate gene silencing on the paternal allele. We present an imprinting model in which KCNQ1 transcription is necessary for appropriate CTCF binding and a novel chromatin conformation to drive allele-specific gene expression.
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Affiliation(s)
- Natali S Sobel Naveh
- Division of Human Genetics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Daniel F Deegan
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Jacklyn Huhn
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Emily Traxler
- Division of Human Genetics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Yemin Lan
- Epigenetics Institute, Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Rosanna Weksberg
- Division of Clinical and Metabolic Genetics, Genetics and Genome Biology, Hospital for Sick Children, and Institute of Medical Science, University of Toronto, Toronto, Canada
| | - Arupa Ganguly
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Nora Engel
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Jennifer M Kalish
- Division of Human Genetics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.,Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.,Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
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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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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] [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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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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Eßinger C, Karch S, Moog U, Fekete G, Lengyel A, Pinti E, Eggermann T, Begemann M. Frequency of KCNQ1 variants causing loss of methylation of Imprinting Centre 2 in Beckwith-Wiedemann syndrome. Clin Epigenetics 2020; 12:63. [PMID: 32393365 PMCID: PMC7216698 DOI: 10.1186/s13148-020-00856-y] [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: 03/10/2020] [Accepted: 04/23/2020] [Indexed: 11/21/2022] Open
Abstract
Background Beckwith-Wiedemann syndrome (BWS) is an imprinting disorder caused by disturbances of the chromosomal region 11p15.5. The most frequent molecular finding in BWS is loss of methylation (LOM) of the Imprinting Centre 2 (IC2) region on the maternal allele, which is localised in intron 10 of the KCNQ1 gene. In rare cases, LOM of IC2 has been reported in families with KCNQ1 germline variants which additionally cause long-QT syndrome (LQTS). Thus, a functional link between disrupted KCNQ1 transcripts and altered IC2 methylation has been suggested, resulting in the co-occurrence of LQTS and BWS in case of maternal inheritance. Whereas these cases were identified by chance or in patients with abnormal electrocardiograms, a systematic screen for KCNQ1 variants in IC2 LOM carriers has not yet been performed. Results We analysed 52 BWS patients with IC2 LOM to determine the frequency of germline variants in KCNQ1 by MLPA and an amplicon-based next generation sequencing approach. We identified one patient with a splice site variant causing premature transcription termination of KCNQ1. Conclusions Our study strengthens the hypothesis that proper KCNQ1 transcription is required for the establishment of IC2 methylation, but that KCNQ1 variants cause IC2 LOM only in a small number of BWS patients.
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Affiliation(s)
- Carla Eßinger
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Pauwelsstr. 30, 52074, Aachen, Germany
| | - Stephanie Karch
- University Children's Hospital, Heidelberg University, Heidelberg, Germany
| | - Ute Moog
- Institute of Human Genetics, Heidelberg University, Heidelberg, Germany
| | - György Fekete
- II. Department of Paediatrics, Semmelweis University, Budapest, Hungary
| | - Anna Lengyel
- II. Department of Paediatrics, Semmelweis University, Budapest, Hungary
| | - Eva Pinti
- II. Department of Paediatrics, Semmelweis University, Budapest, Hungary
| | - 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
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Common genetic variation in the Angelman syndrome imprinting centre affects the imprinting of chromosome 15. Eur J Hum Genet 2020; 28:835-839. [PMID: 32152487 PMCID: PMC7253442 DOI: 10.1038/s41431-020-0595-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 01/21/2020] [Accepted: 02/04/2020] [Indexed: 11/17/2022] Open
Abstract
Angelman syndrome (AS) is a rare neurogenetic imprinting disorder caused by the loss of function of UBE3A. In ~3–5% of AS patients, the disease is due to an imprinting defect (ID). These patients lack DNA methylation of the maternal SNRPN promotor so that a large SNRPN sense/UBE3A antisense transcript (SNHG14) is expressed, which silences UBE3A. In very rare cases, the ID is caused by a deletion of the AS imprinting centre (AS-IC). To search for sequence alterations, we sequenced this region in 168 patients without an AS-IC deletion, but did not detect any sequence alteration. However, the AS-IC harbours six common variants (five single nucleotide variants and one TATG insertion/deletion variant), which constitute five common haplotypes. To determine if any of these haplotypes is associated with an increased risk for an ID, we investigated 119 informative AS-ID trios with the transmission disequilibrium test, which is a family-based association test that measures the over-transmission of an allele or haplotype from heterozygous parents to affected offspring. By this we observed maternal over-transmission of haplotype H-AS3 (p = 0.0073). Interestingly, H-AS3 is the only haplotype that includes the TATG deletion allele. We conclude that this haplotype and possibly the TATG deletion, which removes a SOX2 binding site, increases the risk for a maternal ID and AS. Our data strengthen the notion that the AS-IC is important for establishing and/or maintaining DNA methylation at the SNRPN promotor and show that common genetic variation can affect genomic imprinting.
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Abstract
The mammalian genome experiences profound setting and resetting of epigenetic patterns during the life-course. This is understood best for DNA methylation: the specification of germ cells, gametogenesis, and early embryo development are characterised by phases of widespread erasure and rewriting of methylation. While mitigating against intergenerational transmission of epigenetic information, these processes must also ensure correct genomic imprinting that depends on faithful and long-term memory of gamete-derived methylation states in the next generation. This underscores the importance of understanding the mechanisms of methylation programming in the germline.
De novo methylation in the oocyte is of particular interest because of its intimate association with transcription, which results in a bimodal methylome unique amongst mammalian cells. Moreover, this methylation landscape is entirely set up in a non-dividing cell, making the oocyte a fascinating model system in which to explore mechanistic determinants of methylation. Here, we summarise current knowledge on the oocyte DNA methylome and how it is established, focussing on recent insights from knockout models in the mouse that explore the interplay between methylation and chromatin states. We also highlight some remaining paradoxes and enigmas, in particular the involvement of non-nuclear factors for correct
de novo methylation.
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Affiliation(s)
- Hannah Demond
- Epigenetics Programme, The Babraham Institute, Cambridge, UK
| | - Gavin Kelsey
- Epigenetics Programme, The Babraham Institute, Cambridge, UK.,Centre for Trophoblast Research, University of Cambridge, Cambridge, UK
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Kühnel T, Heinz HSB, Utz N, Božić T, Horsthemke B, Steenpass L. A human somatic cell culture system for modelling gene silencing by transcriptional interference. Heliyon 2020; 6:e03261. [PMID: 32021933 PMCID: PMC6994850 DOI: 10.1016/j.heliyon.2020.e03261] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 01/06/2020] [Accepted: 01/15/2020] [Indexed: 11/30/2022] Open
Abstract
Transcriptional interference and transcription through regulatory elements (transcriptional read-through) are implicated in gene silencing and the establishment of DNA methylation. Transcriptional read-through is needed to seed DNA methylation at imprinted genes in the germ line and can lead to aberrant gene silencing by DNA methylation in human disease. To enable the study of parameters and factors influencing transcriptional interference and transcriptional read-through at human promoters, we established a somatic cell culture system. At two promoters of imprinted genes (UBE3A and SNRPN) and two promoters shown to be silenced by aberrant transcriptional read-through in human disease (MSH2 and HBA2) we tested, if transcriptional read-through is sufficient for gene repression and the acquisition of DNA methylation. Induction of transcriptional read-through from the doxycycline-inducible CMV promoter resulted in consistent repression of all downstream promoters, independent of promoter type and orientation. Repression was dependent on ongoing transcription, since withdrawal of induction resulted in reactivation. DNA methylation was not acquired at any of the promoters. Overexpression of DNMT3A and DNMT3L, factors needed for DNA methylation establishment in oocytes, was still not sufficient for the induction of DNA methylation. This indicates that induction of DNA methylation has more complex requirements than transcriptional read-through and the presence of de novo DNA methyltransferases.
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Affiliation(s)
- Theresa Kühnel
- Institute of Human Genetics, University Hospital Essen, University Duisburg-Essen, Hufelandstr 55, 45147 Essen, Germany
| | - Helena Sophie Barbara Heinz
- Institute of Human Genetics, University Hospital Essen, University Duisburg-Essen, Hufelandstr 55, 45147 Essen, Germany
| | - Nadja Utz
- Institute of Human Genetics, University Hospital Essen, University Duisburg-Essen, Hufelandstr 55, 45147 Essen, Germany
- Present address: Institute of Neuropathology, Justus Liebig University Giessen, Aulweg 128, 35392 Giessen, Germany
| | - Tanja Božić
- Helmholtz Institute for Biomedical Engineering, Division of Stem Cell Biology and Cellular Engineering, RWTH Aachen University Medical School, Pauwelsstr. 20, 52074 Aachen, Germany
| | - Bernhard Horsthemke
- Institute of Human Genetics, University Hospital Essen, University Duisburg-Essen, Hufelandstr 55, 45147 Essen, Germany
| | - Laura Steenpass
- Institute of Human Genetics, University Hospital Essen, University Duisburg-Essen, Hufelandstr 55, 45147 Essen, Germany
- Corresponding author.
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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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