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Hendricks EL, Liebl FLW. The CHD family chromatin remodeling enzyme, Kismet, promotes both clathrin-mediated and activity-dependent bulk endocytosis. PLoS One 2024; 19:e0300255. [PMID: 38512854 PMCID: PMC10956772 DOI: 10.1371/journal.pone.0300255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 02/23/2024] [Indexed: 03/23/2024] Open
Abstract
Chromodomain helicase DNA binding domain (CHD) proteins, including CHD7 and CHD8, remodel chromatin to enable transcriptional programs. Both proteins are important for proper neural development as heterozygous mutations in Chd7 and Chd8 are causative for CHARGE syndrome and correlated with autism spectrum disorders, respectively. Their roles in mature neurons are poorly understood despite influencing the expression of genes required for cell adhesion, neurotransmission, and synaptic plasticity. The Drosophila homolog of CHD7 and CHD8, Kismet (Kis), promotes neurotransmission, endocytosis, and larval locomotion. Endocytosis is essential in neurons for replenishing synaptic vesicles, maintaining protein localization, and preserving the size and composition of the presynaptic membrane. Several forms of endocytosis have been identified including clathrin-mediated endocytosis, which is coupled with neural activity and is the most prevalent form of synaptic endocytosis, and activity-dependent bulk endocytosis, which occurs during periods of intense stimulation. Kis modulates the expression of gene products involved in endocytosis including promoting shaggy/GSK3β expression while restricting PI3K92E. kis mutants electrophysiologically phenocopy a liquid facets mutant in response to paradigms that induce clathrin-mediated endocytosis and activity-dependent bulk endocytosis. Further, kis mutants do not show further reductions in endocytosis when activity-dependent bulk endocytosis or clathrin-mediated endocytosis are pharmacologically inhibited. We find that Kis is important in postsynaptic muscle for proper endocytosis but the ATPase domain of Kis is dispensable for endocytosis. Collectively, our data indicate that Kis promotes both clathrin-mediated endocytosis and activity-dependent bulk endocytosis possibly by promoting transcription of several endocytic genes and maintaining the size of the synaptic vesicle pool.
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Affiliation(s)
- Emily L. Hendricks
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, Illinois, United States of America
| | - Faith L. W. Liebl
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, Illinois, United States of America
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2
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Smith IR, Hendricks EL, Latcheva NK, Marenda DR, Liebl FLW. The CHD Protein Kismet Restricts the Synaptic Localization of Cell Adhesion Molecules at the Drosophila Neuromuscular Junction. Int J Mol Sci 2024; 25:3074. [PMID: 38474321 PMCID: PMC10931923 DOI: 10.3390/ijms25053074] [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: 01/21/2024] [Revised: 03/01/2024] [Accepted: 03/05/2024] [Indexed: 03/14/2024] Open
Abstract
The appropriate expression and localization of cell surface cell adhesion molecules must be tightly regulated for optimal synaptic growth and function. How neuronal plasma membrane proteins, including cell adhesion molecules, cycle between early endosomes and the plasma membrane is poorly understood. Here we show that the Drosophila homolog of the chromatin remodeling enzymes CHD7 and CHD8, Kismet, represses the synaptic levels of several cell adhesion molecules. Neuroligins 1 and 3 and the integrins αPS2 and βPS are increased at kismet mutant synapses but Kismet only directly regulates transcription of neuroligin 2. Kismet may therefore regulate synaptic CAMs indirectly by activating transcription of gene products that promote intracellular vesicle trafficking including endophilin B (endoB) and/or rab11. Knock down of EndoB in all tissues or neurons increases synaptic FasII while knock down of EndoB in kis mutants does not produce an additive increase in FasII. In contrast, neuronal expression of Rab11, which is deficient in kis mutants, leads to a further increase in synaptic FasII in kis mutants. These data support the hypothesis that Kis influences the synaptic localization of FasII by promoting intracellular vesicle trafficking through the early endosome.
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Affiliation(s)
- Ireland R. Smith
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL 62025, USA
| | - Emily L. Hendricks
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL 62025, USA
| | - Nina K. Latcheva
- Department of Biology, Drexel University, 3141 Chestnut St., Philadelphia, PA 19104, USA (D.R.M.)
- Program in Molecular and Cellular Biology and Genetics, Drexel University College of Medicine, Philadelphia, PA 19104, USA
- Neurogenetics Program, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Daniel R. Marenda
- Department of Biology, Drexel University, 3141 Chestnut St., Philadelphia, PA 19104, USA (D.R.M.)
- Program in Molecular and Cellular Biology and Genetics, Drexel University College of Medicine, Philadelphia, PA 19104, USA
- Division of Biological Infrastructure, National Science Foundation, Alexandria, VA 22314, USA
| | - Faith L. W. Liebl
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL 62025, USA
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Kalinousky AJ, Luperchio TR, Schrode KM, Harris JR, Zhang L, DeLeon VB, Fahrner JA, Lauer AM, Bjornsson HT. KMT2D Deficiency Causes Sensorineural Hearing Loss in Mice and Humans. Genes (Basel) 2023; 15:48. [PMID: 38254937 PMCID: PMC10815913 DOI: 10.3390/genes15010048] [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: 12/05/2023] [Revised: 12/19/2023] [Accepted: 12/21/2023] [Indexed: 01/24/2024] Open
Abstract
Individuals with Kabuki syndrome type 1 (KS1) often have hearing loss recognized in middle childhood. Current clinical dogma suggests that this phenotype is caused by frequent infections due to the immune deficiency in KS1 and/or secondary to structural abnormalities of the ear. To clarify some aspects of hearing loss, we collected information on hearing status from 21 individuals with KS1 and found that individuals have both sensorineural and conductive hearing loss, with the average age of presentation being 7 years. Our data suggest that while ear infections and structural abnormalities contribute to the observed hearing loss, these factors do not explain all loss. Using a KS1 mouse model, we found hearing abnormalities from hearing onset, as indicated by auditory brainstem response measurements. In contrast to mouse and human data for CHARGE syndrome, a disorder possessing overlapping clinical features with KS and a well-known cause of hearing loss and structural inner ear abnormalities, there are no apparent structural abnormalities of the cochlea in KS1 mice. The KS1 mice also display diminished distortion product otoacoustic emission levels, which suggests outer hair cell dysfunction. Combining these findings, our data suggests that KMT2D dysfunction causes sensorineural hearing loss compounded with external factors, such as infection.
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Affiliation(s)
- Allison J. Kalinousky
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; (A.J.K.); (T.R.L.); (J.R.H.); (L.Z.); (J.A.F.)
| | - Teresa R. Luperchio
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; (A.J.K.); (T.R.L.); (J.R.H.); (L.Z.); (J.A.F.)
| | - Katrina M. Schrode
- Department of Otolaryngology-Head and Neck Surgery and Center for Hearing and Balance, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; (K.M.S.); (A.M.L.)
| | - Jacqueline R. Harris
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; (A.J.K.); (T.R.L.); (J.R.H.); (L.Z.); (J.A.F.)
- Department of Neurology, Kennedy Krieger Institute, Baltimore, MD 21205, USA
| | - Li Zhang
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; (A.J.K.); (T.R.L.); (J.R.H.); (L.Z.); (J.A.F.)
| | - Valerie B. DeLeon
- Department of Anthropology, University of Florida, Gainesville, FL 32610, USA;
| | - Jill A. Fahrner
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; (A.J.K.); (T.R.L.); (J.R.H.); (L.Z.); (J.A.F.)
- Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Amanda M. Lauer
- Department of Otolaryngology-Head and Neck Surgery and Center for Hearing and Balance, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; (K.M.S.); (A.M.L.)
| | - Hans T. Bjornsson
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; (A.J.K.); (T.R.L.); (J.R.H.); (L.Z.); (J.A.F.)
- Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
- Landspitali University Hospital, 102 Reykjavik, Iceland
- Faculty of Medicine, University of Iceland, 101 Reykjavik, Iceland
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Shpargel KB, Quickstad G. SETting up the genome: KMT2D and KDM6A genomic function in the Kabuki syndrome craniofacial developmental disorder. Birth Defects Res 2023; 115:1885-1898. [PMID: 37800171 PMCID: PMC11190966 DOI: 10.1002/bdr2.2253] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 09/04/2023] [Accepted: 09/14/2023] [Indexed: 10/07/2023]
Abstract
BACKGROUND Kabuki syndrome is a congenital developmental disorder that is characterized by distinctive facial gestalt and skeletal abnormalities. Although rare, the disorder shares clinical features with several related craniofacial syndromes that manifest from mutations in chromatin-modifying enzymes. Collectively, these clinical studies underscore the crucial, concerted functions of chromatin factors in shaping developmental genome structure and driving cellular transcriptional states. Kabuki syndrome predominantly results from mutations in KMT2D, a histone H3 lysine 4 methylase, or KDM6A, a histone H3 lysine 27 demethylase. AIMS In this review, we summarize the research efforts to model Kabuki syndrome in vivo to understand the cellular and molecular mechanisms that lead to the craniofacial and skeletal pathogenesis that defines the disorder. DISCUSSION As several studies have indicated the importance of KMT2D and KDM6A function through catalytic-independent mechanisms, we highlight noncanonical roles for these enzymes as recruitment centers for alternative chromatin and transcriptional machinery.
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Affiliation(s)
- Karl B. Shpargel
- Department of GeneticsUniversity of North CarolinaChapel HillNorth CarolinaUSA
| | - Gabrielle Quickstad
- Department of GeneticsUniversity of North CarolinaChapel HillNorth CarolinaUSA
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Stathopoulou A, Wang P, Thellier C, Kelly RG, Zheng D, Scambler PJ. CHARGE syndrome-associated CHD7 acts at ISL1-regulated enhancers to modulate second heart field gene expression. Cardiovasc Res 2023; 119:2089-2105. [PMID: 37052590 PMCID: PMC10478754 DOI: 10.1093/cvr/cvad059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 01/20/2022] [Accepted: 04/12/2023] [Indexed: 04/14/2023] Open
Abstract
AIMS Haploinsufficiency of the chromo-domain protein CHD7 underlies most cases of CHARGE syndrome, a multisystem birth defect including congenital heart malformation. Context specific roles for CHD7 in various stem, progenitor, and differentiated cell lineages have been reported. Previously, we showed severe defects when Chd7 is absent from cardiopharyngeal mesoderm (CPM). Here, we investigate altered gene expression in the CPM and identify specific CHD7-bound target genes with known roles in the morphogenesis of affected structures. METHODS AND RESULTS We generated conditional KO of Chd7 in CPM and analysed cardiac progenitor cells using transcriptomic and epigenomic analyses, in vivo expression analysis, and bioinformatic comparisons with existing datasets. We show CHD7 is required for correct expression of several genes established as major players in cardiac development, especially within the second heart field (SHF). We identified CHD7 binding sites in cardiac progenitor cells and found strong association with histone marks suggestive of dynamically regulated enhancers during the mesodermal to cardiac progenitor transition of mESC differentiation. Moreover, CHD7 shares a subset of its target sites with ISL1, a pioneer transcription factor in the cardiogenic gene regulatory network, including one enhancer modulating Fgf10 expression in SHF progenitor cells vs. differentiating cardiomyocytes. CONCLUSION We show that CHD7 interacts with ISL1, binds ISL1-regulated cardiac enhancers, and modulates gene expression across the mesodermal heart fields during cardiac morphogenesis.
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Affiliation(s)
- Athanasia Stathopoulou
- Developmental Biology of Birth Defects, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Ping Wang
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, USA
- School of Medical Imaging, Tianjin Medical University, Tianjin, China
| | | | - Robert G Kelly
- Aix-Marseille University, CNRS UMR 7288, IBDM, Marseille, France
| | - Deyou Zheng
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, USA
- Departments of Neurology and Neurosciences, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Peter J Scambler
- Developmental Biology of Birth Defects, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
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Shah SS, Fulton A, Jabroun M, Brightman D, Simpson BN, Bodamer OA. Insights into the genotype-phenotype relationship of ocular manifestations in Kabuki syndrome. Am J Med Genet A 2023; 191:1325-1338. [PMID: 36891680 DOI: 10.1002/ajmg.a.63155] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 02/06/2023] [Accepted: 02/07/2023] [Indexed: 03/10/2023]
Abstract
We aim to assess if genotype-phenotype correlations are present within ocular manifestations of Kabuki syndrome (KS) among a large multicenter cohort. We conducted a retrospective, medical record review including clinical history and comprehensive ophthalmological examinations of a total of 47 individuals with molecularly confirmed KS and ocular manifestations at Boston Children's Hospital and Cincinnati Children's Hospital Medical Center. We assessed information regarding ocular structural, functional, and adnexal elements as well as pertinent associated phenotypic features associated with KS. For both type 1 KS (KS1) and type 2 KS (KS2), we observed more severe eye pathology in nonsense variants towards the C-terminus of each gene, KMT2D and KDM6A, respectively. Furthermore, frameshift variants appeared to be not associated with structural ocular elements. Between both types of KS, ocular structural elements were more frequently identified in KS1 compared with KS2, which only involved the optic disc in our cohort. These results reinforce the need for a comprehensive ophthalmologic exam upon diagnosis of KS and regular follow-up exams. The specific genotype may allow risk stratification of the severity of the ophthalmologic manifestation. However, additional studies involving larger cohorts are needed to replicate our observations and conduct powered analyses to more formally risk-stratify based on genotype, highlighting the importance of multicenter collaborations in rare disease research.
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Affiliation(s)
- Suraj S Shah
- Tufts University School of Medicine, Boston, Massachusetts, USA.,Division of Genetics and Genomics, Department of Pediatrics, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Anne Fulton
- Department of Ophthalmology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Mireille Jabroun
- Department of Ophthalmology, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Ophthalmology and Vision Science, University of Arizona, Tucson, Arizona, USA
| | - Diana Brightman
- Division of Human Genetics, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati School of Medicine, Cincinnati, Ohio, USA
| | - Brittany N Simpson
- Division of Human Genetics, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati School of Medicine, Cincinnati, Ohio, USA
| | - Olaf A Bodamer
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children's Hospital, Boston, Massachusetts, USA.,The Broad Institute of Harvard and MIT, Cambridge, Massachusetts, USA
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7
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Sun Y, Kumar SR, Wong CED, Tian Z, Bai H, Crump JG, Bajpai R, Lien CL. Craniofacial and cardiac defects in chd7 zebrafish mutants mimic CHARGE syndrome. Front Cell Dev Biol 2022; 10:1030587. [PMID: 36568983 PMCID: PMC9768498 DOI: 10.3389/fcell.2022.1030587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 11/03/2022] [Indexed: 12/12/2022] Open
Abstract
Congenital heart defects occur in almost 80% of patients with CHARGE syndrome, a sporadically occurring disease causing craniofacial and other abnormalities due to mutations in the CHD7 gene. Animal models have been generated to mimic CHARGE syndrome; however, heart defects are not extensively described in zebrafish disease models of CHARGE using morpholino injections or genetic mutants. Here, we describe the co-occurrence of craniofacial abnormalities and heart defects in zebrafish chd7 mutants. These mutant phenotypes are enhanced in the maternal zygotic mutant background. In the chd7 mutant fish, we found shortened craniofacial cartilages and extra cartilage formation. Furthermore, the length of the ventral aorta is altered in chd7 mutants. Many CHARGE patients have aortic arch anomalies. It should be noted that the aberrant branching of the first branchial arch artery is observed for the first time in chd7 fish mutants. To understand the cellular mechanism of CHARGE syndrome, neural crest cells (NCCs), that contribute to craniofacial and cardiovascular tissues, are examined using sox10:Cre lineage tracing. In contrast to its function in cranial NCCs, we found that the cardiac NCC-derived mural cells along the ventral aorta and aortic arch arteries are not affected in chd7 mutant fish. The chd7 fish mutants we generated recapitulate some of the craniofacial and cardiovascular phenotypes found in CHARGE patients and can be used to further determine the roles of CHD7.
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Affiliation(s)
- Yuhan Sun
- Saban Research Institute and Heart Institute, Children’s Hospital Los Angeles, Los Angeles, CA, United States,Center for Craniofacial Molecular Biology, Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, United States
| | - S. Ram Kumar
- Saban Research Institute and Heart Institute, Children’s Hospital Los Angeles, Los Angeles, CA, United States,Department of Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Chee Ern David Wong
- Saban Research Institute and Heart Institute, Children’s Hospital Los Angeles, Los Angeles, CA, United States
| | - Zhiyu Tian
- Saban Research Institute and Heart Institute, Children’s Hospital Los Angeles, Los Angeles, CA, United States
| | - Haipeng Bai
- Saban Research Institute and Heart Institute, Children’s Hospital Los Angeles, Los Angeles, CA, United States,State Key Laboratory of Chemical Oncogenomics, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - J. Gage Crump
- Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Ruchi Bajpai
- Center for Craniofacial Molecular Biology, Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, United States,Department of Biochemistry and Molecular Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Ching Ling Lien
- Saban Research Institute and Heart Institute, Children’s Hospital Los Angeles, Los Angeles, CA, United States,Department of Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States,Department of Biochemistry and Molecular Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States,*Correspondence: Ching Ling Lien,
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8
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Kalinousky AJ, Rapp T, Hijazi H, Johnson J, Bjornsson HT, Harris JR. Neurobehavioral phenotype of Kabuki syndrome: Anxiety is a common feature. Front Genet 2022; 13:1007046. [PMID: 36276984 PMCID: PMC9582441 DOI: 10.3389/fgene.2022.1007046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 09/20/2022] [Indexed: 11/18/2022] Open
Abstract
Kabuki syndrome (KS) is a Mendelian Disorder of the Epigenetic Machinery (MDEM) caused by loss of function variants in either of two genes involved in the regulation of histone methylation, KMT2D (34–76%) or KDM6A (9–13%). Previously, representative neurobehavioral deficits of KS were recapitulated in a mouse model, emphasizing the role of KMT2D in brain development, specifically in ongoing hippocampal neurogenesis in the granule cell layer of the dentate gyrus. Interestingly, anxiety, a phenotype that has a known association with decreased hippocampal neurogenesis, has been anecdotally reported in individuals with KS. In this study, anxiety and behavior were assessed in a cohort of 60 individuals with molecularly confirmed KS and 25 unaffected biological siblings, via questionnaires (SCARED/GAS-ID and CBCL/ABCL). Participant age ranged from 4 to 43 years old, with 88.3% of participants having a pathogenic variant in KMT2D, and the rest having variants in KDM6A. In addition, data was collected on adaptive function and positive affect/quality of life in participants with KS using appropriate online surveys including ABAS-III and PROMIS Positive Affect. Survey scores were compared within the KS participants across age groups and between KS participants and their unaffected siblings. We found that children with KS have significantly higher anxiety scores and total behavior problem scores than their unaffected siblings (p = 0.0225, p < 0.0001). Moreover, a large proportion of affected individuals (22.2% of children and 60.0% of adults) surpassed the established threshold for anxiety; this may even be an underestimate given many patients are already treated for anxiety. In this sample, anxiety levels did not correlate with level of cognitive or adaptive function in any KS participants, but negatively correlated with positive affect in children with KS (p = 0.0005). These findings indicate that anxiety is a common neurobehavioral feature of KS. Providers should therefore carefully screen individuals with KS for anxiety as well as other behavioral issues in order to allow for prompt intervention. Neurobehavioral anxiety measures may also prove to be important outcome measures for clinical trials in KS.
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Affiliation(s)
- Allison J. Kalinousky
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Tyler Rapp
- University of North Carolina School of Medicine, University of North Carolina, Chapel Hill, NC, United States
| | - Hadia Hijazi
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | | | - Hans Tomas Bjornsson
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- Faculty of Medicine, University of Iceland, Reykjavík, Iceland
- Landspitali University Hospital, Reykjavík, Iceland
| | - Jacqueline R. Harris
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- Kennedy Krieger Institute, Baltimore, MD, United States
- *Correspondence: Jacqueline R. Harris,
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9
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Consales A, Crippa BL, Colombo L, Villa R, Menni F, Giavoli C, Mosca F, Bedeschi MF. CHARGE syndrome presenting with persistent hypoglycemia: case report and overview of the main genetic syndromes associated with neonatal hypoglycemia. Ital J Pediatr 2022; 48:154. [PMID: 35987847 PMCID: PMC9392907 DOI: 10.1186/s13052-022-01341-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 08/09/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
CHARGE syndrome (CS) is an autosomal dominant genetic condition whose recognition in the neonatal period is complicated by considerable phenotypic variability. Pediatric patients with genetic disorders have a known high incidence of hypoglycemia, due to many concurring factors. To date, neonatal hypoglycemia is a feature poorly explored in the literature associated with CS. This paper adds to the existing literature on hypoglycemia in CS and provides a brief review of the mechanisms through which CS, as well as the main genetic syndromes associated with neonatal hypoglycemia, may determine it.
Case presentation
The patient was a term newborn, first-born daughter to non-consanguineous parents. At birth, axial hypotonia with slight hypertonia of the limbs, and dysplastic auricles were noted. The incidental finding of asymptomatic hypoglycemia led to the initiation of glucose infusion on the II day of life, continued for a total of 8 days (maximum infusion rate: 8 mg/kg/min). In-depth endocrinological examinations showed poor cortisol response to the hypoglycemic stimulus, with normal GH values, thyroid function and ACTH. In view of the suspected hypoadrenalism, oral hydrocortisone therapy was initiated. Inappropriately low values of plasmatic and urinary ketones supported the hypothesis of concomitant transient hyperinsulinism, not requiring therapy. A brain MRI was performed, documenting thinning of the optic nerves, non-displayable olfactory bulbs and dysmorphic corpus callosum. An eye examination revealed bilateral chorioretinal coloboma. Temporal bone CT scan showed absence of the semicircular canals. The unexpected findings of coloboma and absence of semicircular canals led to the suspicion of CS, later confirmed by the molecular analysis of CHD7.
Conclusions
It seems important to consider CS in the differential diagnosis of persistent hypoglycemia in newborns with specific anomalies. At the same time, it is advisable to consider the risk of hypoglycemia in children with CS, as well as other genetic syndromes. Awareness of the many possible causes of hypoglycemia in newborns with genetic conditions may help steer the investigations, allowing for an appropriate and timely treatment.
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10
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Ka M, Kim HG, Kim WY. WDR5-HOTTIP Histone Modifying Complex Regulates Neural Migration and Dendrite Polarity of Pyramidal Neurons via Reelin Signaling. Mol Neurobiol 2022; 59:5104-5120. [PMID: 35672601 PMCID: PMC9378496 DOI: 10.1007/s12035-022-02905-4] [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: 03/11/2022] [Accepted: 05/26/2022] [Indexed: 11/26/2022]
Abstract
WD-repeat domain 5 (WDR5), a core component of histone methyltransferase complexes, is associated with Kabuki syndrome and Kleefstra syndrome that feature intellectual disability and neurodevelopmental delay. Despite its critical status in gene regulation and neurological disorders, the role of WDR5 in neural development is unknown. Here we show that WDR5 is required for normal neuronal placement and dendrite polarization in the developing cerebral cortex. WDR5 knockdown led to defects in both entry into the bipolar transition of pyramidal neurons within the intermediate zone and radial migration into cortical layers. Moreover, WDR5 deficiency disrupted apical and basal polarity of cortical dendrites. Aberrant dendritic spines and synapses accompanied the dendrite polarity phenotype. WDR5 deficiency reduced expression of reelin signaling receptors, ApoER and VdldR, which were associated with abnormal H3K4 methylation and H4 acetylation on their promoter regions. Finally, an lncRNA, HOTTIP, was found to be a partner of WDR5 to regulate dendritic polarity and reelin signaling via histone modification. Our results demonstrate a novel role for WDR5 in neuronal development and provide mechanistic insights into the neuropathology associated with histone methyltransferase dysfunction.
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Affiliation(s)
- Minhan Ka
- Department of Advanced Toxicology Research, Korea Institute of Toxicology, KRICT, Daejeon, 34114, Republic of Korea
| | - Hyung-Goo Kim
- Neurological Disorders Research Center, Qatar Biomedical Research Institute, Hamid Bin Khalifa University, Doha, Qatar
| | - Woo-Yang Kim
- Department of Biological Sciences, Kent State University, Kent, OH, 44242, USA.
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11
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Stadelmaier RT, Kenna MA, Barrett D, Mullen TE, Bodamer O, Agrawal PB, Robson CD, Wojcik MH. Neuroimaging in Kabuki syndrome and another KMT2D-related disorder. Am J Med Genet A 2021; 185:3770-3783. [PMID: 34369642 DOI: 10.1002/ajmg.a.62450] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 07/03/2021] [Accepted: 07/08/2021] [Indexed: 11/09/2022]
Abstract
Recognition of distinct phenotypic features is an important component of genetic diagnosis. Although CHARGE syndrome, Kabuki syndrome, and a recently delineated KMT2D Ex 38/39 allelic disorder exhibit significant overlap, differences on neuroimaging may help distinguish these conditions and guide genetic testing and variant interpretation. We present an infant clinically diagnosed with CHARGE syndrome but subsequently found to have a de novo missense variant in exon 38 of KMT2D, the gene implicated in both Kabuki syndrome and a distinct KMT2D allelic disorder. We compare her brain and inner ear morphology to a retrospective cohort of 21 patients with classic Kabuki syndrome and to typical CHARGE syndrome findings described in the literature. Thirteen of the 21 Kabuki syndrome patients had temporal bone imaging (5/13 CT, 12/13 MRI) and/or brain MRI (12/13) which revealed findings distinct from both CHARGE syndrome and the KMT2D allelic disorder. Our findings further elucidate the spectrum of inner ear dysmorphology distinguishing Kabuki syndrome and the KMT2D allelic disorder from CHARGE syndrome, suggesting that these three disorders may be differentiated at least in part by their inner ear anomalies.
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Affiliation(s)
- Rachel T Stadelmaier
- Division of Newborn Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Margaret A Kenna
- Department of Otolaryngology and Communication Enhancement, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Devon Barrett
- Emory University School of Medicine, Atlanta, Georgia, USA
| | - Thomas E Mullen
- Center for Mendelian Genomics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Olaf Bodamer
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Pankaj B Agrawal
- Division of Newborn Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.,Division of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Caroline D Robson
- Department of Radiology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Monica H Wojcik
- Division of Newborn Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.,Division of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts, USA
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12
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Ufartes R, Grün R, Salinas G, Sitte M, Kahl F, Wong MTY, van Ravenswaaij-Arts CMA, Pauli S. CHARGE syndrome and related disorders: A mechanistic link. Hum Mol Genet 2021; 30:2215-2224. [PMID: 34230955 DOI: 10.1093/hmg/ddab183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 06/23/2021] [Accepted: 06/23/2021] [Indexed: 11/13/2022] Open
Abstract
CHARGE syndrome is an autosomal dominant malformation disorder caused by pathogenic variants in the chromatin remodeler CHD7. Affected are craniofacial structures, cranial nerves and multiple organ systems. Depending on the combination of malformations present, its distinction from other congenital disorders can be challenging. To gain a better insight into the regulatory disturbances in CHARGE syndrome, we performed RNA-Seq analysis on blood samples of 19 children with CHARGE syndrome and a confirmed disease-causing CHD7 variant in comparison to healthy control children. Our analysis revealed a distinct CHARGE syndrome pattern with downregulation of genes that are linked to disorders described to mimic the CHARGE phenotype, i.e. KMT2D and KDM6A (Kabuki syndrome), EP300 and CREBBP (Rubinstein-Taybi syndrome) and ARID1A and ARID1B (Coffin-Siris syndrome). Furthermore, by performing protein-protein interaction studies using co-immunoprecipitation, direct yeast-two hybrid and in situ proximity ligation assays, we could demonstrate an interplay between CHD7, KMT2D, KDM6A and EP300. In summary, our data demonstrate a mechanistic and regulatory link between the developmental disorders CHARGE-, Kabuki- and Rubinstein Taybi-syndrome providing an explanation for the overlapping phenotypes.
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Affiliation(s)
- Roser Ufartes
- Institute of Human Genetics, University Medical Center Göttingen, Heinrich-Düker-Weg 12, 37073 Göttingen, Germany
| | - Regina Grün
- Institute of Human Genetics, University Medical Center Göttingen, Heinrich-Düker-Weg 12, 37073 Göttingen, Germany
| | - Gabriela Salinas
- NGS Integrative Genomics Core Unit, University Medical Center Göttingen, 37073 Göttingen, Germany
| | - Maren Sitte
- NGS Integrative Genomics Core Unit, University Medical Center Göttingen, 37073 Göttingen, Germany
| | - Fritz Kahl
- Department of General-, Visceral- and Pediatric Surgery, University Medical Center Goettingen, UMG, Göttingen, Germany
| | - Monica T Y Wong
- University of Groningen, University Medical Center Groningen, Department of Genetics, 9700 RB Groningen, The Netherlands
| | - Conny M A van Ravenswaaij-Arts
- University of Groningen, University Medical Center Groningen, Department of Genetics, 9700 RB Groningen, The Netherlands
| | - Silke Pauli
- Institute of Human Genetics, University Medical Center Göttingen, Heinrich-Düker-Weg 12, 37073 Göttingen, Germany
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13
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Lettieri A, Oleari R, Paganoni AJJ, Gervasini C, Massa V, Fantin A, Cariboni A. Semaphorin Regulation by the Chromatin Remodeler CHD7: An Emerging Genetic Interaction Shaping Neural Cells and Neural Crest in Development and Cancer. Front Cell Dev Biol 2021; 9:638674. [PMID: 33869187 PMCID: PMC8047133 DOI: 10.3389/fcell.2021.638674] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 02/24/2021] [Indexed: 12/16/2022] Open
Abstract
CHD7 is a chromatin remodeler protein that controls gene expression via the formation of multi-protein complexes with specific transcription factors. During development, CHD7 controls several differentiation programs, mainly by acting on neural progenitors and neural crest (NC) cells. Thus, its roles range from the central nervous system to the peripheral nervous system and the organs colonized by NC cells, including the heart. Accordingly, mutated CHD7 is linked to CHARGE syndrome, which is characterized by several neuronal dysfunctions and by malformations of NC-derived/populated organs. Altered CHD7 has also been associated with different neoplastic transformations. Interestingly, recent evidence revealed that semaphorins, a class of molecules involved in developmental and pathological processes similar to those controlled by CHD7, are regulated by CHD7 in a context-specific manner. In this article, we will review the recent insights that support the existence of genetic interactions between these pathways, both during developmental processes and cancer progression.
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Affiliation(s)
- Antonella Lettieri
- CRC Aldo Ravelli for Neurotechnology and Experimental Brain Therapeutics, Università degli Studi di Milano, Milan, Italy.,Department of Health Sciences, Università degli Studi di Milano, Milan, Italy
| | - Roberto Oleari
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Alyssa J J Paganoni
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Cristina Gervasini
- CRC Aldo Ravelli for Neurotechnology and Experimental Brain Therapeutics, Università degli Studi di Milano, Milan, Italy.,Department of Health Sciences, Università degli Studi di Milano, Milan, Italy
| | - Valentina Massa
- CRC Aldo Ravelli for Neurotechnology and Experimental Brain Therapeutics, Università degli Studi di Milano, Milan, Italy.,Department of Health Sciences, Università degli Studi di Milano, Milan, Italy
| | - Alessandro Fantin
- Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Anna Cariboni
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
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14
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Merdler-Rabinowicz R, Prat D, Pode-Shakked B, Abel G, Chorin O, Somech R, Raas-Rothschild A. Ophthalmic manifestations in Kabuki (make-up) syndrome: A single-center pediatric cohort and systematic review of the literature. Eur J Med Genet 2021; 64:104210. [PMID: 33794347 DOI: 10.1016/j.ejmg.2021.104210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/12/2021] [Accepted: 03/25/2021] [Indexed: 11/28/2022]
Abstract
Kabuki syndrome (KS) is a genetic disorder caused by pathogenic variants in KMT2D or KDM6A, and manifesting with multi-systemic involvement, including recognizable facial features, developmental delay and multiple congenital anomalies. Ophthalmological involvement has been described in varying rates in several studies. We aimed to evaluate the prevalence and nature of ophthalmological findings in a cohort of KS patients in Israel. Medical records of all patients diagnosed with KS in our tertiary center between 2004 and 2020 were retrospectively reviewed. Data collected included physical examination findings, molecular analysis as well as comprehensive ophthalmic characteristics including visual acuity, ocular alignment and motility, ocular adnexa, anterior segments and dilated fundus exams. Finally, an updated systematic review of the literature was performed. Thirteen unrelated patients were included in the study, diagnosed at an age raging from the first months of life to 20 years. Of these, three (23%) showed significant ophthalmological abnormalities, beyond the characteristic structural findings of long palpebral fissures and lower eyelid eversion. These included bilateral posterior colobomata in the first patient; bilateral ptosis, hypermetropia, esotropia, blue sclera and anisocoria in the second; and bilateral congenital cataracts in the third. To conclude, our findings underscore the importance of a comprehensive ophthalmological evaluation as part of the routine multidisciplinary assessment of children suspected/diagnosed with KS.
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Affiliation(s)
- Rona Merdler-Rabinowicz
- Pediatric Department A, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Daphna Prat
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Goldschleger Eye Institute, Sheba Medical Center, Tel Hashomer, Israel
| | - Ben Pode-Shakked
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; The Institute for Rare Diseases, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer, Israel
| | - Gali Abel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; The Institute for Rare Diseases, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer, Israel
| | - Odelia Chorin
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; The Institute for Rare Diseases, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer, Israel
| | - Raz Somech
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Pediatric Department A and Immunology Service, Jeffrey Modell Foundation Center, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel HaShomer, Israel
| | - Annick Raas-Rothschild
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; The Institute for Rare Diseases, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer, Israel.
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15
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Basinski BW, Balikov DA, Aksu M, Li Q, Rao RC. Ubiquitous Chromatin Modifiers in Congenital Retinal Diseases: Implications for Disease Modeling and Regenerative Medicine. Trends Mol Med 2021; 27:365-378. [PMID: 33573910 DOI: 10.1016/j.molmed.2021.01.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 01/04/2021] [Accepted: 01/05/2021] [Indexed: 12/11/2022]
Abstract
Retinal congenital malformations known as microphthalmia, anophthalmia, and coloboma (MAC) are associated with alterations in genes encoding epigenetic proteins that modify chromatin. We review newly discovered functions of such chromatin modifiers in retinal development and discuss the role of epigenetics in MAC in humans and animal models. Further, we highlight how advances in epigenomic technologies provide foundational and regenerative medicine-related insights into blinding disorders. Combining knowledge of epigenetics and pluripotent stem cells (PSCs) is a promising avenue because epigenetic factors cooperate with eye field transcription factors (EFTFs) to direct PSC fate - a foundation for congenital retinal disease modeling and cell therapy.
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Affiliation(s)
- Brian W Basinski
- Department of Ophthalmology and Visual Sciences, W.K. Kellogg Eye Center, University of Michigan, Ann Arbor, MI, USA; Department of Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Daniel A Balikov
- Department of Ophthalmology and Visual Sciences, W.K. Kellogg Eye Center, University of Michigan, Ann Arbor, MI, USA
| | - Michael Aksu
- Department of Ophthalmology and Visual Sciences, W.K. Kellogg Eye Center, University of Michigan, Ann Arbor, MI, USA
| | - Qiang Li
- Department of Ophthalmology and Visual Sciences, W.K. Kellogg Eye Center, University of Michigan, Ann Arbor, MI, USA
| | - Rajesh C Rao
- Department of Ophthalmology and Visual Sciences, W.K. Kellogg Eye Center, University of Michigan, Ann Arbor, MI, USA; Department of Pathology, University of Michigan, Ann Arbor, MI, USA; Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA; Comprehensive Cancer Center, University of Michigan, Ann Arbor, MI, USA; A. Alfred Taubman Medical Research Institute, University of Michigan, Ann Arbor, MI, USA; Section of Ophthalmology, Surgery Service, Veterans Administration Ann Arbor Healthsystem, Ann Arbor, MI, USA.
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16
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Sakaguchi Y, Yoshihashi H, Uehara T, Miyama S, Kosaki K, Takenouchi T. Coloboma may be a shared feature in a spectrum of disorders caused by mutations in the WDR37-PACS1-PACS2 axis. Am J Med Genet A 2020; 185:884-888. [PMID: 33369122 DOI: 10.1002/ajmg.a.62020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 11/16/2020] [Accepted: 11/20/2020] [Indexed: 01/12/2023]
Abstract
We report a male adult with early infantile-onset epilepsy, facial dysmorphism, and iridal and choroidal coloboma who had a de novo heterozygous mutation in PACS2, that is, c.625G > A p.(Glu209Lys). This specific mutation was previously reported in a patient with PACS2-related disorder (early infantile epileptic encephalopathy 66). De novo heterozygous mutations in WDR37 have been shown to cause a novel human disorder, neurooculocardiogenitourinary syndrome (NOCGUS syndrome) (OMIM #618652), characterized by intellectual disability, facial dysmorphism, and coloboma. According to large-scale interactome data, WDR37 interacts most strongly, by far, with PACS1 and PACS2. Clinically, coloboma has been described as a feature in a WDR37-related disorder and a PACS1-related disorder (Schuurs-Hoeijmakers syndrome), but not in a PACS2-related disorder. Our review of the phenotypes of three human disorders caused by WDR37, PACS1, and PACS2 mutations showed a significant overlap of epilepsy, intellectual disability, cerebellar atrophy, and facial features. The present observation of coloboma as a shared feature among these three disorders suggests that this group of genes may be involved in ocular development. We propose that dysregulation of the WDR37-PACS1-PACS2 axis results in a spectrum that is recognizable by intellectual disability, distinctive facial features, and coloboma.
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Affiliation(s)
- Yuri Sakaguchi
- Division of Neurology, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan
| | - Hiroshi Yoshihashi
- Division of Clinical Genetics, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan
| | - Tomoko Uehara
- Center for Medical Genetics, Keio University School of Medicine, Tokyo, Japan
| | - Sahoko Miyama
- Division of Neurology, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan
| | - Kenjiro Kosaki
- Center for Medical Genetics, Keio University School of Medicine, Tokyo, Japan
| | - Toshiki Takenouchi
- Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan
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17
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Schwenty-Lara J, Pauli S, Borchers A. Using Xenopus to analyze neurocristopathies like Kabuki syndrome. Genesis 2020; 59:e23404. [PMID: 33351273 DOI: 10.1002/dvg.23404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 12/09/2020] [Accepted: 12/09/2020] [Indexed: 11/08/2022]
Abstract
Neurocristopathies are human congenital syndromes that arise from defects in neural crest (NC) development and are typically associated with malformations of the craniofacial skeleton. Genetic analyses have been very successful in identifying pathogenic mutations, however, model organisms are required to characterize how these mutations affect embryonic development thereby leading to complex clinical conditions. The African clawed frog Xenopus laevis provides a broad range of in vivo and in vitro tools allowing for a detailed characterization of NC development. Due to the conserved nature of craniofacial morphogenesis in vertebrates, Xenopus is an efficient and versatile system to dissect the morphological and cellular phenotypes as well as the signaling events leading to NC defects. Here, we review a set of techniques and resources how Xenopus can be used as a disease model to investigate the pathogenesis of Kabuki syndrome and neurocristopathies in a wider sense.
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Affiliation(s)
- Janina Schwenty-Lara
- Department of Biology, Molecular Embryology, Philipps-University Marburg, Marburg, Germany
| | - Silke Pauli
- Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany
| | - Annette Borchers
- Department of Biology, Molecular Embryology, Philipps-University Marburg, Marburg, Germany.,DFG Research Training Group, Membrane Plasticity in Tissue Development and Remodeling, GRK 2213, Philipps-University Marburg, Marburg, Germany
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18
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De novo loss-of-function variants in X-linked MED12 are associated with Hardikar syndrome in females. Genet Med 2020; 23:637-644. [PMID: 33244166 DOI: 10.1038/s41436-020-01031-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 10/15/2020] [Indexed: 12/21/2022] Open
Abstract
PURPOSE Hardikar syndrome (MIM 612726) is a rare multiple congenital anomaly syndrome characterized by facial clefting, pigmentary retinopathy, biliary anomalies, and intestinal malrotation, but with preserved cognition. Only four patients have been reported previously, and none had a molecular diagnosis. Our objective was to identify the genetic basis of Hardikar syndrome (HS) and expand the phenotypic spectrum of this disorder. METHODS We performed exome sequencing on two previously reported and five unpublished female patients with a clinical diagnosis of HS. X-chromosome inactivation (XCI) studies were also performed. RESULTS We report clinical features of HS with previously undescribed phenotypes, including a fatal unprovoked intracranial hemorrhage at age 21. We additionally report the discovery of de novo pathogenic nonsense and frameshift variants in MED12 in these seven individuals and evidence of extremely skewed XCI in all patients with informative testing. CONCLUSION Pathogenic missense variants in the X-chromosome gene MED12 have previously been associated with Opitz-Kaveggia syndrome, Lujan syndrome, Ohdo syndrome, and nonsyndromic intellectual disability, primarily in males. We propose a fifth, female-specific phenotype for MED12, and suggest that nonsense and frameshift loss-of-function MED12 variants in females cause HS. This expands the MED12-associated phenotype in females beyond intellectual disability.
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19
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CHD7 regulates cardiovascular development through ATP-dependent and -independent activities. Proc Natl Acad Sci U S A 2020; 117:28847-28858. [PMID: 33127760 DOI: 10.1073/pnas.2005222117] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
CHD7 encodes an ATP-dependent chromatin remodeling factor. Mutation of this gene causes multiple developmental disorders, including CHARGE (Coloboma of the eye, Heart defects, Atresia of the choanae, Retardation of growth/development, Genital abnormalities, and Ear anomalies) syndrome, in which conotruncal anomalies are the most prevalent form of heart defects. How CHD7 regulates conotruncal development remains unclear. In this study, we establish that deletion of Chd7 in neural crest cells (NCCs) causes severe conotruncal defects and perinatal lethality, thus providing mouse genetic evidence demonstrating that CHD7 cell-autonomously regulates cardiac NCC development, thereby clarifying a long-standing controversy in the literature. Using transcriptomic analyses, we show that CHD7 fine-tunes the expression of a gene network that is critical for cardiac NCC development. To gain further molecular insights into gene regulation by CHD7, we performed a protein-protein interaction screen by incubating recombinant CHD7 on a protein array. We find that CHD7 directly interacts with several developmental disorder-mutated proteins including WDR5, a core component of H3K4 methyltransferase complexes. This direct interaction suggested that CHD7 may recruit histone-modifying enzymes to target loci independently of its remodeling functions. We therefore generated a mouse model that harbors an ATPase-deficient allele and demonstrates that mutant CHD7 retains the ability to recruit H3K4 methyltransferase activity to its targets. Thus, our data uncover that CHD7 regulates cardiovascular development through ATP-dependent and -independent activities, shedding light on the etiology of CHD7-related congenital disorders. Importantly, our data also imply that patients carrying a premature stop codon versus missense mutations will likely display different molecular alterations; these patients might therefore require personalized therapeutic interventions.
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20
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Shpargel KB, Mangini CL, Xie G, Ge K, Magnuson T. The KMT2D Kabuki syndrome histone methylase controls neural crest cell differentiation and facial morphology. Development 2020; 147:dev.187997. [PMID: 32541010 DOI: 10.1242/dev.187997] [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: 01/07/2020] [Accepted: 06/02/2020] [Indexed: 12/13/2022]
Abstract
Kabuki syndrome (KS) is a congenital craniofacial disorder resulting from mutations in the KMT2D histone methylase (KS1) or the UTX histone demethylase (KS2). With small cohorts of KS2 patients, it is not clear whether differences exist in clinical manifestations relative to KS1. We mutated KMT2D in neural crest cells (NCCs) to study cellular and molecular functions in craniofacial development with respect to UTX. Similar to UTX, KMT2D NCC knockout mice demonstrate hypoplasia with reductions in frontonasal bone lengths. We have traced the onset of KMT2D and UTX mutant NCC frontal dysfunction to a stage of altered osteochondral progenitor differentiation. KMT2D NCC loss-of-function does exhibit unique phenotypes distinct from UTX mutation, including fully penetrant cleft palate, mandible hypoplasia and deficits in cranial base ossification. KMT2D mutant NCCs lead to defective secondary palatal shelf elevation with reduced expression of extracellular matrix components. KMT2D mutant chondrocytes in the cranial base fail to properly differentiate, leading to defective endochondral ossification. We conclude that KMT2D is required for appropriate cranial NCC differentiation and KMT2D-specific phenotypes may underlie differences between Kabuki syndrome subtypes.
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Affiliation(s)
- Karl B Shpargel
- Department of Genetics and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599-7264, USA
| | - Cassidy L Mangini
- Department of Genetics and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599-7264, USA
| | - Guojia Xie
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kai Ge
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Terry Magnuson
- Department of Genetics and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599-7264, USA
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21
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Di Fede E, Massa V, Augello B, Squeo G, Scarano E, Perri AM, Fischetto R, Causio FA, Zampino G, Piccione M, Curridori E, Mazza T, Castellana S, Larizza L, Ghelma F, Colombo EA, Gandini MC, Castori M, Merla G, Milani D, Gervasini C. Expanding the phenotype associated to KMT2A variants: overlapping clinical signs between Wiedemann-Steiner and Rubinstein-Taybi syndromes. Eur J Hum Genet 2020; 29:88-98. [PMID: 32641752 PMCID: PMC7852672 DOI: 10.1038/s41431-020-0679-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 06/03/2020] [Accepted: 06/23/2020] [Indexed: 12/16/2022] Open
Abstract
Lysine-specific methyltransferase 2A (KMT2A) is responsible for methylation of histone H3 (K4H3me) and contributes to chromatin remodeling, acting as "writer" of the epigenetic machinery. Mutations in KMT2A were first reported in Wiedemann-Steiner syndrome (WDSTS). More recently, KMT2A variants have been described in probands with a specific clinical diagnosis comprised in the so-called chromatinopathies. Such conditions, including WDSTS, are a group of overlapping disorders caused by mutations in genes coding for the epigenetic machinery. Among them, Rubinstein-Taybi syndrome (RSTS) is mainly caused by heterozygous pathogenic variants in CREBBP or EP300. In this work, we used next generation sequencing (either by custom-made panel or by whole exome) to identify alternative causative genes in individuals with a RSTS-like phenotype negative to CREBBP and EP300 mutational screening. In six patients we identified different novel unreported variants in KMT2A gene. The identified variants are de novo in at least four out of six tested individuals and all of them display some typical RSTS phenotypic features but also WDSTS specific signs. This study reinforces the concept that germline variants affecting the epigenetic machinery lead to a shared molecular effect (alteration of the chromatin state) determining superimposable clinical conditions.
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Affiliation(s)
- Elisabetta Di Fede
- Genetica Medica e Biologia Applicata, Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milano, Italy
| | - Valentina Massa
- Genetica Medica e Biologia Applicata, Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milano, Italy.,"Aldo Ravelli" Center for Neurotechnology and Experimental Brain Therapeutics, Università degli Studi di Milano, Milano, Italy
| | - Bartolomeo Augello
- Unità di Genetica Medica, IRCSS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Gabriella Squeo
- Unità di Genetica Medica, IRCSS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Emanuela Scarano
- Ambulatorio di Malattie Rare, Sindromologia ed Auxologia U.O. Pediatria AOU S.Orsola-Malpighi, Bologna, Italy
| | - Anna Maria Perri
- Ambulatorio di Malattie Rare, Sindromologia ed Auxologia U.O. Pediatria AOU S.Orsola-Malpighi, Bologna, Italy
| | - Rita Fischetto
- U.O.C. Malattie Metaboliche Genetica Medica, PO Giovanni XXIII, AOU Policlinico Consorziale, Bari, Italy
| | - Francesco Andrea Causio
- U.O.C. Malattie Metaboliche Genetica Medica, PO Giovanni XXIII, AOU Policlinico Consorziale, Bari, Italy
| | - Giuseppe Zampino
- Centro Malattie Rare e Difetti Congeniti, Fondazione Policlinico Universitario A. Gemelli, Università Cattolica, Roma, Italy
| | - Maria Piccione
- Dipartimento di scienze per la promozione della salute e la cura della madre e del bambino "G. D'Alessandro", Università di Palermo, Palermo, Italy
| | - Elena Curridori
- Dipartimento di clinica pediatrica e malattie rare, Ospedale pediatrico Antonio Cao, Cagliari, Italy
| | - Tommaso Mazza
- Unit of Bioinformatics IRCSS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Stefano Castellana
- Unit of Bioinformatics IRCSS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Lidia Larizza
- Research Laboratory of Medical Cytogenetics and Molecular Genetics, IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - Filippo Ghelma
- Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milano, Italy
| | - Elisa Adele Colombo
- Genetica Medica e Biologia Applicata, Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milano, Italy
| | - Maria Chiara Gandini
- Genetica Medica e Biologia Applicata, Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milano, Italy
| | - Marco Castori
- Unità di Genetica Medica, IRCSS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Giuseppe Merla
- Unità di Genetica Medica, IRCSS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Donatella Milani
- UOSD Pediatria ad alta intensità di cura, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico Milano, Milano, Italy
| | - Cristina Gervasini
- Genetica Medica e Biologia Applicata, Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milano, Italy. .,"Aldo Ravelli" Center for Neurotechnology and Experimental Brain Therapeutics, Università degli Studi di Milano, Milano, Italy.
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22
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Baldridge D, Spillmann RC, Wegner DJ, Wambach JA, White FV, Sisco K, Toler TL, Dickson PI, Cole FS, Shashi V, Grange DK. Phenotypic expansion of KMT2D-related disorder: Beyond Kabuki syndrome. Am J Med Genet A 2020; 182:1053-1065. [PMID: 32083401 DOI: 10.1002/ajmg.a.61518] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 01/29/2020] [Accepted: 01/29/2020] [Indexed: 12/13/2022]
Abstract
Pathogenic variants in KMT2D, which encodes lysine specific methyltransferase 2D, cause autosomal dominant Kabuki syndrome, associated with distinctive dysmorphic features including arched eyebrows, long palpebral fissures with eversion of the lower lid, large protuberant ears, and fetal finger pads. Most disease-causing variants identified to date are putative loss-of-function alleles, although 15-20% of cases are attributed to missense variants. We describe here four patients (including one previously published patient) with de novo KMT2D missense variants and with shared but unusual clinical findings not typically seen in Kabuki syndrome, including athelia (absent nipples), choanal atresia, hypoparathyroidism, delayed or absent pubertal development, and extreme short stature. These individuals also lack the typical dysmorphic facial features found in Kabuki syndrome. Two of the four patients had severe interstitial lung disease. All of these variants cluster within a 40-amino-acid region of the protein that is located just N-terminal of an annotated coiled coil domain. These findings significantly expand the phenotypic spectrum of features associated with variants in KMT2D beyond those seen in Kabuki syndrome and suggest a possible new underlying disease mechanism for these patients.
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Affiliation(s)
- Dustin Baldridge
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Rebecca C Spillmann
- Department of Pediatrics, Division of Medical Genetics, Duke University Medical Center, Durham, North Carolina, USA
| | - Daniel J Wegner
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Jennifer A Wambach
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Frances V White
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Kathleen Sisco
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Tomi L Toler
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Patricia I Dickson
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - F Sessions Cole
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Vandana Shashi
- Department of Pediatrics, Division of Medical Genetics, Duke University Medical Center, Durham, North Carolina, USA
| | - Dorothy K Grange
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri, USA
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23
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Cuvertino S, Hartill V, Colyer A, Garner T, Nair N, Al-Gazali L, Canham N, Faundes V, Flinter F, Hertecant J, Holder-Espinasse M, Jackson B, Lynch SA, Nadat F, Narasimhan VM, Peckham M, Sellers R, Seri M, Montanari F, Southgate L, Squeo GM, Trembath R, van Heel D, Venuto S, Weisberg D, Stals K, Ellard S, Barton A, Kimber SJ, Sheridan E, Merla G, Stevens A, Johnson CA, Banka S. A restricted spectrum of missense KMT2D variants cause a multiple malformations disorder distinct from Kabuki syndrome. Genet Med 2020; 22:867-877. [PMID: 31949313 PMCID: PMC7200597 DOI: 10.1038/s41436-019-0743-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 12/24/2019] [Indexed: 12/19/2022] Open
Abstract
Purpose To investigate if specific exon 38 or 39 KMT2D missense variants (MVs) cause a condition distinct from
Kabuki syndrome type 1 (KS1). Methods Multiple individuals, with MVs in exons 38 or 39 of KMT2D that encode a highly conserved region of 54
amino acids flanked by Val3527 and Lys3583, were identified and phenotyped.
Functional tests were performed to study their pathogenicity and understand the
disease mechanism. Results The consistent clinical features of the affected individuals, from
seven unrelated families, included choanal atresia, athelia or hypoplastic
nipples, branchial sinus abnormalities, neck pits, lacrimal duct anomalies,
hearing loss, external ear malformations, and thyroid abnormalities. None of the
individuals had intellectual disability. The frequency of clinical features,
objective software-based facial analysis metrics, and genome-wide peripheral
blood DNA methylation patterns in these patients were significantly different
from that of KS1. Circular dichroism spectroscopy indicated that these MVs
perturb KMT2D secondary structure through an increased disordered to ɑ-helical
transition. Conclusion KMT2D MVs located in a specific
region spanning exons 38 and 39 and affecting highly conserved residues cause a
novel multiple malformations syndrome distinct from KS1. Unlike KMT2D haploinsufficiency in KS1, these MVs likely
result in disease through a dominant negative mechanism.
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Affiliation(s)
- Sara Cuvertino
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine, and Health, The University of Manchester, Manchester, UK.,Division of Cell Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine, and Health, The University of Manchester, Manchester, UK
| | - Verity Hartill
- Leeds Institute of Medical Research, Faculty of Medicine and Health, The University of Leeds, Leeds, UK.,Department of Clinical Genetics, Chapel Allerton Hospital, Leeds Teaching Hospitals Trust, Leeds, UK
| | - Alice Colyer
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, The University of Leeds, Leeds, UK
| | - Terence Garner
- Division of Developmental Biology & Medicine, School of Biological Sciences, Faculty of Biology, Medicine, and Health, The University of Manchester, Manchester, UK
| | - Nisha Nair
- Centre of Genetics & Genomics Versus Arthritis, Manchester Academic Health Sciences Centre, The University of Manchester, Manchester, UK
| | - Lihadh Al-Gazali
- Department of Paediatrics, College of Medicine & Health Sciences, United Arab University, Al-Ain, UAE
| | - Natalie Canham
- Liverpool Centre for Genomic Medicine, Liverpool Women's NHS Foundation Trust, Liverpool, UK.,North West Thames Regional Genetics Service, Northwick Park Hospital, Harrow, UK
| | - Victor Faundes
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine, and Health, The University of Manchester, Manchester, UK.,Laboratorio de Genética y Enfermedades Metabólicas, Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile, Santiago, Chile
| | - Frances Flinter
- Department of Clinical Genetics, Guy's & St Thomas NHS Foundation Trust, London, UK
| | | | | | - Brian Jackson
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, The University of Leeds, Leeds, UK
| | - Sally Ann Lynch
- Temple street Children's University Hospital, Dublin, Ireland
| | - Fatima Nadat
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, The University of Leeds, Leeds, UK
| | | | - Michelle Peckham
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, The University of Leeds, Leeds, UK
| | - Robert Sellers
- Division of Developmental Biology & Medicine, School of Biological Sciences, Faculty of Biology, Medicine, and Health, The University of Manchester, Manchester, UK
| | - Marco Seri
- Medical Genetics Unit, St. Orsola-Malpighi, University of Bologna, Bologna, Italy
| | - Francesca Montanari
- Medical Genetics Unit, St. Orsola-Malpighi, University of Bologna, Bologna, Italy
| | - Laura Southgate
- Molecular and Clinical Sciences Research Institute, St George's University of London, London, UK.,Department of Medical & Molecular Genetics, King's College London, London, UK
| | - Gabriella Maria Squeo
- Division of Medical Genetics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Foggia, Italy
| | - Richard Trembath
- Department of Medical & Molecular Genetics, King's College London, London, UK
| | | | - Santina Venuto
- Division of Medical Genetics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Foggia, Italy
| | - Daniel Weisberg
- Clinical Psychology Department, Royal Manchester Children's Hospital, Manchester University Foundation NHS Trust, Health Innovation Manchester, Manchester, UK
| | - Karen Stals
- Molecular Genetics Department, Royal Devon and Exeter NHS Foundation Trust, Exeter, UK
| | - Sian Ellard
- Molecular Genetics Department, Royal Devon and Exeter NHS Foundation Trust, Exeter, UK.,Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, UK
| | | | - Anne Barton
- Centre of Genetics & Genomics Versus Arthritis, Manchester Academic Health Sciences Centre, The University of Manchester, Manchester, UK
| | - Susan J Kimber
- Division of Cell Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine, and Health, The University of Manchester, Manchester, UK
| | - Eamonn Sheridan
- Leeds Institute of Medical Research, Faculty of Medicine and Health, The University of Leeds, Leeds, UK.,Department of Clinical Genetics, Chapel Allerton Hospital, Leeds Teaching Hospitals Trust, Leeds, UK
| | - Giuseppe Merla
- Division of Medical Genetics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Foggia, Italy
| | - Adam Stevens
- Division of Developmental Biology & Medicine, School of Biological Sciences, Faculty of Biology, Medicine, and Health, The University of Manchester, Manchester, UK
| | - Colin A Johnson
- Leeds Institute of Medical Research, Faculty of Medicine and Health, The University of Leeds, Leeds, UK
| | - Siddharth Banka
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine, and Health, The University of Manchester, Manchester, UK. .,Manchester Centre for Genomic Medicine, St. Mary's Hospital, Manchester University Foundation NHS Trust, Health Innovation Manchester, Manchester, UK.
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24
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Schwenty-Lara J, Nehl D, Borchers A. The histone methyltransferase KMT2D, mutated in Kabuki syndrome patients, is required for neural crest cell formation and migration. Hum Mol Genet 2020; 29:305-319. [PMID: 31813957 PMCID: PMC7003132 DOI: 10.1093/hmg/ddz284] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 11/18/2019] [Accepted: 11/19/2019] [Indexed: 12/30/2022] Open
Abstract
Kabuki syndrome is an autosomal dominant developmental disorder with high similarities to CHARGE syndrome. It is characterized by a typical facial gestalt in combination with short stature, intellectual disability, skeletal findings and additional features like cardiac and urogenital malformations, cleft palate, hearing loss and ophthalmological anomalies. The major cause of Kabuki syndrome are mutations in KMT2D, a gene encoding a histone H3 lysine 4 (H3K4) methyltransferase belonging to the group of chromatin modifiers. Here we provide evidence that Kabuki syndrome is a neurocrestopathy, by showing that Kmt2d loss-of-function inhibits specific steps of neural crest (NC) development. Using the Xenopus model system, we find that Kmt2d loss-of-function recapitulates major features of Kabuki syndrome including severe craniofacial malformations. A detailed marker analysis revealed defects in NC formation as well as migration. Transplantation experiments confirm that Kmt2d function is required in NC cells. Furthermore, analyzing in vivo and in vitro NC migration behavior demonstrates that Kmt2d is necessary for cell dispersion but not protrusion formation of migrating NC cells. Importantly, Kmt2d knockdown correlates with a decrease in H3K4 monomethylation and H3K27 acetylation supporting a role of Kmt2d in the transcriptional activation of target genes. Consistently, using a candidate approach, we find that Kmt2d loss-of-function inhibits Xenopus Sema3F expression, and overexpression of Sema3F can partially rescue Kmt2d loss-of-function defects. Taken together, our data reveal novel functions of Kmt2d in multiple steps of NC development and support the hypothesis that major features of Kabuki syndrome are caused by defects in NC development.
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Affiliation(s)
- Janina Schwenty-Lara
- Department of Biology, Molecular Embryology, Philipps-Universität Marburg, Marburg 35043, Germany
| | - Denise Nehl
- Department of Biology, Molecular Embryology, Philipps-Universität Marburg, Marburg 35043, Germany
| | - Annette Borchers
- Department of Biology, Molecular Embryology, Philipps-Universität Marburg, Marburg 35043, Germany
- DFG Research Training Group, Membrane Plasticity in Tissue Development and Remodeling, GRK 2213, Philipps-Universität Marburg, Marburg 35043, Germany
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25
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Gervais L, van den Beek M, Josserand M, Sallé J, Stefanutti M, Perdigoto CN, Skorski P, Mazouni K, Marshall OJ, Brand AH, Schweisguth F, Bardin AJ. Stem Cell Proliferation Is Kept in Check by the Chromatin Regulators Kismet/CHD7/CHD8 and Trr/MLL3/4. Dev Cell 2020; 49:556-573.e6. [PMID: 31112698 PMCID: PMC6547167 DOI: 10.1016/j.devcel.2019.04.033] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 03/15/2019] [Accepted: 04/18/2019] [Indexed: 12/13/2022]
Abstract
Chromatin remodeling accompanies differentiation, however, its role in self-renewal is less well understood. We report that in Drosophila, the chromatin remodeler Kismet/CHD7/CHD8 limits intestinal stem cell (ISC) number and proliferation without affecting differentiation. Stem-cell-specific whole-genome profiling of Kismet revealed its enrichment at transcriptionally active regions bound by RNA polymerase II and Brahma, its recruitment to the transcription start site of activated genes and developmental enhancers and its depletion from regions bound by Polycomb, Histone H1, and heterochromatin Protein 1. We demonstrate that the Trithorax-related/MLL3/4 chromatin modifier regulates ISC proliferation, colocalizes extensively with Kismet throughout the ISC genome, and co-regulates genes in ISCs, including Cbl, a negative regulator of Epidermal Growth Factor Receptor (EGFR). Loss of kismet or trr leads to elevated levels of EGFR protein and signaling, thereby promoting ISC self-renewal. We propose that Kismet with Trr establishes a chromatin state that limits EGFR proliferative signaling, preventing tumor-like stem cell overgrowths. Chromatin modifiers Kismet and Trr limit intestinal stem cell proliferation Kismet and Trr colocalize at transcriptionally active regions and co-regulate genes EGFR negative regulator Cbl is a target gene of Kismet and Trr Kismet and Trr limit EGFR signaling in ISCs, preventing tumor-like ISC accumulation
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Affiliation(s)
- Louis Gervais
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France; Sorbonne Universités, UPMC Univ Paris 6, Paris, France.
| | - Marius van den Beek
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France; Sorbonne Universités, UPMC Univ Paris 6, Paris, France
| | - Manon Josserand
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France; Sorbonne Universités, UPMC Univ Paris 6, Paris, France
| | - Jérémy Sallé
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France; Sorbonne Universités, UPMC Univ Paris 6, Paris, France
| | - Marine Stefanutti
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France; Sorbonne Universités, UPMC Univ Paris 6, Paris, France
| | - Carolina N Perdigoto
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France; Sorbonne Universités, UPMC Univ Paris 6, Paris, France
| | - Patricia Skorski
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France; Sorbonne Universités, UPMC Univ Paris 6, Paris, France
| | - Khallil Mazouni
- Institut Pasteur, Department of Developmental and Stem Cell Biology, Paris 75015, France; CNRS, URA2578, Rue du Dr Roux, Paris 75015, France
| | - Owen J Marshall
- The Gurdon Institute and Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 1QN, UK; Menzies Institute for Medical Research, University of Tasmania, 17 Liverpool Street Hobart, Tasmania, 7000, Australia
| | - Andrea H Brand
- The Gurdon Institute and Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 1QN, UK
| | - François Schweisguth
- Institut Pasteur, Department of Developmental and Stem Cell Biology, Paris 75015, France; CNRS, URA2578, Rue du Dr Roux, Paris 75015, France
| | - Allison J Bardin
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France; Sorbonne Universités, UPMC Univ Paris 6, Paris, France.
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26
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Meisner JK, Martin DM. Congenital heart defects in CHARGE: The molecular role of CHD7 and effects on cardiac phenotype and clinical outcomes. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2019; 184:81-89. [PMID: 31833191 DOI: 10.1002/ajmg.c.31761] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 12/02/2019] [Indexed: 02/06/2023]
Abstract
CHARGE syndrome is characterized by a pattern of congenital anomalies (Coloboma of the eye, Heart defects, Atresia of the choanae, Retardation of growth, Genital abnormalities, and Ear abnormalities). De novo mutations of chromodomain helicase DNA binding protein 7 (CHD7) are the primary cause of CHARGE syndrome. The clinical phenotype is highly variable including a wide spectrum of congenital heart defects. Here, we review the range of congenital heart defects and the molecular effects of CHD7 on cardiovascular development that lead to an over-representation of atrioventricular septal, conotruncal, and aortic arch defects in CHARGE syndrome. Further, we review the overlap of cardiovascular and noncardiovascular comorbidities present in CHARGE and their impact on the peri-operative morbidity and mortality in individuals with CHARGE syndrome.
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Affiliation(s)
- Joshua K Meisner
- Department of Pediatrics, University of Michigan, Ann Arbor, Michigan
| | - Donna M Martin
- Department of Pediatrics, University of Michigan, Ann Arbor, Michigan.,Department of Human Genetics, University of Michigan, Ann Arbor, Michigan
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27
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Yang Y, Hao H, Wu X, Guo S, Liu Y, Ran J, Li T, Li D, Liu M, Zhou J. Mixed-lineage leukemia protein 2 suppresses ciliary assembly by the modulation of actin dynamics and vesicle transport. Cell Discov 2019; 5:33. [PMID: 31263570 PMCID: PMC6591415 DOI: 10.1038/s41421-019-0100-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 04/18/2019] [Accepted: 04/22/2019] [Indexed: 01/27/2023] Open
Abstract
Primary cilia are critically involved in the coordination of diverse signaling pathways and ciliary defects are associated with a variety of human diseases. The past decades have witnessed great progress in the core machinery orchestrating ciliary assembly. However, the upstream epigenetic cues that direct ciliogenesis remain elusive. Herein, we demonstrate that mixed-lineage leukemia protein 2 (MLL2), a histone methyltransferase, plays a negative role in ciliogenesis. RNA-sequencing analysis reveals that the expression of five actin-associated proteins is significantly downregulated in MLL2-depleted cells. Overexpression of these proteins partially rescues ciliary abnormality elicited by MLL2 depletion. Our data also show that actin dynamics is remarkably changed in MLL2-depleted cells, resulting in the impairment of cell adhesion, spreading, and motility. In addition, MLL2 depletion promotes ciliary vesicle trafficking to the basal body in an actin-related manner. Together, these results reveal that MLL2 inhibits ciliogenesis by modulating actin dynamics and vesicle transport, and suggest that alteration of MLL2 may contribute to the pathogenesis of cilium-associated diseases.
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Affiliation(s)
- Yang Yang
- 1State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials of the Ministry of Education, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071 China
| | - Huijie Hao
- 1State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials of the Ministry of Education, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071 China
| | - Xiaofan Wu
- 1State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials of the Ministry of Education, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071 China
| | - Song Guo
- 1State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials of the Ministry of Education, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071 China
| | - Yang Liu
- 1State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials of the Ministry of Education, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071 China
| | - Jie Ran
- 2Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Institute of Biomedical Sciences, College of Life Sciences, Shandong Normal University, Jinan, Shandong 250014 China
| | - Te Li
- 1State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials of the Ministry of Education, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071 China
| | - Dengwen Li
- 1State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials of the Ministry of Education, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071 China
| | - Min Liu
- 2Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Institute of Biomedical Sciences, College of Life Sciences, Shandong Normal University, Jinan, Shandong 250014 China
| | - Jun Zhou
- 1State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials of the Ministry of Education, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071 China.,2Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Institute of Biomedical Sciences, College of Life Sciences, Shandong Normal University, Jinan, Shandong 250014 China
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28
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Campos-Sanchez E, Martínez-Cano J, Del Pino Molina L, López-Granados E, Cobaleda C. Epigenetic Deregulation in Human Primary Immunodeficiencies. Trends Immunol 2018; 40:49-65. [PMID: 30509895 DOI: 10.1016/j.it.2018.11.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 11/02/2018] [Accepted: 11/07/2018] [Indexed: 12/20/2022]
Abstract
Primary immunodeficiencies (PIDs) are immune disorders resulting from defects in genes involved in immune regulation, and manifesting as an increased susceptibility to infections, autoimmunity, and cancer. However, the molecular basis of some prevalent entities remains poorly understood. Epigenetic control is essential for immune functions, and epigenetic alterations have been identified in different PIDs, including syndromes such as immunodeficiency-centromeric-instability-facial-anomalies, Kabuki, or Wolf-Hirschhorn, among others. Although the epigenetic changes may differ among these PIDs, the reversibility of epigenetic modifications suggests that they might become potential therapeutic targets. Here, we review recent mechanistic advances in our understanding of epigenetic alterations associated with certain PIDs, propose that a fully epigenetically driven mechanism might underlie some PIDs, and discuss the possible prophylactic and therapeutic implications.
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Affiliation(s)
- Elena Campos-Sanchez
- Department of Cell Biology and Immunology, Centro de Biología Molecular Severo Ochoa (CBMSO), CSIC/UAM, Madrid 28049, Spain; These authors contributed equally to this work
| | - Jorge Martínez-Cano
- Department of Cell Biology and Immunology, Centro de Biología Molecular Severo Ochoa (CBMSO), CSIC/UAM, Madrid 28049, Spain; These authors contributed equally to this work
| | - Lucía Del Pino Molina
- Clinical Immunology Department, Hospital Universitario, La Paz Institute of Biomedical Research, 28046, Madrid, Spain; Lymphocyte Pathophysiology Group, La Paz Institute of Biomedical Research, 28046 Madrid, Spain
| | - Eduardo López-Granados
- Clinical Immunology Department, Hospital Universitario, La Paz Institute of Biomedical Research, 28046, Madrid, Spain; Lymphocyte Pathophysiology Group, La Paz Institute of Biomedical Research, 28046 Madrid, Spain.
| | - Cesar Cobaleda
- Department of Cell Biology and Immunology, Centro de Biología Molecular Severo Ochoa (CBMSO), CSIC/UAM, Madrid 28049, Spain.
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29
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Struzik M, Gawlik M. The role of the nursing team in the care of patients with Kabuki syndrome. MEDICAL SCIENCE PULSE 2018. [DOI: 10.5604/01.3001.0012.5180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Background: Kabuki syndrome is a rare genetic condition characterised by pathological changes within all the systems of the body, but with variable gene expression. All the patients described in the literature so far have specific facial features resembling the masks of actors from the Japanese Kabuki Theatre and mild to moderate mental impairment. Diagnosis is made based by genetic testing for mutations of the KMT2D and KDM6A genes. Therapy is mainly based on symptomatic alleviation of the effects of mutation, rehabilitation and improvement of the quality of patients’ life. Then prognosis of patients with Kabuki syndrome is closely related to the severity of symptoms, which is very variable. Aim of the study: The purpose of the study is to present the nursing problems based on the case report and to present complications caused by the disease entity. Material and methods: The criterion for including the patient in the study was the legal guardian’s (parent’s) consent for the child to participate in the study. Qualitative research was conducted using analysis of medical records, interview with the child and the child’s legal guardian, direct and indirect observation of the child for psycho-social changes related to the disease and interpretation of the data in the context of the theoretical knowledge and our own observations. Case report: The report is based on the case of a 16-year-old girl, diagnosed (at the age of fourteen) with rare genetic disorder – Kabuki syndrome. The patient experiences some characteristic symptoms – big, red lips, lowset and sticky-out ears, drooping eyelids and short fingers and toes. One of the first symptoms suggesting Kabuki syndrome were: spitting up during breastfeeding, problems with swallowing, motor clumsiness and epilepsy. The role of the nursing team during hospitalization was to take care because of habitual dislocation of patella, and to provide psychological suport. At present time the girl uses a wheelchair or she moves on her knees Results: The manifestations of chronic disease contribute to the feeling of excessive stress, regardless of the patient’s age. An adequate diet enriched with proteins contributes to the prevention of bedsores among individuals with Kabuki syndrome, immobilised to various degrees. Regular consultations with specialists, such as cardiologist, neurologist, gastroenterologist, orthopaedist, ophthalmologist, psychologist, orthodontist, speech therapist, immunologist, endocrinologist and dietician reduce the risk of complications associated with the disease in the patient with Kabuki syndrome. Early implementation of rehabilitation, focused to increase muscle tension, contributes to maintaining autonomy and self-care in patients with Kabuki syndrome.
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30
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Moccia A, Srivastava A, Skidmore JM, Bernat JA, Wheeler M, Chong JX, Nickerson D, Bamshad M, Hefner MA, Martin DM, Bielas SL. Genetic analysis of CHARGE syndrome identifies overlapping molecular biology. Genet Med 2018; 20:1022-1029. [PMID: 29300383 PMCID: PMC6034995 DOI: 10.1038/gim.2017.233] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 11/15/2017] [Indexed: 11/09/2022] Open
Abstract
PURPOSE CHARGE syndrome is an autosomal-dominant, multiple congenital anomaly condition characterized by vision and hearing loss, congenital heart disease, and malformations of craniofacial and other structures. Pathogenic variants in CHD7, encoding adenosine triphosphate-dependent chromodomain helicase DNA binding protein 7, are present in the majority of affected individuals. However, no causal variant can be found in 5-30% (depending on the cohort) of individuals with a clinical diagnosis of CHARGE syndrome. METHODS We performed whole-exome sequencing (WES) on 28 families from which at least one individual presented with features highly suggestive of CHARGE syndrome. RESULTS Pathogenic variants in CHD7 were present in 15 of 28 individuals (53.6%), whereas 4 (14.3%) individuals had pathogenic variants in other genes (RERE, KMT2D, EP300, or PUF60). A variant of uncertain clinical significance in KDM6A was identified in one (3.5%) individual. The remaining eight (28.6%) individuals were not found to have pathogenic variants by WES. CONCLUSION These results demonstrate that the phenotypic features of CHARGE syndrome overlap with multiple other rare single-gene syndromes. Additionally, they implicate a shared molecular pathology that disrupts epigenetic regulation of multiple-organ development.
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Affiliation(s)
- Amanda Moccia
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Anshika Srivastava
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Jennifer M Skidmore
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - John A Bernat
- Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Marsha Wheeler
- University of Washington Center for Mendelian Genomics, University of Washington, Seattle, Washington, USA
| | - Jessica X Chong
- University of Washington Center for Mendelian Genomics, University of Washington, Seattle, Washington, USA
| | - Deborah Nickerson
- University of Washington Center for Mendelian Genomics, University of Washington, Seattle, Washington, USA
| | - Michael Bamshad
- University of Washington Center for Mendelian Genomics, University of Washington, Seattle, Washington, USA
| | - Margaret A Hefner
- Department of Pediatrics, Saint Louis University School of Medicine, St. Louis, Missouri, USA
| | - Donna M Martin
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan, USA.
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, Michigan, USA.
| | - Stephanie L Bielas
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan, USA.
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31
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Rivera-Reyes R, Kleppa MJ, Kispert A. Proteomic analysis identifies transcriptional cofactors and homeobox transcription factors as TBX18 binding proteins. PLoS One 2018; 13:e0200964. [PMID: 30071041 PMCID: PMC6071992 DOI: 10.1371/journal.pone.0200964] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 05/30/2018] [Indexed: 01/04/2023] Open
Abstract
The TBX18 transcription factor is a crucial developmental regulator of several organ systems in mice, and loss of its transcriptional repression activity causes dilative nephropathies in humans. The molecular complexes with which TBX18 regulates transcription are poorly understood prompting us to use an unbiased proteomic approach to search for protein interaction partners. Using overexpressed dual tagged TBX18 as bait, we identified by tandem purification and subsequent LC-MS analysis TBX18 binding proteins in 293 cells. Clustering of functional annotations of the identified proteins revealed a highly significant enrichment of transcriptional cofactors and homeobox transcription factors. Using nuclear recruitment assays as well as GST pull-downs, we validated CBFB, GAR1, IKZF2, NCOA5, SBNO2 and CHD7 binding to the T-box of TBX18 in vitro. From these transcriptional cofactors, CBFB, CHD7 and IKZF2 enhanced the transcriptional repression of TBX18, while NCOA5 and SBNO2 dose-dependently relieved it. All tested homeobox transcription factors interacted with the T-box of TBX18 in pull-down assays, with members of the Pbx and Prrx subfamilies showing coexpression with Tbx18 in the developing ureter of the mouse. In summary, we identified and characterized new TBX18 binding partners that may influence the transcriptional activity of TBX18 in vivo.
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Affiliation(s)
| | - Marc-Jens Kleppa
- Institut für Molekularbiologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Andreas Kispert
- Institut für Molekularbiologie, Medizinische Hochschule Hannover, Hannover, Germany
- * E-mail:
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32
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The chromatin basis of neurodevelopmental disorders: Rethinking dysfunction along the molecular and temporal axes. Prog Neuropsychopharmacol Biol Psychiatry 2018; 84:306-327. [PMID: 29309830 DOI: 10.1016/j.pnpbp.2017.12.013] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 12/19/2017] [Accepted: 12/24/2017] [Indexed: 12/13/2022]
Abstract
The complexity of the human brain emerges from a long and finely tuned developmental process orchestrated by the crosstalk between genome and environment. Vis à vis other species, the human brain displays unique functional and morphological features that result from this extensive developmental process that is, unsurprisingly, highly vulnerable to both genetically and environmentally induced alterations. One of the most striking outcomes of the recent surge of sequencing-based studies on neurodevelopmental disorders (NDDs) is the emergence of chromatin regulation as one of the two domains most affected by causative mutations or Copy Number Variations besides synaptic function, whose involvement had been largely predicted for obvious reasons. These observations place chromatin dysfunction at the top of the molecular pathways hierarchy that ushers in a sizeable proportion of NDDs and that manifest themselves through synaptic dysfunction and recurrent systemic clinical manifestation. Here we undertake a conceptual investigation of chromatin dysfunction in NDDs with the aim of systematizing the available evidence in a new framework: first, we tease out the developmental vulnerabilities in human corticogenesis as a structuring entry point into the causation of NDDs; second, we provide a much needed clarification of the multiple meanings and explanatory frameworks revolving around "epigenetics", highlighting those that are most relevant for the analysis of these disorders; finally we go in-depth into paradigmatic examples of NDD-causing chromatin dysregulation, with a special focus on human experimental models and datasets.
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33
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Sekiguchi K, Itonaga T, Maeda T, Fukami M, Yorifuji T, Ihara K. A case of CHARGE syndrome associated with hyperinsulinemic hypoglycemia in infancy. Eur J Med Genet 2018; 61:312-314. [DOI: 10.1016/j.ejmg.2018.01.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 12/30/2017] [Accepted: 01/13/2018] [Indexed: 10/18/2022]
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34
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Modes of Interaction of KMT2 Histone H3 Lysine 4 Methyltransferase/COMPASS Complexes with Chromatin. Cells 2018; 7:cells7030017. [PMID: 29498679 PMCID: PMC5870349 DOI: 10.3390/cells7030017] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 02/22/2018] [Accepted: 02/27/2018] [Indexed: 02/07/2023] Open
Abstract
Regulation of gene expression is achieved by sequence-specific transcriptional regulators, which convey the information that is contained in the sequence of DNA into RNA polymerase activity. This is achieved by the recruitment of transcriptional co-factors. One of the consequences of co-factor recruitment is the control of specific properties of nucleosomes, the basic units of chromatin, and their protein components, the core histones. The main principles are to regulate the position and the characteristics of nucleosomes. The latter includes modulating the composition of core histones and their variants that are integrated into nucleosomes, and the post-translational modification of these histones referred to as histone marks. One of these marks is the methylation of lysine 4 of the core histone H3 (H3K4). While mono-methylation of H3K4 (H3K4me1) is located preferentially at active enhancers, tri-methylation (H3K4me3) is a mark found at open and potentially active promoters. Thus, H3K4 methylation is typically associated with gene transcription. The class 2 lysine methyltransferases (KMTs) are the main enzymes that methylate H3K4. KMT2 enzymes function in complexes that contain a necessary core complex composed of WDR5, RBBP5, ASH2L, and DPY30, the so-called WRAD complex. Here we discuss recent findings that try to elucidate the important question of how KMT2 complexes are recruited to specific sites on chromatin. This is embedded into short overviews of the biological functions of KMT2 complexes and the consequences of H3K4 methylation.
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35
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Sakata S, Okada S, Aoyama K, Hara K, Tani C, Kagawa R, Utsunomiya-Nakamura A, Miyagawa S, Ogata T, Mizuno H, Kobayashi M. Individual Clinically Diagnosed with CHARGE Syndrome but with a Mutation in KMT2D, a Gene Associated with Kabuki Syndrome: A Case Report. Front Genet 2017; 8:210. [PMID: 29321794 PMCID: PMC5732153 DOI: 10.3389/fgene.2017.00210] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 11/28/2017] [Indexed: 11/13/2022] Open
Abstract
We report a Japanese female patient presenting with classic features of CHARGE syndrome, including choanal atresia, growth and development retardation, ear malformations, genital anomalies, multiple endocrine deficiency, and unilateral facial nerve palsy. She was clinically diagnosed with typical CHARGE syndrome, but genetic analysis using the TruSight One Sequence Panel revealed a germline heterozygous mutation in KMT2D with no pathogenic CHD7 alterations associated with CHARGE syndrome. Kabuki syndrome is a rare multisystem disorder characterized by five cardinal manifestations including typical facial features, skeletal anomalies, dermatoglyphic abnormalities, mild to moderate intellectual disability, and postnatal growth deficiency. Germline mutations in KMT2D underlie the molecular pathogenesis of 52–76% of patients with Kabuki syndrome. This is an instructive case that clearly represents a phenotypic overlap between Kabuki syndrome and CHARGE syndrome. It suggests the importance of considering the possibility of a diagnosis of Kabuki syndrome even if patients present with typical symptoms and meet diagnostic criteria of CHARGE syndrome. The case also emphasizes the impact of non-biased exhaustive genetic analysis by next-generation sequencing in the genetic diagnosis of rare congenital disorders with atypical manifestations.
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Affiliation(s)
- Sonoko Sakata
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Satoshi Okada
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Kohei Aoyama
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Keiichi Hara
- Department of Pediatrics, National Hospital Organization Kure Medical Center, Kure, Japan
| | - Chihiro Tani
- Department of Diagnostic Radiology, Hiroshima University Graduate School of Biomedical and Health Science, Hiroshima, Japan
| | - Reiko Kagawa
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Akari Utsunomiya-Nakamura
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Shinichiro Miyagawa
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan.,Miyagawa Kid's Clinic, Hiroshima, Japan
| | - Tsutomu Ogata
- Department of Pediatrics, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Haruo Mizuno
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.,Department of Pediatrics, International University of Health and Welfare School of Medicine, Chiba, Japan
| | - Masao Kobayashi
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
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Corsten-Janssen N, Scambler PJ. Clinical and molecular effects of CHD7 in the heart. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2017; 175:487-495. [PMID: 29088513 DOI: 10.1002/ajmg.c.31590] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Revised: 09/28/2017] [Accepted: 10/01/2017] [Indexed: 12/28/2022]
Abstract
Heart defects caused by loss-of-function mutations in CHD7 are a frequent cause of morbidity and mortality in CHARGE syndrome. Here we review the clinical and molecular aspects of CHD7 that are related to the cardiovascular manifestations of the syndrome. The types of heart defects found in patients with CHD7 mutations are variable, with an overrepresentation of atrioventricular septal defect and outflow tract defect including aortic arch anomalies compared to nonsyndromic heart defects. Chd7 haploinsufficiency in mouse is a good model for studying the heart effects seen in CHARGE syndrome, and mouse models reveal a role for Chd7 in multiple lineages during heart development. Formation of the great vessels requires Chd7 expression in the pharyngeal surface ectoderm, and this expression likely has an non-autonomous effect on neural crest cells. In the cardiogenic mesoderm, Chd7 is required for atrioventricular cushion development and septation of the outflow tract. Emerging knowledge about the function of CHD7 in the heart indicates that it may act in concert with transcription factors such as TBX1 and SMADs to regulate genes such as p53 and the cardiac transcription factor NKX2.5.
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Affiliation(s)
- Nicole Corsten-Janssen
- Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Peter J Scambler
- UCL Great Ormond Street Institute of Child Health, Section Developmental Biology of Birth Defects, London, UK
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37
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Pauli S, Bajpai R, Borchers A. CHARGEd with neural crest defects. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2017; 175:478-486. [PMID: 29082625 DOI: 10.1002/ajmg.c.31584] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 08/23/2017] [Accepted: 08/31/2017] [Indexed: 12/15/2022]
Abstract
Neural crest cells are highly migratory pluripotent cells that give rise to diverse derivatives including cartilage, bone, smooth muscle, pigment, and endocrine cells as well as neurons and glia. Abnormalities in neural crest-derived tissues contribute to the etiology of CHARGE syndrome, a complex malformation disorder that encompasses clinical symptoms like coloboma, heart defects, atresia of the choanae, retarded growth and development, genital hypoplasia, ear anomalies, and deafness. Mutations in the chromodomain helicase DNA-binding protein 7 (CHD7) gene are causative of CHARGE syndrome and loss-of-function data in different model systems have firmly established a role of CHD7 in neural crest development. Here, we will summarize our current understanding of the function of CHD7 in neural crest development and discuss possible links of CHARGE syndrome to other developmental disorders.
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Affiliation(s)
- Silke Pauli
- Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany
| | - Ruchi Bajpai
- Center for Craniofacial Molecular Biology, Ostrow School of Dentistry and Department of Biochemistry and Molecular Biology, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Annette Borchers
- Department of Biology, Molecular Embryology, Philipps-University Marburg, Marburg, Germany
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38
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CHARGE and Kabuki Syndromes: Gene-Specific DNA Methylation Signatures Identify Epigenetic Mechanisms Linking These Clinically Overlapping Conditions. Am J Hum Genet 2017; 100:773-788. [PMID: 28475860 PMCID: PMC5420353 DOI: 10.1016/j.ajhg.2017.04.004] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 04/06/2017] [Indexed: 01/13/2023] Open
Abstract
Epigenetic dysregulation has emerged as a recurring mechanism in the etiology of neurodevelopmental disorders. Two such disorders, CHARGE and Kabuki syndromes, result from loss of function mutations in chromodomain helicase DNA-binding protein 7 (CHD7LOF) and lysine (K) methyltransferase 2D (KMT2DLOF), respectively. Although these two syndromes are clinically distinct, there is significant phenotypic overlap. We therefore expected that epigenetically driven developmental pathways regulated by CHD7 and KMT2D would overlap and that DNA methylation (DNAm) alterations downstream of the mutations in these genes would identify common target genes, elucidating a mechanistic link between these two conditions, as well as specific target genes for each disorder. Genome-wide DNAm profiles in individuals with CHARGE and Kabuki syndromes with CHD7LOF or KMT2DLOF identified distinct sets of DNAm differences in each of the disorders, which were used to generate two unique, highly specific and sensitive DNAm signatures. These DNAm signatures were able to differentiate pathogenic mutations in these two genes from controls and from each other. Analysis of the DNAm targets in each gene-specific signature identified both common gene targets, including homeobox A5 (HOXA5), which could account for some of the clinical overlap in CHARGE and Kabuki syndromes, as well as distinct gene targets. Our findings demonstrate how characterization of the epigenome can contribute to our understanding of disease pathophysiology for epigenetic disorders, paving the way for explorations of novel therapeutics.
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39
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Lintas C, Persico AM. Unraveling molecular pathways shared by Kabuki and Kabuki-like syndromes. Clin Genet 2017; 94:283-295. [PMID: 28139835 DOI: 10.1111/cge.12983] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 01/19/2017] [Indexed: 12/12/2022]
Abstract
Kabuki syndrome (KS) is a rare genetic syndrome characterized by a typical facial gestalt, variable degrees of intellectual disability, organ malformations, postnatal growth retardation and skeletal abnormalities. So far, KMT2D or KDM6A mutation has been identified as the main cause of KS, accounting for 56%-75% and 3%-8% of cases, respectively. Patients without mutations in 1 of the 2 causative KS genes are often referred to as affected by Kabuki-like syndrome. Overall, they represent approximately 30% of KS cases, pointing toward substantial genetic heterogeneity for this condition. Here, we review all currently available literature describing KS-like phenotypes (or phenocopies) associated with genetic variants located in loci different from KMT2D and KDM6A . We also report on a new KS phenocopy harboring a 5 Mb de novo deletion in chr10p11.22-11.21. An enrichment analysis aimed at identifying functional Gene Ontology classes shared by the 2 known KS causative genes and by new candidate genes currently associated with KS-like phenotypes primarily converges upon abnormal chromatin remodeling and transcriptional dysregulation as pivotal to the pathophysiology of KS phenotypic hallmarks. The identification of mutations in genes belonging to the same functional pathways of KMT2D and KDM6A can help design molecular screenings targeted to KS-like phenotypes.
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Affiliation(s)
- C Lintas
- Unit of Child and Adolescent NeuroPsychiatry, University Campus Bio-Medico, Rome, Italy.,Laboratory of Molecular Psychiatry and Neurogenetics, Department of Medicine, University Campus Bio-Medico, Rome, Italy
| | - A M Persico
- Unit of Child and Adolescent NeuroPsychiatry, "G. Martino" University Hospital, University of Messina, Messina, Italy.,Mafalda Luce Center for Pervasive Developmental Disorders, Milan, Italy
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40
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Badalato L, Farhan SMK, Dilliott AA, Bulman DE, Hegele RA, Goobie SL. KMT2D p.Gln3575His segregating in a family with autosomal dominant choanal atresia strengthens the Kabuki/CHARGE connection. Am J Med Genet A 2016; 173:183-189. [PMID: 27991736 DOI: 10.1002/ajmg.a.38010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 09/21/2016] [Indexed: 11/10/2022]
Abstract
Choanal atresia is rarely reported in Kabuki syndrome, but is a common feature of CHARGE syndrome. Otherwise, the two conditions have a number of overlapping features, and the molecular links between them have recently been elucidated. Here, we report a case of a mother and her two children who presented with congenital choanal atresia. We performed whole exome sequencing on DNA from the mother and her two unaffected parents, and identified a de novo, novel variant in KMT2D. KMT2D p.Gln3575His segregated with disease status in the family, and is associated with a unique and conserved phenotype in the affected family members, with features overlapping with Kabuki and CHARGE syndromes. Our findings further support the potential etiological link between these two classically distinct conditions. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Lauren Badalato
- Faculty of Medicine, Department of Genetics, Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Sali M K Farhan
- Department of Biochemistry and Medicine, Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Allison A Dilliott
- Department of Biochemistry and Medicine, Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | | | - Dennis E Bulman
- Faculty of Medicine, Departments of Pediatrics, Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Robert A Hegele
- Department of Biochemistry and Medicine, Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Sharan L Goobie
- Division of Medical Genetics, Department of Pediatrics, London Health Sciences Centre, Western University, London, Ontario, Canada.,Medical Genetics, Department of Pediatrics, IWK Health Centre, Dalhousie University, Halifax, Nova Scotia, Canada
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41
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Bögershausen N, Altunoglu U, Beleggia F, Yigit G, Kayserili H, Nürnberg P, Li Y, Altmüller J, Wollnik B. An unusual presentation of Kabuki syndrome with orbital cysts, microphthalmia, and cholestasis with bile duct paucity. Am J Med Genet A 2016; 170:3282-3288. [PMID: 27530281 DOI: 10.1002/ajmg.a.37931] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 08/03/2016] [Indexed: 01/09/2023]
Abstract
Kabuki syndrome (KS) is a rare developmental disorder characterized by multiple congenital malformations, postnatal growth retardation, intellectual disability, and recognizable facial features. It is mainly caused by mutations in either KMT2D or KDM6A. We describe a 14-year-old boy with KS presenting with an unusual combination of bilateral microphthalmia with orbital cystic venous lymphatic malformation and neonatal cholestasis with bile duct paucity, in addition to the typical clinical features of KS. We identified the novel KMT2D mutation c.10588delC, p.(Glu3530Serfs*128) by Mendeliome (Illumina TruSight One®) sequencing, a next generation sequencing panel targeting 4,813 genes linked to human genetic disease. We analyzed the Mendeliome data for additional mutations which might explain the exceptional clinical presentation of our patient but did not find any, leading us to suspect that the above named symptoms might be part of the KMT2D-associated spectrum of anomalies. We thus extend the range of KS-associated malformations and propose a hypothetical connection between KMT2D and Notch signaling. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Nina Bögershausen
- Institute of Human Genetics, University Medical Center Goettingen, Goettingen, Germany
| | - Umut Altunoglu
- Istanbul Medical Faculty, Department of Medical Genetics, Istanbul University, Istanbul, Turkey
| | - Filippo Beleggia
- Institute of Human Genetics, University of Duesseldorf, Duesseldorf, Germany
| | - Gökhan Yigit
- Institute of Human Genetics, University Medical Center Goettingen, Goettingen, Germany
| | - Hülya Kayserili
- Department of Medical Genetics, Koç University School of Medicine, Istanbul, Turkey
| | - Peter Nürnberg
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Yun Li
- Institute of Human Genetics, University Medical Center Goettingen, Goettingen, Germany
| | - Janine Altmüller
- Cologne Center for Genomics, University of Cologne, Cologne, Germany.,Institute of Human Genetics, University of Cologne, Cologne, Germany
| | - Bernd Wollnik
- Institute of Human Genetics, University Medical Center Goettingen, Goettingen, Germany
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Abstract
The Mendelian disorders of the epigenetic machinery are genetic disorders that involve disruption of the various components of the epigenetic machinery (writers, erasers, readers, and remodelers) and are thus expected to have widespread downstream epigenetic consequences. Studying this group may offer a unique opportunity to learn about the role of epigenetics in health and disease. Among these patients, neurological dysfunction and, in particular, intellectual disability appears to be a common phenotype; however, this is often seen in association with other more specific features in respective disorders. The specificity of some of the clinical features raises the question whether specific cell types are particularly sensitive to the loss of these factors. Most of these disorders demonstrate dosage sensitivity as loss of a single allele appears to be sufficient to cause the observed phenotypes. Although the pathogenic sequence is unknown for most of these disorders, there are several examples where disrupted expression of downstream target genes accounts for a substantial portion of the phenotype; hence, it may be useful to systematically map such disease-relevant target genes. Finally, two of these disorders (Rubinstein-Taybi and Kabuki syndromes) have shown post-natal rescue of markers of the neurological dysfunction with drugs that lead to histone deacetylase inhibition, indicating that some of these disorders may be treatable causes of intellectual disability.
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Affiliation(s)
- Hans Tomas Bjornsson
- McKusick-Nathans Institute of Genetic Medicine and Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA
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43
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Bögershausen N, Gatinois V, Riehmer V, Kayserili H, Becker J, Thoenes M, Simsek-Kiper PÖ, Barat-Houari M, Elcioglu NH, Wieczorek D, Tinschert S, Sarrabay G, Strom TM, Fabre A, Baynam G, Sanchez E, Nürnberg G, Altunoglu U, Capri Y, Isidor B, Lacombe D, Corsini C, Cormier-Daire V, Sanlaville D, Giuliano F, Le Quan Sang KH, Kayirangwa H, Nürnberg P, Meitinger T, Boduroglu K, Zoll B, Lyonnet S, Tzschach A, Verloes A, Di Donato N, Touitou I, Netzer C, Li Y, Geneviève D, Yigit G, Wollnik B. Mutation Update for Kabuki Syndrome GenesKMT2DandKDM6Aand Further Delineation of X-Linked Kabuki Syndrome Subtype 2. Hum Mutat 2016; 37:847-64. [DOI: 10.1002/humu.23026] [Citation(s) in RCA: 104] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 05/26/2016] [Indexed: 12/29/2022]
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Abstract
Kabuki syndrome is a rare genetic malformation syndrome that is characterized by distinct facies, structural defects and intellectual disability. Kabuki syndrome may be caused by mutations in one of two histone methyltransferase genes: KMT2D and KDM6A. We describe a male child of nonconsanguineous Irish parents presenting with multiple malformations, including bilateral extreme microphthalmia; cleft palate; congenital diaphragmatic hernia; duplex kidney; as well as facial features of Kabuki syndrome, including interrupted eyebrows and lower lid ectropion. A de-novo germline mutation in KMT2D was identified. Whole-exome sequencing failed to reveal mutations in any of the known microphthalmia/anopthalmia genes. We also identified four other patients with Kabuki syndrome and microphthalmia. We postulate that Kabuki syndrome may produce this type of ocular phenotype as a result of extensive interaction between KMT2D, WAR complex proteins and PAXIP1. Children presenting with microphthalmia/anophthalmia should be examined closely for other signs of Kabuki syndrome, especially at an age where the facial gestalt might be less readily appreciable.
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45
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Functional Insights into Chromatin Remodelling from Studies on CHARGE Syndrome. Trends Genet 2015; 31:600-611. [PMID: 26411921 PMCID: PMC4604214 DOI: 10.1016/j.tig.2015.05.009] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 05/25/2015] [Accepted: 05/26/2015] [Indexed: 12/27/2022]
Abstract
CHARGE syndrome is a rare genetic syndrome characterised by a unique combination of multiple organ anomalies. Dominant loss-of-function mutations in the gene encoding chromodomain helicase DNA binding protein 7 (CHD7), which is an ATP-dependent chromatin remodeller, have been identified as the cause of CHARGE syndrome. Here, we review recent work aimed at understanding the mechanism of CHD7 function in normal and pathological states, highlighting results from biochemical and in vivo studies. The emerging picture from this work suggests that the mechanisms by which CHD7 fine-tunes gene expression are context specific, consistent with the pleiotropic nature of CHARGE syndrome.
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CHARGE syndrome: a review of the immunological aspects. Eur J Hum Genet 2015; 23:1451-9. [PMID: 25689927 DOI: 10.1038/ejhg.2015.7] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 12/18/2014] [Accepted: 12/25/2014] [Indexed: 01/21/2023] Open
Abstract
CHARGE syndrome is caused by a dominant variant in the CHD7 gene. Multiple organ systems can be affected because of haploinsufficiency of CHD7 during embryonic development. CHARGE syndrome shares many clinical features with the 22q11.2 deletion syndrome. Immunological abnormalities have been described, but are generally given little attention in studies on CHARGE syndrome. However, structured information on immunological abnormalities in CHARGE patients is necessary to develop optimal guidelines for diagnosis, treatment and follow-up in these patients. Here, we provide an overview of the current literature on immunological abnormalities in CHARGE syndrome. We also explore immunological abnormalities in comparable multiple congenital anomaly syndromes to identify common immunological phenotypes and genetic pathways that might regulate the immune system. Finally, we aim to identify gaps in our knowledge on the immunological aspects in CHARGE syndrome that need further study.
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Abstract
Epigenetic events including chromatin remodeling and histone modifications have recently emerged as important contributors to a variety of neurodevelopmental disorders. This review focuses on CHARGE syndrome, a multiple anomaly condition caused by mutations in the gene encoding CHD7, an ATP-dependent chromatin remodeling protein. CHD7 exhibits pleiotropic effects during embryonic development, consistent with highly variable clinical features in CHARGE syndrome. In this review, a historical description of CHARGE is provided, followed by establishment of diagnostic criteria, gene discovery, and development of animal models. Current understanding of epigenetic CHD7 functions and interacting proteins in cells and tissues is also presented, and final emphasis is placed on challenges and major questions to be answered with ongoing research efforts.
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Affiliation(s)
- Donna M Martin
- Department of Human Genetics at The University of Michigan Medical School, Ann Arbor, MI, 48109 ; Department of Pediatrics and Communicable Diseases at The University of Michigan Medical School, Ann Arbor, MI, 48109
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Shyr C, Tarailo-Graovac M, Gottlieb M, Lee JJY, van Karnebeek C, Wasserman WW. FLAGS, frequently mutated genes in public exomes. BMC Med Genomics 2014; 7:64. [PMID: 25466818 PMCID: PMC4267152 DOI: 10.1186/s12920-014-0064-y] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 10/24/2014] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Dramatic improvements in DNA-sequencing technologies and computational analyses have led to wide use of whole exome sequencing (WES) to identify the genetic basis of Mendelian disorders. More than 180 novel rare-disease-causing genes with Mendelian inheritance patterns have been discovered through sequencing the exomes of just a few unrelated individuals or family members. As rare/novel genetic variants continue to be uncovered, there is a major challenge in distinguishing true pathogenic variants from rare benign mutations. METHODS We used publicly available exome cohorts, together with the dbSNP database, to derive a list of genes (n = 100) that most frequently exhibit rare (<1%) non-synonymous/splice-site variants in general populations. We termed these genes FLAGS for FrequentLy mutAted GeneS and analyzed their properties. RESULTS Analysis of FLAGS revealed that these genes have significantly longer protein coding sequences, a greater number of paralogs and display less evolutionarily selective pressure than expected. FLAGS are more frequently reported in PubMed clinical literature and more frequently associated with diseased phenotypes compared to the set of human protein-coding genes. We demonstrated an overlap between FLAGS and the rare-disease causing genes recently discovered through WES studies (n = 10) and the need for replication studies and rigorous statistical and biological analyses when associating FLAGS to rare disease. Finally, we showed how FLAGS are applied in disease-causing variant prioritization approach on exome data from a family affected by an unknown rare genetic disorder. CONCLUSIONS We showed that some genes are frequently affected by rare, likely functional variants in general population, and are frequently observed in WES studies analyzing diverse rare phenotypes. We found that the rate at which genes accumulate rare mutations is beneficial information for prioritizing candidates. We provided a ranking system based on the mutation accumulation rates for prioritizing exome-captured human genes, and propose that clinical reports associating any disease/phenotype to FLAGS be evaluated with extra caution.
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Affiliation(s)
- Casper Shyr
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Vancouver, BC, Canada. .,Treatable Intellectual Disability Endeavour in British Columbia, Vancouver, Canada. .,Bioinformatics Graduate Program, University of British Columbia, Vancouver, BC, Canada.
| | - Maja Tarailo-Graovac
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Vancouver, BC, Canada. .,Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada. .,Treatable Intellectual Disability Endeavour in British Columbia, Vancouver, Canada.
| | - Michael Gottlieb
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Vancouver, BC, Canada.
| | - Jessica J Y Lee
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Vancouver, BC, Canada. .,Genome Science and Technology Graduate Program, University of British Columbia, Vancouver, BC, Canada.
| | - Clara van Karnebeek
- Treatable Intellectual Disability Endeavour in British Columbia, Vancouver, Canada. .,Division of Biochemical Diseases, BC Children's Hospital, Vancouver, BC, Canada. .,Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada.
| | - Wyeth W Wasserman
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Vancouver, BC, Canada. .,Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada. .,Treatable Intellectual Disability Endeavour in British Columbia, Vancouver, Canada.
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Chen YH, Sun MH, Hsia SH, Lai CC, Wu WC. Rare ocular features in a case of Kabuki syndrome (Niikawa-Kuroki syndrome). BMC Ophthalmol 2014; 14:143. [PMID: 25421742 PMCID: PMC4251844 DOI: 10.1186/1471-2415-14-143] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Accepted: 11/18/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Kabuki syndrome is a multi-system disorder with peculiar facial features, and ophthalmic abnormalities are frequently involved. This case report of a child with Kabuki syndrome describes two new previously unreported ophthalmic conditions. CASE PRESENTATION A 3-year-old Taiwanese boy with Kabuki syndrome had a short stature, spinal dysraphism, intellectual disability and typical facial features. Ophthalmic findings which have been previously reported in the literature and in this patient, included ptosis, esotropia, coloboma of the iris, retina, choroid and optic disc, and microcornea. The newly identified ophthalmic features in this patient included colobomatous microphthalmos and a dysplastic and elevated disc without central cupping. The genetic analysis identified an MLL2 gene mutation. CONCLUSION The presentations of a dysplastic disc and colobomatous microphthalmia are rarely reported in patients with Kabuki syndrome, but these ophthalmic abnormalities may affect vision. Detailed ophthalmic evaluations in children with Kabuki syndrome are advised.
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Affiliation(s)
| | | | | | | | - Wei-Chi Wu
- Department of Ophthalmology, Chang Gung Memorial Hospital, No, 5, Fu-Hsing Street, Kweishan, Taoyuan 333, Taiwan.
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