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Nunes N, Carvalho Nunes B, Zamariolli M, Cordeiro de Queiroz Soares D, Caires dos Santos L, Gollo Dantas A, Ayres Meloni V, Iole Belangero S, Gil-Da-Silva-Lopes VL, Ae Kim C, Melaragno MI. Variants in Candidate Genes for Phenotype Heterogeneity in Patients with the 22q11.2 Deletion Syndrome. Genet Res (Camb) 2024; 2024:5549592. [PMID: 38586596 PMCID: PMC10998724 DOI: 10.1155/2024/5549592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 02/29/2024] [Accepted: 03/20/2024] [Indexed: 04/09/2024] Open
Abstract
22q11.2 deletion syndrome (22q11.2DS) is a microdeletion syndrome with a broad and heterogeneous phenotype, even though most of the deletions present similar sizes, involving ∼3 Mb of DNA. In a relatively large population of a Brazilian 22q11.2DS cohort (60 patients), we investigated genetic variants that could act as genetic modifiers and contribute to the phenotypic heterogeneity, using a targeted NGS (Next Generation Sequencing) with a specific Ion AmpliSeq panel to sequence nine candidate genes (CRKL, MAPK1, HIRA, TANGO2, PI4KA, HDAC1, ZDHHC8, ZFPM2, and JAM3), mapped in and outside the 22q11.2 hemizygous deleted region. In silico prediction was performed, and the whole-genome sequencing annotation analysis package (WGSA) was used to predict the possible pathogenic effect of single nucleotide variants (SNVs). For the in silico prediction of the indels, we used the genomic variants filtered by a deep learning model in NGS (GARFIELD-NGS). We identified six variants, 4 SNVs and 2 indels, in MAPK1, JAM3, and ZFPM2 genes with possibly synergistic deleterious effects in the context of the 22q11.2 deletion. Our results provide the opportunity for the discovery of the co-occurrence of genetic variants with 22q11.2 deletions, which may influence the patients´ phenotype.
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Affiliation(s)
- Natalia Nunes
- Genetics Division, Department of Morphology and Genetics, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Beatriz Carvalho Nunes
- Genetics Division, Department of Morphology and Genetics, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Malú Zamariolli
- Genetics Division, Department of Morphology and Genetics, Universidade Federal de São Paulo, São Paulo, Brazil
| | | | - Leonardo Caires dos Santos
- Genetics Division, Department of Morphology and Genetics, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Anelisa Gollo Dantas
- Genetics Division, Department of Morphology and Genetics, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Vera Ayres Meloni
- Genetics Division, Department of Morphology and Genetics, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Sintia Iole Belangero
- Genetics Division, Department of Morphology and Genetics, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Vera Lúcia Gil-Da-Silva-Lopes
- Department of Translational Medicine, School of Medical Sciences, University of Campinas, Campinas, São Paulo, Brazil
| | - Chong Ae Kim
- Genetics Unit, Instituto da Criança, Universidade de São Paulo, São Paulo, Brazil
| | - Maria Isabel Melaragno
- Genetics Division, Department of Morphology and Genetics, Universidade Federal de São Paulo, São Paulo, Brazil
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Edwards W, Bussey OK, Conlon FL. The Tbx20-TLE interaction is essential for the maintenance of the second heart field. Development 2023; 150:dev201677. [PMID: 37756602 PMCID: PMC10629681 DOI: 10.1242/dev.201677] [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: 02/03/2023] [Accepted: 09/14/2023] [Indexed: 09/29/2023]
Abstract
T-box transcription factor 20 (Tbx20) plays a multifaceted role in cardiac morphogenesis and controls a broad gene regulatory network. However, the mechanism by which Tbx20 activates and represses target genes in a tissue-specific and temporal manner remains unclear. Studies show that Tbx20 directly interacts with the Transducin-like Enhancer of Split (TLE) family of proteins to mediate transcriptional repression. However, a function for the Tbx20-TLE transcriptional repression complex during heart development has yet to be established. We created a mouse model with a two amino acid substitution in the Tbx20 EH1 domain, thereby disrupting the Tbx20-TLE interaction. Disruption of this interaction impaired crucial morphogenic events, including cardiac looping and chamber formation. Transcriptional profiling of Tbx20EH1Mut hearts and analysis of putative direct targets revealed misexpression of the retinoic acid pathway and cardiac progenitor genes. Further, we show that altered cardiac progenitor development and function contribute to the severe cardiac defects in our model. Our studies indicate that TLE-mediated repression is a primary mechanism by which Tbx20 controls gene expression.
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Affiliation(s)
- Whitney Edwards
- Department of Biology and Genetics, McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Integrative Program for Biological & Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Olivia K. Bussey
- Department of Biology and Genetics, McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Integrative Program for Biological & Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Frank L. Conlon
- Department of Biology and Genetics, McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Integrative Program for Biological & Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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3
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Kocere A, Lalonde RL, Mosimann C, Burger A. Lateral thinking in syndromic congenital cardiovascular disease. Dis Model Mech 2023; 16:dmm049735. [PMID: 37125615 PMCID: PMC10184679 DOI: 10.1242/dmm.049735] [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] [Indexed: 05/02/2023] Open
Abstract
Syndromic birth defects are rare diseases that can present with seemingly pleiotropic comorbidities. Prime examples are rare congenital heart and cardiovascular anomalies that can be accompanied by forelimb defects, kidney disorders and more. Whether such multi-organ defects share a developmental link remains a key question with relevance to the diagnosis, therapeutic intervention and long-term care of affected patients. The heart, endothelial and blood lineages develop together from the lateral plate mesoderm (LPM), which also harbors the progenitor cells for limb connective tissue, kidneys, mesothelia and smooth muscle. This developmental plasticity of the LPM, which founds on multi-lineage progenitor cells and shared transcription factor expression across different descendant lineages, has the potential to explain the seemingly disparate syndromic defects in rare congenital diseases. Combining patient genome-sequencing data with model organism studies has already provided a wealth of insights into complex LPM-associated birth defects, such as heart-hand syndromes. Here, we summarize developmental and known disease-causing mechanisms in early LPM patterning, address how defects in these processes drive multi-organ comorbidities, and outline how several cardiovascular and hematopoietic birth defects with complex comorbidities may be LPM-associated diseases. We also discuss strategies to integrate patient sequencing, data-aggregating resources and model organism studies to mechanistically decode congenital defects, including potentially LPM-associated orphan diseases. Eventually, linking complex congenital phenotypes to a common LPM origin provides a framework to discover developmental mechanisms and to anticipate comorbidities in congenital diseases affecting the cardiovascular system and beyond.
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Affiliation(s)
- Agnese Kocere
- University of Colorado School of Medicine, Anschutz Medical Campus, Department of Pediatrics, Section of Developmental Biology, Aurora, CO 80045, USA
- Department of Molecular Life Science, University of Zurich, 8057 Zurich, Switzerland
| | - Robert L. Lalonde
- University of Colorado School of Medicine, Anschutz Medical Campus, Department of Pediatrics, Section of Developmental Biology, Aurora, CO 80045, USA
| | - Christian Mosimann
- University of Colorado School of Medicine, Anschutz Medical Campus, Department of Pediatrics, Section of Developmental Biology, Aurora, CO 80045, USA
| | - Alexa Burger
- University of Colorado School of Medicine, Anschutz Medical Campus, Department of Pediatrics, Section of Developmental Biology, Aurora, CO 80045, USA
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4
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Funato N. Craniofacial Phenotypes and Genetics of DiGeorge Syndrome. J Dev Biol 2022; 10:jdb10020018. [PMID: 35645294 PMCID: PMC9149807 DOI: 10.3390/jdb10020018] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 05/11/2022] [Accepted: 05/11/2022] [Indexed: 02/06/2023] Open
Abstract
The 22q11.2 deletion is one of the most common genetic microdeletions, affecting approximately 1 in 4000 live births in humans. A 1.5 to 2.5 Mb hemizygous deletion of chromosome 22q11.2 causes DiGeorge syndrome (DGS) and velocardiofacial syndrome (VCFS). DGS/VCFS are associated with prevalent cardiac malformations, thymic and parathyroid hypoplasia, and craniofacial defects. Patients with DGS/VCFS manifest craniofacial anomalies involving the cranium, cranial base, jaws, pharyngeal muscles, ear-nose-throat, palate, teeth, and cervical spine. Most craniofacial phenotypes of DGS/VCFS are caused by proximal 1.5 Mb microdeletions, resulting in a hemizygosity of coding genes, microRNAs, and long noncoding RNAs. TBX1, located on chromosome 22q11.21, encodes a T-box transcription factor and is a candidate gene for DGS/VCFS. TBX1 regulates the fate of progenitor cells in the cranial and pharyngeal apparatus during embryogenesis. Tbx1-null mice exhibit the most clinical features of DGS/VCFS, including craniofacial phenotypes. Despite the frequency of DGS/VCFS, there has been a limited review of the craniofacial phenotypes of DGC/VCFS. This review focuses on these phenotypes and summarizes the current understanding of the genetic factors that impact DGS/VCFS-related phenotypes. We also review DGS/VCFS mouse models that have been designed to better understand the pathogenic processes of DGS/VCFS.
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Affiliation(s)
- Noriko Funato
- Department of Signal Gene Regulation, Advanced Therapeutic Sciences, Medical and Dental Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo 113-8510, Japan
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Magaletta ME, Lobo M, Kernfeld EM, Aliee H, Huey JD, Parsons TJ, Theis FJ, Maehr R. Integration of single-cell transcriptomes and chromatin landscapes reveals regulatory programs driving pharyngeal organ development. Nat Commun 2022; 13:457. [PMID: 35075189 PMCID: PMC8786836 DOI: 10.1038/s41467-022-28067-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 01/07/2022] [Indexed: 12/13/2022] Open
Abstract
Maldevelopment of the pharyngeal endoderm, an embryonic tissue critical for patterning of the pharyngeal region and ensuing organogenesis, ultimately contributes to several classes of human developmental syndromes and disorders. Such syndromes are characterized by a spectrum of phenotypes that currently cannot be fully explained by known mutations or genetic variants due to gaps in characterization of critical drivers of normal and dysfunctional development. Despite the disease-relevance of pharyngeal endoderm, we still lack a comprehensive and integrative view of the molecular basis and gene regulatory networks driving pharyngeal endoderm development. To close this gap, we apply transcriptomic and chromatin accessibility single-cell sequencing technologies to generate a multi-omic developmental resource spanning pharyngeal endoderm patterning to the emergence of organ-specific epithelia in the developing mouse embryo. We identify cell-type specific gene regulation, distill GRN models that define developing organ domains, and characterize the role of an immunodeficiency-associated forkhead box transcription factor.
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Affiliation(s)
- Margaret E Magaletta
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
- Diabetes Center of Excellence, University of Massachusetts Medical School, Worcester, MA, USA
| | - Macrina Lobo
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
- Diabetes Center of Excellence, University of Massachusetts Medical School, Worcester, MA, USA
| | - Eric M Kernfeld
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
- Diabetes Center of Excellence, University of Massachusetts Medical School, Worcester, MA, USA
| | - Hananeh Aliee
- Institute of Computational Biology, Helmholtz Zentrum München, Munich, Germany
| | - Jack D Huey
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
- Diabetes Center of Excellence, University of Massachusetts Medical School, Worcester, MA, USA
| | - Teagan J Parsons
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
- Diabetes Center of Excellence, University of Massachusetts Medical School, Worcester, MA, USA
| | - Fabian J Theis
- Institute of Computational Biology, Helmholtz Zentrum München, Munich, Germany
- Department of Mathematics, Technische Universität München, Munich, Germany
- School of Life Sciences Weihenstephan, Technische Universität München, Freising, Germany
| | - René Maehr
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA.
- Diabetes Center of Excellence, University of Massachusetts Medical School, Worcester, MA, USA.
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6
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Jiang X, Li T, Liu S, Fu Q, Li F, Chen S, Sun K, Xu R, Xu Y. Variants in a cis-regulatory element of TBX1 in conotruncal heart defect patients impair GATA6-mediated transactivation. Orphanet J Rare Dis 2021; 16:334. [PMID: 34332615 PMCID: PMC8325851 DOI: 10.1186/s13023-021-01981-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 07/25/2021] [Indexed: 12/14/2022] Open
Abstract
Background TBX1 (T-box transcription factor 1) is a major candidate gene that likely contributes to the etiology of velo-cardio-facial syndrome/DiGeorge syndrome (VCFS/DGS). Although the haploinsufficiency of TBX1 in both mice and humans results in congenital cardiac malformations, little has been elucidated about its upstream regulation. We aimed to explore the transcriptional regulation and dysregulation of TBX1. Methods Different TBX1 promoter reporters were constructed. Luciferase assays and electrophoretic mobility shift assays (EMSAs) were used to identify a cis-regulatory element within the TBX1 promoter region and its trans-acting factor. The expression of proteins was identified by immunohistochemistry and immunofluorescence. Variants in the cis-regulatory element were screened in conotruncal defect (CTD) patients. In vitro functional assays were performed to show the effects of the variants found in CTD patients on the transactivation of TBX1. Results We identified a cis-regulatory element within intron 1 of TBX1 that was found to be responsive to GATA6 (GATA binding protein 6), a transcription factor crucial for cardiogenesis. The expression patterns of GATA6 and TBX1 overlapped in the pharyngeal arches of human embryos. Transfection experiments and EMSA indicated that GATA6 could activate the transcription of TBX1 by directly binding with its GATA cis-regulatory element in vitro. Furthermore, sequencing analyses of 195 sporadic CTD patients without the 22q11.2 deletion or duplication identified 3 variants (NC_000022.11:g.19756832C > G, NC_000022.11:g.19756845C > T, and NC_000022.11:g. 19756902G > T) in the non-coding cis-regulatory element of TBX1. Luciferase assays showed that all 3 variants led to reduced transcription of TBX1 when incubated with GATA6. Conclusions Our findings showed that TBX1 might be a direct transcriptional target of GATA6, and variants in the non-coding cis-regulatory element of TBX1 disrupted GATA6-mediated transactivation. Supplementary Information The online version contains supplementary material available at 10.1186/s13023-021-01981-4.
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Affiliation(s)
- Xuechao Jiang
- Scientific Research Center, Xinhua Hospital, Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Tingting Li
- Department of Pediatric Cardiology, Xinhua Hospital, Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Sijie Liu
- Department of Pediatric Cardiology, Xinhua Hospital, Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Qihua Fu
- Medical Laboratory, Shanghai Children's Medical Center, Affiliated to Shanghai Jiao Tong University School of Medicine , Shanghai, 200127, China
| | - Fen Li
- Department of Pediatric Cardiology, Shanghai Children's Medical Center, Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China
| | - Sun Chen
- Department of Pediatric Cardiology, Xinhua Hospital, Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Kun Sun
- Department of Pediatric Cardiology, Xinhua Hospital, Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Rang Xu
- Scientific Research Center, Xinhua Hospital, Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China.
| | - Yuejuan Xu
- Department of Pediatric Cardiology, Xinhua Hospital, Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China.
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Dell'Edera D, Allegretti A, Ventura M, Mercuri L, Mitidieri A, Cuscianna G, Epifania AA, Morizio E, Alfonsi M, Guanciali-Franchi P. Mayer-Rokitansky-Küster-Hauser syndrome with 22q11.21 microduplication: a case report. J Med Case Rep 2021; 15:208. [PMID: 33883018 PMCID: PMC8058992 DOI: 10.1186/s13256-021-02716-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 02/02/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome (Online Mendelian Inheritance in Man [OMIM] #277000) is a congenital condition characterized by the total or partial agenesis of vagina and uterus. Agenesis can be isolated (MRKH 1) or associated with other renal, vertebral or cardiac defects (MRKH 2). CASE PRESENTATION In this paper, we report a case of a Caucasian patient showing the clinical signs associated with MRKH. Array-based comparative genomic hybridization (a-CGH) analysis revealed a microduplication of approximately 3.01 megabases (Mb) located on the long arm of chromosome 22 (22q11.21). Microduplications affecting the 22q11.21 region have been shown to be associated with MRKH syndrome and Müllerian aplasia. The phenotype of patients with 22q11.2 duplication (OMIM #608363) appears extremely variable, ranging from apparently normal to mild learning difficulties or with multiple defects, sharing features with DiGeorge/velocardiofacial (DGS/VCFS) syndrome. CONCLUSIONS The altered gene expression together with other genetic, nongenetic, epigenetic or environmental factors can cause the extremely variable phenotype in patients carrying such duplication. Therefore, we can consider MRKH syndrome to be one of the clinical features of DGS/VCFS syndrome.
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Affiliation(s)
- Domenico Dell'Edera
- Medical Genetics Unit, "Madonna delle Grazie" Hospital, Contrada Cattedra Ambulante, Snc, 75100, Matera, Italy.
| | - Arianna Allegretti
- Medical Genetics Unit, "Madonna delle Grazie" Hospital, Contrada Cattedra Ambulante, Snc, 75100, Matera, Italy
| | - Mario Ventura
- Department of Biology, University of Bari, Bari, Italy
| | | | - Angela Mitidieri
- Medical Genetics Unit, "Madonna delle Grazie" Hospital, Contrada Cattedra Ambulante, Snc, 75100, Matera, Italy
| | - Giacinto Cuscianna
- Unit of Diagnostic Radiology and General Interventional Radiology, "Madonna delle Grazie" Hospital, Matera, Italy
| | - Annunziata Anna Epifania
- Medical Genetics Unit, "Madonna delle Grazie" Hospital, Contrada Cattedra Ambulante, Snc, 75100, Matera, Italy
| | - Elisena Morizio
- Department of Medical Genetics, 'G. D'Annunzio' University, Chieti, Italy
| | - Melissa Alfonsi
- Medical Genetics Unit, SS Annunziata Hospital, Chieti, Italy
| | - Paolo Guanciali-Franchi
- Department of Medical Genetics, 'G. D'Annunzio' University, Chieti, Italy.,Medical Genetics Unit, SS Annunziata Hospital, Chieti, Italy
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Cardiac Neural Crest Cells: Their Rhombomeric Specification, Migration, and Association with Heart and Great Vessel Anomalies. Cell Mol Neurobiol 2020; 41:403-429. [PMID: 32405705 DOI: 10.1007/s10571-020-00863-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 05/05/2020] [Indexed: 02/06/2023]
Abstract
Outflow tract abnormalities are the most frequent congenital heart defects. These are due to the absence or dysfunction of the two main cell types, i.e., neural crest cells and secondary heart field cells that migrate in opposite directions at the same stage of development. These cells directly govern aortic arch patterning and development, ascending aorta dilatation, semi-valvular and coronary artery development, aortopulmonary septation abnormalities, persistence of the ductus arteriosus, trunk and proximal pulmonary arteries, sub-valvular conal ventricular septal/rotational defects, and non-compaction of the left ventricle. In some cases, depending on the functional defects of these cells, additional malformations are found in the expected spatial migratory area of the cells, namely in the pharyngeal arch derivatives and cervico-facial structures. Associated non-cardiovascular anomalies are often underestimated, since the multipotency and functional alteration of these cells can result in the modification of multiple neural, epidermal, and cervical structures at different levels. In most cases, patients do not display the full phenotype of abnormalities, but congenital cardiac defects involving the ventricular outflow tract, ascending aorta, aortic arch and supra-aortic trunks should be considered as markers for possible impaired function of these cells. Neural crest cells should not be considered as a unique cell population but on the basis of their cervical rhombomere origins R3-R5 or R6-R7-R8 and specific migration patterns: R3-R4 towards arch II, R5-R6 arch III and R7-R8 arch IV and VI. A better understanding of their development may lead to the discovery of unknown associated abnormalities, thereby enabling potential improvements to be made to the therapeutic approach.
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9
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Phillips HM, Stothard CA, Shaikh Qureshi WM, Kousa AI, Briones-Leon JA, Khasawneh RR, O'Loughlin C, Sanders R, Mazzotta S, Dodds R, Seidel K, Bates T, Nakatomi M, Cockell SJ, Schneider JE, Mohun TJ, Maehr R, Kist R, Peters H, Bamforth SD. Pax9 is required for cardiovascular development and interacts with Tbx1 in the pharyngeal endoderm to control 4th pharyngeal arch artery morphogenesis. Development 2019; 146:dev.177618. [PMID: 31444215 PMCID: PMC6765178 DOI: 10.1242/dev.177618] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 08/14/2019] [Indexed: 12/16/2022]
Abstract
Developmental defects affecting the heart and aortic arch arteries are a significant phenotype observed in individuals with 22q11 deletion syndrome and are caused by a microdeletion on chromosome 22q11. TBX1, one of the deleted genes, is expressed throughout the pharyngeal arches and is considered a key gene, when mutated, for the arch artery defects. Pax9 is expressed in the pharyngeal endoderm and is downregulated in Tbx1 mutant mice. We show here that Pax9-deficient mice are born with complex cardiovascular malformations that affect the outflow tract and aortic arch arteries with failure of the 3rd and 4th pharyngeal arch arteries to form correctly. Transcriptome analysis indicated that Pax9 and Tbx1 may function together, and mice double heterozygous for Tbx1/Pax9 presented with a significantly increased incidence of interrupted aortic arch when compared with Tbx1 heterozygous mice. Using a novel Pax9Cre allele, we demonstrated that the site of this Tbx1-Pax9 genetic interaction is the pharyngeal endoderm, therefore revealing that a Tbx1-Pax9-controlled signalling mechanism emanating from the pharyngeal endoderm is required for crucial tissue interactions during normal morphogenesis of the pharyngeal arch artery system. Summary: A strong genetic interaction between Tbx1 and Pax9 that leads to 4th PAA-derived defects in double heterozygous mice is cell-autonomous within the pharyngeal endoderm.
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Affiliation(s)
- Helen M Phillips
- Institute of Genetic Medicine, Newcastle University, Newcastle-upon-Tyne NE1 3BZ, UK
| | - Catherine A Stothard
- Institute of Genetic Medicine, Newcastle University, Newcastle-upon-Tyne NE1 3BZ, UK
| | | | | | | | - Ramada R Khasawneh
- Institute of Genetic Medicine, Newcastle University, Newcastle-upon-Tyne NE1 3BZ, UK
| | - Chloe O'Loughlin
- Institute of Genetic Medicine, Newcastle University, Newcastle-upon-Tyne NE1 3BZ, UK
| | - Rachel Sanders
- Institute of Genetic Medicine, Newcastle University, Newcastle-upon-Tyne NE1 3BZ, UK
| | - Silvia Mazzotta
- Institute of Genetic Medicine, Newcastle University, Newcastle-upon-Tyne NE1 3BZ, UK
| | - Rebecca Dodds
- Institute of Genetic Medicine, Newcastle University, Newcastle-upon-Tyne NE1 3BZ, UK
| | - Kerstin Seidel
- Institute of Genetic Medicine, Newcastle University, Newcastle-upon-Tyne NE1 3BZ, UK
| | - Timothy Bates
- School of Dental Sciences, Newcastle University, Newcastle-upon-Tyne NE2 4BW, UK
| | - Mitsushiro Nakatomi
- Institute of Genetic Medicine, Newcastle University, Newcastle-upon-Tyne NE1 3BZ, UK
| | - Simon J Cockell
- Bioinformatics Support Unit, Newcastle University, Newcastle-upon-Tyne NE2 4HH, UK
| | | | | | - René Maehr
- Diabetes Center of Excellence, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Ralf Kist
- Institute of Genetic Medicine, Newcastle University, Newcastle-upon-Tyne NE1 3BZ, UK.,School of Dental Sciences, Newcastle University, Newcastle-upon-Tyne NE2 4BW, UK
| | - Heiko Peters
- Institute of Genetic Medicine, Newcastle University, Newcastle-upon-Tyne NE1 3BZ, UK
| | - Simon D Bamforth
- Institute of Genetic Medicine, Newcastle University, Newcastle-upon-Tyne NE1 3BZ, UK
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10
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Woodward KJ, Stampalia J, Vanyai H, Rijhumal H, Potts K, Taylor F, Peverall J, Grumball T, Sivamoorthy S, Alinejad-Rokny H, Wray J, Whitehouse A, Nagarajan L, Scurlock J, Afchani S, Edwards M, Murch A, Beilby J, Baynam G, Kiraly-Borri C, McKenzie F, Heng JIT. Atypical nested 22q11.2 duplications between LCR22B and LCR22D are associated with neurodevelopmental phenotypes including autism spectrum disorder with incomplete penetrance. Mol Genet Genomic Med 2019; 7:e00507. [PMID: 30614210 PMCID: PMC6393688 DOI: 10.1002/mgg3.507] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 09/18/2018] [Accepted: 10/10/2018] [Indexed: 12/04/2022] Open
Abstract
Background Chromosome 22q11.2 is susceptible to genomic rearrangements and the most frequently reported involve deletions and duplications between low copy repeats LCR22A to LCR22D. Atypical nested deletions and duplications are rarer and can provide a valuable opportunity to investigate the dosage effects of a smaller subset of genes within the 22q11.2 genomic disorder region. Methods We describe thirteen individuals from six families, each with atypical nested duplications within the central 22q11.2 region between LCR22B and LCR22D. We then compared the molecular and clinical data for patients from this study and the few reported atypical duplication cases, to the cases with larger typical duplications between LCR22A and LCR22D. Further, we analyzed genes with the nested region to identify candidates highly enriched in human brain tissues. Results We observed that atypical nested duplications are heterogeneous in size, often familial, and associated with incomplete penetrance and highly variable clinical expressivity. We found that the nested atypical duplications are a possible risk factor for neurodevelopmental phenotypes, particularly for autism spectrum disorder (ASD), speech and language delay, and behavioral abnormalities. In addition, we analyzed genes within the nested region between LCR22B and LCR22D to identify nine genes (ZNF74, KLHL22, MED15, PI4KA, SERPIND1, CRKL, AIFM3, SLC7A4, and BCRP2) with enriched expression in the nervous system, each with unique spatiotemporal patterns in fetal and adult brain tissues. Interestingly, PI4KA is prominently expressed in the brain, and this gene is included either partially or completely in all of our subjects. Conclusion Our findings confirm variable expressivity and incomplete penetrance for atypical nested 22q11.2 duplications and identify genes such as PI4KA to be directly relevant to brain development and disorder. We conclude that further work is needed to elucidate the basis of variable neurodevelopmental phenotypes and to exclude the presence of a second disorder. Our findings contribute to the genotype–phenotype data for atypical nested 22q11.2 duplications, with implications for genetic counseling.
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Affiliation(s)
- Karen J Woodward
- Diagnostic Genomics, PathWest Laboratory Medicine, Perth, Western Australia, Australia.,School of Biomedical Sciences, University of Western Australia, Perth, Western Australia, Australia
| | - Julie Stampalia
- Diagnostic Genomics, PathWest Laboratory Medicine, Perth, Western Australia, Australia
| | - Hannah Vanyai
- The Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, Australia.,Centre for Medical Research, University of Western Australia, Nedlands, Western Australia, Australia
| | - Hashika Rijhumal
- Diagnostic Genomics, PathWest Laboratory Medicine, Perth, Western Australia, Australia
| | - Kim Potts
- Diagnostic Genomics, PathWest Laboratory Medicine, Perth, Western Australia, Australia
| | - Fiona Taylor
- Diagnostic Genomics, PathWest Laboratory Medicine, Perth, Western Australia, Australia
| | - Joanne Peverall
- Diagnostic Genomics, PathWest Laboratory Medicine, Perth, Western Australia, Australia
| | - Tanya Grumball
- Diagnostic Genomics, PathWest Laboratory Medicine, Perth, Western Australia, Australia
| | - Soruba Sivamoorthy
- Diagnostic Genomics, PathWest Laboratory Medicine, Perth, Western Australia, Australia
| | - Hamid Alinejad-Rokny
- The Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, Australia.,Centre for Medical Research, University of Western Australia, Nedlands, Western Australia, Australia
| | - John Wray
- Telethon Kids Institute, University of Western Australia, Perth, Western Australia, Australia
| | - Andrew Whitehouse
- Telethon Kids Institute, University of Western Australia, Perth, Western Australia, Australia
| | - Lakshmi Nagarajan
- Children's Neuroscience Service, Princess Margaret Hospital, Subiaco, Western Australia, Australia.,School of Paediatrics and Child Health, University of Western Australia, Perth, Western Australia, Australia
| | | | - Sabine Afchani
- State Child Development Centre, West Perth, Western Australia, Australia.,Lockridge Child Development Centre, Lockridge, Western Australia, Australia
| | - Matthew Edwards
- School of Medicine, Western Sydney University, Penrith South DC, New South Wales, Australia
| | - Ashleigh Murch
- Diagnostic Genomics, PathWest Laboratory Medicine, Perth, Western Australia, Australia.,School of Biomedical Sciences, University of Western Australia, Perth, Western Australia, Australia
| | - John Beilby
- Diagnostic Genomics, PathWest Laboratory Medicine, Perth, Western Australia, Australia.,School of Biomedical Sciences, University of Western Australia, Perth, Western Australia, Australia
| | - Gareth Baynam
- Genetic Services of Western Australia, Perth, Western Australia, Australia.,Department of Health, Office of Population Health Genomics, Public Health and Clinical Services Division, Perth, Western Australia, Australia.,Institute for Immunology and Infectious Diseases, Murdoch University, Perth, Western Australia, Australia.,Western Australian Register of Developmental Anomalies, Perth, Western Australia, Australia.,Spatial Sciences, Science and Engineering, Curtin University, Perth, Western Australia, Australia.,Telethon Kids Institute, University of Western Australia, Perth, Western Australia, Australia.,School of Paediatrics and Child Health, University of Western Australia, Perth, Western Australia, Australia
| | - Cathy Kiraly-Borri
- Genetic Services of Western Australia, Perth, Western Australia, Australia.,Children's Neuroscience Service, Princess Margaret Hospital, Subiaco, Western Australia, Australia
| | - Fiona McKenzie
- Genetic Services of Western Australia, Perth, Western Australia, Australia.,School of Paediatrics and Child Health, University of Western Australia, Perth, Western Australia, Australia
| | - Julian I T Heng
- Curtin Health Innovation Research Institute and Sarich Neuroscience Institute, Curtin University, Crawley, Western Australia, Australia.,The Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, Australia.,Centre for Medical Research, University of Western Australia, Nedlands, Western Australia, Australia
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11
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Partial microduplication in the histone acetyltransferase complex member KANSL1 is associated with congenital heart defects in 22q11.2 microdeletion syndrome patients. Sci Rep 2017; 7:1795. [PMID: 28496102 PMCID: PMC5431949 DOI: 10.1038/s41598-017-01896-w] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 04/06/2017] [Indexed: 12/16/2022] Open
Abstract
22q11.2 microdeletion syndrome (22q11.2DS) is the most common microdeletion disorder in humans, with an incidence of 1/4000 live births. It is caused by a heterozygous deletion of 1.5–3 Mb on chromosome region 22q11.2. Patients with the deletion present features that include neuropsychiatric problems, craniofacial abnormalities and cardiovascular malformations. However, the phenotype is highly variable and the factors related to the clinical heterogeneity are not fully understood. About 65% of patients with 22q11.2DS have congenital heart defects (CHD). The main goal of this study was to identify common CNVs in 22q11.2DS patients that could be associated with the incomplete penetrance of CHD. Analysis of genomic DNA from 253 patients with 22q11.2DS using array technology showed an association between a microduplication located in region 17q21.31 and CHD (p-value = 0.023, OR = 2.75, 95% CI = 1.17–7.03). This region includes the first three exons of KANSL1 gene. Bioinformatic analysis showed that KANSL1 and CRKL, a gene in the commonly deleted region of 22q11.2DS, are part of the same regulatory module in a miRNA-mRNA network. These results show that a KANSL1 microduplication, in combination with the 22q11.2 deletion, is associated with increased risk of CHD in these patients, suggesting that KANSL1 plays a role as a modifier gene in 22q11.2DS patients.
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12
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Prasad S, Katina S, Hennessy RJ, Murphy KC, Bowman AW, Waddington JL. Craniofacial dysmorphology in 22q11.2 deletion syndrome by 3D laser surface imaging and geometric morphometrics: illuminating the developmental relationship to risk for psychosis. Am J Med Genet A 2016; 167A:529-36. [PMID: 25691406 PMCID: PMC4737262 DOI: 10.1002/ajmg.a.36893] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 10/31/2014] [Indexed: 11/17/2022]
Abstract
Persons with 22q11.2 deletion syndrome (22q11.2DS) are characterized inter alia by facial dysmorphology and greatly increased risk for psychotic illness. Recent studies indicate facial dysmorphology in adults with schizophrenia. This study evaluates the extent to which the facial dysmorphology of 22q11.2DS is similar to or different from that evident in schizophrenia. Twenty‐one 22q11.2DS‐sibling control pairs were assessed using 3D laser surface imaging. Geometric morphometrics was applied to 30 anatomical landmarks, 480 geometrically homologous semi‐landmarks on curves and 1720 semi‐landmarks interpolated on each 3D facial surface. Principal component (PC) analysis of overall shape space indicated PC2 to strongly distinguish 22q11.2DS from controls. Visualization of PC2 indicated 22q11.2DS and schizophrenia to be similar in terms of overall widening of the upper face, lateral displacement of the eyes/orbits, prominence of the cheeks, narrowing of the lower face, narrowing of nasal prominences and posterior displacement of the chin; they differed in terms of facial length (increased in 22q11.2DS, decreased in schizophrenia), mid‐face and nasal prominences (displaced upwards and outwards in 22q11.2DS, less prominent in schizophrenia); lips (more prominent in 22q11.2DS; less prominent in schizophrenia) and mouth (open mouth posture in 22q11.2DS; closed mouth posture in schizophrenia). These findings directly implicate dysmorphogenesis in a cerebral‐craniofacial domain that is common to 22q11.2DS and schizophrenia and which may repay further clinical and genetic interrogation in relation to the developmental origins of psychotic illness. © 2015 The Authors. American Journal of Medical Genetics Part A Published by Wiley Periodicals, Inc.
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Affiliation(s)
- Sarah Prasad
- Department of Psychiatry, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, Ireland
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13
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Sinha T, Li D, Théveniau-Ruissy M, Hutson MR, Kelly RG, Wang J. Loss of Wnt5a disrupts second heart field cell deployment and may contribute to OFT malformations in DiGeorge syndrome. Hum Mol Genet 2014; 24:1704-16. [PMID: 25410658 DOI: 10.1093/hmg/ddu584] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Outflow tract (OFT) malformation accounts for ∼30% of human congenital heart defects and manifests frequently in TBX1 haplo-insufficiency associated DiGeorge (22q11.2 deletion) syndrome. OFT myocardium originates from second heart field (SHF) progenitors in the pharyngeal and splanchnic mesoderm (SpM), but how these progenitors are deployed to the OFT is unclear. We find that SHF progenitors in the SpM gradually gain epithelial character and are deployed to the OFT as a cohesive sheet. Wnt5a, a non-canonical Wnt, is expressed specifically in the caudal SpM and may regulate oriented cell intercalation to incorporate SHF progenitors into an epithelial-like sheet, thereby generating the pushing force to deploy SHF cells rostrally into the OFT. Using enhancer trap and Cre transgenes, our lineage tracing experiments show that in Wnt5a null mice, SHF progenitors are trapped in the SpM and fail to be deployed to the OFT efficiently, resulting in a reduction in the inferior OFT myocardial wall and its derivative, subpulmonary myocardium. Concomitantly, the superior OFT and subaortic myocardium are expanded. Finally, in chick embryos, blocking the Wnt5a function in the caudal SpM perturbs polarized elongation of SHF progenitors, and compromises their deployment to the OFT. Collectively, our results highlight a critical role for Wnt5a in deploying SHF progenitors from the SpM to the OFT. Given that Wnt5a is a putative transcriptional target of Tbx1, and the similar reduction of subpulmonary myocardium in Tbx1 mutant mice, our results suggest that perturbing Wnt5a-mediated SHF deployment may be an important pathogenic mechanism contributing to OFT malformations in DiGeorge syndrome.
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Affiliation(s)
- Tanvi Sinha
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Alabama, USA
| | - Ding Li
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Alabama, USA
| | | | - Mary R Hutson
- Department of Pediatrics, Duke University School of Medicine, Durham, North Carolina
| | - Robert G Kelly
- Aix Marseille Université, CNRS, IBDM UMR 7288, Marseille 13288, France
| | - Jianbo Wang
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Alabama, USA,
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14
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Dupont C, Grati FR, Choy KW, Jaillard S, Toutain J, Maurin ML, Martínez-Conejero JA, Beneteau C, Coussement A, Molina-Gomes D, Horelli-Kuitunen N, Aboura A, Tabet AC, Besseau-Ayasse J, Bessieres-Grattagliano B, Simoni G, Ayala G, Benzacken B, Vialard F. Prenatal diagnosis of 24 cases of microduplication 22q11.2: an investigation of phenotype-genotype correlations. Prenat Diagn 2014; 35:35-43. [PMID: 25118001 DOI: 10.1002/pd.4478] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 07/29/2014] [Accepted: 08/06/2014] [Indexed: 12/24/2022]
Abstract
OBJECTIVE Microduplication 22q11.2 is primarily characterized by a highly variable clinical phenotype, which ranges from apparently normal or slightly dysmorphic features (in the presence or absence of learning disorders) to severe malformations with profound mental retardation. Hence, genetic counseling is particularly challenging when microduplication 22q11.2 is identified in a prenatal diagnosis. Here, we report on 24 prenatal cases of microduplication 22q11.2. METHODS Seventeen of the cases were also reanalyzed by microarray analysis, in order to determine copy number variations (CNVs, which are thought to influence expressivity). We also searched for possible correlations between fetal phenotypes, indications for invasive prenatal diagnosis, inheritance, and pregnancy outcomes. RESULTS Of the 24 cases, 15 were inherited, six occurred de novo, and three were of unknown origin. Termination of pregnancy occurred in seven cases and was mainly decided on the basis of ultrasound findings. Moreover, additional CNVs were found in some patients and we try to make a genotype-phenotype correlation. CONCLUSION We discuss the complexity of genetic counseling for microduplication 22q11.2 and comment on possible explanations for the clinical heterogeneity of this syndrome. In particular, we assessed the co-existence of additional CNVs and their contribution to phenotypic variations in chromosome 22q11.2 microduplication syndrome.
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Affiliation(s)
- Céline Dupont
- Unité de Cytogénétique, Département de Génétique, Hôpital Robert Debré-AP-HP, CHU Paris, Paris, France
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15
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Karunamuni GH, Ma P, Gu S, Rollins AM, Jenkins MW, Watanabe M. Connecting teratogen-induced congenital heart defects to neural crest cells and their effect on cardiac function. BIRTH DEFECTS RESEARCH. PART C, EMBRYO TODAY : REVIEWS 2014; 102:227-50. [PMID: 25220155 PMCID: PMC4238913 DOI: 10.1002/bdrc.21082] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 08/26/2014] [Indexed: 12/26/2022]
Abstract
Neural crest cells play many key roles in embryonic development, as demonstrated by the abnormalities that result from their specific absence or dysfunction. Unfortunately, these key cells are particularly sensitive to abnormalities in various intrinsic and extrinsic factors, such as genetic deletions or ethanol-exposure that lead to morbidity and mortality for organisms. This review discusses the role identified for a segment of neural crest in regulating the morphogenesis of the heart and associated great vessels. The paradox is that their derivatives constitute a small proportion of cells to the cardiovascular system. Findings supporting that these cells impact early cardiac function raises the interesting possibility that they indirectly control cardiovascular development at least partially through regulating function. Making connections between insults to the neural crest, cardiac function, and morphogenesis is more approachable with technological advances. Expanding our understanding of early functional consequences could be useful in improving diagnosis and testing therapies.
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Affiliation(s)
- Ganga H. Karunamuni
- Department of Pediatrics, Case Western Reserve University School of Medicine, Case Medical Center Division of Pediatric Cardiology, Rainbow Babies and Children’s Hospital, Cleveland OH 44106
| | - Pei Ma
- Department of Biomedical Engineering, Case Western Reserve University School of Engineering, Cleveland OH 44106
| | - Shi Gu
- Department of Biomedical Engineering, Case Western Reserve University School of Engineering, Cleveland OH 44106
| | - Andrew M. Rollins
- Department of Biomedical Engineering, Case Western Reserve University School of Engineering, Cleveland OH 44106
| | - Michael W. Jenkins
- Department of Pediatrics, Case Western Reserve University School of Medicine, Case Medical Center Division of Pediatric Cardiology, Rainbow Babies and Children’s Hospital, Cleveland OH 44106
- Department of Biomedical Engineering, Case Western Reserve University School of Engineering, Cleveland OH 44106
| | - Michiko Watanabe
- Department of Pediatrics, Case Western Reserve University School of Medicine, Case Medical Center Division of Pediatric Cardiology, Rainbow Babies and Children’s Hospital, Cleveland OH 44106
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16
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Epigenetics in cardiac development, function, and disease. Cell Tissue Res 2014; 356:585-600. [DOI: 10.1007/s00441-014-1887-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 04/02/2014] [Indexed: 12/13/2022]
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17
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Basson MA. Epistatic interactions between Chd7 and Fgf8 during cerebellar development: Implications for CHARGE syndrome. Rare Dis 2014; 2:e28688. [PMID: 25054096 PMCID: PMC4091603 DOI: 10.4161/rdis.28688] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Revised: 03/20/2014] [Accepted: 03/27/2014] [Indexed: 12/28/2022] Open
Abstract
CHARGE syndrome is a rare, autosomal dominant condition caused by mutations in the CHD7 gene. Although central nervous system defects have been reported, the detailed description and analysis of these anomalies in CHARGE syndrome patients lag far behind the description of other, more easily observed defects. We recently described cerebellar abnormalities in CHARGE syndrome patients and used mouse models to identify the underlying causes. Our studies identified altered expression of the homeobox genes Otx2 and Gbx2 in the developing neural tube of Chd7−/− embryos. Furthermore, we showed that the expression of Fgf8 is sensitive to Chd7 gene dosage and demonstrated an epistatic relationship between these genes during cerebellar vermis development. These findings provided, for the first time, an example of cerebellar vermis hypoplasia in a human syndrome that can be linked to deregulated FGF signaling. I discuss some of these observations and their implications for CHARGE syndrome.
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Affiliation(s)
- M Albert Basson
- Department of Craniofacial Development and Stem Cell Biology; King's College London; Guy's Hospital Tower Wing; London, UK
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18
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Abstract
Otitis media (OM) is a common cause of childhood hearing loss. The large medical costs involved in treating this condition have meant that research to understand the pathology of this disease and identify new therapeutic interventions is important. There is evidence that susceptibility to OM has a significant genetic component, although little is known about the key genetic pathways involved. Mouse models for disease have become an important resource to understand a variety of human pathologies, including OM, due to the ability to easily manipulate their genetic components. This has enabled researchers to create models of acute OM, and has aided in the identification of a number of new genes associated with chronic disease, through the use of mutagenesis programs. The use of mouse models has identified a number of key molecular signalling pathways involved in the development of this condition, with genes identified from models shown to be associated with human OM.
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19
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Wang J, Bai Y, Li H, Greene SB, Klysik E, Yu W, Schwartz RJ, Williams TJ, Martin JF. MicroRNA-17-92, a direct Ap-2α transcriptional target, modulates T-box factor activity in orofacial clefting. PLoS Genet 2013; 9:e1003785. [PMID: 24068957 PMCID: PMC3777996 DOI: 10.1371/journal.pgen.1003785] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Accepted: 07/25/2013] [Indexed: 01/23/2023] Open
Abstract
Among the most common human congenital anomalies, cleft lip and palate (CL/P) affects up to 1 in 700 live births. MicroRNA (miR)s are small, non-coding RNAs that repress gene expression post-transcriptionally. The miR-17-92 cluster encodes six miRs that have been implicated in human cancers and heart development. We discovered that miR-17-92 mutant embryos had severe craniofacial phenotypes, including incompletely penetrant CL/P and mandibular hypoplasia. Embryos that were compound mutant for miR-17-92 and the related miR-106b-25 cluster had completely penetrant CL/P. Expression of Tbx1 and Tbx3, the DiGeorge/velo-cardio-facial (DGS) and Ulnar-mammary syndrome (UMS) disease genes, was expanded in miR-17-92 mutant craniofacial structures. Both Tbx1 and Tbx3 had functional miR seed sequences that mediated gene repression. Analysis of miR-17-92 regulatory regions uncovered conserved and functional AP-2α recognition elements that directed miR-17-92 expression. Together, our data indicate that miR-17-92 modulates expression of critical T-box transcriptional regulators during midface development and is itself a target of Bmp-signaling and the craniofacial pioneer factor AP-2α. Our data are the first genetic evidence that an individual miR or miR cluster is functionally important in mammalian CL/P.
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Affiliation(s)
- Jun Wang
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Yan Bai
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
- Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas, United States of America
| | - Hong Li
- Department of Craniofacial Biology, UC Denver, Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Stephanie B. Greene
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Elzbieta Klysik
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Wei Yu
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, United States of America
| | - Robert J. Schwartz
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, United States of America
- Texas Heart Institute, Houston, Texas, United States of America
| | - Trevor J. Williams
- Department of Craniofacial Biology, UC Denver, Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - James F. Martin
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
- Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas, United States of America
- Texas Heart Institute, Houston, Texas, United States of America
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America
- * E-mail:
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20
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Digilio MC, Luca AD, Lepri F, Guida V, Ferese R, Dentici ML, Angioni A, Marino B, Dallapiccola B. JAG1 mutation in a patient with deletion 22q11.2 syndrome and tetralogy of Fallot. Am J Med Genet A 2013; 161A:3133-6. [PMID: 23956173 DOI: 10.1002/ajmg.a.36148] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2012] [Accepted: 06/21/2013] [Indexed: 11/09/2022]
Abstract
Deletion 22q11.2 (del22q11.2) syndrome, also known as DiGeorge/Velo-cardio-facial syndrome (DG/VCFS), and Alagille syndrome are genetic disorders characteristically associated with congenital heart defects (CHDs). We report on a patient with tetralogy of Fallot (TOF) and clinical features of DG/VCFS, hemizygous for del22q11.2 and heterozygous for the 2810G > A (p.Arg937Gln) mutation in the JAG1 gene associated with Alagille syndrome. The clinical features of del22q11.2 syndrome are present in the patient, including facial anomalies, typical TOF, speech delay with hypernasal voice, and learning difficulties. TOF and mild hepatic involvement, consisting of slightly elevated aminotransferase conjugated bilirubin levels, were the only features of Alagille syndrome in our patient. The anatomic type of TOF displayed no distinctive recognizable pattern for either DG/VCFS or Alagille syndrome. It is likely that hemizygosity of the TBX1 gene was causally related to TOF in this patient, although a synergistic pathogenic role of the JAG1 gene mutation in causing the heart defect cannot be excluded. JAG1 mutations have been previously detected in patients with nonsyndromic TOF and recent molecular evidence supports the cumulative effect of multiple genetic defects in the etiology of human malformations. We hypothesize that a similar mechanism could be present in this patient with del22q11.2 syndrome associated with a JAG1 missense mutation acting as possible modifier factor for TOF.
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21
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Nevis K, Obregon P, Walsh C, Guner-Ataman B, Burns CG, Burns CE. Tbx1 is required for second heart field proliferation in zebrafish. Dev Dyn 2013; 242:550-9. [PMID: 23335360 DOI: 10.1002/dvdy.23928] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 01/03/2013] [Accepted: 01/03/2013] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND The mammalian outflow tract (OFT) and primitive right ventricle arise by accretion of newly differentiated cells to the arterial pole of the heart tube from multi-potent progenitor cells of the second heart field (SHF). While mounting evidence suggests that the genetic pathways regulating SHF development are highly conserved in zebrafish, this topic remains an active area of investigation. RESULTS Here, we extend previous observations demonstrating that zebrafish tbx1 (van gogh, vgo) mutants show ventricular and OFT defects consistent with a conserved role in SHF-mediated cardiogenesis. Surprisingly, we reveal through double in situ analyses that tbx1 transcripts are excluded from cardiac progenitor cells and differentiated cardiomyocytes, suggesting a non-autonomous role in SHF development. Further, we find that the diminutive ventricle in vgo animals results from a 25% decrease in cardiomyocyte number that occurs subsequent to heart tube stages. Lastly, we report that although SHF progenitors are specified in the absence of Tbx1, they fail to be maintained due to compromised SHF progenitor cell proliferation. CONCLUSIONS These studies highlight conservation of Tbx1 function in zebrafish SHF biology.
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Affiliation(s)
- Kathleen Nevis
- Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, USA
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22
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Keyte A, Hutson MR. The neural crest in cardiac congenital anomalies. Differentiation 2012; 84:25-40. [PMID: 22595346 DOI: 10.1016/j.diff.2012.04.005] [Citation(s) in RCA: 161] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 04/02/2012] [Accepted: 04/04/2012] [Indexed: 02/07/2023]
Abstract
This review discusses the function of neural crest as they relate to cardiovascular defects. The cardiac neural crest cells are a subpopulation of cranial neural crest discovered nearly 30 years ago by ablation of premigratory neural crest. The cardiac neural crest cells are necessary for normal cardiovascular development. We begin with a description of the crest cells in normal development, including their function in remodeling the pharyngeal arch arteries, outflow tract septation, valvulogenesis, and development of the cardiac conduction system. The cells are also responsible for modulating signaling in the caudal pharynx, including the second heart field. Many of the molecular pathways that are known to influence specification, migration, patterning and final targeting of the cardiac neural crest cells are reviewed. The cardiac neural crest cells play a critical role in the pathogenesis of various human cardiocraniofacial syndromes such as DiGeorge, Velocardiofacial, CHARGE, Fetal Alcohol, Alagille, LEOPARD, and Noonan syndromes, as well as Retinoic Acid Embryopathy. The loss of neural crest cells or their dysfunction may not always directly cause abnormal cardiovascular development, but are involved secondarily because crest cells represent a major component in the complex tissue interactions in the head, pharynx and outflow tract. Thus many of the human syndromes linking defects in the heart, face and brain can be better understood when considered within the context of a single cardiocraniofacial developmental module with the neural crest being a key cell type that interconnects the regions.
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Affiliation(s)
- Anna Keyte
- Department of Pediatrics (Neonatology), Neonatal-Perinatal Research Institute, Box 103105, Duke University Medical Center, Durham, NC 27710, USA
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23
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Halder A, Jain M, Chaudhary I, Varma B. Chromosome 22q11.2 microdeletion in monozygotic twins with discordant phenotype and deletion size. Mol Cytogenet 2012; 5:13. [PMID: 22413934 PMCID: PMC3325853 DOI: 10.1186/1755-8166-5-13] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Accepted: 03/13/2012] [Indexed: 02/01/2023] Open
Abstract
We report on a pair of male monozygotic twins with 22q11.2 microdeletion, discordant phenotype and discordant deletion size. The second twin had findings suggestive of DiGeorge syndrome, while the first twin had milder anomalies without any cardiac malformation. The second twin had presented with intractable convulsion, cyanosis and cardiovascular failure in the fourth week of life and expired on the sixth week of life, whereas the first twin had some characteristic facial appearance with developmental delay but no other signs of the 22q11.2 microdeletion syndrome including cardiovascular malformation. The fluorescence in situ hybridization (FISH) analysis had shown a microdeletion on the chromosome 22q11.2 in both twins. The interphase FISH did not find any evidence for the mosaicism. The genomic DNA microarray analysis, using HumanCytoSNP-12 BeadChip (Illumina), was identical between the twins except different size of deletion of 22q11.2. The zygosity using HumanCytoSNP-12 BeadChip (Illumina) microarray analysis suggested monozygosity. This observation indicates that altered size of the deletion may be the underlying etiology for the discordance in phenotype in monozygotic twins. We think early post zygotic events (mitotic non-allelic homologous recombination) could have been played a role in the alteration of 22q11.2 deletion size and, thus phenotypic variability in the monozygotic twins.
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Affiliation(s)
- Ashutosh Halder
- Department of Reproductive Biology, All India Institute of Medical Sciences, New Delhi, India
| | - Manish Jain
- Department of Reproductive Biology, All India Institute of Medical Sciences, New Delhi, India
| | - Isha Chaudhary
- Department of Reproductive Biology, All India Institute of Medical Sciences, New Delhi, India
| | - Binuja Varma
- The Centre for Genomic Application, 254 Okhla Industrial Area Phase III, New Delhi, India
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24
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Zhou J, Pashmforoush M, Sucov HM. Endothelial neuropilin disruption in mice causes DiGeorge syndrome-like malformations via mechanisms distinct to those caused by loss of Tbx1. PLoS One 2012; 7:e32429. [PMID: 22396765 PMCID: PMC3292556 DOI: 10.1371/journal.pone.0032429] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Accepted: 01/30/2012] [Indexed: 11/20/2022] Open
Abstract
The spectrum of human congenital malformations known as DiGeorge syndrome (DGS) is replicated in mice by mutation of Tbx1. Vegfa has been proposed as a modifier of DGS, based in part on the occurrence of comparable phenotypes in Tbx1 and Vegfa mutant mice. Many additional genes have been shown to cause DGS-like phenotypes in mice when mutated; these generally intersect in some manner with Tbx1, and therefore impact the same developmental processes in which Tbx1 itself is involved. In this study, using Tie2Cre, we show that endothelial-specific mutation of the gene encoding the VEGFA coreceptor neuropilin-1 (Nrp1) also replicates the most prominent terminal phenotypes that typify DGS. However, the developmental etiologies of these defects are fundamentally different from those caused by absence of TBX1. In Tie2Cre/Nrp1 mutants, initial pharyngeal organization is normal but subsequent pharyngeal organ growth is impaired, second heart field differentiation is normal but cardiac outflow tract cushion organization is distorted, neural crest cell migration is normal, and palatal mesenchyme proliferation is impaired with no change in apoptosis. Our results demonstrate that impairment of VEGF-dependent endothelial pathways leads to a spectrum of DiGeorge syndrome-type malformations, through processes that are distinguishable from those controlled by Tbx1.
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Affiliation(s)
| | | | - Henry M. Sucov
- Broad Center for Regenerative Medicine and Stem Cell Research, University of Southern California Keck School of Medicine, Los Angeles, California, United States of America
- * E-mail:
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Mesbah K, Rana MS, Francou A, van Duijvenboden K, Papaioannou VE, Moorman AF, Kelly RG, Christoffels VM. Identification of a Tbx1/Tbx2/Tbx3 genetic pathway governing pharyngeal and arterial pole morphogenesis. Hum Mol Genet 2011; 21:1217-29. [PMID: 22116936 DOI: 10.1093/hmg/ddr553] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The 22q11.2 deletion syndrome (22q11.2DS) is the most common microdeletion disorder and is characterized by abnormal development of the pharyngeal apparatus and heart. Cardiovascular malformations (CVMs) affecting the outflow tract (OFT) are frequently observed in 22q11.2DS and are among the most commonly occurring heart defects. The gene encoding T-box transcription factor 1 (Tbx1) has been identified as a major candidate for 22q11.2DS. However, CVMs are generally considered to have a multigenic basis and single-gene mutations underlying these malformations are rare. The T-box family members Tbx2 and Tbx3 are individually required in regulating aspects of OFT and pharyngeal development. Here, using expression and three-dimensional reconstruction analysis, we show that Tbx1 and Tbx2/Tbx3 are largely uniquely expressed but overlap in the caudal pharyngeal mesoderm during OFT development, suggesting potential combinatorial requirements. Cross-regulation between Tbx1 and Tbx2/Tbx3 was analyzed using mouse genetics and revealed that Tbx1 deficiency affects Tbx2 and Tbx3 expression in neural crest-derived cells and pharyngeal mesoderm, whereas Tbx2 and Tbx3 function redundantly upstream of Tbx1 and Hh ligand expression in pharyngeal endoderm and bone morphogenetic protein- and fibroblast growth factor-signaling in cardiac progenitors. Moreover, in vivo, we show that loss of two of the three genes results in severe pharyngeal hypoplasia and heart tube extension defects. These findings reveal an indispensable T-box gene network governing pharyngeal and OFT development and identify TBX2 and TBX3 as potential modifier genes of the cardiopharyngeal phenotypes found in TBX1-haploinsufficient 22q11.2DS patients.
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Affiliation(s)
- Karim Mesbah
- Developmental Biology Institute of Marseille-Luminy, Aix-Marseille University, CNRS UMR6216, Marseille, France
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Furniss F, Biswas AB, Gumber R, Singh N. Cognitive phenotype of velocardiofacial syndrome: a review. RESEARCH IN DEVELOPMENTAL DISABILITIES 2011; 32:2206-2213. [PMID: 21764255 DOI: 10.1016/j.ridd.2011.05.039] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Revised: 05/26/2011] [Accepted: 05/30/2011] [Indexed: 05/31/2023]
Abstract
The behavioural phenotype of velocardiofacial syndrome (VCFS), one of the most common human multiple anomaly syndromes, includes developmental disabilities, frequently including intellectual disability (ID) and high risk of diagnosis of psychotic disorders including schizophrenia. VCFS may offer a model of the relationship between ID and risk of major mental health difficulties. This paper reviews literature on the cognitive phenotype and its relationship with a polymorphism of the gene coding for catechol O-methyltransferase (COMT), a gene haploinsufficient in VCFS which modulates prefrontal dopamine levels. Principal features of the variable cognitive phenotype of VCFS in young people are ID, superiority of verbal over performance I.Q. and verbal over visuospatial memory, and difficulties with number and object magnitude comparisons, time perception and memory for serial order, and orienting of attention. Despite some improvements with age, problems with higher order attentional tasks involving planning persist, possibly modulated by COMT activity levels. Candidate cognitive endophenotypes include problems with retrieval of contextual information from memory and in executive control and focussing of attention. Longitudinal research using common core batteries of psychometric assessments, and experimental measures of cognitive function capable of direct translation for use with animal models, will further advance understanding of the developmental dynamics of VCFS.
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Affiliation(s)
- Frederick Furniss
- The Hesley Group, Doncaster, UK & School of Psychology, University of Leicester, Hesley Hall, Stripe Road, Tickhill, Doncaster DN11 9HH, United Kingdom.
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Guo C, Sun Y, Zhou B, Adam RM, Li X, Pu WT, Morrow BE, Moon A, Li X. A Tbx1-Six1/Eya1-Fgf8 genetic pathway controls mammalian cardiovascular and craniofacial morphogenesis. J Clin Invest 2011; 121:1585-95. [PMID: 21364285 DOI: 10.1172/jci44630] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Accepted: 01/05/2011] [Indexed: 12/16/2022] Open
Abstract
Shared molecular programs govern the formation of heart and head during mammalian embryogenesis. Development of both structures is disrupted in human chromosomal microdeletion of 22q11.2 (del22q11), which causes DiGeorge syndrome (DGS) and velo-cardio-facial syndrome (VCFS). Here, we have identified a genetic pathway involving the Six1/Eya1 transcription complex that regulates cardiovascular and craniofacial development. We demonstrate that murine mutation of both Six1 and Eya1 recapitulated most features of human del22q11 syndromes, including craniofacial, cardiac outflow tract, and aortic arch malformations. The mutant phenotypes were attributable in part to a reduction of fibroblast growth factor 8 (Fgf8), which was shown to be a direct downstream effector of Six1 and Eya1. Furthermore, we showed that Six1 and Eya1 genetically interacted with Fgf8 and the critical del22q11 gene T-box transcription factor 1 (Tbx1) in mice. Together, these findings reveal a Tbx1-Six1/Eya1-Fgf8 genetic pathway that is crucial for mammalian cardiocraniofacial morphogenesis and provide insights into the pathogenesis of human del22q11 syndromes.
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Affiliation(s)
- Chaoshe Guo
- Department of Urology, Children's Hospital Boston, and Department of Surgery and Pathology, Harvard Medical School, Boston, Massachusetts 02115, USA
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Sambasivan R, Kuratani S, Tajbakhsh S. An eye on the head: the development and evolution of craniofacial muscles. Development 2011; 138:2401-15. [DOI: 10.1242/dev.040972] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Skeletal muscles exert diverse functions, enabling both crushing with great force and movement with exquisite precision. A remarkably distinct repertoire of genes and ontological features characterise this tissue, and recent evidence has shown that skeletal muscles of the head, the craniofacial muscles, are evolutionarily, morphologically and molecularly distinct from those of the trunk. Here, we review the molecular basis of craniofacial muscle development and discuss how this process is different to trunk and limb muscle development. Through evolutionary comparisons of primitive chordates (such as amphioxus) and jawless vertebrates (such as lampreys) with jawed vertebrates, we also provide some clues as to how this dichotomy arose.
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Affiliation(s)
- Ramkumar Sambasivan
- Institut Pasteur, Stem Cells and Development, Paris, F-75015, France
- CNRS URA 2578, 25 rue du Dr Roux, Paris, F-75015, France
| | - Shigeru Kuratani
- Laboratory for Evolutionary Morphology, RIKEN Center for Developmental Biology, 2-2-3 Minatojima-minami, Chuo-ku, Kobe, Hyogo 650-0047, Japan
| | - Shahragim Tajbakhsh
- Institut Pasteur, Stem Cells and Development, Paris, F-75015, France
- CNRS URA 2578, 25 rue du Dr Roux, Paris, F-75015, France
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Parisot P, Mesbah K, Théveniau-Ruissy M, Kelly RG. Tbx1, subpulmonary myocardium and conotruncal congenital heart defects. ACTA ACUST UNITED AC 2011; 91:477-84. [PMID: 21591244 DOI: 10.1002/bdra.20803] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Revised: 01/25/2011] [Accepted: 02/09/2011] [Indexed: 12/22/2022]
Abstract
Conotruncal congenital heart defects, including defects in septation and alignment of the ventricular outlets, account for approximately a third of all congenital heart defects. Failure of the left ventricle to obtain an independent outlet results in incomplete separation of systemic and pulmonary circulation at birth. The embryonic outflow tract, a transient cylinder of myocardium connecting the embryonic ventricles to the aortic sac, plays a critical role in this process during normal development. The outflow tract (OFT) is derived from a population of cardiac progenitor cells called the second heart field that contributes to the arterial pole of the heart tube during cardiac looping. During septation, the OFT is remodeled to form the base of the ascending aorta and pulmonary trunk. Tbx1, the major candidate gene for DiGeorge syndrome, is a critical transcriptional regulator of second heart field development. DiGeorge syndrome patients are haploinsufficient for Tbx1 and present a spectrum of conotruncal anomalies including tetralogy of Fallot, pulmonary atresia, and common arterial trunk. In this review, we focus on the role of Tbx1 in the regulation of second heart field deployment and, in particular, in the development of a specific population of myocardial cells at the base of the pulmonary trunk. Recent data characterizing additional properties and regulators of development of this region of the heart, including the retinoic acid, hedgehog, and semaphorin signaling pathways, are discussed. These findings identify future subpulmonary myocardium as the clinically relevant component of the second heart field and provide new mechanistic insight into a spectrum of common conotruncal congenital heart defects.
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Affiliation(s)
- Pauline Parisot
- Developmental Biology Institute of Marseilles-Luminy, UMR 6216/CNRS, Université de la Méditerranée, Marseilles, France
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Toth G, Zraly CB, Thomson TL, Jones C, Lapetino S, Muraskas J, Zhang J, Dingwall AK. Congenital anomalies and rhabdoid tumor associated with 22q11 germline deletion and somatic inactivation of the SMARCB1 tumor suppressor. Genes Chromosomes Cancer 2011; 50:379-88. [PMID: 21412926 DOI: 10.1002/gcc.20862] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Accepted: 01/26/2011] [Indexed: 12/31/2022] Open
Abstract
The most common microdeletion in humans involves the 22q11 region. Congenital anomalies associated with 22q11 loss include cardiac and facial defects. Less frequent is the co-presentation of malignant rhabdoid tumors that are highly aggressive childhood malignancies typically found in renal or extra-renal soft tissues and central nervous system. A newborn patient presented with multiple congenital anomalies consistent with 22q11 deletion syndrome including cleft lip and palate, ear tags and ventricular septal defects co-presenting with an axillary rhabdoid tumor. Comparative genomic hybridization revealed a 2.8 Mb germline deletion in the 22q11.2 region containing genes required for normal fetal development and the SMARCB1 tumor suppressor gene. Analysis of tumor DNA revealed a somatic deletion of exon 7 in the second allele of SMARCB1. Expression of SMARCB1 was absent, while tumor markers including MYC, GFAP, and CLAUDIN-6 were upregulated. The presence of tandem oriented BCRL modules located within interspersed low copy repeat elements throughout the 22q11 distal region may predispose this area for microdeletions through nonalleleic homologous recombination.
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Affiliation(s)
- George Toth
- Stritch School of Medicine, Loyola University of Chicago, Maywood, IL 60153, USA
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Gongal PA, French CR, Waskiewicz AJ. Aberrant forebrain signaling during early development underlies the generation of holoprosencephaly and coloboma. Biochim Biophys Acta Mol Basis Dis 2010; 1812:390-401. [PMID: 20850526 DOI: 10.1016/j.bbadis.2010.09.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Accepted: 09/08/2010] [Indexed: 01/10/2023]
Abstract
In this review, we highlight recent literature concerning the signaling mechanisms underlying the development of two neural birth defects, holoprosencephaly and coloboma. Holoprosencephaly, the most common forebrain defect, occurs when the cerebral hemispheres fail to separate and is typically associated with mispatterning of embryonic midline tissue. Coloboma results when the choroid fissure in the eye fails to close. It is clear that Sonic hedgehog (Shh) signaling regulates both forebrain and eye development, with defects in Shh, or components of the Shh signaling cascade leading to the generation of both birth defects. In addition, other intercellular signaling pathways are known factors in the incidence of holoprosencephaly and coloboma. This review will outline recent advances in our understanding of forebrain and eye embryonic pattern formation, with a focus on zebrafish studies of Shh and retinoic acid pathways. Given the clear overlap in the mechanisms that generate both diseases, we propose that holoprosencephaly and coloboma can represent mild and severe aspects of single phenotypic spectrum resulting from aberrant forebrain development. This article is part of a Special Issue entitled Zebrafish Models of Neurological Diseases.
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Affiliation(s)
- Patricia A Gongal
- Department of Biological Sciences, University of Alberta, Edmonton, Canada
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Abstract
OBJECTIVE Within the last decade or so, there has been an acceleration of research attempting to connect specific genetic lesions to the patterns of brain structure and activation. This article comments on observations that have been made based on these recent data and discusses their importance for the field of investigations into developmental disorders. METHODS In making these observations, the authors focus on one specific genomic lesion, the well-studied, yet still incompletely understood, 22q11.2 deletion syndrome. RESULTS The authors demonstrate the degree of variability in the phenotype that occurs at both the brain and behavioral levels of genomic disorders and describe how this variability is, on close inspection, represented at the genomic level. CONCLUSION The authors emphasize the importance of combining genetic/genomic analyses and neuroimaging for research and for future clinical diagnostic purposes and for the purposes of developing individualized, patient-tailored treatment and remediation approaches.
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Tan TY, Gordon CT, Amor DJ, Farlie PG. Developmental perspectives on copy number abnormalities of the 22q11.2 region. Clin Genet 2010; 78:201-18. [DOI: 10.1111/j.1399-0004.2010.01456.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Scambler PJ. 22q11 deletion syndrome: a role for TBX1 in pharyngeal and cardiovascular development. Pediatr Cardiol 2010; 31:378-90. [PMID: 20054531 DOI: 10.1007/s00246-009-9613-0] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Accepted: 12/07/2009] [Indexed: 12/24/2022]
Abstract
Tbx1 is a member of the Tbox family of binding domain transcription factors. TBX1 maps within the region of 22q11 deleted in humans with DiGeorge or velocardiofacial syndrome. Mice haploinsufficient for Tbx1 have phenotypes that recapitulate major features of the syndrome, notably abnormal growth and remodelling of the pharyngeal arch arteries. The Tbx1 haploinsufficiency phenotype is modified by genetic background and by mutations in putative downstream targets. Homozygous null mutations of Tbx1 have more severe defects including failure of outflow tract septation, and absence of the caudal pharyngeal arches. Tbx1 is a transcriptional activator, and loss of this activity has been linked to alterations in the expression of various genes involved in cardiovascular morphogenesis. In particular, Fgf and retinoic acid signalling are dysregulated in Tbx1 mutants. This article summarises the tissue specific and temporal requirements for Tbx1, and attempts to synthesis what is know about the developmental pathways under its control.
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Affiliation(s)
- Peter J Scambler
- Molecular Medicine Unit, Institute of Child Health, 30, Guilford St., London WC1N 1EH, UK.
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Abstract
BACKGROUND Despite the substantial heritability of the psychoses and their genuine public health burden, the applicability of the genomic approach in psychiatry has been strongly questioned or prematurely dismissed. METHODS selective review of the recent literature on molecular genetic and genomic approaches to the psychoses including the early output from genome-wide association studies and the genomic analysis of DNA structural variation. RESULTS Susceptibility variants at strong candidate genes have been identified including neuregulin, dysbindin, DISC1 and neurexin 1. Rare but highly penetrant copy number variants and new mutations affecting genes involved in neurodevelopment, cell signalling and synaptic function have been described showing some overlapping genetic architecture with other developmental disorders including autism. The de-novo mutations described offer an explanation for the familial sporadic divide and the persistence of schizophrenia in the population. The functional effects of risk variants at the level of cognition and connectivity has been described and recently, ZNF804A has been identified, and the MHC re-identified as risk loci, and it has been shown that at least a third of the variation in liability is due to multiple common risk variants of small effect with a substantial shared genetic liability between schizophrenia and bipolar affective disorder. CONCLUSIONS The genomics have done much for the psychoses to date and more is anticipated.
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Affiliation(s)
- M Gill
- Neuropsychiatric Genetics Research Group, Department of Psychiatry, School of Medicine, Trinity College Dublin 8, Ireland.
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Heike CL, Starr JR, Rieder MJ, Cunningham ML, Edwards KL, Stanaway IB, Crawford DC. Single nucleotide polymorphism discovery in TBX1 in individuals with and without 22q11.2 deletion syndrome. ACTA ACUST UNITED AC 2010; 88:54-63. [PMID: 19645056 DOI: 10.1002/bdra.20604] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND Children with 22q11.2 deletion syndrome (22q11.2DS) have a wide range of clinical features. TBX1 has been proposed as a candidate gene for some of the features in this condition. Polymorphisms in the nondeleted TBX1, which may affect the function of the sole TBX1 gene in individuals with the 22q11.2DS, may be a key to understanding the phenotypic variability among individuals with a shared deletion. Comprehensive single nucleotide polymorphism (SNP) discovery by resequencing candidate genes can identify genetic variants that influence a given phenotype. The purpose of this study was to further characterize the sequence variability in TBX1 by identifying all common SNPs in this gene. METHODS We resequenced TBX1 in 29 children with a documented 22q11.2 deletion and 95 nondeleted, healthy individuals. We estimated allele frequencies, performed tagSNP selection, and inferred haplotypes. We also compared SNP frequencies between 22q11.2DS and control samples. RESULTS We identified 355 biallelic markers among the 190 chromosomes resequenced in the control panel. The vast majority of the markers identified were SNPs (n = 331), and the remainder indels (n = 24). We did not identify SNPs or indels in the cis- regulatory element (FOX-binding site) upstream of TBX1. In children with 22q11.2DS we detected 187 biallelic markers, six of which were indels. Four of the seven coding SNPs identified in the controls were identified in children with 22q11.2DS. CONCLUSIONS This comprehensive SNP discovery data can be used to select SNPs to genotype for future association studies assessing the role of TBX1 and phenotypic variability in individuals with 22q11.2DS.
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Affiliation(s)
- Carrie L Heike
- Department of Pediatrics, Division of Craniofacial Medicine, University of Washington and Seattle Children's Hospital, Seattle, Washington 98105-5371, USA.
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Beaujard MP, Chantot S, Dubois M, Keren B, Carpentier W, Mabboux P, Whalen S, Vodovar M, Siffroi JP, Portnoï MF. Atypical deletion of 22q11.2: detection using the FISH TBX1 probe and molecular characterization with high-density SNP arrays. Eur J Med Genet 2009; 52:321-7. [PMID: 19467348 DOI: 10.1016/j.ejmg.2009.05.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2008] [Accepted: 05/09/2009] [Indexed: 12/24/2022]
Abstract
Despite the heterogeneous clinical presentations, the majority of patients with 22q11.2 deletion syndrome (22q11.2 DS) have either a common recurrent 3 Mb deletion or a less common, 1.5 Mb nested deletion, with breakpoint sites in flanking low-copy repeats (LCR) sequences. Only a small number of atypical deletions have been reported and precisely defined. Haploinsufficiency of the TBX1 gene was determined to be the likely cause of 22q11.2 DS. The diagnostic procedure usually used is FISH using commercially probes (N25 or TUPLE1). However, this test does not contain TBX1, and fails to detect deletions that are either proximal or distal to the FISH probes. Here, we report on two patients with clinical features suggestive of 22q11.2 DS, a male infant with facial dysmorphia, pulmonary atresia, ventricular septal defect, neonatal hypocalcemia, and his affected mother, with facial dysmorphia, learning disabilities, and hypernasal speech. They were tested negative for 22q11.2 DS using N25 or TUPLE1 probes, but were shown deleted for a probe containing TBX1. Delineation of the deletion was performed using high-density SNP arrays (Illumina, 370K). This atypical deletion was spanning 1.89 Mb. The distal breakpoint resided in LCR-D, sharing the same distal breakpoint with the 3 Mb common deletion. The proximal breakpoint was located 105 kb telomeric to TUPLE1, representing a new breakpoint variant that does not correspond to known LCRs of 22q11.2. We conclude that FISH with the TBX1 probe is an accurate diagnostic tool for 22q11.2 DS, with a higher sensitivity than FISH using standard probes, detecting all but the rarest deletions, greatly reducing the false negative rate.
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Gothelf D, Frisch A, Michaelovsky E, Weizman A, Shprintzen RJ. Velo-Cardio-Facial Syndrome. JOURNAL OF MENTAL HEALTH RESEARCH IN INTELLECTUAL DISABILITIES 2009; 2:149-167. [PMID: 20111667 PMCID: PMC2811959 DOI: 10.1080/19315860902756136] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Velocardiofacial syndrome (VCFS) also known as DiGeorge, conotruncal anomaly face and Cayler syndromes is caused by a microdeletion in the long arm of chromosome 22. We review the history of the syndrome from the first clinical reports almost half a century ago to the current intriguing molecular findings associating genes from the microdeletion region and the physical and neuropsychiatric phenotype of the syndrome. Velocardiofacial syndrome has a wide spectrum of more than 200 physical manifestations including palate and cardiac anomalies. Yet, the most challenging manifestations of VCFS are the learning disabilities and neuropsychiatric disorders. As VCFS is relatively common and as up to one third of the subjects with VCFS develop schizophrenia like psychotic disorder the syndrome is the most commonly known genetic risk factor to schizophrenia. Identifying the genetic, cognitive and psychiatric risk factors for VCFS-schizophrenia is under the focus of intensive research.
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Affiliation(s)
- Doron Gothelf
- The Behavioral Neurogenetics Center, Feinberg Department of Child Psychiatry Schneider Children’s Medical Center of Israel, Petah Tiqwa, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel
| | - Amos Frisch
- Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel
- Felsenstein Medical Research Center, Rabin Medical Center, Petah Tiqwa, Israel
| | - Elena Michaelovsky
- Felsenstein Medical Research Center, Rabin Medical Center, Petah Tiqwa, Israel
| | - Abraham Weizman
- Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel
- Felsenstein Medical Research Center, Rabin Medical Center, Petah Tiqwa, Israel
- Research Unit, Geha Mental Health Center, Petah Tiqwa, Israel
| | - Robert J. Shprintzen
- Velo-Cardio-Facial Syndrome International Center and the Center for Genetic Communicative Disorders, Department of Otolaryngology and Communication Science, Upstate Medical University, Syracuse, NY
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Microduplication 22q11.2: a new chromosomal syndrome. Eur J Med Genet 2009; 52:88-93. [PMID: 19254783 DOI: 10.1016/j.ejmg.2009.02.008] [Citation(s) in RCA: 156] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Accepted: 02/16/2009] [Indexed: 11/24/2022]
Abstract
The chromosome 22q11.2 region has long been implicated in genomic diseases. The low-copy repeats spanning the region predispose to homologous recombination events, and mediate nonallelic homologous recombinations that result in rearrangements of 22q11.2. Chromosome duplication of the region that is deleted in patients with DGS/VCFS has been reported, establishing a new genomic duplication syndrome complementary to the 22q11.2 deletion syndrome. Recent data suggest that the frequency of the microduplications 22q11.2 is approximately half that of the deletions. Up till now about 50 unrelated cases of 22q11.2 duplications have been reported. A high frequency of familial duplications has been reported. The phenotype of patients is extremely variable, ranging from multiple defects to mild learning difficulties, sharing features with DGS/VCFS, including heart defects, urogenital abnormalities, velopharyngeal insufficiency with or without cleft palate, and with some individuals being essentially normal. The basis of phenotype variability remains to be elucidated. The large majority of affected individuals have identical 3Mb duplications. The 22q11.2 microduplication syndrome can be diagnosed with high accuracy by interphase fluorescence in situ hybridization, and several other molecular laboratory techniques. The 3Mb duplication encompasses a region containing 40 genes including the TBX1 gene that has been shown to be the major disease gene responsible for the DGS/VCFS. Interestingly, TBX1 gain-of-function mutations, resulting in the same phenotypic spectrum as haploinsufficiency caused by loss-of-function mutations or deletions, have been observed, confirming that TBX1 overexpression might be responsible for the dup22q11.2 disorder.
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Choi M, Klingensmith J. Chordin is a modifier of tbx1 for the craniofacial malformations of 22q11 deletion syndrome phenotypes in mouse. PLoS Genet 2009; 5:e1000395. [PMID: 19247433 PMCID: PMC2640462 DOI: 10.1371/journal.pgen.1000395] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2008] [Accepted: 01/28/2009] [Indexed: 01/21/2023] Open
Abstract
Point mutations in TBX1 can recapitulate many of the structural defects of 22q11 deletion syndromes (22q11DS), usually associated with a chromosomal deletion at 22q1.2. 22q11DS often includes specific cardiac and pharyngeal organ anomalies, but the presence of characteristic craniofacial defects is highly variable. Even among family members with a single TBX1 point mutation but no cytological deletion, cleft palate and low-set ears may or may not be present. In theory, such differences could depend on an unidentified, second-site lesion that modifies the craniofacial consequences of TBX1 deficiency. We present evidence for such a locus in a mouse model. Null mutations of chordin have been reported to cause severe defects recapitulating 22q11DS, which we show are highly dependent on genetic background. In an inbred strain in which chordin(-/-) is fully penetrant, we found a closely linked, strong modifier--a mutation in a Tbx1 intron causing severe splicing defects. Without it, lack of chordin results in a low penetrance of mandibular hypoplasia but no cardiac or thoracic organ malformations. This hypomorphic Tbx1 allele per se results in defects resembling 22q11DS but with a low penetrance of hallmark craniofacial malformations, unless chordin is mutant. Thus, chordin is a modifier for the craniofacial anomalies of Tbx1 mutations, demonstrating the existence of a second-site modifier for a specific subset of the phenotypes associated with 22q11DS.
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Affiliation(s)
- Murim Choi
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - John Klingensmith
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, United States of America
- * E-mail:
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Koop D, Holland LZ. The basal chordate amphioxus as a simple model for elucidating developmental mechanisms in vertebrates. ACTA ACUST UNITED AC 2008; 84:175-87. [DOI: 10.1002/bdrc.20128] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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