1
|
Malta M, AlMutiri R, Martin CS, Srour M. Holoprosencephaly: Review of Embryology, Clinical Phenotypes, Etiology and Management. CHILDREN 2023; 10:children10040647. [PMID: 37189898 DOI: 10.3390/children10040647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 02/21/2023] [Accepted: 03/27/2023] [Indexed: 03/31/2023]
Abstract
Holoprosencephaly (HPE) is the most common malformation of the prosencephalon in humans. It is characterized by a continuum of structural brain anomalies resulting from the failure of midline cleavage of the prosencephalon. The three classic subtypes of HPE are alobar, semilobar and lobar, although a few additional categories have been added to this original classification. The severity of the clinical phenotype is broad and usually mirrors the radiologic and associated facial features. The etiology of HPE includes both environmental and genetic factors. Disruption of sonic hedgehog (SHH) signaling is the main pathophysiologic mechanism underlying HPE. Aneuploidies, chromosomal copy number variants and monogenic disorders are identified in a large proportion of HPE patients. Despite the high postnatal mortality and the invariable presence of developmental delay, recent advances in diagnostic methods and improvements in patient management over the years have helped to increase survival rates. In this review, we provide an overview of the current knowledge related to HPE, and discuss the classification, clinical features, genetic and environmental etiologies and management.
Collapse
|
2
|
Brownstein CA, Douard E, Haynes RL, Koh HY, Haghighi A, Keywan C, Martin B, Alexandrescu S, Haas EA, Vargas SO, Wojcik MH, Jacquemont S, Poduri AH, Goldstein RD, Holm IA. Copy Number Variation and Structural Genomic Findings in 116 Cases of Sudden Unexplained Death between 1 and 28 Months of Age. ADVANCED GENETICS (HOBOKEN, N.J.) 2023; 4:2200012. [PMID: 36910592 PMCID: PMC10000288 DOI: 10.1002/ggn2.202200012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 08/31/2022] [Indexed: 11/09/2022]
Abstract
In sudden unexplained death in pediatrics (SUDP) the cause of death is unknown despite an autopsy and investigation. The role of copy number variations (CNVs) in SUDP has not been well-studied. Chromosomal microarray (CMA) data are generated for 116 SUDP cases with age at death between 1 and 28 months. CNVs are classified using the American College of Medical Genetics and Genomics guidelines and CNVs in our cohort are compared to an autism spectrum disorder (ASD) cohort, and to a control cohort. Pathogenic CNVs are identified in 5 of 116 cases (4.3%). Variants of uncertain significance (VUS) favoring pathogenic CNVs are identified in 9 cases (7.8%). Several CNVs are associated with neurodevelopmental phenotypes including seizures, ASD, developmental delay, and schizophrenia. The structural variant 47,XXY is identified in two cases (2/69 boys, 2.9%) not previously diagnosed with Klinefelter syndrome. Pathogenicity scores for deletions are significantly elevated in the SUDP cohort versus controls (p = 0.007) and are not significantly different from the ASD cohort. The finding of pathogenic or VUS favoring pathogenic CNVs, or structural variants, in 12.1% of cases, combined with the observation of higher pathogenicity scores for deletions in SUDP versus controls, suggests that CMA should be included in the genetic evaluation of SUDP.
Collapse
|
3
|
Barratt KS, Drover KA, Thomas ZM, Arkell RM. Patterning of the antero-ventral mammalian brain: Lessons from holoprosencephaly comparative biology in man and mouse. WIREs Mech Dis 2022; 14:e1552. [PMID: 35137563 DOI: 10.1002/wsbm.1552] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 11/30/2021] [Accepted: 12/21/2021] [Indexed: 12/13/2022]
Abstract
Adult form and function are dependent upon the activity of specialized signaling centers that act early in development at the embryonic midline. These centers instruct the surrounding cells to adopt a positional fate and to form the patterned structures of the phylotypic embryo. Abnormalities in these processes have devastating consequences for the individual, as exemplified by holoprosencephaly in which anterior midline development fails, leading to structural defects of the brain and/or face. In the 25 years since the first association between human holoprosencephaly and the sonic hedgehog gene, a combination of human and animal genetic studies have enhanced our understanding of the genetic and embryonic causation of this congenital defect. Comparative biology has extended the holoprosencephaly network via the inclusion of gene mutations from multiple signaling pathways known to be required for anterior midline formation. It has also clarified aspects of holoprosencephaly causation, showing that it arises when a deleterious variant is present within a permissive genome, and that environmental factors, as well as embryonic stochasticity, influence the phenotypic outcome of the variant. More than two decades of research can now be distilled into a framework of embryonic and genetic causation. This framework means we are poised to move beyond our current understanding of variants in signaling pathway molecules. The challenges now at the forefront of holoprosencephaly research include deciphering how the mutation of genes involved in basic cell processes can also cause holoprosencephaly, determining the important constituents of the holoprosencephaly permissive genome, and identifying environmental compounds that promote holoprosencephaly. This article is categorized under: Congenital Diseases > Stem Cells and Development Congenital Diseases > Genetics/Genomics/Epigenetics Congenital Diseases > Molecular and Cellular Physiology Congenital Diseases > Environmental Factors.
Collapse
Affiliation(s)
- Kristen S Barratt
- John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Kyle A Drover
- John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Zoe M Thomas
- John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Ruth M Arkell
- John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory, Australia
| |
Collapse
|
4
|
Lo HF, Hong M, Krauss RS. Concepts in Multifactorial Etiology of Developmental Disorders: Gene-Gene and Gene-Environment Interactions in Holoprosencephaly. Front Cell Dev Biol 2022; 9:795194. [PMID: 35004690 PMCID: PMC8727999 DOI: 10.3389/fcell.2021.795194] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 11/29/2021] [Indexed: 12/17/2022] Open
Abstract
Many common developmental disorders are thought to arise from a complex set of genetic and environmental risk factors. These factors interact with each other to affect the strength and duration of key developmental signaling pathways, thereby increasing the possibility that they fail to achieve the thresholds required for normal embryonic patterning. One such disorder, holoprosencephaly (HPE), serves as a useful model system in understanding various forms of multifactorial etiology. Genomic analysis of HPE cases, epidemiology, and mechanistic studies of animal models have illuminated multiple potential ways that risk factors interact to produce adverse developmental outcomes. Among these are: 1) interactions between driver and modifier genes; 2) oligogenic inheritance, wherein each parent provides predisposing variants in one or multiple distinct loci; 3) interactions between genetic susceptibilities and environmental risk factors that may be insufficient on their own; and 4) interactions of multiple genetic variants with multiple non-genetic risk factors. These studies combine to provide concepts that illuminate HPE and are also applicable to additional disorders with complex etiology, including neural tube defects, congenital heart defects, and oro-facial clefting.
Collapse
Affiliation(s)
- Hsiao-Fan Lo
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Mingi Hong
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Robert S Krauss
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| |
Collapse
|
5
|
Meurer L, Ferdman L, Belcher B, Camarata T. The SIX Family of Transcription Factors: Common Themes Integrating Developmental and Cancer Biology. Front Cell Dev Biol 2021; 9:707854. [PMID: 34490256 PMCID: PMC8417317 DOI: 10.3389/fcell.2021.707854] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 06/28/2021] [Indexed: 01/19/2023] Open
Abstract
The sine oculis (SIX) family of transcription factors are key regulators of developmental processes during embryogenesis. Members of this family control gene expression to promote self-renewal of progenitor cell populations and govern mechanisms of cell differentiation. When the function of SIX genes becomes disrupted, distinct congenital defects develops both in animal models and humans. In addition to the embryonic setting, members of the SIX family have been found to be critical regulators of tumorigenesis, promoting cell proliferation, epithelial-to-mesenchymal transition, and metastasis. Research in both the fields of developmental biology and cancer research have provided an extensive understanding of SIX family transcription factor functions. Here we review recent progress in elucidating the role of SIX family genes in congenital disease as well as in the promotion of cancer. Common themes arise when comparing SIX transcription factor function during embryonic and cancer development. We highlight the complementary nature of these two fields and how knowledge in one area can open new aspects of experimentation in the other.
Collapse
Affiliation(s)
- Logan Meurer
- Department of Basic Sciences, NYIT College of Osteopathic Medicine at Arkansas State University, Jonesboro, AR, United States
| | - Leonard Ferdman
- Department of Basic Sciences, NYIT College of Osteopathic Medicine at Arkansas State University, Jonesboro, AR, United States
| | - Beau Belcher
- Department of Biological Sciences, Arkansas State University, Jonesboro, AR, United States
| | - Troy Camarata
- Department of Basic Sciences, NYIT College of Osteopathic Medicine at Arkansas State University, Jonesboro, AR, United States
| |
Collapse
|
6
|
de Castro VF, Mattos D, de Carvalho FM, Cavalcanti DP, Duenas-Roque MM, Llerena J, Cosentino VR, Honjo RS, Leite JCL, Sanseverino MT, de Souza MPA, Bernardi P, Bolognese AM, Santana da Silva LC, Barbero P, Correia PS, Bueno LSM, Savastano CP, Orioli IM. New SHH and Known SIX3 Variants in a Series of Latin American Patients with Holoprosencephaly. Mol Syndromol 2021; 12:219-233. [PMID: 34421500 DOI: 10.1159/000515044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 02/04/2021] [Indexed: 11/19/2022] Open
Abstract
Holoprosencephaly (HPE) is the failure of the embryonic forebrain to develop into 2 hemispheres promoting midline cerebral and facial defects. The wide phenotypic variability and causal heterogeneity make genetic counseling difficult. Heterozygous variants with incomplete penetrance and variable expressivity in the SHH, SIX3, ZIC2, and TGIF1 genes explain ∼25% of the known causes of nonchromosomal HPE. We studied these 4 genes and clinically described 27 Latin American families presenting with nonchromosomal HPE. Three new SHH variants and a third known SIX3 likely pathogenic variant found by Sanger sequencing explained 15% of our cases. Genotype-phenotype correlation in these 4 families and published families with identical or similar driver gene, mutated domain, conservation of residue in other species, and the type of variant explain the pathogenicity but not the phenotypic variability. Nine patients, including 2 with SHH pathogenic variants, presented benign variants of the SHH, SIX3, ZIC2, and TGIF1 genes with potential alteration of splicing, a causal proposition in need of further studies. Finding more families with the same SIX3 variant may allow further identification of genetic or environmental modifiers explaining its variable phenotypic expression.
Collapse
Affiliation(s)
- Viviane Freitas de Castro
- ECLAMC at Departamento de Genética, UFRJ, Rio de Janeiro, Brazil.,Instituto Nacional de Genética Médica Populacional INAGEMP, Porto Alegre, Brazil
| | - Daniel Mattos
- ECLAMC at Departamento de Genética, UFRJ, Rio de Janeiro, Brazil.,Instituto Nacional de Genética Médica Populacional INAGEMP, Porto Alegre, Brazil
| | - Flavia Martinez de Carvalho
- Instituto Nacional de Genética Médica Populacional INAGEMP, Porto Alegre, Brazil.,ECLAMC at Laboratorio Epidemiol. Malformações Congênitas, IOC/FIOCRUZ, Rio de Janeiro, Brazil
| | | | - Milagros M Duenas-Roque
- ECLAMC at Servicio de Genética, Hospital Nacional Edgardo Rebagliati Martins/EsSalud, Lima, Peru
| | - Juan Llerena
- Instituto Nacional de Genética Médica Populacional INAGEMP, Porto Alegre, Brazil.,ECLAMC at Centro de Genética Médica, IFF/FIOCRUZ, Rio de Janeiro, Brazil
| | | | | | | | | | | | - Pricila Bernardi
- Núcleo de Genética Clínica, Departamento de Clínica Médica/UFSC, Florianópolis, Brazil
| | - Ana Maria Bolognese
- Departamento de Ortodontia, Faculdade de Odontologia/UFRJ, Rio de Janeiro, Brazil
| | - Luiz Carlos Santana da Silva
- Instituto Nacional de Genética Médica Populacional INAGEMP, Porto Alegre, Brazil.,Laboratório de Erros Inatos de Metabolismo, Instituto de Ciências Biológicas/UFP, Belém, Brazil
| | - Pablo Barbero
- RENAC, Centro Nacional de Genética Médica Dr. Eduardo E. Castilla/MS, Buenos Aires, Argentina
| | | | | | | | - Iêda Maria Orioli
- ECLAMC at Departamento de Genética, UFRJ, Rio de Janeiro, Brazil.,Instituto Nacional de Genética Médica Populacional INAGEMP, Porto Alegre, Brazil
| |
Collapse
|
7
|
Riddle A, Nagaraj U, Hopkin RJ, Kline-Fath B, Venkatesan C. Fetal Magnetic Resonance Imaging (MRI) in Holoprosencephaly and Associations With Clinical Outcome: Implications for Fetal Counseling. J Child Neurol 2021; 36:357-364. [PMID: 33226281 DOI: 10.1177/0883073820972290] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Holoprosencephaly is the most common malformation of forebrain development and includes a wide spectrum of severity. The objective of this retrospective study was to evaluate fetal magnetic resonance imaging (MRI) associations with outcome. Of the 63 cases identified on antenatal ultrasonography, 28 cases were confirmed on fetal MRI. There were 17 live births; 9 patients died within the first month of life. There were 7 survivors. The vast majority were nonambulatory and required feeding support; none required respiratory support. We found that presence and number of non-holoprosencephaly-associated malformations was also associated with survival. Of 5 patients with 3 or more systemic anomalies, 4 died regardless of holoprosencephaly subtype and 1 was lost to follow-up. Patients with suspected holoprosencephaly on ultrasonography should have full body fetal MRI and echocardiogram to better evaluate systemic anomalies. Counseling should involve pediatric palliative care services to prepare families in caring for babies with limited life span.
Collapse
Affiliation(s)
- Artur Riddle
- Division of Neurology, 2518Cincinnati Children's Hospital, Cincinnati, OH, USA.,Division of Human Genetics, 2518Cincinnati Children's Hospital, Cincinnati, OH, USA.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA.,Division of Pediatric Neurology, 6684Oregon Health & Science University, Portland, OR, USA
| | - Usha Nagaraj
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA.,Division of Radiology and Medical Imaging, Cincinnati Children's Hospital, Cincinnati, OH, USA
| | - Robert J Hopkin
- Division of Human Genetics, 2518Cincinnati Children's Hospital, Cincinnati, OH, USA.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Beth Kline-Fath
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA.,Division of Radiology and Medical Imaging, Cincinnati Children's Hospital, Cincinnati, OH, USA
| | - Charu Venkatesan
- Division of Neurology, 2518Cincinnati Children's Hospital, Cincinnati, OH, USA.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| |
Collapse
|
8
|
Baumann H, Ott F, Weber J, Trilck-Winkler M, Münchau A, Zittel S, Kostić VS, Kaiser FJ, Klein C, Busch H, Seibler P, Lohmann K. Linking Penetrance and Transcription in DYT-THAP1: Insights From a Human iPSC-Derived Cortical Model. Mov Disord 2021; 36:1381-1391. [PMID: 33547842 DOI: 10.1002/mds.28506] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 11/20/2020] [Accepted: 12/16/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND The THAP1 gene encodes a transcription factor, and pathogenic variants cause a form of autosomal dominant, isolated dystonia (DYT-THAP1) with reduced penetrance. Factors underlying both reduced penetrance and the disease mechanism of DYT-THAP1 are largely unknown. METHODS We performed transcriptome analysis on 29 cortical neuronal precursors derived from human-induced pluripotent stem cell lines generated from manifesting and nonmanifesting THAP1 mutation carriers and control individuals. RESULTS Whole transcriptome analysis showed a penetrance-linked signature with expressional changes more pronounced in the group of manifesting (MMCs) than in nonmanifesting mutation carriers (NMCs) when compared to controls. A direct comparison of the transcriptomes in MMCs versus NMCs showed significant upregulation of the DRD4 gene in MMCs. A gene set enrichment analysis demonstrated alterations in various neurotransmitter release cycle pathways, extracellular matrix organization, and deoxyribonucleic acid methylation between MMCs and NMCs. When specifically considering transcription factors, the expression of YY1 and SIX2 differed in MMCs versus NMCs. Further, THAP1 was upregulated in the group of MMCs. CONCLUSIONS To our knowledge, this is the first report systematically analyzing reduced penetrance in DYT-THAP1 in a human model using transcriptomes. Our findings indicate that transcriptional alterations during cortical development influence DYT-THAP1 pathogenesis and penetrance. We reinforce previously linked pathways including dopamine and eukaryotic translation initiation factor 2 alpha signaling in the pathogenesis of dystonia including DYT-THAP1 and suggest extracellular matrix organization and deoxyribonucleic acid methylation as mediators of disease protection. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Collapse
Affiliation(s)
- Hauke Baumann
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Fabian Ott
- Institute of Experimental Dermatology and Institute of Cardiogenetics, University of Lübeck, Lübeck, Germany
| | - Joachim Weber
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | | | - Alexander Münchau
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany.,Institute of Systems Motor Science, University of Lübeck, Lübeck, Germany
| | - Simone Zittel
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Frank J Kaiser
- Institute of Human Genetics, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.,Institute of Human Genetics, University of Lübeck, Lübeck, Germany
| | - Christine Klein
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Hauke Busch
- Institute of Experimental Dermatology and Institute of Cardiogenetics, University of Lübeck, Lübeck, Germany
| | - Philip Seibler
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Katja Lohmann
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| |
Collapse
|
9
|
Reynolds K, Zhang S, Sun B, Garland M, Ji Y, Zhou CJ. Genetics and signaling mechanisms of orofacial clefts. Birth Defects Res 2020; 112:1588-1634. [PMID: 32666711 PMCID: PMC7883771 DOI: 10.1002/bdr2.1754] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 06/11/2020] [Accepted: 06/15/2020] [Indexed: 12/31/2022]
Abstract
Craniofacial development involves several complex tissue movements including several fusion processes to form the frontonasal and maxillary structures, including the upper lip and palate. Each of these movements are controlled by many different factors that are tightly regulated by several integral morphogenetic signaling pathways. Subject to both genetic and environmental influences, interruption at nearly any stage can disrupt lip, nasal, or palate fusion and result in a cleft. Here, we discuss many of the genetic risk factors that may contribute to the presentation of orofacial clefts in patients, and several of the key signaling pathways and underlying cellular mechanisms that control lip and palate formation, as identified primarily through investigating equivalent processes in animal models, are examined.
Collapse
Affiliation(s)
- Kurt Reynolds
- Department of Biochemistry and Molecular Medicine, University of California at Davis, School of Medicine, Sacramento, CA 95817
- Institute for Pediatric Regenerative Medicine of Shriners Hospitals for Children, University of California at Davis, School of Medicine, Sacramento, CA 95817
- Biochemistry, Molecular, Cellular, and Developmental Biology (BMCDB) graduate group, University of California, Davis, CA 95616
| | - Shuwen Zhang
- Department of Biochemistry and Molecular Medicine, University of California at Davis, School of Medicine, Sacramento, CA 95817
- Institute for Pediatric Regenerative Medicine of Shriners Hospitals for Children, University of California at Davis, School of Medicine, Sacramento, CA 95817
| | - Bo Sun
- Department of Biochemistry and Molecular Medicine, University of California at Davis, School of Medicine, Sacramento, CA 95817
- Institute for Pediatric Regenerative Medicine of Shriners Hospitals for Children, University of California at Davis, School of Medicine, Sacramento, CA 95817
| | - Michael Garland
- Department of Biochemistry and Molecular Medicine, University of California at Davis, School of Medicine, Sacramento, CA 95817
- Institute for Pediatric Regenerative Medicine of Shriners Hospitals for Children, University of California at Davis, School of Medicine, Sacramento, CA 95817
| | - Yu Ji
- Department of Biochemistry and Molecular Medicine, University of California at Davis, School of Medicine, Sacramento, CA 95817
- Institute for Pediatric Regenerative Medicine of Shriners Hospitals for Children, University of California at Davis, School of Medicine, Sacramento, CA 95817
- Biochemistry, Molecular, Cellular, and Developmental Biology (BMCDB) graduate group, University of California, Davis, CA 95616
| | - Chengji J. Zhou
- Department of Biochemistry and Molecular Medicine, University of California at Davis, School of Medicine, Sacramento, CA 95817
- Institute for Pediatric Regenerative Medicine of Shriners Hospitals for Children, University of California at Davis, School of Medicine, Sacramento, CA 95817
- Biochemistry, Molecular, Cellular, and Developmental Biology (BMCDB) graduate group, University of California, Davis, CA 95616
| |
Collapse
|
10
|
Hong M, Christ A, Christa A, Willnow TE, Krauss RS. Cdon mutation and fetal alcohol converge on Nodal signaling in a mouse model of holoprosencephaly. eLife 2020; 9:60351. [PMID: 32876567 PMCID: PMC7467722 DOI: 10.7554/elife.60351] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 08/10/2020] [Indexed: 02/07/2023] Open
Abstract
Holoprosencephaly (HPE), a defect in midline patterning of the forebrain and midface, arises ~1 in 250 conceptions. It is associated with predisposing mutations in the Nodal and Hedgehog (HH) pathways, with penetrance and expressivity graded by genetic and environmental modifiers, via poorly understood mechanisms. CDON is a multifunctional co-receptor, including for the HH pathway. In mice, Cdon mutation synergizes with fetal alcohol exposure, producing HPE phenotypes closely resembling those seen in humans. We report here that, unexpectedly, Nodal signaling is a major point of synergistic interaction between Cdon mutation and fetal alcohol. Window-of-sensitivity, genetic, and in vitro findings are consistent with a model whereby brief exposure of Cdon mutant embryos to ethanol during gastrulation transiently and partially inhibits Nodal pathway activity, with consequent effects on midline patterning. These results illuminate mechanisms of gene-environment interaction in a multifactorial model of a common birth defect.
Collapse
Affiliation(s)
- Mingi Hong
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, United States
| | - Annabel Christ
- Max-Delbruck-Center for Molecular Medicine, Berlin, Germany
| | - Anna Christa
- Max-Delbruck-Center for Molecular Medicine, Berlin, Germany
| | | | - Robert S Krauss
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, United States
| |
Collapse
|
11
|
Tatsi C, Xekouki P, Nioti O, Bachrach B, Belyavskaya E, Lyssikatos C, Stratakis CA. A novel mutation in the glucocorticoid receptor gene as a cause of severe glucocorticoid resistance complicated by hypertensive encephalopathy. J Hypertens 2019; 37:1475-1481. [PMID: 31145715 PMCID: PMC10913058 DOI: 10.1097/hjh.0000000000002048] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Glucocorticoid resistance syndrome (GRS) is caused by mutations of the glucocorticoid receptor (coded by the NR3C1 gene) and presents with signs of mineralocorticoid and/or androgen excess. PATIENT A female patient presented at the age of almost 3 years with hypertensive and hypoglycemic seizure. She was diagnosed with GRS and was treated with antihypertensive medications and dexamethasone. She was later found to have MRI findings of punctuate microinfarcts at the basal ganglia, left thalamus and pons, possibly associated with uncontrolled hypertension. Increase of the dexamethasone dose up to 14 mg/day resulted in sufficient control of her symptoms. RESULTS Two mutations in the NR3C1 gene were identified: a novel mutation in exon 2 (p.E198X), and a previously described mutation in exon 8 (p.R714Q). CONCLUSION GRS may present with life-threatening complications; this is the first report of hypertensive encephalopathy in association with GRS. Successful management of patients might require high doses of dexamethasone to control blood pressure.
Collapse
Affiliation(s)
- Christina Tatsi
- Section on Genetics and Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, Maryland
| | - Paraskevi Xekouki
- Section on Genetics and Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, Maryland
| | - Olga Nioti
- Section on Genetics and Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, Maryland
| | - Bert Bachrach
- Pediatric Diabetes and Endocrinology Department, University of Missouri Children's Hospital, Columbia, Missouri, USA
| | - Elena Belyavskaya
- Section on Genetics and Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, Maryland
| | - Charalampos Lyssikatos
- Section on Genetics and Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, Maryland
| | - Constantine A Stratakis
- Section on Genetics and Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, Maryland
| |
Collapse
|
12
|
Solomon BD, Kruszka P, Muenke M. Holoprosencephaly flashcards: An updated summary for the clinician. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2018; 178:117-121. [DOI: 10.1002/ajmg.c.31621] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 04/12/2018] [Indexed: 11/10/2022]
Affiliation(s)
| | - Paul Kruszka
- Medical Genetics Branch, National Human Genome Research InstituteBethesda Maryland
| | - Maximilian Muenke
- Medical Genetics Branch, National Human Genome Research InstituteBethesda Maryland
| |
Collapse
|
13
|
Dubourg C, Kim A, Watrin E, de Tayrac M, Odent S, David V, Dupé V. Recent advances in understanding inheritance of holoprosencephaly. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2018; 178:258-269. [PMID: 29785796 DOI: 10.1002/ajmg.c.31619] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 04/13/2018] [Accepted: 04/16/2018] [Indexed: 12/16/2022]
Abstract
Holoprosencephaly (HPE) is a complex genetic disorder of the developing forebrain characterized by high phenotypic and genetic heterogeneity. HPE was initially defined as an autosomal dominant disease, but recent research has shown that its mode of transmission is more complex. The past decade has witnessed rapid development of novel genetic technologies and significant progresses in clinical studies of HPE. In this review, we recapitulate genetic epidemiological studies of the largest European HPE cohort and summarize the novel genetic discoveries of HPE based on recently developed diagnostic methods. Our main purpose is to present different inheritance patterns that exist for HPE with a particular emphasis on oligogenic inheritance and its implications in genetic counseling.
Collapse
Affiliation(s)
- Christèle Dubourg
- Univ Rennes, CNRS, IGDR (Institut de génétique et développement de Rennes) - UMR 6290, F - 35000, Rennes, France.,Service de Génétique Moléculaire et Génomique, CHU, Rennes, France
| | - Artem Kim
- Univ Rennes, CNRS, IGDR (Institut de génétique et développement de Rennes) - UMR 6290, F - 35000, Rennes, France
| | - Erwan Watrin
- Univ Rennes, CNRS, IGDR (Institut de génétique et développement de Rennes) - UMR 6290, F - 35000, Rennes, France
| | - Marie de Tayrac
- Univ Rennes, CNRS, IGDR (Institut de génétique et développement de Rennes) - UMR 6290, F - 35000, Rennes, France.,Service de Génétique Moléculaire et Génomique, CHU, Rennes, France
| | - Sylvie Odent
- Univ Rennes, CNRS, IGDR (Institut de génétique et développement de Rennes) - UMR 6290, F - 35000, Rennes, France.,Service de Génétique Clinique, CHU, Rennes, France
| | - Véronique David
- Univ Rennes, CNRS, IGDR (Institut de génétique et développement de Rennes) - UMR 6290, F - 35000, Rennes, France.,Service de Génétique Moléculaire et Génomique, CHU, Rennes, France
| | - Valérie Dupé
- Univ Rennes, CNRS, IGDR (Institut de génétique et développement de Rennes) - UMR 6290, F - 35000, Rennes, France
| |
Collapse
|
14
|
Martinez AF, Kruszka PS, Muenke M. Extracephalic manifestations of nonchromosomal, nonsyndromic holoprosencephaly. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2018; 178:246-257. [PMID: 29761634 DOI: 10.1002/ajmg.c.31616] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 03/29/2018] [Accepted: 04/11/2018] [Indexed: 12/13/2022]
Abstract
Nonchromosomal, nonsyndromic holoprosencephaly (NCNS-HPE) has traditionally been considered as a condition of brain and craniofacial maldevelopment. In this review, we present the results of a comprehensive literature search supporting a wide spectrum of extracephalic manifestations identified in patients with NCNS-HPE. These manifestations have been described in case reports and in large cohorts of patients with "single-gene" mutations, suggesting that the NCNS-HPE phenotype can be more complex than traditionally thought. Likely, a complex network of interacting genetic variants and environmental factors is responsible for these systemic abnormalities that deviate from the usual brain and craniofacial findings in NCNS-HPE. In addition to the systemic consequences of pituitary dysfunction (as a direct result of brain midline defects), here we describe a number of extracephalic findings of NCNS-HPE affecting various organ systems. It is our goal to provide a guide of extracephalic features for clinicians given the important clinical implications of these manifestations for the management and care of patients with HPE and their mutation-positive relatives. The health risks associated with some manifestations (e.g., fatty liver disease) may have historically been neglected in affected families.
Collapse
Affiliation(s)
- Ariel F Martinez
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Paul S Kruszka
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Maximilian Muenke
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| |
Collapse
|
15
|
Hong M, Krauss RS. Modeling the complex etiology of holoprosencephaly in mice. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2018; 178:140-150. [PMID: 29749693 DOI: 10.1002/ajmg.c.31611] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 03/28/2018] [Accepted: 04/02/2018] [Indexed: 12/14/2022]
Abstract
Holoprosencephaly (HPE) is a common developmental defect caused by failure to define the midline of the forebrain and/or midface. HPE is associated with heterozygous mutations in Nodal and Sonic hedgehog (SHH) pathway components, but clinical presentation is highly variable, and many mutation carriers are unaffected. It is therefore thought that such mutations interact with more common modifiers, genetic and/or environmental, to produce severe patterning defects. Modifiers are difficult to identify, as their effects are context-dependent and occur within the complex genetic and environmental landscapes that characterize human populations. This has made a full understanding of HPE etiology challenging. We discuss here the use of mice, a genetically tractable model sensitive to teratogens, as a system to address this challenge. Mice carrying mutations in human HPE genes often display wide variations in phenotypic penetrance and expressivity when placed on different genetic backgrounds, demonstrating the existence of silent HPE modifier genes. Studies with mouse lines carrying SHH pathway mutations on appropriate genetic backgrounds have led to identification of both genetic and environmental modifiers that synergize with the mutations to produce a spectrum of HPE phenotypes. These models favor a scenario in which multiple modifying influences-both genetic and environmental, sensitizing and protective-interact with bona fide HPE mutations to grade phenotypic outcomes. Despite the complex interplay of HPE risk factors, mouse models have helped establish some clear concepts in HPE etiology. A combination of mouse and human cohort studies should improve our understanding of this fascinating and medically important issue.
Collapse
Affiliation(s)
- Mingi Hong
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Robert S Krauss
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York
| |
Collapse
|
16
|
Paspaliaris V, Vrachnis N, Iliodromiti Z, Antonakopoulos N, Papaioannou G, Vlachadis N, Anastasiadou F, Sotiriou S, Garas A, Thomaidis L, Manolakos E. 7q Deletion/12q Duplication Is the Possible Cause of an Alobar Holoprosencephaly Case. Mol Syndromol 2018; 9:52-57. [PMID: 29456484 DOI: 10.1159/000481972] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/15/2017] [Indexed: 11/19/2022] Open
Abstract
Holoprosencephaly (HPE) spectrum disorder is the most common congenital malformation of the human brain with absence of or incomplete midline cleavage. Its cause is heterogenic, making genetic counseling a challenge. In this case report, a pregnancy affected by alobar HPE is described. Using aCGH, an 8.9-Mb deletion at 7q36.1q36.3 together with a 4.9-Mb duplication at 12q24.32q24.33 is assumed to be the possible reason for this alobar HPE case. It is discussed that disruption of key elements of the developing brain, taking environmental factors into account, contributes to the HPE spectrum. The use of aCGH for invasive prenatal testing is starting to become the standard technique, providing accurate information about the cause of congenital diseases for couples receiving genetic counseling.
Collapse
Affiliation(s)
- Vassilis Paspaliaris
- Access to genome (ATG P.C.), Clinical Laboratory Genetics, University of Athens, Athens, Greece
| | | | | | | | - Giorgos Papaioannou
- Department of Gynecology, Attikon Hospital, University of Athens, Athens, Greece
| | | | - Foteini Anastasiadou
- Department of Clinical Embryology, Larissa Medical School, University of Thessaly, Larissa, Greece
| | - Sotirios Sotiriou
- Department of Clinical Embryology, Larissa Medical School, University of Thessaly, Larissa, Greece
| | - Antonios Garas
- Department of Gynecology, Larissa Medical School, University of Thessaly, Larissa, Greece
| | - Lorreta Thomaidis
- Developmental Assessment Unit, 2nd Department of Pediatrics, P&A Kyriakou Children's Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Emmanouil Manolakos
- Access to genome (ATG P.C.), Clinical Laboratory Genetics, University of Athens, Athens, Greece.,Developmental Assessment Unit, 2nd Department of Pediatrics, P&A Kyriakou Children's Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece.,Department of Medical Genetics, University of Cagliari, Binaghi Hospital, Cagliari, Italy
| |
Collapse
|
17
|
Percival CJ, Green R, Roseman CC, Gatti DM, Morgan JL, Murray SA, Donahue LR, Mayeux JM, Pollard KM, Hua K, Pomp D, Marcucio R, Hallgrímsson B. Developmental constraint through negative pleiotropy in the zygomatic arch. EvoDevo 2018; 9:3. [PMID: 29423138 PMCID: PMC5787316 DOI: 10.1186/s13227-018-0092-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2017] [Accepted: 01/08/2018] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Previous analysis suggested that the relative contribution of individual bones to regional skull lengths differ between inbred mouse strains. If the negative correlation of adjacent bone lengths is associated with genetic variation in a heterogeneous population, it would be an example of negative pleiotropy, which occurs when a genetic factor leads to opposite effects in two phenotypes. Confirming negative pleiotropy and determining its basis may reveal important information about the maintenance of overall skull integration and developmental constraint on skull morphology. RESULTS We identified negative correlations between the lengths of the frontal and parietal bones in the midline cranial vault as well as the zygomatic bone and zygomatic process of the maxilla, which contribute to the zygomatic arch. Through gene association mapping of a large heterogeneous population of Diversity Outbred (DO) mice, we identified a quantitative trait locus on chromosome 17 driving the antagonistic contribution of these two zygomatic arch bones to total zygomatic arch length. Candidate genes in this region were identified and real-time PCR of the maxillary processes of DO founder strain embryos indicated differences in the RNA expression levels for two of the candidate genes, Camkmt and Six2. CONCLUSIONS A genomic region underlying negative pleiotropy of two zygomatic arch bones was identified, which provides a mechanism for antagonism in component bone lengths while constraining overall zygomatic arch length. This type of mechanism may have led to variation in the contribution of individual bones to the zygomatic arch noted across mammals. Given that similar genetic and developmental mechanisms may underlie negative correlations in other parts of the skull, these results provide an important step toward understanding the developmental basis of evolutionary variation and constraint in skull morphology.
Collapse
Affiliation(s)
| | - Rebecca Green
- Alberta Children’s Hospital Institute for Child and Maternal Health, University of Calgary, Calgary, AB Canada
- The McCaig Bone and Joint Institute, University of Calgary, Calgary, AB Canada
- Department of Cell Biology and Anatomy, University of Calgary, Calgary, AB Canada
| | - Charles C. Roseman
- Program in Ecology Evolution and Conservation Biology, University of Illinois, Urbana, IL USA
| | | | | | | | | | - Jessica M. Mayeux
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA USA
| | - K. Michael Pollard
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA USA
| | - Kunjie Hua
- Department of Genetics, University of North Carolina Medical School, Chapel Hill, NC USA
| | - Daniel Pomp
- Department of Genetics, University of North Carolina Medical School, Chapel Hill, NC USA
| | - Ralph Marcucio
- The Orthopaedic Trauma Institute, Department of Orthopaedic Surgery, UCSF School of Medicine, San Francisco, CA USA
| | - Benedikt Hallgrímsson
- Alberta Children’s Hospital Institute for Child and Maternal Health, University of Calgary, Calgary, AB Canada
- The McCaig Bone and Joint Institute, University of Calgary, Calgary, AB Canada
- Department of Cell Biology and Anatomy, University of Calgary, Calgary, AB Canada
| |
Collapse
|
18
|
Abstract
The ZIC2 transcription factor is one of the most commonly mutated genes in Holoprosencephaly (HPE) probands. HPE is a severe congenital defect of forebrain development which occurs when the cerebral hemispheres fail to separate during the early stages of organogenesis and is typically associated with mispatterning of the embryonic midline. Recent study of genotype-phenotype correlations in HPE cases has defined distinctive features of ZIC2-associated HPE presentation and genetics, revealing that ZIC2 mutation does not produce the craniofacial abnormalities generally thought to characterise HPE but leads to a range of non-forebrain phenotypes. Furthermore, the studies confirm the extent of ZIC2 allelic heterogeneity and that pathogenic variants of ZIC2 are associated with both classic and middle interhemispheric variant (MIHV) HPE which arise from defective ventral and dorsal forebrain patterning, respectively. An allelic series of mouse mutants has helped to delineate the cellular and molecular mechanisms by which one gene leads to defects in these related but distinct embryological processes.
Collapse
Affiliation(s)
- Kristen S Barratt
- Early Mammalian Development Laboratory, John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia
| | - Ruth M Arkell
- Early Mammalian Development Laboratory, John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia.
| |
Collapse
|
19
|
Stokes B, Berger SI, Hall BA, Weiss K, Hadley DW, Murdock DR, Ramanathan S, Clark RD, Roessler E, Kruszka P, Muenke M. SIX3 deletions and incomplete penetrance in families affected by holoprosencephaly. Congenit Anom (Kyoto) 2018; 58:29-32. [PMID: 28670735 PMCID: PMC5750110 DOI: 10.1111/cga.12234] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 05/09/2017] [Accepted: 06/25/2017] [Indexed: 12/27/2022]
Abstract
Holoprosencephaly (HPE) is failure of the forebrain to divide completely during embryogenesis. Incomplete penetrance has not been reported previously in SIX3 whole gene deletions, which are known to cause HPE. Both chromosomal microarray and whole exome sequencing (WES) were used to evaluate families with inherited HPE. Two families showed inherited deletions that contain SIX3 and were incompletely penetrant for HPE. Using WES, we ruled out parental mosaicism, a SIX3 hypomorph, and clinically significant variants in genes that are known to interact with SIX3 as causes of incomplete penetrance. We demonstrate the importance of molecular cascade testing in families with HPE and we answer important questions about incomplete penetrance.
Collapse
Affiliation(s)
- Bethany Stokes
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Seth I. Berger
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Beth A. Hall
- Minnesota Perinatal Physicians, Allina Health, Minneapolis Minnesota
| | - Karin Weiss
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Donald W. Hadley
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - David R. Murdock
- Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Subhadra Ramanathan
- Division of Medical Genetics, Department of Pediatrics, Loma Linda University Children's Hospital, Loma Linda, California
| | - Robin D. Clark
- Division of Medical Genetics, Department of Pediatrics, Loma Linda University Children's Hospital, Loma Linda, California
| | - Erich Roessler
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Paul Kruszka
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Maximilian Muenke
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| |
Collapse
|
20
|
Genes and pathways in optic fissure closure. Semin Cell Dev Biol 2017; 91:55-65. [PMID: 29198497 DOI: 10.1016/j.semcdb.2017.10.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 08/29/2017] [Accepted: 10/10/2017] [Indexed: 12/22/2022]
Abstract
Embryonic development of the vertebrate eye begins with the formation of an optic vesicle which folds inwards to form a double-layered optic cup with a fissure on the ventral surface, known as the optic fissure. Closure of the optic fissure is essential for subsequent growth and development of the eye. A defect in this process can leave a gap in the iris, retina or optic nerve, known as a coloboma, which can lead to severe visual impairment. This review brings together current information about genes and pathways regulating fissure closure from human coloboma patients and animal models. It focuses especially on current understanding of the morphological changes and processes of epithelial remodelling occurring at the fissure margins.
Collapse
|
21
|
Li Y, Wang R, Qiao N, Peng G, Zhang K, Tang K, Han JDJ, Jing N. Transcriptome analysis reveals determinant stages controlling human embryonic stem cell commitment to neuronal cells. J Biol Chem 2017; 292:19590-19604. [PMID: 28972157 PMCID: PMC5712601 DOI: 10.1074/jbc.m117.796383] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 09/17/2017] [Indexed: 12/22/2022] Open
Abstract
Proper neural commitment is essential for ensuring the appropriate development of the human brain and for preventing neurodevelopmental diseases such as autism spectrum disorders, schizophrenia, and intellectual disorders. However, the molecular mechanisms underlying the neural commitment in humans remain elusive. Here, we report the establishment of a neural differentiation system based on human embryonic stem cells (hESCs) and on comprehensive RNA sequencing analysis of transcriptome dynamics during early hESC differentiation. Using weighted gene co-expression network analysis, we reveal that the hESC neurodevelopmental trajectory has five stages: pluripotency (day 0); differentiation initiation (days 2, 4, and 6); neural commitment (days 8-10); neural progenitor cell proliferation (days 12, 14, and 16); and neuronal differentiation (days 18, 20, and 22). These stages were characterized by unique module genes, which may recapitulate the early human cortical development. Moreover, a comparison of our RNA-sequencing data with several other transcriptome profiling datasets from mice and humans indicated that Module 3 associated with the day 8-10 stage is a critical window of fate switch from the pluripotency to the neural lineage. Interestingly, at this stage, no key extrinsic signals were activated. In contrast, using CRISPR/Cas9-mediated gene knockouts, we also found that intrinsic hub transcription factors, including the schizophrenia-associated SIX3 gene and septo-optic dysplasia-related HESX1 gene, are required to program hESC neural determination. Our results improve the understanding of the mechanism of neural commitment in the human brain and may help elucidate the etiology of human mental disorders and advance therapies for managing these conditions.
Collapse
Affiliation(s)
- Yuanyuan Li
- From the State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology and
| | - Ran Wang
- From the State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology and
| | - Nan Qiao
- Chinese Academy of Sciences Key Laboratory of Computational Biology, Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031
| | - Guangdun Peng
- From the State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology and
| | - Ke Zhang
- From the State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology and
| | - Ke Tang
- the Institute of Life Science, Nanchang University, Nanchang, Jiangxi 330031, and
| | - Jing-Dong J Han
- Chinese Academy of Sciences Key Laboratory of Computational Biology, Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031
| | - Naihe Jing
- From the State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology and
- the School of Life Science and Technology, ShanghaiTech University, 100 Haike Road, Shanghai 201210, China
| |
Collapse
|
22
|
Wai LT, Chandran S. Cyclopia: isolated and with agnathia-otocephaly complex. BMJ Case Rep 2017; 2017:bcr-2017-220159. [PMID: 28855214 DOI: 10.1136/bcr-2017-220159] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Cyclopia is a rare form of lethal holoprosencephaly (HPE) due to incomplete cleavage of prosencephalon during embryogenesis, leading to failure of the orbits of the eye to divide into two cavities. We report two cases, one with cyclopia and another case of cyclopia with agnathia-otocephaly complex (AOC). AOC (also known as agnathia-microstomia-synotia syndrome) is a rare lethal congenital malformation of the first branchial arch characterised by the association of agnathia (agenesis of mandible) or mandibular hypoplasia, melotia (anteromedial malposition of ears), microstomia (small mouth), aglossia or microglossia (absent or rudimentary tongue). These two reported cases had in common a single eye and alobar HPE. The first case was live born and the second stillborn. Both mothers did not have antenatal care.
Collapse
Affiliation(s)
- Lin Tun Wai
- Department of Neonatology, Children's Hospital, Mandalay, Myanmar
| | - Suresh Chandran
- Adj Asst Professor , Department of Neonatology, Duke NUS Medical School, Singapore.,Adj Asst Professor, Department of Neonatology, Yong Loo Lin School of Medicine, Singapore.,Adj Asst Professor, Department of Neonatology, Lee Kong Chian School of Medicine, Singapore.,Department of Neonatology, KK Women's and Children's Hospital, Singapore
| |
Collapse
|
23
|
Weiss K, Kruszka P, Guillen Sacoto MJ, Addissie YA, Hadley DW, Hadsall CK, Stokes B, Hu P, Roessler E, Solomon B, Wiggs E, Thurm A, Hufnagel RB, Zein WM, Hahn JS, Stashinko E, Levey E, Baldwin D, Clegg NJ, Delgado MR, Muenke M. In-depth investigations of adolescents and adults with holoprosencephaly identify unique characteristics. Genet Med 2017. [PMID: 28640243 PMCID: PMC5763157 DOI: 10.1038/gim.2017.68] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Purpose With improved medical care, some individuals with holoprosencephaly (HPE) are surviving into adulthood. We investigated the clinical manifestations of adolescents and adults with HPE and explored the underlying molecular causes. Methods Participants included 20 subjects 15 years of age and older. Clinical assessments included dysmorphology exams, cognitive testing, swallowing studies, ophthalmic examination, and brain magnetic resonance imaging. Genetic testing included chromosomal microarray, Sanger sequencing for SHH, ZIC2, SIX3, and TGIF, and whole-exome sequencing (WES) of 10 trios. Results Semilobar HPE was the most common subtype of HPE, seen in 50% of the participants. Neurodevelopmental disabilities were found to correlate with HPE subtype. Factors associated with long-term survival included HPE subtype not alobar, female gender, and nontypical facial features. Four participants had de novo pathogenic variants in ZIC2. WES analysis of 11 participants did not reveal plausible candidate genes, suggesting complex inheritance in these cases. Indeed, in two probands there was a history of uncontrolled maternal type 1 diabetes. Conclusion Individuals with various HPE subtypes can survive into adulthood and the neurodevelopmental outcomes are variable. Based on the facial characteristics and molecular evaluations, we suggest that classic genetic causes of HPE may play a smaller role in this cohort.
Collapse
Affiliation(s)
- Karin Weiss
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Paul Kruszka
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Maria J Guillen Sacoto
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Yonit A Addissie
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Donald W Hadley
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Casey K Hadsall
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Bethany Stokes
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Ping Hu
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Erich Roessler
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Beth Solomon
- Speech and Language Pathology Section, Department of Rehabilitation Medicine, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Edythe Wiggs
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Audrey Thurm
- Pediatrics and Developmental Neuroscience Branch, National Institute of Mental Health, Bethesda, Maryland, USA
| | - Robert B Hufnagel
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Wadih M Zein
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Jin S Hahn
- Stanford University School of Medicine and Lucile Packard Children's Hospital, Stanford, California, USA
| | - Elaine Stashinko
- Neurology and Developmental Medicine, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Eric Levey
- Neurology and Developmental Medicine, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Debbie Baldwin
- Department of Neurology, Texas Scottish Rite Hospital for Children, Dallas, Texas, USA
| | - Nancy J Clegg
- Department of Neurology, Texas Scottish Rite Hospital for Children, Dallas, Texas, USA
| | - Mauricio R Delgado
- Department of Neurology, Texas Scottish Rite Hospital for Children, Dallas, Texas, USA.,Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
| | - Maximilian Muenke
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| |
Collapse
|
24
|
Hilbrands R, Keymolen K, Michotte A, Marichal M, Cools F, Goossens A, Veld PI, De Schepper J, Hattersley A, Heimberg H. Pancreas and gallbladder agenesis in a newborn with semilobar holoprosencephaly, a case report. BMC MEDICAL GENETICS 2017; 18:57. [PMID: 28525974 PMCID: PMC5438508 DOI: 10.1186/s12881-017-0419-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 05/09/2017] [Indexed: 11/10/2022]
Abstract
BACKGROUND Pancreatic agenesis is an extremely rare cause of neonatal diabetes mellitus and has enabled the discovery of several key transcription factors essential for normal pancreas and beta cell development. CASE PRESENTATION We report a case of a Caucasian female with complete pancreatic agenesis occurring together with semilobar holoprosencephaly (HPE), a more common brain developmental disorder. Clinical findings were later confirmed by autopsy, which also identified agenesis of the gallbladder. Although the sequences of a selected set of genes related to pancreas agenesis or HPE were wild-type, the patient's phenotype suggests a genetic defect that emerges early in embryonic development of brain, gallbladder and pancreas. CONCLUSIONS Developmental defects of the pancreas and brain can occur together. Identifying the genetic defect may identify a novel key regulator in beta cell development.
Collapse
Affiliation(s)
- Robert Hilbrands
- Diabetes Research Center, Vrije Universiteit Brussel, Laarbeeklaan 103, Jette, 1090, Brussels, Belgium.,Diabetes Clinic, Universitair Ziekenhuis Brussel, Brussels, Belgium
| | - Kathelijn Keymolen
- Center for Medical Genetics, Reproduction and Genetics, Reproduction Genetics and Regenerative Medicine, Universitair Ziekenhuis Brussel, Jette, Belgium
| | - Alex Michotte
- Department of Pathology, Universitair Ziekenhuis Brussel, Jette, Belgium
| | - Miriam Marichal
- Department of Pathology, Universitair Ziekenhuis Brussel, Jette, Belgium
| | - Filip Cools
- Department of Pediatrics, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Jette, Belgium
| | - Anieta Goossens
- Department of Pathology, Universitair Ziekenhuis Brussel, Jette, Belgium
| | - Peter In't Veld
- Diabetes Research Center, Vrije Universiteit Brussel, Laarbeeklaan 103, Jette, 1090, Brussels, Belgium
| | - Jean De Schepper
- Department of Pediatrics, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Jette, Belgium
| | - Andrew Hattersley
- Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, UK
| | - Harry Heimberg
- Diabetes Research Center, Vrije Universiteit Brussel, Laarbeeklaan 103, Jette, 1090, Brussels, Belgium.
| |
Collapse
|
25
|
Hong M, Krauss RS. Ethanol itself is a holoprosencephaly-inducing teratogen. PLoS One 2017; 12:e0176440. [PMID: 28441416 PMCID: PMC5404885 DOI: 10.1371/journal.pone.0176440] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 04/10/2017] [Indexed: 02/05/2023] Open
Abstract
Ethanol is a teratogen, inducing a variety of structural defects in developing humans and animals that are exposed in utero. Mechanisms of ethanol teratogenicity in specific defects are not well understood. Oxidative metabolism of ethanol by alcohol dehydrogenase or cytochrome P450 2E1 has been implicated in some of ethanol's teratogenic effects, either via production of acetaldehyde or competitive inhibition of retinoic acid synthesis. Generalized oxidative stress in response to ethanol may also play a role in its teratogenicity. Among the developmental defects that ethanol has been implicated in is holoprosencephaly, a failure to define the midline of the forebrain and midface that is associated with a deficiency in Sonic hedgehog pathway function. Etiologically, holoprosencephaly is thought to arise from a complex combination of genetic and environmental factors. We have developed a gene-environment interaction model of holoprosencephaly in mice, in which mutation of the Sonic hedgehog coreceptor, Cdon, synergizes with transient in utero exposure to ethanol. This system was used to address whether oxidative metabolism is required for ethanol's teratogenic activity in holoprosencephaly. We report here that t-butyl alcohol, which is neither a substrate nor an inhibitor of alcohol dehydrogenases or Cyp2E1, is a potent inducer of holoprosencephaly in Cdon mutant mice. Additionally, antioxidant treatment did not prevent ethanol- or t-butyl alcohol-induced HPE in these mice. These findings are consistent with the conclusion that ethanol itself, rather than a consequence of its metabolism, is a holoprosencephaly-inducing teratogen.
Collapse
Affiliation(s)
- Mingi Hong
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY, United States of America
| | - Robert S. Krauss
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY, United States of America
| |
Collapse
|
26
|
Geng X, Acosta S, Lagutin O, Gil HJ, Oliver G. Six3 dosage mediates the pathogenesis of holoprosencephaly. Development 2016; 143:4462-4473. [PMID: 27770010 PMCID: PMC5201039 DOI: 10.1242/dev.132142] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 10/12/2016] [Indexed: 01/06/2023]
Abstract
Holoprosencephaly (HPE) is defined as the incomplete separation of the two cerebral hemispheres. The pathology of HPE is variable and, based on the severity of the defect, HPE is divided into alobar, semilobar, and lobar. Using a novel hypomorphic Six3 allele, we demonstrate in mice that variability in Six3 dosage results in different HPE phenotypes. Furthermore, we show that whereas the semilobar phenotype results from severe downregulation of Shh expression in the rostral diencephalon ventral midline, the alobar phenotype is caused by downregulation of Foxg1 expression in the anterior neural ectoderm. Consistent with these results, in vivo activation of the Shh signaling pathway rescued the semilobar phenotype but not the alobar phenotype. Our findings show that variations in Six3 dosage result in different forms of HPE.
Collapse
Affiliation(s)
- Xin Geng
- Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Sandra Acosta
- Center for Vascular and Developmental Biology, Feinberg Cardiovascular Research Institute, Northwestern University, Chicago, IL 60611, USA
| | - Oleg Lagutin
- Department of Genetics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Hyea Jin Gil
- Center for Vascular and Developmental Biology, Feinberg Cardiovascular Research Institute, Northwestern University, Chicago, IL 60611, USA
| | - Guillermo Oliver
- Center for Vascular and Developmental Biology, Feinberg Cardiovascular Research Institute, Northwestern University, Chicago, IL 60611, USA
| |
Collapse
|
27
|
Dubourg C, Carré W, Hamdi-Rozé H, Mouden C, Roume J, Abdelmajid B, Amram D, Baumann C, Chassaing N, Coubes C, Faivre-Olivier L, Ginglinger E, Gonzales M, Levy-Mozziconacci A, Lynch SA, Naudion S, Pasquier L, Poidvin A, Prieur F, Sarda P, Toutain A, Dupé V, Akloul L, Odent S, de Tayrac M, David V. Mutational Spectrum in Holoprosencephaly Shows That FGF is a New Major Signaling Pathway. Hum Mutat 2016; 37:1329-1339. [DOI: 10.1002/humu.23038] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 06/22/2016] [Indexed: 12/31/2022]
Affiliation(s)
- Christèle Dubourg
- Service de Génétique Moléculaire et Génomique; CHU; Rennes France
- UMR6290 Institut de Génétique et Développement de Rennes; Université de Rennes 1; Rennes France
| | - Wilfrid Carré
- Service de Génétique Moléculaire et Génomique; CHU; Rennes France
- UMR6290 Institut de Génétique et Développement de Rennes; Université de Rennes 1; Rennes France
| | - Houda Hamdi-Rozé
- Service de Génétique Moléculaire et Génomique; CHU; Rennes France
- UMR6290 Institut de Génétique et Développement de Rennes; Université de Rennes 1; Rennes France
| | - Charlotte Mouden
- UMR6290 Institut de Génétique et Développement de Rennes; Université de Rennes 1; Rennes France
| | - Joëlle Roume
- Service de Génétique Médicale; CHI; Poissy France
| | | | - Daniel Amram
- Unité de Génétique Clinique; CHI; Créteil France
| | | | | | | | | | | | - Marie Gonzales
- Service de Génétique et Embryologie Médicales; Hôpital Armand Trousseau; Paris France
| | | | - Sally-Ann Lynch
- Medical Genetics; Our Lady's Children Hospital; Dublin Ireland
| | | | | | - Amélie Poidvin
- Service d'Endocrinologie; CHU Robert Debré; Paris France
| | | | - Pierre Sarda
- Département de Génétique Médicale; CHU; Montpellier France
| | | | - Valérie Dupé
- UMR6290 Institut de Génétique et Développement de Rennes; Université de Rennes 1; Rennes France
| | - Linda Akloul
- Service de Génétique Clinique; CHU; Rennes France
| | - Sylvie Odent
- UMR6290 Institut de Génétique et Développement de Rennes; Université de Rennes 1; Rennes France
- Service de Génétique Clinique; CHU; Rennes France
| | - Marie de Tayrac
- Service de Génétique Moléculaire et Génomique; CHU; Rennes France
- UMR6290 Institut de Génétique et Développement de Rennes; Université de Rennes 1; Rennes France
| | - Véronique David
- Service de Génétique Moléculaire et Génomique; CHU; Rennes France
- UMR6290 Institut de Génétique et Développement de Rennes; Université de Rennes 1; Rennes France
| |
Collapse
|
28
|
Mouden C, Dubourg C, Carré W, Rose S, Quelin C, Akloul L, Hamdi-Rozé H, Viot G, Salhi H, Darnault P, Odent S, Dupé V, David V. Complex mode of inheritance in holoprosencephaly revealed by whole exome sequencing. Clin Genet 2016; 89:659-68. [DOI: 10.1111/cge.12722] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 12/28/2015] [Accepted: 12/30/2015] [Indexed: 12/12/2022]
Affiliation(s)
- C. Mouden
- UMR6290 Institut de Génétique et Développement de Rennes; Université de Rennes 1; Rennes France
| | - C. Dubourg
- UMR6290 Institut de Génétique et Développement de Rennes; Université de Rennes 1; Rennes France
- Laboratoire de Génétique Moléculaire et Génomique; C.H.U. de Rennes; Rennes France
| | - W. Carré
- Laboratoire de Génétique Moléculaire et Génomique; C.H.U. de Rennes; Rennes France
| | - S. Rose
- UMR1085 Institut de Recherche sur la Santé, l'Environnement et le Travail; Université de Rennes 1; Rennes France
| | - C. Quelin
- Service de Génétique Clinique; C.H.U. de Rennes; Rennes France
| | - L. Akloul
- Service de Génétique Clinique; C.H.U. de Rennes; Rennes France
| | - H. Hamdi-Rozé
- UMR6290 Institut de Génétique et Développement de Rennes; Université de Rennes 1; Rennes France
- Laboratoire de Génétique Moléculaire et Génomique; C.H.U. de Rennes; Rennes France
| | - G. Viot
- Service de Génétique Médicale; Maternité Port Royal; Paris France
| | - H. Salhi
- Foetopathologie et Anatomie Pathologique Pédiatrique; Hôpital Cochin; Paris France
| | - P. Darnault
- Service de Radiologie et Imagerie Médicale; C.H.U. de Rennes; Rennes France
| | - S. Odent
- UMR6290 Institut de Génétique et Développement de Rennes; Université de Rennes 1; Rennes France
- Service de Génétique Clinique; C.H.U. de Rennes; Rennes France
| | - V. Dupé
- UMR6290 Institut de Génétique et Développement de Rennes; Université de Rennes 1; Rennes France
| | - V. David
- UMR6290 Institut de Génétique et Développement de Rennes; Université de Rennes 1; Rennes France
- Laboratoire de Génétique Moléculaire et Génomique; C.H.U. de Rennes; Rennes France
| |
Collapse
|
29
|
Abstract
It is thought that most structural birth defects are caused by a complex combination of genetic and environmental factors that interact to interfere with morphogenetic processes. It is important not only to identify individual genetic and environmental risk factors for particular defects but also to identify which environmental factors interact specifically with which genetic variants that predispose to the same defect. Genomic and epidemiological studies are critical to this end. Development and analysis of model systems will also be essential for this goal, as well as for understanding the mechanisms that underlie specific gene-environment interactions.
Collapse
|
30
|
Beccari L, Marco-Ferreres R, Tabanera N, Manfredi A, Souren M, Wittbrodt B, Conte I, Wittbrodt J, Bovolenta P. A trans-Regulatory Code for the Forebrain Expression of Six3.2 in the Medaka Fish. J Biol Chem 2015; 290:26927-26942. [PMID: 26378230 PMCID: PMC4646366 DOI: 10.1074/jbc.m115.681254] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 09/11/2015] [Indexed: 12/16/2022] Open
Abstract
A well integrated and hierarchically organized gene regulatory network is responsible for the progressive specification of the forebrain. The transcription factor Six3 is one of the central components of this network. As such, Six3 regulates several components of the network, but its upstream regulators are still poorly characterized. Here we have systematically identified such regulators, taking advantage of the detailed functional characterization of the regulatory region of the medaka fish Six3.2 ortholog and of a time/cost-effective trans-regulatory screening, which complemented and overcame the limitations of in silico prediction approaches. The candidates resulting from this search were validated with dose-response luciferase assays and expression pattern criteria. Reconfirmed candidates with a matching expression pattern were also tested with chromatin immunoprecipitation and functional studies. Our results confirm the previously proposed direct regulation of Pax6 and further demonstrate that Msx2 and Pbx1 are bona fide direct regulators of early Six3.2 distribution in distinct domains of the medaka fish forebrain. They also point to other transcription factors, including Tcf3, as additional regulators of different spatial-temporal domains of Six3.2 expression. The activity of these regulators is discussed in the context of the gene regulatory network proposed for the specification of the forebrain.
Collapse
Affiliation(s)
- Leonardo Beccari
- Centro de Biología Molecular "Severo Ochoa," Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, c/ Nicolas Cabrera 1, Madrid 28049, Spain,; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), c/ Nicolas Cabrera 1, Madrid 28049, Spain; Instituto Cajal, Consejo Superior de Investigaciones Científicas, Avda. Dr. Arce 37, Madrid, 28002, Spain,.
| | - Raquel Marco-Ferreres
- Centro de Biología Molecular "Severo Ochoa," Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, c/ Nicolas Cabrera 1, Madrid 28049, Spain,; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), c/ Nicolas Cabrera 1, Madrid 28049, Spain; Instituto Cajal, Consejo Superior de Investigaciones Científicas, Avda. Dr. Arce 37, Madrid, 28002, Spain
| | - Noemi Tabanera
- Centro de Biología Molecular "Severo Ochoa," Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, c/ Nicolas Cabrera 1, Madrid 28049, Spain,; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), c/ Nicolas Cabrera 1, Madrid 28049, Spain; Instituto Cajal, Consejo Superior de Investigaciones Científicas, Avda. Dr. Arce 37, Madrid, 28002, Spain
| | - Anna Manfredi
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, Avda. Dr. Arce 37, Madrid, 28002, Spain
| | - Marcel Souren
- the Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Beate Wittbrodt
- the Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Ivan Conte
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, Avda. Dr. Arce 37, Madrid, 28002, Spain,; the Telethon Institute of Genetics and Medicine, Via Campi Flegrei 34, Pozzuoli, Naples, 80078, Italy
| | - Jochen Wittbrodt
- the Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Paola Bovolenta
- Centro de Biología Molecular "Severo Ochoa," Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, c/ Nicolas Cabrera 1, Madrid 28049, Spain,; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), c/ Nicolas Cabrera 1, Madrid 28049, Spain; Instituto Cajal, Consejo Superior de Investigaciones Científicas, Avda. Dr. Arce 37, Madrid, 28002, Spain,.
| |
Collapse
|
31
|
Poelmans S, Kawamoto T, Cristofoli F, Politis C, Vermeesch J, Bailleul-Forestier I, Hens G, Devriendt K, Verdonck A, Carels C. Genotypic and phenotypic variation in six patients with solitary median maxillary central incisor syndrome. Am J Med Genet A 2015; 167A:2451-8. [PMID: 26080100 DOI: 10.1002/ajmg.a.37207] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 06/03/2015] [Indexed: 11/09/2022]
Abstract
Solitary Median Maxillary Central Incisor occurs in 1 of 50,000 live births. It is the mildest manifestation of the holoprosencephaly spectrum and is genetically heterogeneous. Here we report six patients with solitary median maxillary central incisor, and a range of other phenotypic anomalies with different degrees of severity, varying from mild signs of holoprosencephaly to associated intellectual disability, and with different genetic background. Using array comparative genomic hybridization, pathogenic copy number variants were found in three of the six patients. Two patients had a deletion at the 18p11 chromosomal region that includes TGIF1 while the other patient had a deletion at 7q36, including the SHH gene. In one patient, a mutation in SIX3 was detected with exome sequencing, while in the two remaining patients all known holoprosencephaly genes were excluded using multiplex ligation-dependent probe amplification and sequencing, and remain unsolved. One of the two latter patients had isolated solitary median maxillary central incisor without other visible dentofacial anomalies, while the other had clinical features not part of the known holoprosencephaly spectrum.
Collapse
Affiliation(s)
- Simon Poelmans
- Department of Oral Health Sciences-Orthodontics, KU Leuven and Dentistry, University Hospitals Leuven, Leuven, Belgium
| | - Tatsuro Kawamoto
- Department of Orthodontics and Craniofacial Biology, College of Dentistry, Radboudumc, Nijmegen, The Netherlands
- Department of Maxillofacial Reconstruction and Function, Maxillofacial Orthognathics, Division of Maxillofacial/Neck Reconstruction, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
| | - Francesca Cristofoli
- Department of Human Genetics, KU Leuven and Centre for Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Constantinus Politis
- Department of Oral and Maxillofacial Surgery, KU Leuven and University Hospitals Leuven, Leuven, Belgium
| | - Joris Vermeesch
- Department of Human Genetics, KU Leuven and Centre for Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Isabelle Bailleul-Forestier
- Department of Oral Health Sciences-Paediatric Dentistry and Special Care, KU Leuven and Dentistry, University Hospitals Leuven, Leuven, Belgium
- Department of Paediatric Dentistry, Paul Sabatier University, Hôpitaux de Toulouse, France
| | - Greet Hens
- Department of Otorhinolaryngology, Head and Neck Surgery, KU Leuven and University Hospitals Leuven, Leuven, Belgium
| | - Koenraad Devriendt
- Department of Human Genetics, KU Leuven and Centre for Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Anna Verdonck
- Department of Oral Health Sciences-Orthodontics, KU Leuven and Dentistry, University Hospitals Leuven, Leuven, Belgium
| | - Carine Carels
- Department of Oral Health Sciences-Orthodontics, KU Leuven and Dentistry, University Hospitals Leuven, Leuven, Belgium
- Department of Orthodontics and Craniofacial Biology, College of Dentistry, Radboudumc, Nijmegen, The Netherlands
| |
Collapse
|
32
|
Prenatal Diagnosis of Central Nervous System Anomalies by High-Resolution Chromosomal Microarray Analysis. BIOMED RESEARCH INTERNATIONAL 2015; 2015:426379. [PMID: 26064910 PMCID: PMC4443641 DOI: 10.1155/2015/426379] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 04/07/2015] [Indexed: 12/20/2022]
Abstract
The aims of this study were to evaluate the contribution of chromosomal microarray analysis (CMA) in the prenatal diagnosis of fetuses with central nervous system (CNS) anomalies but normal chromosomal karyotype. A total of 46 fetuses with CNS anomalies with or without other ultrasound anomalies but normal karyotypes were evaluated by array-based comparative genomic hybridisation (aCGH) or single-nucleotide polymorphism (SNP) array. The result showed that CNVs were detected in 17 (37.0%) fetuses. Of these, CNVs identified in 5 (5/46, 10.9%) fetuses were considered to be likely pathogenic, and CNVs detected in 3 (3/46, 6.5%) fetuses were defined as being of uncertain clinical significance. Fetuses with CNS malformations plus other ultrasound anomalies had a higher rate of pathogenic CNVs than those with isolated CNS anomalies (13.6% versus 8.3%), but there was no significant difference (Fisher's exact test, P > 0.05). Pathogenic CNVs were detected most frequently in fetuses with Dandy-Walker syndrome (2/6, 33.3%) when compared with other types of neural malformations, and holoprosencephaly (2/7, 28.6%) ranked the second. CMA is valuable in prenatal genetic diagnosis of fetuses with CNS anomalies. It should be considered as part of prenatal diagnosis in fetuses with CNS malformations and normal karyotypes.
Collapse
|
33
|
Gold KS, Brand AH. Optix defines a neuroepithelial compartment in the optic lobe of the Drosophila brain. Neural Dev 2014; 9:18. [PMID: 25074684 PMCID: PMC4127074 DOI: 10.1186/1749-8104-9-18] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 06/25/2014] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND During early brain development, the organisation of neural progenitors into a neuroepithelial sheet maintains tissue integrity during growth. Neuroepithelial cohesion and patterning is essential for orderly proliferation and neural fate specification. Neuroepithelia are regionalised by the expression of transcription factors and signalling molecules, resulting in the formation of distinct developmental, and ultimately functional, domains. RESULTS We have discovered that the Six3/6 family orthologue Optix is an essential regulator of neuroepithelial maintenance and patterning in the Drosophila brain. Six3 and Six6 are required for mammalian eye and forebrain development, and mutations in humans are associated with severe eye and brain malformation. In Drosophila, Optix is expressed in a sharply defined region of the larval optic lobe, and its expression is reciprocal to that of the transcription factor Vsx1. Optix gain- and loss-of-function affects neuroepithelial adhesion, integrity and polarity. We find restricted cell lineage boundaries that correspond to transcription factor expression domains. CONCLUSION We propose that the optic lobe is compartmentalised by expression of Optix and Vsx1. Our findings provide insight into the spatial patterning of a complex region of the brain, and suggest an evolutionarily conserved principle of visual system development.
Collapse
Affiliation(s)
| | - Andrea H Brand
- The Gurdon Institute and Department of Physiology, Development & Neuroscience, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK.
| |
Collapse
|
34
|
Savastano CP, El-Jaick KB, Costa-Lima MA, Abath CMB, Bianca S, Cavalcanti DP, Félix TM, Scarano G, Llerena JC, Vargas FR, Moreira MÂM, Seuánez HN, Castilla EE, Orioli IM. Molecular analysis of holoprosencephaly in South America. Genet Mol Biol 2014; 37:250-62. [PMID: 24764759 PMCID: PMC3983586 DOI: 10.1590/s1415-47572014000200011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Holoprosencephaly (HPE) is a spectrum of brain and facial malformations primarily reflecting genetic factors, such as chromosomal abnormalities and gene mutations. Here, we present a clinical and molecular analysis of 195 probands with HPE or microforms; approximately 72% of the patients were derived from the Latin American Collaborative Study of Congenital Malformations (ECLAMC), and 82% of the patients were newborns. Alobar HPE was the predominant brain defect in almost all facial defect categories, except for patients without oral cleft and median or lateral oral clefts. Ethmocephaly, cebocephaly, and premaxillary agenesis were primarily observed among female patients. Premaxillary agenesis occurred in six of the nine diabetic mothers. Recurrence of HPE or microform was approximately 19%. The frequency of microdeletions, detected using Multiplex Ligation-dependant Probe Amplification (MLPA) was 17% in patients with a normal karyotype. Cytogenetics or QF-PCR analyses revealed chromosomal anomalies in 27% of the probands. Mutational analyses in genes SHH, ZIC2, SIX3 and TGIF were performed in 119 patients, revealing eight mutations in SHH, two mutations in SIX3 and two mutations in ZIC2. Thus, a detailed clinical description of new HPE cases with identified genetic anomalies might establish genotypic and phenotypic correlations and contribute to the development of additional strategies for the analysis of new cases.
Collapse
Affiliation(s)
- Clarice Pagani Savastano
- Estudo Colaborativo Latino Americano de Malformações Congênitas, Departamento de Genética, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil . ; Instituto Nacional de Genética Médica Populacional, Rio de Janeiro, RJ, Brazil
| | - Kênia Balbi El-Jaick
- Departamento de Genética e Biologia Molecular, Universidade Federal do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | | | | | - Sebastiano Bianca
- Centro di Consulenza Genetica e di Teratologia della Riproduzione, Dipartimento Materno Infantile, ARNAS Garibaldi Nesima, Catania, CT, Italy
| | | | - Têmis Maria Félix
- Serviço de Genética Médica, Hospital das Clínicas de Porto Alegre, Porto Alegre, RS, Brazil
| | - Gioacchino Scarano
- Registro Campano Difetti Congeniti, Azienda Ospedaliera "Gaetano Rummo", Benevento, BN, Italy
| | - Juan Clinton Llerena
- Centro de Genética Médica, Instituto Fernandes Figueira, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil
| | - Fernando Regla Vargas
- Departamento de Genética e Biologia Molecular, Universidade Federal do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil . ; Estudo Colaborativo Latino Americano de Malformações Congênitas, Laboratório de Epidemiologia de Defeitos Congênitos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil
| | | | - Hector N Seuánez
- Programa de Genética, Instituto Nacional de Câncer, Rio de Janeiro, RJ, Brazil
| | - Eduardo Enrique Castilla
- Instituto Nacional de Genética Médica Populacional, Rio de Janeiro, RJ, Brazil . ; Estudio Colaborativo Latino Americano de Malformaciones Congenitas, Centro de Educación Médica e Investigación Clínica, Buenos Aires, Argentina
| | - Iêda Maria Orioli
- Estudo Colaborativo Latino Americano de Malformações Congênitas, Departamento de Genética, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil . ; Instituto Nacional de Genética Médica Populacional, Rio de Janeiro, RJ, Brazil
| |
Collapse
|
35
|
Savastano CP, Bernardi P, Seuánez HN, Moreira MÂM, Orioli IM. Rare nasal cleft in a patient with holoprosencephaly due to a mutation in the ZIC2 gene. ACTA ACUST UNITED AC 2014; 100:300-6. [PMID: 24677696 DOI: 10.1002/bdra.23216] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 12/08/2013] [Accepted: 12/12/2013] [Indexed: 01/13/2023]
Abstract
BACKGROUND Holoprosencephaly (HPE) is a spectrum of midline malformations of the prosencephalon generally reflected in a continuum of midline facial anomalies. Patients with mutation in the ZIC2 gene usually present a normal or mildly dysmorphic face associated with a severe brain malformation. Here we present a rare unilateral nasal cleft (Tessier cleft n. 1) with holoprosencephaly in a patient with a ZIC2 mutation. CASE The male newborn presented with alobar HPE, microcephaly, ocular hypertelorism, upslanting palpebral fissures, a bulky nose with a left paramedian alar cleft. Mutational screening for HPE genes revealed the occurrence of a frameshift mutation in the ZIC2 gene. The mutation was inherited from the father who presented only mild ocular hypotelorism but had an affected child with HPE from his first marriage. CONCLUSION The occurrence of oral clefts is common in patients with HPE, but unusual in patients with mutation in the ZIC2 gene. To our knowledge, clefts of the nasal alae have been reported only once or twice in patients with ZIC2 mutations. In documented patients from the literature, only 2% of individuals with described pathogenic mutations in the ZIC2 gene (3/171) presented facial clefts, one of them a nasal cleft, while common oral clefts were observed in 27% of individuals (7/26) described with nonpathogenic ZIC2 mutations or presenting a concomitant mutation in another HPE gene. When compared with the general population, nasal clefts are common in ZIC2 mutations and these mutations must be searched for in undiagnosed cases.
Collapse
Affiliation(s)
- Clarice Pagani Savastano
- Estudo Colaborativo Latino Americano de Malformações Congênitas (ECLAMC), Departamento de Genética, Universidade Federal do Rio de Janeiro, Brazil; INAGEMP - Instituto Nacional de Genética Médica Populacional, Rio de Janeiro, Brazil
| | | | | | | | | |
Collapse
|
36
|
Quintana A, Garabedian MJ, Wallerstein RJ. Antenatal detection of maternal unipartental disomy of chromosome 2 in a fetus with non-chromosomal, non-syndromic alobar holoprosencephaly. Am J Med Genet A 2013; 164A:276-8. [PMID: 24243683 DOI: 10.1002/ajmg.a.36204] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 07/29/2013] [Indexed: 11/10/2022]
Affiliation(s)
- Andrea Quintana
- Department of Obstetrics and Gynecology, Santa Clara Valley Medical Center, San Jose, California
| | | | | |
Collapse
|
37
|
Tatsi C, Sertedaki A, Voutetakis A, Valavani E, Magiakou MA, Kanaka-Gantenbein C, Chrousos GP, Dacou-Voutetakis C. Pituitary stalk interruption syndrome and isolated pituitary hypoplasia may be caused by mutations in holoprosencephaly-related genes. J Clin Endocrinol Metab 2013; 98:E779-84. [PMID: 23476075 DOI: 10.1210/jc.2012-3982] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
CONTEXT Holoprosencephaly (HPE) is a developmental defect characterized by wide phenotypic variability, ranging from minor midline malformations (eg, single central incisor) to severe deformities. In 10-15% of HPE patients, mutations in specific genes have been identified (eg, SHH, TGIF, SIX3). Pituitary stalk interruption syndrome (PSIS) constitutes a distinct abnormality of unknown pathogenesis, whereas isolated pituitary hypoplasia (IPH) has been linked to various developmental genes. OBJECTIVE Three of our patients with PSIS had a single central incisor, a malformation encountered in some HPE cases. Based on this observation, we initiated a search for mutations in HPE-associated genes in 30 patients with PSIS or IPH. DESIGN AND PARTICIPANTS The entire coding region of the TGIF, SHH, and SIX3 genes was sequenced in patients with combined pituitary hormone deficiency associated with either PSIS or IPH and in healthy controls. RESULTS Two novel mutations in the HPE-related genes were detected (ie, c.799 C>T, p.Q267X in the TGIF gene, and c.1279G>A, p.G427R in the SHH gene) in 2 of our patients. The overall incidence of HPE-related gene mutations in our nonsyndromic and nonchromosomal patients was 6.6%. No molecular defect in the SIX3 gene was detected in our cohort. CONCLUSIONS The data suggest that HPE-related gene mutations are implicated in the etiology of isolated pituitary defects (PSIS or IPH). Alternatively, PSIS or IPH may constitute mild forms of an expanded HPE spectrum.
Collapse
Affiliation(s)
- Christina Tatsi
- Division of Endocrinology, Metabolism, and Diabetes, First Department of Pediatrics, Athens University Medical School, 11527 Athens, Greece
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Solomon BD, Pineda-Alvarez DE, Gropman AL, Willis MJ, Hadley DW, Muenke M. High Intellectual Function in Individuals with Mutation-Positive Microform Holoprosencephaly. Mol Syndromol 2012; 3:140-142. [PMID: 23112757 DOI: 10.1159/000341373] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/20/2012] [Indexed: 11/19/2022] Open
Abstract
Holoprosencephaly is the most common malformation of the forebrain and typically results in severe neurocognitive impairment with accompanying midline facial anomalies. Holoprosencephaly is heterogeneous and may be caused by chromosome aberrations or environmental factors, occur in the context of a syndrome or be due to heterozygous mutations in over 10 identified genes. The presence of these mutations may result in an extremely wide spectrum of severity, ranging from brain malformations incompatible with life to individuals with normal brain findings and subtle midline facial differences. Typically, clinicians regard intellectual disability as a sign that a parent or relative of a severely affected patient may be a mildly affected mutation 'carrier' with what is termed microform holoprosencephaly. Here we present 5 patients with clear phenotypic signs of microform holoprosencephaly, all of whom have evidence of above-average intellectual function. In 4 of these 5 individuals, the molecular cause of holoprosencephaly has been identified and includes mutations affecting SHH, SIX3, GLI2, and FGF8. This report expands the phenotypic spectrum of holoprosencephaly and is important in the counseling of patient and affected families.
Collapse
Affiliation(s)
- B D Solomon
- Medical Genetics Branch, Naval Medical Center, San Diego, Calif., USA
| | | | | | | | | | | |
Collapse
|
39
|
Carlin D, Sepich D, Grover VK, Cooper MK, Solnica-Krezel L, Inbal A. Six3 cooperates with Hedgehog signaling to specify ventral telencephalon by promoting early expression of Foxg1a and repressing Wnt signaling. Development 2012; 139:2614-24. [PMID: 22736245 PMCID: PMC3383232 DOI: 10.1242/dev.076018] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/01/2012] [Indexed: 01/18/2023]
Abstract
Six3 exerts multiple functions in the development of anterior neural tissue of vertebrate embryos. Whereas complete loss of Six3 function in the mouse results in failure of forebrain formation, its hypomorphic mutations in human and mouse can promote holoprosencephaly (HPE), a forebrain malformation that results, at least in part, from abnormal telencephalon development. However, the roles of Six3 in telencephalon patterning and differentiation are not well understood. To address the role of Six3 in telencephalon development, we analyzed zebrafish embryos deficient in two out of three Six3-related genes, six3b and six7, representing a partial loss of Six3 function. We found that telencephalon forms in six3b;six7-deficient embryos; however, ventral telencephalic domains are smaller and dorsal domains are larger. Decreased cell proliferation or excess apoptosis cannot account for the ventral deficiency. Instead, six3b and six7 are required during early segmentation for specification of ventral progenitors, similar to the role of Hedgehog (Hh) signaling in telencephalon development. Unlike in mice, we observe that Hh signaling is not disrupted in embryos with reduced Six3 function. Furthermore, six3b overexpression is sufficient to compensate for loss of Hh signaling in isl1- but not nkx2.1b-positive cells, suggesting a novel Hh-independent role for Six3 in telencephalon patterning. We further find that Six3 promotes ventral telencephalic fates through transient regulation of foxg1a expression and repression of the Wnt/β-catenin pathway.
Collapse
Affiliation(s)
- Dan Carlin
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232, USA
- Department of Developmental Biology, Washington University School of Medicine, St Louis, MO 63110, USA
| | - Diane Sepich
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232, USA
- Department of Developmental Biology, Washington University School of Medicine, St Louis, MO 63110, USA
| | - Vandana K. Grover
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Michael K. Cooper
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Lilianna Solnica-Krezel
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232, USA
- Department of Developmental Biology, Washington University School of Medicine, St Louis, MO 63110, USA
| | - Adi Inbal
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232, USA
- Department of Medical Neurobiology, IMRIC, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel
| |
Collapse
|
40
|
Pineda-Alvarez DE, Solomon BD, Roessler E, Balog JZ, Hadley DW, Zein WM, Brooks BP, Muenke M. Patients within the broad holoprosencephaly spectrum have distinct and subtle ophthalmologic anomalies: Response to Khan. Am J Med Genet A 2012; 158A:1244-1245. [DOI: 10.1002/ajmg.a.35207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
41
|
Roessler E, Vélez JI, Zhou N, Muenke M. Utilizing prospective sequence analysis of SHH, ZIC2, SIX3 and TGIF in holoprosencephaly probands to describe the parameters limiting the observed frequency of mutant gene×gene interactions. Mol Genet Metab 2012; 105:658-64. [PMID: 22310223 PMCID: PMC3309119 DOI: 10.1016/j.ymgme.2012.01.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Revised: 01/05/2012] [Accepted: 01/05/2012] [Indexed: 11/29/2022]
Abstract
Clinical molecular diagnostic centers routinely screen SHH, ZIC2, SIX3 and TGIF for mutations that can help to explain holoprosencephaly and related brain malformations. Here we report a prospective Sanger sequence analysis of 189 unrelated probands referred to our diagnostic lab for genetic testing. We identified 28 novel unique mutations in this group (15%) and no instances of deleterious mutations in two genes in the same subject. Our result extends that of other diagnostic centers and suggests that among the aggregate 475 prospectively sequenced holoprosencephaly probands there is negligible evidence for direct gene-gene interactions among these tested genes. We model the predictions of the observed mutation frequency in the context of the hypothesis that gene×gene interactions are a prerequisite for forebrain malformations, i.e. the "multiple-hit" hypothesis. We conclude that such a direct interaction would be expected to be rare and that more subtle genetic and environmental interactions are a better explanation for the clinically observed inter- and intra-familial variability.
Collapse
Affiliation(s)
- Erich Roessler
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jorge I. Vélez
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Nan Zhou
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Maximilian Muenke
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| |
Collapse
|
42
|
Morris AC. The genetics of ocular disorders: insights from the zebrafish. ACTA ACUST UNITED AC 2012; 93:215-28. [PMID: 21932431 DOI: 10.1002/bdrc.20211] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Proper formation of the vertebrate eye requires a precisely coordinated sequence of morphogenetic events that integrate the developmental contributions of the skin ectoderm, neuroectoderm, and head mesenchyme. Disruptions in this process result in ocular malformations or retinal degeneration and can cause significant visual impairment. The zebrafish is an excellent vertebrate model for the study of eye development and disease due to the transparency of the embryo, its ex utero development, and its amenability to forward genetic screens. This review will present an overview of the genetic methodologies utilized in the zebrafish, a description of several zebrafish models of congenital ocular diseases, and a discussion of the utility of the zebrafish for assessing the pathogenicity of candidate disease alleles.
Collapse
Affiliation(s)
- Ann C Morris
- Department of Biology, University of Kentucky, Lexington, USA.
| |
Collapse
|
43
|
Raam MS, Solomon BD, Muenke M. Holoprosencephaly: a guide to diagnosis and clinical management. Indian Pediatr 2011; 48:457-66. [PMID: 21743112 DOI: 10.1007/s13312-011-0078-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
CONTEXT Holoprosencephaly affects 1 in 8,000 live births and is the most common structural anomaly of the developing forebrain, resulting in facial dysmorphism, neurologic impairment, and additional clinical sequelae. Given the increasing relative contribution of genetic diseases to perinatal morbidity and mortality in India, proper recognition and management of holoprosencephaly can improve care for a significant number of affected Indian children. EVIDENCE ACQUISITION We used the PubMed database (search terms: "holoprosencephaly," "HPE," "holoprosencephaly India") and cross-referenced articles regarding holoprosencephaly, using our research group's extensive experience as a guide for identifying seminal papers in the field. RESULTS Holoprosencephaly is classified into four types based on the nature of the brain malformations as seen on neuroimaging and/or pathologic examination, with typically recognizable craniofacial phenotypes. Despite the identification of several genetic loci and other etiologic agents involved in pathogenesis, additional causes are elusive. Moreover, satisfactory explanations for phenomena such as incomplete penetrance and variable expressivity are lacking. CONCLUSIONS For each patient, pediatricians should follow a diagnostic protocol including dysmorphology examination, complete family history and ascertainment of risk factors, and neuroimaging. Many medical issues, including hypothalamic dysfunction, endocrinologic dysfunction, motor impairment, respiratory issues, seizures, and hydrocephalus should be prioritized in management. Pediatricians should work with genetic specialists to identify syndromic forms and to perform cytogenetic investigation, molecular screening, and genetic counseling in order to fully characterize prognosis and recurrence risk.
Collapse
Affiliation(s)
- Manu S Raam
- HHMI-NIH Research Scholars Program, Howard Hughes Medical Institute, Chevy Chase, MD, United States
| | | | | |
Collapse
|
44
|
|
45
|
Pineda-Alvarez DE, Solomon BD, Roessler E, Balog JZ, Hadley DW, Zein WM, Hadsall CK, Brooks BP, Muenke M. A broad range of ophthalmologic anomalies is part of the holoprosencephaly spectrum. Am J Med Genet A 2011; 155A:2713-20. [PMID: 21976454 PMCID: PMC3200498 DOI: 10.1002/ajmg.a.34261] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Accepted: 07/17/2011] [Indexed: 01/15/2023]
Abstract
Holoprosencephaly (HPE) is the most common disorder of the developing forebrain in humans, and is characterized by failed or incomplete cleavage of the cerebral hemispheres and deep brain structures. HPE includes wide phenotypic variability, with a continuum of both brain and craniofacial anomalies. While "classic" eye findings, including the spectrum of midline anomalies ranging from cyclopia to hypotelorism, as well as chorioretinal coloboma and microphthalmia, have been frequently described in patients with HPE, other subtle eye anomalies may also occur. In our study we prospectively analyzed a small cohort of 10 patients in whom we identified mutations in SHH, SIX3, ZIC2, or FGF8, the latter of which is a very recently described HPE-associated gene. We found that 9 of 10 patients had at least two ophthalmologic anomalies, including refractive errors, microcornea, microphthalmia, blepharoptosis, exotropia, and uveal coloboma. These findings contribute to the understanding of the phenotypic variability of the HPE spectrum, and highlight findings in one medically important but often incompletely investigated system.
Collapse
Affiliation(s)
- Daniel E. Pineda-Alvarez
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Benjamin D. Solomon
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Erich Roessler
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Joan Z. Balog
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Donald W. Hadley
- Social and Behavioral Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Wadih M. Zein
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Casey K. Hadsall
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Brian P. Brooks
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Maximilian Muenke
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| |
Collapse
|
46
|
Mercier S, Dubourg C, Garcelon N, Campillo-Gimenez B, Gicquel I, Belleguic M, Ratié L, Pasquier L, Loget P, Bendavid C, Jaillard S, Rochard L, Quélin C, Dupé V, David V, Odent S. New findings for phenotype-genotype correlations in a large European series of holoprosencephaly cases. J Med Genet 2011; 48:752-60. [PMID: 21940735 PMCID: PMC3386902 DOI: 10.1136/jmedgenet-2011-100339] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
BACKGROUND Holoprosencephaly (HPE) is the most common forebrain defect in humans. It results from incomplete midline cleavage of the prosencephalon. METHODS A large European series of 645 HPE probands (and 699 relatives), consisting of 51% fetuses and 49% liveborn children, is reported. RESULTS Mutations in the four main genes involved in HPE (SHH, ZIC2, SIX3, TGIF) were identified in 25% of cases. The SHH, SIX3, and TGIF mutations were inherited in more than 70% of these cases, whereas 70% of the mutations in ZIC2 occurred de novo. Moreover, rearrangements were detected in 22% of the 260 patients screened by array comparative genomic hybridisation. 15 probands had two mutations providing additional support for the 'multiple-hit process' in HPE. There was a positive correlation between the severity of the brain malformation and facial features for SHH, SIX3, and TGIF, but no such correlation was found for ZIC2 mutations. The most severe HPE types were associated with SIX3 and ZIC2 mutations, whereas microforms were associated with SHH mutations. The study focused on the associated brain malformations, including neuronal migration defects, which predominated in individuals with ZIC2 mutations, and neural tube defects, which were frequently associated with ZIC2 (rachischisis) and TGIF mutations. Extracraniofacial features were observed in 27% of the individuals in this series (up to 40% of those with ZIC2 mutations) and a significant correlation was found between renal/urinary defects and mutations of SHH and ZIC2. CONCLUSIONS An algorithm is proposed based on these new phenotype-genotype correlations, to facilitate molecular analysis and genetic counselling for HPE.
Collapse
Affiliation(s)
- Sandra Mercier
- IGDR, Institut de Génétique et Développement de Rennes
CNRS : UMR6061Université de Rennes 1IFR140Faculté de Médecine - CS 34317 2 Av du Professeur Léon Bernard 35043 RENNES CEDEX,FR
- Service de génétique médicale
CHU RennesUniversité de Rennes 116 bd de Bulgarie BP 90437, 35203 Rennes Cedex 2,FR
| | - Christèle Dubourg
- IGDR, Institut de Génétique et Développement de Rennes
CNRS : UMR6061Université de Rennes 1IFR140Faculté de Médecine - CS 34317 2 Av du Professeur Léon Bernard 35043 RENNES CEDEX,FR
| | - Nicolas Garcelon
- LIM, Laboratoire d'Informatique Médicale
Université de Rennes 1Laboratoire d'Informatique Médicale CHU - Pontchaillou 2, rue Henri Le Guilloux 35033 RENNES,FR
| | - Boris Campillo-Gimenez
- LIM, Laboratoire d'Informatique Médicale
Université de Rennes 1Laboratoire d'Informatique Médicale CHU - Pontchaillou 2, rue Henri Le Guilloux 35033 RENNES,FR
| | - Isabelle Gicquel
- IGDR, Institut de Génétique et Développement de Rennes
CNRS : UMR6061Université de Rennes 1IFR140Faculté de Médecine - CS 34317 2 Av du Professeur Léon Bernard 35043 RENNES CEDEX,FR
| | - Marion Belleguic
- Service de génétique médicale
CHU RennesUniversité de Rennes 116 bd de Bulgarie BP 90437, 35203 Rennes Cedex 2,FR
| | - Leslie Ratié
- IGDR, Institut de Génétique et Développement de Rennes
CNRS : UMR6061Université de Rennes 1IFR140Faculté de Médecine - CS 34317 2 Av du Professeur Léon Bernard 35043 RENNES CEDEX,FR
| | - Laurent Pasquier
- Service de génétique médicale
CHU RennesUniversité de Rennes 116 bd de Bulgarie BP 90437, 35203 Rennes Cedex 2,FR
| | - Philippe Loget
- Service d'anatomie et cytologie pathologiques
Hôpital PontchaillouUniversité de Rennes 1CHU Rennes2, rue Henri-le-Guilloux, 35000 Rennes,FR
| | - Claude Bendavid
- IGDR, Institut de Génétique et Développement de Rennes
CNRS : UMR6061Université de Rennes 1IFR140Faculté de Médecine - CS 34317 2 Av du Professeur Léon Bernard 35043 RENNES CEDEX,FR
| | - Sylvie Jaillard
- IGDR, Institut de Génétique et Développement de Rennes
CNRS : UMR6061Université de Rennes 1IFR140Faculté de Médecine - CS 34317 2 Av du Professeur Léon Bernard 35043 RENNES CEDEX,FR
| | - Lucie Rochard
- IGDR, Institut de Génétique et Développement de Rennes
CNRS : UMR6061Université de Rennes 1IFR140Faculté de Médecine - CS 34317 2 Av du Professeur Léon Bernard 35043 RENNES CEDEX,FR
| | - Chloé Quélin
- Service de génétique médicale
CHU RennesUniversité de Rennes 116 bd de Bulgarie BP 90437, 35203 Rennes Cedex 2,FR
| | - Valérie Dupé
- IGDR, Institut de Génétique et Développement de Rennes
CNRS : UMR6061Université de Rennes 1IFR140Faculté de Médecine - CS 34317 2 Av du Professeur Léon Bernard 35043 RENNES CEDEX,FR
| | - Véronique David
- IGDR, Institut de Génétique et Développement de Rennes
CNRS : UMR6061Université de Rennes 1IFR140Faculté de Médecine - CS 34317 2 Av du Professeur Léon Bernard 35043 RENNES CEDEX,FR
| | - Sylvie Odent
- IGDR, Institut de Génétique et Développement de Rennes
CNRS : UMR6061Université de Rennes 1IFR140Faculté de Médecine - CS 34317 2 Av du Professeur Léon Bernard 35043 RENNES CEDEX,FR
- Service de génétique médicale
CHU RennesUniversité de Rennes 116 bd de Bulgarie BP 90437, 35203 Rennes Cedex 2,FR
| |
Collapse
|
47
|
Pineda-Alvarez DE, Roessler E, Hu P, Srivastava K, Solomon BD, Siple CE, Fan CM, Muenke M. Missense substitutions in the GAS1 protein present in holoprosencephaly patients reduce the affinity for its ligand, SHH. Hum Genet 2011; 131:301-10. [PMID: 21842183 DOI: 10.1007/s00439-011-1078-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Accepted: 08/02/2011] [Indexed: 10/17/2022]
Abstract
Holprosencephaly (HPE) is the most common disorder of the developing forebrain in humans, and is characterized by varying degrees of abnormal union of the cerebral hemispheres. These defects are typically co-associated with midline craniofacial anomalies. The combination of forebrain and craniofacial defects that comprise HPE can present along a broad and variable phenotypic spectrum. Both the SHH and NODAL signaling pathways play important roles in the pathogenesis of this disorder. Disruption of these pathways by chromosomal rearrangements, mutations in pathway-related genes and/or biochemical alterations are proposed to contribute to HPE in a large number of patients. Additional factors that are not yet fully delineated are also very likely to be involved in the pathogenesis and phenotypic heterogeneity of the disorder. Genetic loss of GAS1, a cell membrane receptor and positive regulator of SHH, has been demonstrated to contribute to the HPE phenotypic spectrum in animal models. We have evaluated the coding and flanking sequence of GAS1 in 394 patients who have clinical findings within the HPE phenotypic spectrum, and now report five novel missense sequence variants among five unrelated HPE probands. Finally, we tested the effect of these variants (as well as previously reported GAS1 variants) on the ability of GAS1 to bind to SHH. Here, we demonstrate that sequence variants in GAS1 can impair its physical interaction with SHH, suggesting a decrease in the SHH downstream signaling cascade as a pathogenic mechanism of disease.
Collapse
Affiliation(s)
- Daniel E Pineda-Alvarez
- Medical Genetics Branch, National Human Genome Research Institute (NHGRI), National Institutes of Health, Bethesda, MD 20892-3717, USA
| | | | | | | | | | | | | | | |
Collapse
|
48
|
Petracchi F, Crespo L, Michia C, Igarzabal L, Gadow E. Holoprosencephaly at prenatal diagnosis: analysis of 28 cases regarding etiopathogenic diagnoses. Prenat Diagn 2011; 31:887-91. [PMID: 21706511 DOI: 10.1002/pd.2796] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Revised: 04/27/2011] [Accepted: 04/30/2011] [Indexed: 11/08/2022]
Abstract
OBJECTIVE To assess the likelihood of finding an etiopathogenic cause in an ultrasonographic prenatal diagnosis of holoprosencephaly. MATERIALS AND METHODS From January 1996 to June 2010, 13 883 prenatal diagnoses through chorionic villus sampling or amniocentesis were made. Every fetus with holoprosencephaly at ultrasound was evaluated. Gestational age, additional ultrasound findings, and fetal karyotype were recorded. Molecular diagnosis and parental karyotype were studied, if relevant. RESULTS Twenty-eight fetuses were diagnosed with holoprosencephaly (0.20%). All cases had additional ultrasound findings (100%). A definitive etiology was found in 23 cases (82.14%): karyotype was abnormal in 19 (67.9%) and normal in 8 (28.5%) cases. In the normal karyotype group, although molecular testing was performed in a few cases, one mutation of gene SIX 3 was diagnosed, one diagnosis of dysgnathia complex was made, and two fetuses presented Smith-Lemli-Opitz syndrome. No etiopathogenic diagnosis was made in five fetuses. CONCLUSIONS Our results showed that a definitive etiology can be established in most cases of prenatal holoprosencephaly. Chromosomal anomalies were the most frequent finding. However, in euploid fetuses, molecular diagnosis is worthwhile, as different genes with different inheritance patterns may be responsible for this malformation. Thorough evaluation proved beneficial for assessing more accurate prognosis and recurrence risks.
Collapse
Affiliation(s)
- F Petracchi
- Genetic Unit, Department of Obstetrics and Gynecology, Centro de Educación Médica en Investigaciones Clínicas, CEMIC, Instituto Universitario, Buenos Aires, Argentina.
| | | | | | | | | |
Collapse
|
49
|
Kauvar EF, Hu P, Pineda-Alvarez DE, Solomon BD, Dutra A, Pak E, Blessing B, Proud V, Shanske AL, Stevens CA, Rosenfeld JA, Shaffer LG, Roessler E, Muenke M. Minimal evidence for a direct involvement of twisted gastrulation homolog 1 (TWSG1) gene in human holoprosencephaly. Mol Genet Metab 2011; 102:470-80. [PMID: 21227728 PMCID: PMC3152819 DOI: 10.1016/j.ymgme.2010.12.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Revised: 12/14/2010] [Accepted: 12/14/2010] [Indexed: 10/18/2022]
Abstract
Holoprosencephaly (HPE) is the most common disorder of human forebrain and facial development. Presently understood etiologies include both genetic and environmental factors, acting either alone, or more likely, in combination. The majority of patients without overt chromosomal abnormalities or recognizable associated syndromes have unidentified etiologies. A potential candidate gene, Twisted Gastrulation Homolog 1 (TWSG1), was previously suggested as a contributor to the complex genetics of human HPE based on (1) cytogenetic studies of patients with 18p deletions, (2) animal studies of TWSG1 deficient mice, and (3) the relationship of TWSG1 to bone morphogenetic protein (BMP) signaling, which modulates the primary pathway implicated in HPE, Sonic Hedgehog (SHH) signaling. Here we present the first analysis of a large cohort of patients with HPE for coding sequence variations in TWSG1. We also performed fine mapping of 18p for a subset of patients with partial 18p deletions. Surprisingly, minimal evidence for alterations of TWSG1 was found, suggesting that sequence alterations of TWSG1 are neither a common direct cause nor a frequent modifying factor for human HPE pathologies.
Collapse
Affiliation(s)
- Emily F. Kauvar
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
- Howard Hughes Medical Institute – National Institutes of Health Research Scholars Program, Bethesda, MD, USA
| | - Ping Hu
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Daniel E. Pineda-Alvarez
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Benjamin D. Solomon
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Amalia Dutra
- Genetic Disease Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Evgenia Pak
- Genetic Disease Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Brooke Blessing
- Division of Medical Genetics, Children’s Hospital of The King’s Daughters, Norfolk, VA, USA
| | - Virginia Proud
- Division of Medical Genetics, Children’s Hospital of The King’s Daughters, Norfolk, VA, USA
| | - Alan L. Shanske
- Center for Craniofacial Disorders, Children’s Hospital at Montefiore Medical Center, Bronx, NY, USA
| | - Cathy A. Stevens
- Department of Pediatrics, University of Tennessee College of Medicine, Chattanooga, TN, USA
| | | | | | - Erich Roessler
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Maximilian Muenke
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
- Corresponding author: Address: 35 Convent Drive, MSC 3717, Bldg 35, Rm 1B-203, Bethesda, MD, 20892-3717, USA. Tel: (301) 402-8167. Fax: (301) 480-7876. (M. Muenke)
| |
Collapse
|
50
|
Wannasilp N, Solomon BD, Warren-Mora N, Clegg NJ, Delgado MR, Lacbawan F, Hu P, Winder TL, Roessler E, Muenke M. Holoprosencephaly in a family segregating novel variants in ZIC2 and GLI2. Am J Med Genet A 2011; 155A:860-4. [PMID: 21416594 DOI: 10.1002/ajmg.a.33903] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2010] [Accepted: 12/23/2010] [Indexed: 02/03/2023]
Abstract
Holoprosencephaly (HPE) is the most common malformation of the human forebrain. Typical manifestations in affected patients include a characteristic pattern of structural brain and craniofacial anomalies. HPE may be caused by mutations in over 10 identified genes; the inheritance is traditionally viewed as autosomal dominant with highly variable expressivity and incomplete penetrance. We present the description of a family simultaneously segregating two novel variants in the HPE-associated genes, ZIC2 and GLI2, as well as the results of extensive population-based studies of the variant region in GLI2. This is the first time that multiple HPE-associated variants in these genes have been reported in one family, and raises important questions about how clinicians and researchers should view the inheritance of conditions such as HPE.
Collapse
Affiliation(s)
- Nilrat Wannasilp
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|