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Kim JA, Schimpf S, Yano ST, Nordli D, Phitsanuwong C. Categorizing Monogenic Epilepsies by Genetic Mechanisms May Predict Efficacy of the Ketogenic Diet. Pediatr Neurol 2024; 160:11-17. [PMID: 39173306 DOI: 10.1016/j.pediatrneurol.2024.07.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 02/19/2024] [Accepted: 07/25/2024] [Indexed: 08/24/2024]
Abstract
BACKGROUND The ketogenic diet (KD) is an effective treatment for epilepsy. In recent years, studies have shown favorable efficacy of KD in epilepsy from genetic disorders. In this study, we propose an approach to KD in monogenic epilepsy: we evaluate the utility of categorizing genetic variants based on rational associations with the known mechanisms of KD. METHODS Patients with monogenic epilepsy treated with KD were reviewed. The genetic etiologies were categorized into five groups: (1) conditions causing cellular energy impairment, (2) GABA-pathies, (3) mToR-pathies, (4) ion channelopathies, and (5) no known mechanisms associated with KD mechanisms. Treatment response was defined as a median reduction in seizure frequency of greater than 50%. RESULTS Of 35 patients, 24 (69%) were responders at three months. Based on categories, Group 1 had the highest response rate with seven of seven (100%), followed by Group 2, six of seven (86%), and Group 3, two of three (67%). Patients in Groups 4 and 5 had poorer responses with three of seven (43%) and four of 11 (36%) response rates, respectively (P < 0.01). Median percentage of seizure reduction showed Group 1 with the highest reduction of 97.5%, Group 2 at 94%, and Groups 3, 4, and 5 at 62.5%, 30%, and 40%, respectively (P = 0.036). CONCLUSION Our findings show a favorable response to KD in patients with monogenic epilepsy (69% at three months) with the highest response in patients with conditions involving cellular energy impairment and GABA-pathies. The KD, therefore, should be considered early in patients with monogenic epilepsy, especially those involving genes associated with cellular energy impairment or GABA-pathies.
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Affiliation(s)
- Jeong-A Kim
- Section of Child Neurology, The University of Chicago Medicine, Chicago, Illinois
| | - Stephanie Schimpf
- Section of Child Neurology, The University of Chicago Medicine, Chicago, Illinois; Ketogenic Diet Program, The University of Chicago Comer Children's Hospital, Chicago, Illinois
| | - Sho T Yano
- Section of Child Neurology, The University of Chicago Medicine, Chicago, Illinois
| | - Douglas Nordli
- Section of Child Neurology, The University of Chicago Medicine, Chicago, Illinois
| | - Chalongchai Phitsanuwong
- Section of Child Neurology, The University of Chicago Medicine, Chicago, Illinois; Ketogenic Diet Program, The University of Chicago Comer Children's Hospital, Chicago, Illinois.
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2
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González Rodríguez J, de-la-Rosa Fernández E, Loizate Sarrionandia I, Benítez García E, Herrero Moyano M, Morales Moreno HJ, Suárez Hernández J. 5q14.3 Microdeletion Syndrome With Simultaneous Involvement of MEF2C and RASA1. Clinical Case and Review of the Literature. Pediatr Dermatol 2024. [PMID: 39258307 DOI: 10.1111/pde.15748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2024] [Revised: 08/02/2024] [Accepted: 08/13/2024] [Indexed: 09/12/2024]
Abstract
5q14.3 microdeletion syndrome is a rare condition involving multiple genes such as MEF2C and RASA1 and is potentially classified as a neurocutaneous syndrome. Deletion of the MEF2C gene accounts for the majority of clinical manifestations, including global developmental delay, intellectual disability, seizures, and behavioral disorders. RASA1 deletion is linked to capillary malformations with arteriovenous malformations (CM-AVM). Until now, only 17 cases have been described with deletions of both genes. We present the first case described in Spain with the microdeletion in the 5q14.3 cytoband simultaneously affecting both MEF2C and RASA1, exhibiting the typical manifestations of this entity, and review the published cases to date.
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Affiliation(s)
- José González Rodríguez
- Department of Dermatology, Hospital Universitario Nuestra Señora de la Candelaria, Santa Cruz de Tenerife, Spain
| | - Eduardo de-la-Rosa Fernández
- Department of Dermatology, Hospital Universitario Nuestra Señora de la Candelaria, Santa Cruz de Tenerife, Spain
| | - Irene Loizate Sarrionandia
- Department of Dermatology, Hospital Universitario Nuestra Señora de la Candelaria, Santa Cruz de Tenerife, Spain
| | - Elsa Benítez García
- Department of Dermatology, Hospital Universitario Nuestra Señora de la Candelaria, Santa Cruz de Tenerife, Spain
| | - Maria Herrero Moyano
- Department of Dermatology, Hospital Universitario Nuestra Señora de la Candelaria, Santa Cruz de Tenerife, Spain
| | - Héctor Juan Morales Moreno
- Department of Dermatology, Hospital Universitario Nuestra Señora de la Candelaria, Santa Cruz de Tenerife, Spain
| | - José Suárez Hernández
- Department of Dermatology, Hospital Universitario Nuestra Señora de la Candelaria, Santa Cruz de Tenerife, Spain
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Cho JY, Rumschlag JA, Tsvetkov E, Proper DS, Lang H, Berto S, Assali A, Cowan CW. MEF2C Hypofunction in GABAergic Cells Alters Sociability and Prefrontal Cortex Inhibitory Synaptic Transmission in a Sex-Dependent Manner. BIOLOGICAL PSYCHIATRY GLOBAL OPEN SCIENCE 2024; 4:100289. [PMID: 38390348 PMCID: PMC10881314 DOI: 10.1016/j.bpsgos.2024.100289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 12/20/2023] [Accepted: 12/28/2023] [Indexed: 02/24/2024] Open
Abstract
Background Heterozygous mutations or deletions of MEF2C cause a neurodevelopmental disorder termed MEF2C haploinsufficiency syndrome (MCHS), characterized by autism spectrum disorder and neurological symptoms. In mice, global Mef2c heterozygosity has produced multiple MCHS-like phenotypes. MEF2C is highly expressed in multiple cell types of the developing brain, including GABAergic (gamma-aminobutyric acidergic) inhibitory neurons, but the influence of MEF2C hypofunction in GABAergic neurons on MCHS-like phenotypes remains unclear. Methods We employed GABAergic cell type-specific manipulations to study mouse Mef2c heterozygosity in a battery of MCHS-like behaviors. We also performed electroencephalography, single-cell transcriptomics, and patch-clamp electrophysiology and optogenetics to assess the impact of Mef2c haploinsufficiency on gene expression and prefrontal cortex microcircuits. Results Mef2c heterozygosity in developing GABAergic cells produced female-specific deficits in social preference and altered approach-avoidance behavior. In female, but not male, mice, we observed that Mef2c heterozygosity in developing GABAergic cells produced 1) differentially expressed genes in multiple cell types, including parvalbumin-expressing GABAergic neurons, 2) baseline and social-related frontocortical network activity alterations, and 3) reductions in parvalbumin cell intrinsic excitability and inhibitory synaptic transmission onto deep-layer pyramidal neurons. Conclusions MEF2C hypofunction in female, but not male, developing GABAergic cells is important for typical sociability and approach-avoidance behaviors and normal parvalbumin inhibitory neuron function in the prefrontal cortex of mice. While there is no apparent sex bias in autism spectrum disorder symptoms of MCHS, our findings suggest that GABAergic cell-specific dysfunction in females with MCHS may contribute disproportionately to sociability symptoms.
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Affiliation(s)
- Jennifer Y. Cho
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina
- Medical Scientist Training Program, Medical University of South Carolina, Charleston, South Carolina
| | - Jeffrey A. Rumschlag
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Evgeny Tsvetkov
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina
| | - Divya S. Proper
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina
| | - Hainan Lang
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Stefano Berto
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina
| | - Ahlem Assali
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina
| | - Christopher W. Cowan
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina
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4
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Bailon-Zambrano R, Sucharov J, Mumme-Monheit A, Murry M, Stenzel A, Pulvino AT, Mitchell JM, Colborn KL, Nichols JT. Variable paralog expression underlies phenotype variation. eLife 2022; 11:e79247. [PMID: 36134886 PMCID: PMC9555865 DOI: 10.7554/elife.79247] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 09/21/2022] [Indexed: 11/16/2022] Open
Abstract
Human faces are variable; we look different from one another. Craniofacial disorders further increase facial variation. To understand craniofacial variation and how it can be buffered, we analyzed the zebrafish mef2ca mutant. When this transcription factor encoding gene is mutated, zebrafish develop dramatically variable craniofacial phenotypes. Years of selective breeding for low and high penetrance of mutant phenotypes produced strains that are either resilient or sensitive to the mef2ca mutation. Here, we compared gene expression between these strains, which revealed that selective breeding enriched for high and low mef2ca paralog expression in the low- and high-penetrance strains, respectively. We found that mef2ca paralog expression is variable in unselected wild-type zebrafish, motivating the hypothesis that heritable variation in paralog expression underlies mutant phenotype severity and variation. In support, mutagenizing the mef2ca paralogs, mef2aa, mef2b, mef2cb, and mef2d demonstrated modular buffering by paralogs. Specifically, some paralogs buffer severity while others buffer variability. We present a novel, mechanistic model for phenotypic variation where variable, vestigial paralog expression buffers development. These studies are a major step forward in understanding the mechanisms of facial variation, including how some genetically resilient individuals can overcome a deleterious mutation.
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Affiliation(s)
- Raisa Bailon-Zambrano
- Department of Craniofacial Biology, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Juliana Sucharov
- Department of Craniofacial Biology, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Abigail Mumme-Monheit
- Department of Craniofacial Biology, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Matthew Murry
- Department of Craniofacial Biology, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Amanda Stenzel
- Department of Craniofacial Biology, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Anthony T Pulvino
- Department of Craniofacial Biology, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Jennyfer M Mitchell
- Department of Craniofacial Biology, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Kathryn L Colborn
- Department of Surgery, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - James T Nichols
- Department of Craniofacial Biology, University of Colorado Anschutz Medical CampusAuroraUnited States
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5
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Cooley Coleman JA, Sarasua SM, Moore HW, Boccuto L, Cowan CW, Skinner SA, DeLuca JM. Clinical findings from the landmark MEF2C-related disorders natural history study. Mol Genet Genomic Med 2022; 10:e1919. [PMID: 35416405 PMCID: PMC9184670 DOI: 10.1002/mgg3.1919] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 01/27/2022] [Accepted: 02/25/2022] [Indexed: 11/26/2022] Open
Abstract
Introduction MEF2C‐related disorders are characterized by developmental and cognitive delay, limited language and walking, hypotonia, and seizures. A recent systematic review identified 117 patients with MEF2C‐related disorders across 43 studies. Despite these reports, the disorder is not easily recognized and assessments are hampered by small sample sizes. Our objective was to gather developmental and clinical information on a large number of patients. Methods We developed a survey based on validated instruments and subject area experts to gather information from parents of children with this condition. No personal identifiers were collected. Surveys and data were collected via REDCap and analyzed using Excel and SAS v9.4. Results Seventy‐three parents completed the survey, with 39.7% reporting a MEF2C variant and 54.8% reporting a deletion involving MEF2C. Limited speech (82.1%), seizures (86.3%), bruxism (87.7%), repetitive movements (94.5%), and high pain tolerance (79.5%) were some of the prominent features. Patients with MEF2C variants were similarly affected as those with deletions. Female subjects showed higher verbal abilities. Conclusion This is the largest natural history study to date and establishes a comprehensive review of developmental and clinical features for MEF2C‐related disorders. This data can help providers diagnose patients and form the basis for longitudinal or genotype–phenotype studies.
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Affiliation(s)
- Jessica A Cooley Coleman
- School of Nursing, Clemson University, Clemson, South Carolina, USA.,Greenwood Genetic Center, Greenwood, South Carolina, USA
| | - Sara M Sarasua
- School of Nursing, Clemson University, Clemson, South Carolina, USA
| | | | - Luigi Boccuto
- School of Nursing, Clemson University, Clemson, South Carolina, USA
| | - Christopher W Cowan
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina, USA
| | | | - Jane M DeLuca
- School of Nursing, Clemson University, Clemson, South Carolina, USA.,Greenwood Genetic Center, Greenwood, South Carolina, USA
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Cooley Coleman JA, Sarasua SM, Boccuto L, Moore HW, Skinner SA, DeLuca JM. Tremors: A concept analysis. Nurs Open 2021; 8:2419-2428. [PMID: 33797860 PMCID: PMC8363388 DOI: 10.1002/nop2.840] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 01/15/2021] [Accepted: 02/17/2021] [Indexed: 11/26/2022] Open
Abstract
AIM This article seeks to clarify and define the concept of tremors. DESIGN The Walker & Avant (2005) concept analysis method was followed. METHODS A search of PubMed, Academic Search Complete, CINAHL, ERIC, Google and Google Scholar was performed. RESULTS Through this process, uses of the concept were assessed including definitions and categories of tremors. Defining attributes were found to include "movement disorder," "shaking motions," "involuntary," "oscillatory," "rhythmic," "not painful or life threatening," "always present but variable" and "can sometimes be repressed." We identified two model cases and a borderline case, antecedents, consequences and empirical referents (including measurement tools) of tremors. CONCLUSION The concept analysis process has clarified and illuminated an operational definition of tremors: that tremors are a movement disorder characterized by shaking motions that are involuntary, oscillatory, rhythmic, non-painful, always present although vary in severity, and can be repressed by changing posture or going into a rest position.
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Affiliation(s)
| | | | | | | | | | - Jane M. DeLuca
- School of NursingClemson UniversityClemsonSCUSA
- Greenwood Genetic CenterGreenwoodSCUSA
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7
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The zebrafish grime mutant uncovers an evolutionarily conserved role for Tmem161b in the control of cardiac rhythm. Proc Natl Acad Sci U S A 2021; 118:2018220118. [PMID: 33597309 DOI: 10.1073/pnas.2018220118] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The establishment of cardiac function in the developing embryo is essential to ensure blood flow and, therefore, growth and survival of the animal. The molecular mechanisms controlling normal cardiac rhythm remain to be fully elucidated. From a forward genetic screen, we identified a unique mutant, grime, that displayed a specific cardiac arrhythmia phenotype. We show that loss-of-function mutations in tmem161b are responsible for the phenotype, identifying Tmem161b as a regulator of cardiac rhythm in zebrafish. To examine the evolutionary conservation of this function, we generated knockout mice for Tmem161b. Tmem161b knockout mice are neonatal lethal and cardiomyocytes exhibit arrhythmic calcium oscillations. Mechanistically, we find that Tmem161b is expressed at the cell membrane of excitable cells and live imaging shows it is required for action potential repolarization in the developing heart. Electrophysiology on isolated cardiomyocytes demonstrates that Tmem161b is essential to inhibit Ca2+ and K+ currents in cardiomyocytes. Importantly, Tmem161b haploinsufficiency leads to cardiac rhythm phenotypes, implicating it as a candidate gene in heritable cardiac arrhythmia. Overall, these data describe Tmem161b as a highly conserved regulator of cardiac rhythm that functions to modulate ion channel activity in zebrafish and mice.
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8
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Cooley Coleman JA, Sarasua SM, Boccuto L, Moore HW, Skinner SA, DeLuca JM. Comprehensive investigation of the phenotype of MEF2C-related disorders in human patients: A systematic review. Am J Med Genet A 2021; 185:3884-3894. [PMID: 34184825 DOI: 10.1002/ajmg.a.62412] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 06/14/2021] [Accepted: 06/15/2021] [Indexed: 12/31/2022]
Abstract
MEF2C-related disorders (aka MEF2C-haploinsufficiency) are caused by variations in or involving the MEF2C gene and are characterized by intellectual disability, developmental delay, lack of speech, limited walking, and seizures. Despite these findings, the disorder is not easily recognized clinically. We performed a systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to assemble the most comprehensive list of patients and their phenotypes. Through searching PubMed, Web of Science, and MEDLINE, 43 articles met the inclusion criteria and were fully reviewed. One hundred and seventeen patients were identified from these publications with most having a phenotype of intellectual disability, developmental delay, seizures, hypotonia, absent speech, inability to walk, stereotypic movements, and MRI abnormalities. Nonclassical findings included one patient with a question mark ear, two patients with a jugular pit, one patient with a unique neuroendocrine finding, and nine patients that did not have MEF2C deletions or disruptions but may be affected due to a positional effect on MEF2C. This systematic review characterizes the phenotype of MEF2C-related disorders, documents the severity of this condition, and will help providers to better diagnose and care for patients and their families. Additionally, this compiled information provides a comprehensive resource for investigators interested in pursuing specific genotype-phenotype correlations.
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Affiliation(s)
- Jessica A Cooley Coleman
- School of Nursing, Clemson University, Clemson, South Carolina, USA.,Greenwood Genetic Center, Greenwood, South Carolina, USA
| | - Sara M Sarasua
- School of Nursing, Clemson University, Clemson, South Carolina, USA
| | - Luigi Boccuto
- School of Nursing, Clemson University, Clemson, South Carolina, USA
| | | | | | - Jane M DeLuca
- School of Nursing, Clemson University, Clemson, South Carolina, USA.,Greenwood Genetic Center, Greenwood, South Carolina, USA
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Chaudhary R, Agarwal V, Kaushik AS, Rehman M. Involvement of myocyte enhancer factor 2c in the pathogenesis of autism spectrum disorder. Heliyon 2021; 7:e06854. [PMID: 33981903 PMCID: PMC8082549 DOI: 10.1016/j.heliyon.2021.e06854] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 12/09/2020] [Accepted: 04/15/2021] [Indexed: 12/29/2022] Open
Abstract
Myocyte enhancer factor 2 (MEF2), a family of transcription factor of MADS (minichromosome maintenance 1, agamous, deficiens and serum response factor)-box family needed in the growth and differentiation of a variety of human cells, such as neural, immune, endothelial, and muscles. As per existing literature, MEF2 transcription factors have also been associated with synaptic plasticity, the developmental mechanisms governing memory and learning, and several neurologic conditions, like autism spectrum disorders (ASDs). Recent genomic findings have ascertained a link between MEF2 defects, particularly in the MEF2C isoform and the ASD. In this review, we summarized a concise overview of the general regulation, structure and functional roles of the MEF2C transcription factor. We further outlined the potential role of MEF2C as a risk factor for various neurodevelopmental disorders, such as ASD, MEF2C Haploinsufficiency Syndrome and Fragile X syndrome.
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Affiliation(s)
- Rishabh Chaudhary
- Department of Pharmaceutical Sciences, School of Biosciences and Biotechnology, Babasaheb Bhimrao Ambedkar University, Lucknow, India
| | - Vipul Agarwal
- Department of Pharmaceutical Sciences, School of Biosciences and Biotechnology, Babasaheb Bhimrao Ambedkar University, Lucknow, India
| | - Arjun Singh Kaushik
- Department of Pharmaceutical Sciences, School of Biosciences and Biotechnology, Babasaheb Bhimrao Ambedkar University, Lucknow, India
| | - Mujeeba Rehman
- Department of Pharmaceutical Sciences, School of Biosciences and Biotechnology, Babasaheb Bhimrao Ambedkar University, Lucknow, India
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DNA methylome signatures of prenatal exposure to synthetic glucocorticoids in hippocampus and peripheral whole blood of female guinea pigs in early life. Transl Psychiatry 2021; 11:63. [PMID: 33462183 PMCID: PMC7813870 DOI: 10.1038/s41398-020-01186-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 12/15/2020] [Accepted: 12/16/2020] [Indexed: 12/17/2022] Open
Abstract
Synthetic glucocorticoids (sGC) are administered to women at risk of preterm delivery, approximately 10% of all pregnancies. In animal models, offspring exposed to elevated glucocorticoids, either by administration of sGC or endogenous glucocorticoids as a result of maternal stress, show increased risk of developing behavioral, endocrine, and metabolic dysregulation. DNA methylation may play a critical role in long-lasting programming of gene regulation underlying these phenotypes. However, peripheral tissues such as blood are often the only accessible source of DNA for epigenetic analyses in humans. Here, we examined the hypothesis that prenatal sGC administration alters DNA methylation signatures in guinea pig offspring hippocampus and whole blood. We compared these signatures across the two tissue types to assess epigenetic biomarkers of common molecular pathways affected by sGC exposure. Guinea pigs were treated with sGC or saline in late gestation. Genome-wide modifications of DNA methylation were analyzed at single nucleotide resolution using reduced representation bisulfite sequencing in juvenile female offspring. Results indicate that there are tissue-specific as well as common methylation signatures of prenatal sGC exposure. Over 90% of the common methylation signatures associated with sGC exposure showed the same directionality of change in methylation. Among differentially methylated genes, 134 were modified in both hippocampus and blood, of which 61 showed methylation changes at identical CpG sites. Gene pathway analyses indicated that prenatal sGC exposure alters the methylation status of gene clusters involved in brain development. These data indicate concordance across tissues of epigenetic programming in response to alterations in glucocorticoid signaling.
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Zhou WZ, Zhang J, Li Z, Lin X, Li J, Wang S, Yang C, Wu Q, Ye AY, Wang M, Wang D, Pu TZ, Wu YY, Wei L. Targeted resequencing of 358 candidate genes for autism spectrum disorder in a Chinese cohort reveals diagnostic potential and genotype-phenotype correlations. Hum Mutat 2019; 40:801-815. [PMID: 30763456 PMCID: PMC6593842 DOI: 10.1002/humu.23724] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 02/11/2019] [Accepted: 02/11/2019] [Indexed: 12/30/2022]
Abstract
Autism spectrum disorder (ASD) is a childhood neuropsychiatric disorder with a complex genetic architecture. The diagnostic potential of a targeted panel of ASD genes has only been evaluated in small cohorts to date and is especially understudied in the Chinese population. Here, we designed a capture panel with 358 genes (111 syndromic and 247 nonsyndromic) for ASD and sequenced a Chinese cohort of 539 cases evaluated with the Autism Diagnostic Interview‐Revised (ADI‐R) and the Autism Diagnostic Observation Schedule (ADOS) as well as 512 controls. ASD cases were found to carry significantly more ultra‐rare functional variants than controls. A subset of 78 syndromic and 54 nonsyndromic genes was the most significantly associated and should be given high priority in the future screening of ASD patients. Pathogenic and likely pathogenic variants were detected in 9.5% of cases. Variants in SHANK3 and SHANK2 were the most frequent, especially in females, and occurred in 1.2% of cases. Duplications of 15q11–13 were detected in 0.8% of cases. Variants in CNTNAP2 and MEF2C were correlated with epilepsy/tics in cases. Our findings reveal the diagnostic potential of ASD genetic panel testing and new insights regarding the variant spectrum. Genotype–phenotype correlations may facilitate the diagnosis and management of ASD.
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Affiliation(s)
- Wei-Zhen Zhou
- Center for Bioinformatics, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China.,State Key Laboratory of Cardiovascular Disease, Beijing Key Laboratory for Molecular Diagnostics of Cardiovascular Diseases, Diagnostic Laboratory Service, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jie Zhang
- Center for Bioinformatics, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
| | - Ziyi Li
- Center for Bioinformatics, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
| | - Xiaojing Lin
- National Institute of Biological Sciences, Beijing, China
| | - Jiarui Li
- Center for Bioinformatics, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
| | - Sheng Wang
- National Institute of Biological Sciences, Beijing, China.,College of Biological Sciences, China Agricultural University, Beijing, China
| | - Changhong Yang
- National Institute of Biological Sciences, Beijing, China.,College of Life Sciences, Beijing Normal University, Beijing, China
| | - Qixi Wu
- School of Life Sciences, Peking University, Beijing, China
| | - Adam Yongxin Ye
- Center for Bioinformatics, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Beijing, China.,Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Meng Wang
- Center for Bioinformatics, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
| | - Dandan Wang
- National Institute of Biological Sciences, Beijing, China
| | | | - Yu-Yu Wu
- Yuning Psychiatry Clinic, Taipei, Taiwan
| | - Liping Wei
- Center for Bioinformatics, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
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Antagonizing Increased miR-135a Levels at the Chronic Stage of Experimental TLE Reduces Spontaneous Recurrent Seizures. J Neurosci 2019; 39:5064-5079. [PMID: 31015341 DOI: 10.1523/jneurosci.3014-18.2019] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 03/31/2019] [Accepted: 04/16/2019] [Indexed: 01/01/2023] Open
Abstract
Mesial temporal lobe epilepsy (mTLE) is a chronic neurological disease characterized by recurrent seizures. The antiepileptic drugs currently available to treat mTLE are ineffective in one-third of patients and lack disease-modifying effects. miRNAs, a class of small noncoding RNAs which control gene expression at the post-transcriptional level, play a key role in the pathogenesis of mTLE and other epilepsies. Although manipulation of miRNAs at acute stages has been reported to reduce subsequent spontaneous seizures, it is uncertain whether targeting miRNAs at chronic stages of mTLE can also reduce seizures. Furthermore, the functional role and downstream targets of most epilepsy-associated miRNAs remain poorly understood. Here, we show that miR-135a is selectively upregulated within neurons in epileptic brain and report that targeting miR-135a in vivo using antagomirs after onset of spontaneous recurrent seizures can reduce seizure activity at the chronic stage of experimental mTLE in male mice. Further, by using an unbiased approach combining immunoprecipitation and RNA sequencing, we identify several novel neuronal targets of miR-135a, including Mef2a Mef2 proteins are key regulators of excitatory synapse density. Mef2a and miR-135a show reciprocal expression regulation in human (of both sexes) and experimental TLE, and miR-135a regulates dendritic spine number and type through Mef2. Together, our data show that miR-135a is target for reducing seizure activity in chronic epilepsy, and that deregulation of miR-135a in epilepsy may alter Mef2a expression and thereby affect synaptic function and plasticity.SIGNIFICANCE STATEMENT miRNAs are post-transcriptional regulators of gene expression with roles in the pathogenesis of epilepsy. However, the precise mechanism of action and therapeutic potential of most epilepsy-associated miRNAs remain poorly understood. Our study reveals dramatic upregulation of the key neuronal miRNA miR-135a in both experimental and human mesial temporal lobe epilepsy. Silencing miR-135a in experimental temporal lobe epilepsy reduces seizure activity at the spontaneous recurrent seizure stage. These data support the exciting possibility that miRNAs can be targeted to combat seizures after spontaneous seizure activity has been established. Further, by using unbiased approaches novel neuronal targets of miR-135a, including members of the Mef2 protein family, are identified that begin to explain how deregulation of miR-135a may contribute to epilepsy.
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Wang J, Zhang Q, Chen Y, Yu S, Wu X, Bao X, Wen Y. Novel MEF2C point mutations in Chinese patients with Rett (-like) syndrome or non-syndromic intellectual disability: insights into genotype-phenotype correlation. BMC MEDICAL GENETICS 2018; 19:191. [PMID: 30376817 PMCID: PMC6208086 DOI: 10.1186/s12881-018-0699-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 09/26/2018] [Indexed: 12/26/2022]
Abstract
BACKGROUND MEF2C (Myocyte-specific enhancer factor 2C) has been associated with neurodevelopmental disorders. This study aimed at delineating the clinical profiles of MEF2C gene mutations. METHODS In total, 112 Chinese patients with intellectual disability (ID) were recruited, including 44 patients presented with Rett syndrome (RTT) or RTT-like syndrome, and 68 patients with non-syndromic ID. Targeted next-generation sequencing (NGS) was performed. Detailed clinical information was collected. RESULTS Five heterozygous MEF2C gene mutations were identified, of which three were novel. The MEF2C mutant rate was 4.5% (5/112) in total, and 6.8% (3/44) in the RTT (-like) cohort. All patients with MEF2C gene mutation presented with cognitive impairment, gross motor delay, speech disorder and autistic features. Four patients had epilepsy, which responded well to antiepileptic drugs. One female was diagnosed with classical RTT, two females with RTT-like syndrome, and two males with non-syndromic ID. Generally, the phenotype of two males with relatively downstream mutations (c.565C > T, p.Arg 189*; c.766C > T, p.Arg 256*) was milder than that of three females with upstream mutations (c.48C > G, p.Asn16Lys; c.334G > T, p.Glu112* and c.403-1G > T). CONCLUSIONS Our findings expanded the current understanding of the consequences of MEF2C dysfunctions, especially MEF2C point mutations. MEF2C mutations are associated with a broad clinical spectrum, ranged from classical RTT to non-syndromic ID. Through our study, it can be inferred that there is correlation between the phenotype and MEF2C-genotype, the mutation site. Overall, the MEF2C gene mutational analysis should be performed in ID cohort, especially in patients with features overlapped with RTT.
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Affiliation(s)
- Jiaping Wang
- Department of Pediatrics, Peking University First Hospital, No 1, Xi'anmen Street, Xicheng District, Beijing, 100034, China
| | - Qingping Zhang
- Department of Pediatrics, Peking University First Hospital, No 1, Xi'anmen Street, Xicheng District, Beijing, 100034, China
| | - Yan Chen
- Department of Pediatrics, Peking University First Hospital, No 1, Xi'anmen Street, Xicheng District, Beijing, 100034, China
| | - Shujie Yu
- Department of neurology, Harbin children's hospital, Harbin, 150010, Heilongjiang Province, China
| | - Xiru Wu
- Department of Pediatrics, Peking University First Hospital, No 1, Xi'anmen Street, Xicheng District, Beijing, 100034, China
| | - Xinhua Bao
- Department of Pediatrics, Peking University First Hospital, No 1, Xi'anmen Street, Xicheng District, Beijing, 100034, China.
| | - Yongxin Wen
- Department of Pediatrics, Peking University First Hospital, No 1, Xi'anmen Street, Xicheng District, Beijing, 100034, China
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Muench C, Schwandt M, Jung J, Cortes CR, Momenan R, Lohoff FW. The major depressive disorder GWAS-supported variant rs10514299 in TMEM161B-MEF2C predicts putamen activation during reward processing in alcohol dependence. Transl Psychiatry 2018; 8:131. [PMID: 30006604 PMCID: PMC6045574 DOI: 10.1038/s41398-018-0184-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 03/13/2018] [Accepted: 05/11/2018] [Indexed: 01/25/2023] Open
Abstract
Alcohol dependence (AD) frequently co-occurs with major depressive disorder (MDD). While this comorbidity is associated with an increase in disease burden, worse treatment outcomes, and greater economic costs, the underlying neurobiology remains poorly understood. A recent large-scale GWAS of MDD has identified a locus in the TMEM161B-MEF2C region (rs10514299) as a novel risk variant; however, the biological relevance of this variant has not yet been studied. Given previous reports of disrupted reward processing in both AD and MDD, we hypothesized that rs10514299 would be associated with differences in striatal BOLD responses during reward/loss anticipation in AD. DNA samples from 45 recently detoxified patients with AD and 45 healthy controls (HC) were genotyped for rs10514299. Participants performed the Monetary Incentive Delay task in a 3-Tesla MRI scanner. Effects of rs10514299 on striatal activation during anticipation of high/low reward/loss were investigated. Furthermore, we examined associations between rs10514299 and lifetime AD diagnosis in two independent clinical samples [NIAAA: n = 1858 (1123 cases, 735 controls); SAGE: n = 3838 (1848 cases, 1990 controls)], as well as its association with depression severity in a subsample of individuals with a lifetime AD diagnosis (n = 953). Patients carrying the T allele showed significantly greater putamen activation during anticipation of high reward (p = 0.014), low reward (at trend-level; p = 0.081), high loss (p = 0.024), and low loss (p = 0.046) compared to HCs. Association analyses in the NIAAA sample showed a trend-level relationship between rs10514299 and a lifetime AD diagnosis in the European American subgroup (odds ratio = 0.82, p = 0.09). This finding was not replicated in the SAGE sample. In the NIAAA sample, the T allele was significantly associated with greater depression symptom severity in individuals with a lifetime AD diagnosis (β = 1.25, p = 0.02); this association was driven by the African American ancestry subgroup (β = 2.11, p = 0.008). We show for the first time that the previously identified MDD risk variant rs10514299 in TMEM161B-MEF2C predicts neuronal correlates of reward processing in an AD phenotype, possibly explaining part of the shared pathophysiology and comorbidity between the disorders.
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Affiliation(s)
- Christine Muench
- Section on Clinical Genomics and Experimental Therapeutics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - Melanie Schwandt
- Office of the Clinical Director, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - Jeesun Jung
- Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - Carlos R Cortes
- Clinical NeuroImaging Research Core, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - Reza Momenan
- Clinical NeuroImaging Research Core, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - Falk W Lohoff
- Section on Clinical Genomics and Experimental Therapeutics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA.
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15
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Abstract
Infantile spasms are a devastating epileptic encephalopathy characterized by early life spasms and later seizures. Clinical outcomes of infantile spasms are poor and therapeutic options are limited with significant adverse effects. Therefore, new strategies to treat infantile spasms are of the utmost importance. Animals models of infantile spasms are a critical component of developing new therapies. Here, we review current chronic animal models of infantile spasms and consider future advances that may help improve patient care, as well as our scientific understanding of this debilitating disease.
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16
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Tu S, Akhtar MW, Escorihuela RM, Amador-Arjona A, Swarup V, Parker J, Zaremba JD, Holland T, Bansal N, Holohan DR, Lopez K, Ryan SD, Chan SF, Yan L, Zhang X, Huang X, Sultan A, McKercher SR, Ambasudhan R, Xu H, Wang Y, Geschwind DH, Roberts AJ, Terskikh AV, Rissman RA, Masliah E, Lipton SA, Nakanishi N. NitroSynapsin therapy for a mouse MEF2C haploinsufficiency model of human autism. Nat Commun 2017; 8:1488. [PMID: 29133852 PMCID: PMC5684358 DOI: 10.1038/s41467-017-01563-8] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 09/27/2017] [Indexed: 01/07/2023] Open
Abstract
Transcription factor MEF2C regulates multiple genes linked to autism spectrum disorder (ASD), and human MEF2C haploinsufficiency results in ASD, intellectual disability, and epilepsy. However, molecular mechanisms underlying MEF2C haploinsufficiency syndrome remain poorly understood. Here we report that Mef2c +/-(Mef2c-het) mice exhibit behavioral deficits resembling those of human patients. Gene expression analyses on brains from these mice show changes in genes associated with neurogenesis, synapse formation, and neuronal cell death. Accordingly, Mef2c-het mice exhibit decreased neurogenesis, enhanced neuronal apoptosis, and an increased ratio of excitatory to inhibitory (E/I) neurotransmission. Importantly, neurobehavioral deficits, E/I imbalance, and histological damage are all ameliorated by treatment with NitroSynapsin, a new dual-action compound related to the FDA-approved drug memantine, representing an uncompetitive/fast off-rate antagonist of NMDA-type glutamate receptors. These results suggest that MEF2C haploinsufficiency leads to abnormal brain development, E/I imbalance, and neurobehavioral dysfunction, which may be mitigated by pharmacological intervention.
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Affiliation(s)
- Shichun Tu
- Neurodegenerative Disease Center, Scintillon Institute, San Diego, CA, 92121, USA.
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA.
| | - Mohd Waseem Akhtar
- Neurodegenerative Disease Center, Scintillon Institute, San Diego, CA, 92121, USA
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Rosa Maria Escorihuela
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
- Departament de PsiquiatriaiMedicina Legal, Institut de Neurociències, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Alejandro Amador-Arjona
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Vivek Swarup
- Center for Autism Research and Treatment (CART), University of California, Los Angeles, CA, 90095, USA
| | - James Parker
- Neurodegenerative Disease Center, Scintillon Institute, San Diego, CA, 92121, USA
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Jeffrey D Zaremba
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Timothy Holland
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Neha Bansal
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Daniel R Holohan
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Kevin Lopez
- Neurodegenerative Disease Center, Scintillon Institute, San Diego, CA, 92121, USA
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Scott D Ryan
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada, N1G 2W1
| | - Shing Fai Chan
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Li Yan
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Xiaofei Zhang
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Xiayu Huang
- Bioinformatics Core Facility, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Abdullah Sultan
- Neurodegenerative Disease Center, Scintillon Institute, San Diego, CA, 92121, USA
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Scott R McKercher
- Neurodegenerative Disease Center, Scintillon Institute, San Diego, CA, 92121, USA
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
- Department of Molecular Medicine and Neuroscience, Neuroscience Translational Center, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Rajesh Ambasudhan
- Neurodegenerative Disease Center, Scintillon Institute, San Diego, CA, 92121, USA
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Huaxi Xu
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Yuqiang Wang
- Institute of New Drug Research, Jinan University College of Pharmacy, Guangzhou, 510632, China
| | - Daniel H Geschwind
- Center for Autism Research and Treatment (CART), University of California, Los Angeles, CA, 90095, USA
| | - Amanda J Roberts
- Department of Neuroscience and Mouse Behavioral Assessment Core, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Alexey V Terskikh
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Robert A Rissman
- Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, CA, 92093, USA
- Veterans Affairs San Diego Healthcare System, San Diego, CA, 92161, USA
| | - Eliezer Masliah
- Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, CA, 92093, USA
- National Institute on Aging, NIH, Bethesda, MD, 20892, USA
| | - Stuart A Lipton
- Neurodegenerative Disease Center, Scintillon Institute, San Diego, CA, 92121, USA.
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA.
- Department of Molecular Medicine and Neuroscience, Neuroscience Translational Center, The Scripps Research Institute, La Jolla, CA, 92037, USA.
- Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, CA, 92093, USA.
| | - Nobuki Nakanishi
- Neurodegenerative Disease Center, Scintillon Institute, San Diego, CA, 92121, USA.
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA.
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17
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Nowakowska B. Clinical interpretation of copy number variants in the human genome. J Appl Genet 2017; 58:449-457. [PMID: 28963714 PMCID: PMC5655614 DOI: 10.1007/s13353-017-0407-4] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 08/31/2017] [Accepted: 09/05/2017] [Indexed: 12/15/2022]
Abstract
Molecular methods, by which copy number variants (CNVs) detection is available, have been gradually introduced into routine diagnostics over the last 15 years. Despite this, some CNVs continue to be a huge challenge when it comes to clinical interpretation. CNVs are an important source of normal and pathogenic variants, but, in many cases, their impact on human health depends on factors that are not yet known. Therefore, perception of their clinical consequences can change over time, as our knowledge grows. This review summarises guidelines that facilitate correct classification of identified changes and discusses difficulties with the interpretation of rare, small CNVs.
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Affiliation(s)
- Beata Nowakowska
- Department of Medical Genetics, Institute of Mother and Child, Kasprzaka 17a, 01-211, Warsaw, Poland.
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18
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Chen LF, Zhou AS, West AE. Transcribing the connectome: roles for transcription factors and chromatin regulators in activity-dependent synapse development. J Neurophysiol 2017; 118:755-770. [PMID: 28490640 DOI: 10.1152/jn.00067.2017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 05/09/2017] [Accepted: 05/09/2017] [Indexed: 12/21/2022] Open
Abstract
The wiring of synaptic connections in the developing mammalian brain is shaped by both intrinsic and extrinsic signals. One point where these regulatory pathways converge is via the sensory experience-dependent regulation of new gene transcription. Recent studies have elucidated a number of molecular mechanisms that allow nuclear transcription factors and chromatin regulatory proteins to encode aspects of specificity in experience-dependent synapse development. Here we review the evidence for the transcriptional mechanisms that sculpt activity-dependent aspects of synaptic connectivity during postnatal development and discuss how disruption of these processes is associated with aberrant brain development in autism and intellectual disability.
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Affiliation(s)
- Liang-Fu Chen
- Department of Neurobiology, Duke University, Durham, North Carolina
| | - Allen S Zhou
- Department of Neurobiology, Duke University, Durham, North Carolina
| | - Anne E West
- Department of Neurobiology, Duke University, Durham, North Carolina
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19
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Vrečar I, Innes J, Jones EA, Kingston H, Reardon W, Kerr B, Clayton-Smith J, Douzgou S. Further Clinical Delineation of the MEF2C Haploinsufficiency Syndrome: Report on New Cases and Literature Review of Severe Neurodevelopmental Disorders Presenting with Seizures, Absent Speech, and Involuntary Movements. J Pediatr Genet 2017; 6:129-141. [PMID: 28794905 DOI: 10.1055/s-0037-1601335] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 02/16/2017] [Indexed: 01/24/2023]
Abstract
Mutations in the MEF2C ( myocyte enhancer factor 2 ) gene have been established as a cause for an intellectual disability syndrome presenting with seizures, absence of speech, stereotypic movements, hypotonia, and limited ambulation. Phenotypic overlap with Rett's and Angelman's syndromes has been noted. Following the first reports of 5q14.3q15 microdeletions encompassing the MEF2C gene, further cases with point mutations and partial gene deletions of the MEF2C gene have been described. We present the clinical phenotype of our cohort of six patients with MEF2C mutations and compare our findings with previously reported patients as well as with a growing number of genetic conditions presenting with a severe neurodevelopmental, Rett-like, phenotype. We aim to add to the current knowledge of the natural history of the "MEF2C haploinsufficiency syndrome" as well as of the differential diagnosis, clinical management, and genetic counseling in this diagnostically challenging group of patients.
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Affiliation(s)
- Irena Vrečar
- Manchester Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust, Academic Health Sciences Centre, Manchester, United Kingdom.,Clinical Institute of Medical Genetics, University Medical Centre of Ljubljana, Ljubljana, Slovenia
| | - Josie Innes
- Manchester Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust, Academic Health Sciences Centre, Manchester, United Kingdom
| | - Elizabeth A Jones
- Manchester Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust, Academic Health Sciences Centre, Manchester, United Kingdom.,Division of Evolution and Genomic Sciences, University of Manchester, School of Biological Sciences, Manchester, United Kingdom
| | - Helen Kingston
- Manchester Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust, Academic Health Sciences Centre, Manchester, United Kingdom.,Division of Evolution and Genomic Sciences, University of Manchester, School of Biological Sciences, Manchester, United Kingdom
| | - William Reardon
- Department of Clinical Genetics, Our Lady's Children Hospital Crumlin, Dublin, Ireland
| | - Bronwyn Kerr
- Manchester Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust, Academic Health Sciences Centre, Manchester, United Kingdom.,Division of Evolution and Genomic Sciences, University of Manchester, School of Biological Sciences, Manchester, United Kingdom
| | - Jill Clayton-Smith
- Manchester Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust, Academic Health Sciences Centre, Manchester, United Kingdom.,Division of Evolution and Genomic Sciences, University of Manchester, School of Biological Sciences, Manchester, United Kingdom
| | - Sofia Douzgou
- Manchester Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust, Academic Health Sciences Centre, Manchester, United Kingdom.,Division of Evolution and Genomic Sciences, University of Manchester, School of Biological Sciences, Manchester, United Kingdom
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20
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Liu Z, Li Z, Zhi X, Du Y, Lin Z, Wu J. Identification of De Novo DNMT3A Mutations That Cause West Syndrome by Using Whole-Exome Sequencing. Mol Neurobiol 2017; 55:2483-2493. [PMID: 28386848 DOI: 10.1007/s12035-017-0483-9] [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] [Received: 12/09/2016] [Accepted: 03/07/2017] [Indexed: 10/19/2022]
Abstract
Epileptic encephalopathies (EEs) are a group of severe neurodevelopmental disorders with extreme genetic heterogeneity. Recent trio-based whole-exome sequencing (WES) studies have demonstrated that de novo mutations (DNMs) play prominent roles in severe EE. In this study, we searched for potential causal DNMs by using high-coverage WES of four unrelated Chinese parent-offspring trios affected by West syndrome. Through extensive bioinformatic analysis, we identified three novel DNMs in DNMT3A, CDKL5, and MAMDC2 in three trios and two compound heterozygous mutations in KMT2A in one trio. The DNMs in CDKL5 and DNMT3A were considered to be deleterious on the basis of the consensus of several genetic damage prediction tools. In addition, spatiotemporal expression patterns revealed a high level of DNMT3A expression during the early embryonic stage in nearly all brain regions. We also observed that certain high-confidence genes for epilepsy were shared among the co-expression and genetic interaction networks of DNMT3A, CDKL5, and KMT2A. Furthermore, all the candidate epilepsy genes in the co-expression network of DNMT3A were significantly enriched in the early developmental stages of the brain according to a rank-based enrichment test. In particular, we found that the DNMs of DNMT3A were shared among EE, autism spectrum disorder (ASD), and intellectual disability (ID) and mainly occurred in the functional domain of DNMT3A. Together, our findings support an association between DNMT3A mutations and EE susceptibility and suggest a shared molecular pathophysiology among EE and other neuropsychiatric disorders.
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Affiliation(s)
- Zhenwei Liu
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, 325027, China
| | - Zhongshan Li
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, 325027, China
| | - Xiao Zhi
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, 325027, China.,School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, 325035, China
| | - Yaoqiang Du
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, 325027, China.,School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, 325035, China
| | - Zhongdong Lin
- Department of Pediatric Neurology, The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, 325027, China
| | - Jinyu Wu
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, 325027, China.
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21
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Genome-Wide DNA Methylation Patterns Analysis of Noncoding RNAs in Temporal Lobe Epilepsy Patients. Mol Neurobiol 2017; 55:793-803. [PMID: 28058582 DOI: 10.1007/s12035-016-0353-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Accepted: 12/13/2016] [Indexed: 12/13/2022]
Abstract
Temporal lobe epilepsy (TLE) is the most common form of adult epilepsy and frequently evolving drug resistance. Although there is growing consensus that noncoding ribonucleic acids (ncRNAs) are modulators of TLE, the knowledge about the deoxyribonucleic acid (DNA) methylation patterns of ncRNAs in TLE remains limited. In the current study, we constructed DNA methylation profiles from 30 TLE patients and 30 healthy controls for ncRNAs, primarily focusing on long ncRNAs (lncRNAs) and microRNAs (miRNAs), by reannotating data of DNA methylation BeadChip. Statistics analyses have revealed a global hypermethylation pattern in miRNA and lncRNA gene in TLE patients. Bioinformatic analyses have found aberrantly methylated miRNAs and lncRNAs are related to ion channel activity, drug metabolism, mitogen-activated protein kinase (MAPK) signaling pathway, and neurotrophin signaling pathway. Aberrantly methylated ncRNA and pathway target might be involved in TLE development and progression. The methylated and demethylated ncRNAs identified in this study provide novel insights for developing TLE biomarkers and potential therapeutic targets.
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22
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Adachi M, Lin PY, Pranav H, Monteggia LM. Postnatal Loss of Mef2c Results in Dissociation of Effects on Synapse Number and Learning and Memory. Biol Psychiatry 2016; 80:140-148. [PMID: 26642739 PMCID: PMC4826326 DOI: 10.1016/j.biopsych.2015.09.018] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 09/04/2015] [Accepted: 09/24/2015] [Indexed: 12/11/2022]
Abstract
BACKGROUND Myocyte enhancer factor 2 (MEF2) transcription factors play critical roles in diverse cellular processes during central nervous system development. Studies attempting to address the role of MEF2 in brain have largely relied on overexpression of a constitutive MEF2 construct that impairs memory formation or knockdown of MEF2 function that increases spine numbers and enhances memory formation. Genetic deletion of individual MEF2 isoforms in brain during embryogenesis demonstrated that Mef2c loss negatively regulates spine numbers resulting in learning and memory deficits, possibly as a result of its essential role in development. METHODS To investigate MEF2C function in brain further, we genetically deleted Mef2c during postnatal development in mice. We characterized these conditional Mef2c knockout mice in an array of behavioral paradigms and examined the impact of postnatal loss of Mef2c on long-term potentiation. RESULTS We observed increased spine numbers in hippocampus of the conditional Mef2c knockout mice. However, the postnatal loss of Mef2c did not impact learning and memory, long-term potentiation, or social and repetitive behaviors. CONCLUSIONS Our findings demonstrate a critical role for MEF2C in the regulation of spine numbers with a dissociation of learning and memory, synaptic plasticity, and measures of autism-related behaviors in postnatal brain.
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Affiliation(s)
- Megumi Adachi
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Pei-Yi Lin
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Heena Pranav
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Lisa M Monteggia
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas.
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Abstract
Alzheimer's disease (AD) is a progressive, neurodegenerative disease and the most common form of dementia in elderly people. It is an emerging public health problem that poses a huge societal burden. Linkage analysis was the first milestone in unraveling the mutations in APP, PSEN1, and PSEN2 that cause early-onset AD, followed by the discovery of apolipoprotein E-ε4 allele as the only one genetic risk factor for late-onset AD. Genome-wide association studies have revolutionized genetic research and have identified over 20 genetic loci associated with late-onset AD. Recently, next-generation sequencing technologies have enabled the identification of rare disease variants, including unmasking small mutations with intermediate risk of AD in PLD3, TREM2, UNC5C, AKAP9, and ADAM10. This review provides an overview of the genetic basis of AD and the relationship between these risk genes and the neuropathologic features of AD. An understanding of genetic mechanisms underlying AD pathogenesis and the potentially implicated pathways will lead to the development of novel treatment for this devastating disease.
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Affiliation(s)
- Mohan Giri
- Department of Geriatrics, The First Affiliated Hospital of Chongqing Medical University, Yuzhong District, Chongqing, People’s Republic of China
| | - Man Zhang
- Department of Geriatrics, The First Affiliated Hospital of Chongqing Medical University, Yuzhong District, Chongqing, People’s Republic of China
| | - Yang Lü
- Department of Geriatrics, The First Affiliated Hospital of Chongqing Medical University, Yuzhong District, Chongqing, People’s Republic of China
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Shim JS, Min K, Lee SH, Park JE, Park SH, Kim M, Shim SH. MEF2C-Related 5q14.3 Microdeletion Syndrome Detected by Array CGH: A Case Report. Ann Rehabil Med 2015; 39:482-7. [PMID: 26161356 PMCID: PMC4496521 DOI: 10.5535/arm.2015.39.3.482] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 08/25/2014] [Indexed: 11/05/2022] Open
Abstract
Genetic screening is being widely applied to trace the origin of global developmental delay or intellectual disability. The 5q14.3 microdeletion has recently been uncovered as a clinical syndrome presenting with severe intellectual disability, limited walking ability, febrile convulsions, absence of speech, and minor brain malformations. MEF2C was suggested as a gene mainly responsible for the 5q14.3 microdeletion syndrome. We present the case of a 6-year-old girl, who is the first patient in Korea with de novo interstitial microdeletions involving 5q14.3, showing the typical clinical features of 5q14.3 microdeletion syndrome with a smaller size of chromosomal involvement compared to the previous reports. The microdeletion was not detected by subtelomeric multiplex ligation-dependent probe amplification, but by array comparative genomic hybridization, which is advisable for the detection of a small-sized genetic abnormality.
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Affiliation(s)
- Jae Sun Shim
- Department of Rehabilitation Medicine, CHA Bundang Medical Center, CHA University, Seongnam, Korea
| | - Kyunghoon Min
- Department of Rehabilitation Medicine, CHA Bundang Medical Center, CHA University, Seongnam, Korea
| | - Seung Hoon Lee
- Department of Rehabilitation Medicine, CHA Bundang Medical Center, CHA University, Seongnam, Korea
| | - Ji Eun Park
- Genetics Laboratory, Fertility Center of CHA Gangnam Medical Center, CHA University, Seoul, Korea
| | - Sang Hee Park
- Genetics Laboratory, Fertility Center of CHA Gangnam Medical Center, CHA University, Seoul, Korea
| | - MinYoung Kim
- Department of Rehabilitation Medicine, CHA Bundang Medical Center, CHA University, Seongnam, Korea
| | - Sung Han Shim
- Genetics Laboratory, Fertility Center of CHA Gangnam Medical Center, CHA University, Seoul, Korea. ; Department of Biomedical Science, College of Life Science, CHA University, Pocheon, Korea
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25
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Lee BH, Smith T, Paciorkowski AR. Autism spectrum disorder and epilepsy: Disorders with a shared biology. Epilepsy Behav 2015; 47:191-201. [PMID: 25900226 PMCID: PMC4475437 DOI: 10.1016/j.yebeh.2015.03.017] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 03/06/2015] [Accepted: 03/13/2015] [Indexed: 12/17/2022]
Abstract
There is an increasing recognition of clinical overlap in patients presenting with epilepsy and autism spectrum disorder (ASD), and a great deal of new information regarding the genetic causes of both disorders is available. Several biological pathways appear to be involved in both disease processes, including gene transcription regulation, cellular growth, synaptic channel function, and maintenance of synaptic structure. We review several genetic disorders where ASD and epilepsy frequently co-occur, and we discuss the screening tools available for practicing neurologists and epileptologists to help determine which patients should be referred for formal ASD diagnostic evaluation. Finally, we make recommendations regarding the workflow of genetic diagnostic testing available for children with both ASD and epilepsy. This article is part of a Special Issue entitled "Autism and Epilepsy".
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Affiliation(s)
- Bo Hoon Lee
- Department of Pediatrics, University of Rochester Medical Center, Rochester, NY, USA
| | - Tristram Smith
- Division of Neurodevelopmental and Behavioral Pediatrics, Department of Pediatrics, University of Rochester Medical Center, Rochester, NY, USA
| | - Alex R Paciorkowski
- Department of Pediatrics, University of Rochester Medical Center, Rochester, NY, USA; Department of Neurology, University of Rochester Medical Center, Rochester, NY, USA; Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, NY, USA; Center for Neural Development and Disease, University of Rochester Medical Center, Rochester, NY, USA.
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26
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Chan SF, Huang X, McKercher SR, Zaidi R, Okamoto SI, Nakanishi N, Lipton SA. Transcriptional profiling of MEF2-regulated genes in human neural progenitor cells derived from embryonic stem cells. GENOMICS DATA 2015; 3:24-27. [PMID: 25485232 PMCID: PMC4255278 DOI: 10.1016/j.gdata.2014.10.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
[Briefly describe the contents of the Data in Brief article. Tell the reader the repository and reference number for the data in the abstract to.] The myocyte enhancer factor 2 (MEF2) family of transcription factors is highly expressed in the brain, and constitutes a key determinant of neuronal survival, differentiation, and synaptic plasticity. However, genome-wide transcriptional profiling of MEF2-regulated genes has not yet been fully elucidated, particularly at the neural stem cell stage. Here we report the results of microarray analysis comparing mRNAs isolated from human neural progenitor/stem cells (hNPCs) derived from embryonic stem cells expressing a control vector versus progenitors expressing a constitutively-active form of MEF2 (MEF2CA), which increases MEF2 activity. Microarray experiments were performed using the Illumina Human HT-12 V4.0 expression beadchip (GEO#: GSE57184). By comparing vector-control cells to MEF2CA cells, microarray analysis identified 1880 unique genes that were differentially expressed. Among these genes, 1121 genes were upregulated and 759 genes were down-regulated. Our results provide a valuable resource for identifying transcriptional targets of MEF2 in hNPCs.
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Affiliation(s)
- Shing Fai Chan
- Neuroscience and Aging Research Center, Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Xiayu Huang
- Bioinformatics and Systems Biology Program, Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Scott R. McKercher
- Neuroscience and Aging Research Center, Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Rameez Zaidi
- Neuroscience and Aging Research Center, Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Shu-ichi Okamoto
- Neuroscience and Aging Research Center, Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Nobuki Nakanishi
- Neuroscience and Aging Research Center, Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Stuart A. Lipton
- Neuroscience and Aging Research Center, Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
- Corresponding author. Tel.: + 1 858 795 5261.
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27
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Szymańska K, Szczałuba K, Ługowska A, Obersztyn E, Radkowski M, Nowakowska BA, Kuśmierska K, Tryfon J, Demkow U. The analysis of genetic aberrations in children with inherited neurometabolic and neurodevelopmental disorders. BIOMED RESEARCH INTERNATIONAL 2014; 2014:424796. [PMID: 24949445 PMCID: PMC4052700 DOI: 10.1155/2014/424796] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 04/11/2014] [Accepted: 04/16/2014] [Indexed: 02/05/2023]
Abstract
Inherited encephalopathies include a broad spectrum of heterogeneous disorders. To provide a correct diagnosis, an integrated approach including genetic testing is warranted. We report seven patients with difficult to diagnose inborn paediatric encephalopathies. The diagnosis could not be attained only by means of clinical and laboratory investigations and MRI. Additional genetic testing was required. Cytogenetics, PCR based tests, and array-based comparative genome hybridization were performed. In 4 patients with impaired language abilities we found the presence of microduplication in the region 16q23.1 affecting two dose-sensitive genes: WWOX (OMIM 605131) and MAF (OMIM 177075) (1 case), an interstitial deletion of the 17p11.2 region (2 patients further diagnosed as Smith-Magenis syndrome), and deletion encompassing first three exons of Myocyte Enhancer Factor gene 2MEF2C (1 case). The two other cases represented progressing dystonia. Characteristic GAG deletion in DYT1 consistently with the diagnosis of torsion dystonia was confirmed in 1 case. Last enrolled patient presented with clinical picture consistent with Krabbe disease confirmed by finding of two pathogenic variants of GALC gene and the absence of mutations in PSAP. The integrated diagnostic approach including genetic testing in selected examples of complicated hereditary diseases of the brain is largely discussed in this paper.
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Affiliation(s)
- Krystyna Szymańska
- Department of Clinical and Experimental Neuropathology, Mossakowski Medical Research Centre, Polish Academy of Sciences, 02-106 Warsaw, Poland
- Department of Child Psychiatry, Medical University of Warsaw, 00-576 Warsaw, Poland
| | - Krzysztof Szczałuba
- GenCentrum (Regional Center for Clinical Genetics and Modern Technologies), 25-375 Kielce, Poland
| | - Agnieszka Ługowska
- Department of Genetics, Institute of Psychiatry and Neurology, 02-957 Warsaw, Poland
| | - Ewa Obersztyn
- Department of Medical Genetics, Institute of Mother and Child, 01-211 Warsaw, Poland
| | - Marek Radkowski
- Department of Immunopathology of Infectious Diseases, Medical University of Warsaw, 02-091 Warsaw, Poland
| | - Beata A. Nowakowska
- Department of Medical Genetics, Institute of Mother and Child, 01-211 Warsaw, Poland
| | - Katarzyna Kuśmierska
- Clinic of Child and Adolescent Neurology, Institute of Mother and Child, 01-211 Warsaw, Poland
| | - Jolanta Tryfon
- Department of Laboratory Diagnostics and Clinical Immunology, Medical University of Warsaw, 00-576 Warsaw, Poland
| | - Urszula Demkow
- Clinic of Child and Adolescent Neurology, Institute of Mother and Child, 01-211 Warsaw, Poland
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28
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Bartnik M, Nowakowska B, Derwińska K, Wiśniowiecka-Kowalnik B, Kędzior M, Bernaciak J, Ziemkiewicz K, Gambin T, Sykulski M, Bezniakow N, Korniszewski L, Kutkowska-Kaźmierczak A, Klapecki J, Szczałuba K, Shaw CA, Mazurczak T, Gambin A, Obersztyn E, Bocian E, Stankiewicz P. Application of array comparative genomic hybridization in 256 patients with developmental delay or intellectual disability. J Appl Genet 2013; 55:125-44. [PMID: 24297458 PMCID: PMC3909616 DOI: 10.1007/s13353-013-0181-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 10/17/2013] [Accepted: 10/20/2013] [Indexed: 12/22/2022]
Abstract
We used whole-genome exon-targeted oligonucleotide array comparative genomic hybridization (array CGH) in a cohort of 256 patients with developmental delay (DD)/intellectual disability (ID) with or without dysmorphic features, additional neurodevelopmental abnormalities, and/or congenital malformations. In 69 patients, we identified 84 non-polymorphic copy-number variants, among which 41 are known to be clinically relevant, including two recently described deletions, 4q21.21q21.22 and 17q24.2. Chromosomal microarray analysis revealed also 15 potentially pathogenic changes, including three rare deletions, 5q35.3, 10q21.3, and 13q12.11. Additionally, we found 28 copy-number variants of unknown clinical significance. Our results further support the notion that copy-number variants significantly contribute to the genetic etiology of DD/ID and emphasize the efficacy of the detection of novel candidate genes for neurodevelopmental disorders by whole-genome array CGH.
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Affiliation(s)
- Magdalena Bartnik
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland
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29
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Qiao Y, Badduke C, Mercier E, Lewis SME, Pavlidis P, Rajcan-Separovic E. miRNA and miRNA target genes in copy number variations occurring in individuals with intellectual disability. BMC Genomics 2013; 14:544. [PMID: 23937676 PMCID: PMC3750877 DOI: 10.1186/1471-2164-14-544] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2013] [Accepted: 08/06/2013] [Indexed: 12/20/2022] Open
Abstract
Background MicroRNAs (miRNAs) are a family of short, non-coding RNAs modulating expression of human protein coding genes (miRNA target genes). Their dysfunction is associated with many human diseases, including neurodevelopmental disorders. It has been recently shown that genomic copy number variations (CNVs) can cause aberrant expression of integral miRNAs and their target genes, and contribute to intellectual disability (ID). Results To better understand the CNV-miRNA relationship in ID, we investigated the prevalence and function of miRNAs and miRNA target genes in five groups of CNVs. Three groups of CNVs were from 213 probands with ID (24 de novo CNVs, 46 familial and 216 common CNVs), one group of CNVs was from a cohort of 32 cognitively normal subjects (67 CNVs) and one group of CNVs represented 40 ID related syndromic regions listed in DECIPHER (30 CNVs) which served as positive controls for CNVs causing or predisposing to ID. Our results show that 1). The number of miRNAs is significantly higher in de novo or DECIPHER CNVs than in familial or common CNV subgroups (P < 0.01). 2). miRNAs with brain related functions are more prevalent in de novo CNV groups compared to common CNV groups. 3). More miRNA target genes are found in de novo, familial and DECIPHER CNVs than in the common CNV subgroup (P < 0.05). 4). The MAPK signaling cascade is found to be enriched among the miRNA target genes from de novo and DECIPHER CNV subgroups. Conclusions Our findings reveal an increase in miRNA and miRNA target gene content in de novo versus common CNVs in subjects with ID. Their expression profile and participation in pathways support a possible role of miRNA copy number change in cognition and/or CNV-mediated developmental delay. Systematic analysis of expression/function of miRNAs in addition to coding genes integral to CNVs could uncover new causes of ID.
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Affiliation(s)
- Ying Qiao
- Department of Pathology and Lab Medicine, BC Child and Family Research Institute, University of British Columbia, Vancouver, BC V5Z 4H4, Canada
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30
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MEF2C Haploinsufficiency features consistent hyperkinesis, variable epilepsy, and has a role in dorsal and ventral neuronal developmental pathways. Neurogenetics 2013; 14:99-111. [PMID: 23389741 DOI: 10.1007/s10048-013-0356-y] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 01/23/2013] [Indexed: 12/11/2022]
Abstract
MEF2C haploinsufficiency syndrome is an emerging neurodevelopmental disorder associated with intellectual disability, autistic features, epilepsy, and abnormal movements. We report 16 new patients with MEF2C haploinsufficiency, including the oldest reported patient with MEF2C deletion at 5q14.3. We detail the neurobehavioral phenotype, epilepsy, and abnormal movements, and compare our subjects with those previously reported in the literature. We also investigate Mef2c expression in the developing mouse forebrain. A spectrum of neurofunctional deficits emerges, with hyperkinesis a consistent finding. Epilepsy varied from absent to severe, and included intractable myoclonic seizures and infantile spasms. Subjects with partial MEF2C deletion were statistically less likely to have epilepsy. Finally, we confirm that Mef2c is present both in dorsal primary neuroblasts and ventral gamma-aminobutyric acid(GABA)ergic interneurons in the forebrain of the developing mouse. Given interactions with several key neurodevelopmental genes such as ARX, FMR1, MECP2, and TBR1, it appears that MEF2C plays a role in several developmental stages of both dorsal and ventral neuronal cell types.
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31
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Helsmoortel C, Vandeweyer G, Kooy RF. On the spot: very local chromosomal rearrangements. F1000 BIOLOGY REPORTS 2012. [PMID: 23189093 PMCID: PMC3505860 DOI: 10.3410/b4-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Over the last decade, the detection of chromosomal abnormalities has shifted from conventional karyotyping under a light microscope to molecular detection using microarrays. The latter technology identified copy number variation as a major source of variation in the human genome; moreover, copy number variants were found responsible for 10-20% of cases of intellectual disability. Recent technological advances in microarray technology have also enabled the detection of very small local chromosomal rearrangements, sometimes affecting the function of only a single gene. Here, we illustrate how high resolution microarray analysis has led to increased insights into the contribution of specific genes in disease.
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Affiliation(s)
- Céline Helsmoortel
- Cognitive Genetics, Department of Medical Genetics, University of Antwerp Prins Boudewijnlaan 43, B-2650 Edegem, Belgium
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Du Y, Liu B, Guo F, Xu G, Ding Y, Liu Y, Sun X, Xu G. The essential role of Mbd5 in the regulation of somatic growth and glucose homeostasis in mice. PLoS One 2012; 7:e47358. [PMID: 23077600 PMCID: PMC3471830 DOI: 10.1371/journal.pone.0047358] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 09/11/2012] [Indexed: 12/16/2022] Open
Abstract
Methyl-CpG binding domain protein 5 (MBD5) belongs to the MBD family proteins, which play central roles in transcriptional regulation and development. The significance of MBD5 function is highlighted by recent studies implicating it as a candidate gene involved in human 2q23.1 microdeletion syndrome. To investigate the physiological role of Mbd5, we generated knockout mice. The Mbd5-deficient mice showed growth retardation, wasting and pre-weaning lethality. The observed growth retardation was associated with the impairment of GH/IGF-1 axis in Mbd5-null pups. Conditional knockout of Mbd5 in the brain resulted in the similar phenotypes as whole body deletion, indicating that Mbd5 functions in the nervous system to regulate postnatal growth. Moreover, the mutant mice also displayed enhanced glucose tolerance and elevated insulin sensitivity as a result of increased insulin signaling, ultimately resulting in disturbed glucose homeostasis and hypoglycemia. These results indicate Mbd5 as an essential factor for mouse postnatal growth and maintenance of glucose homeostasis.
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Affiliation(s)
- Yarui Du
- The State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, People’s Republic of China
| | - Bo Liu
- The State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, People’s Republic of China
| | - Fan Guo
- The State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, People’s Republic of China
| | - Guifang Xu
- The State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, People’s Republic of China
| | - Yuqiang Ding
- Tongji University School of Medicine, Shanghai, People’s Republic of China
| | - Yong Liu
- Institute of Nutrition Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, People’s Republic of China
| | - Xin Sun
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Guoliang Xu
- The State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, People’s Republic of China
- * E-mail:
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33
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Fenoglio C, Ridolfi E, Galimberti D, Scarpini E. MicroRNAs as active players in the pathogenesis of multiple sclerosis. Int J Mol Sci 2012. [PMID: 23202949 PMCID: PMC3497323 DOI: 10.3390/ijms131013227] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
MicroRNAs (miRNAs) are a recently discovered group of small noncoding RNAs that regulate gene expression post-transcriptionally. They are highly expressed in cells of the immune system, as well as in the central nervous system, and they are deregulated in various neurological disorders. Emerging evidence underlines an involvement of miRNAs in the pathogenesis of Multiple Sclerosis (MS). A number of miRNAs have been found to be dysregulated in blood cells from MS patients, in brain lesions, as well as in biological fluids such as serum and plasma. Despite miRNA altered expression likely showing a high tissue specificity, some profile similarities could be observed for certain miRNAs such as miR-326-such as upregulation in both active lesions and blood-though not for others such as miR-323, which demonstrated upregulation in whole blood, active brain lesions, and T-reg cells, but not in the serum of MS patients. In this review, the possible role of miRNAs in MS pathogenesis will be discussed according to all the available literature, with a particular emphasis on the possibility of considering extracellular miRNAs as a new source for both biomarker identification and therapeutic target discovery.
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Affiliation(s)
- Chiara Fenoglio
- Department of Pathophysiology and transplantation, "Dino Ferrari" Center, University of Milan, IRCCS Foundation Cà Granda, Ospedale Maggiore Policlinico, 20122 Milan, Italy.
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34
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Cameron DA, Middleton FA, Chenn A, Olson EC. Hierarchical clustering of gene expression patterns in the Eomes + lineage of excitatory neurons during early neocortical development. BMC Neurosci 2012; 13:90. [PMID: 22852769 PMCID: PMC3583225 DOI: 10.1186/1471-2202-13-90] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Accepted: 07/11/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cortical neurons display dynamic patterns of gene expression during the coincident processes of differentiation and migration through the developing cerebrum. To identify genes selectively expressed by the Eomes + (Tbr2) lineage of excitatory cortical neurons, GFP-expressing cells from Tg(Eomes::eGFP) Gsat embryos were isolated to > 99% purity and profiled. RESULTS We report the identification, validation and spatial grouping of genes selectively expressed within the Eomes + cortical excitatory neuron lineage during early cortical development. In these neurons 475 genes were expressed ≥ 3-fold, and 534 genes ≤ 3-fold, compared to the reference population of neuronal precursors. Of the up-regulated genes, 328 were represented at the Genepaint in situ hybridization database and 317 (97%) were validated as having spatial expression patterns consistent with the lineage of differentiating excitatory neurons. A novel approach for quantifying in situ hybridization patterns (QISP) across the cerebral wall was developed that allowed the hierarchical clustering of genes into putative co-regulated groups. Forty four candidate genes were identified that show spatial expression with Intermediate Precursor Cells, 49 candidate genes show spatial expression with Multipolar Neurons, while the remaining 224 genes achieved peak expression in the developing cortical plate. CONCLUSIONS This analysis of differentiating excitatory neurons revealed the expression patterns of 37 transcription factors, many chemotropic signaling molecules (including the Semaphorin, Netrin and Slit signaling pathways), and unexpected evidence for non-canonical neurotransmitter signaling and changes in mechanisms of glucose metabolism. Over half of the 317 identified genes are associated with neuronal disease making these findings a valuable resource for studies of neurological development and disease.
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Affiliation(s)
- David A Cameron
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
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35
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Zweier M, Rauch A. The MEF2C-Related and 5q14.3q15 Microdeletion Syndrome. Mol Syndromol 2012; 2:164-170. [PMID: 22670137 DOI: 10.1159/000337496] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Disorders related to the autosomal transcription factor MEF2C located in 5q14.3 were first described in 2009 and have since evolved to one of the more common microdeletion syndromes. Mutational screening in a larger cohort revealed heterozygous de novo mutations of MEF2C in about 1% of patients with moderate to severe intellectual disability, and the phenotype is similar in patients with intragenic deletions and multigenic microdeletions. Clinically, MEF2C-related disorders are characterized by severe intellectual disability with absent speech and limited walking abilities, hypotonia, seizures, and a variety of minor brain anomalies. The majority of patients show a similar facial gestalt with broad forehead, flat nasal bridge, hypotonic mouth, and small chin, as well as strabismus, but this phenotype is clinically not well recognized. The course of the disease is generally quite uniform, but patients with point mutations and smaller deletions seem to have a higher chance of walking skills and a lower risk of refractory seizures. Patients in whom the microdeletion also includes the RASA1 gene show features of the respective capillary and arterio-venous malformations and fistula syndrome. The phenotypic overlap with Rett syndrome is explained by a shared pathway and, accordingly, diminished MECP2 and CDKL5 expression is measureable in patients with MEF2C defects. Further research of this pathway may therefore eventually lead to a common therapeutic target.
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Affiliation(s)
- M Zweier
- Institute of Human Genetics, Friedrich-Alexander University of Erlangen-Nuremberg, Erlangen, Germany
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36
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Paciorkowski AR, Thio LL, Dobyns WB. Genetic and biologic classification of infantile spasms. Pediatr Neurol 2011; 45:355-67. [PMID: 22114996 PMCID: PMC3397192 DOI: 10.1016/j.pediatrneurol.2011.08.010] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Accepted: 08/15/2011] [Indexed: 10/15/2022]
Abstract
Infantile spasms constitute an age-dependent epilepsy, highly associated with cognitive impairment, autism, and movement disorders. Previous classification systems focused on a distinction between symptomatic and cryptogenic etiologies, and have not kept pace with recent discoveries of mutations in genes in key pathways of central nervous system development in patients with infantile spasms. Children with certain genetic syndromes are much likelier to manifest infantile spasms, and we review the literature to propose a genetic classification of these disorders. Children demonstrating genetic associations with infantile spasms also manifest phenotypes beyond epilepsy that may be explained by recent advances in the understanding of underlying biological mechanisms. Therefore we propose a biologic classification of genes highly associated with infantile spasms, and articulate models for infantile spasms pathogenesis based on those data. The two best described pathways of pathogenesis involve abnormalities in the gene regulatory network of gamma-aminobutyric acidergic forebrain development and abnormalities in molecules expressed at the synapse. These genetic and biologic classifications are flexible, and they should encourage much needed progress in syndrome recognition, clinical genetic testing, and the development of new therapies targeting specific pathways of pathogenesis.
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Affiliation(s)
- Alex R Paciorkowski
- Department of Neurology, University of Washington, Seattle, Washington, USA.
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Talkowski ME, Mullegama SV, Rosenfeld JA, van Bon BWM, Shen Y, Repnikova EA, Gastier-Foster J, Thrush DL, Kathiresan S, Ruderfer DM, Chiang C, Hanscom C, Ernst C, Lindgren AM, Morton CC, An Y, Astbury C, Brueton LA, Lichtenbelt KD, Ades LC, Fichera M, Romano C, Innis JW, Williams CA, Bartholomew D, Van Allen MI, Parikh A, Zhang L, Wu BL, Pyatt RE, Schwartz S, Shaffer LG, de Vries BBA, Gusella JF, Elsea SH. Assessment of 2q23.1 microdeletion syndrome implicates MBD5 as a single causal locus of intellectual disability, epilepsy, and autism spectrum disorder. Am J Hum Genet 2011; 89:551-63. [PMID: 21981781 DOI: 10.1016/j.ajhg.2011.09.011] [Citation(s) in RCA: 157] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 09/17/2011] [Accepted: 09/19/2011] [Indexed: 12/15/2022] Open
Abstract
Persons with neurodevelopmental disorders or autism spectrum disorder (ASD) often harbor chromosomal microdeletions, yet the individual genetic contributors within these regions have not been systematically evaluated. We established a consortium of clinical diagnostic and research laboratories to accumulate a large cohort with genetic alterations of chromosomal region 2q23.1 and acquired 65 subjects with microdeletion or translocation. We sequenced translocation breakpoints; aligned microdeletions to determine the critical region; assessed effects on mRNA expression; and examined medical records, photos, and clinical evaluations. We identified a single gene, methyl-CpG-binding domain 5 (MBD5), as the only locus that defined the critical region. Partial or complete deletion of MBD5 was associated with haploinsufficiency of mRNA expression, intellectual disability, epilepsy, and autistic features. Fourteen alterations, including partial deletions of noncoding regions not typically captured or considered pathogenic by current diagnostic screening, disrupted MBD5 alone. Expression profiles and clinical characteristics were largely indistinguishable between MBD5-specific alteration and deletion of the entire 2q23.1 interval. No copy-number alterations of MBD5 were observed in 7878 controls, suggesting MBD5 alterations are highly penetrant. We surveyed MBD5 coding variations among 747 ASD subjects compared to 2043 non-ASD subjects analyzed by whole-exome sequencing and detected an association with a highly conserved methyl-CpG-binding domain missense variant, p.79Gly>Glu (c.236G>A) (p = 0.012). These results suggest that genetic alterations of MBD5 cause features of 2q23.1 microdeletion syndrome and that this epigenetic regulator significantly contributes to ASD risk, warranting further consideration in research and clinical diagnostic screening and highlighting the importance of chromatin remodeling in the etiology of these complex disorders.
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Affiliation(s)
- Michael E Talkowski
- Center for Human Genetic Research, Massachusetts General Hospital, Boston, MA 02114, USA
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Hao H, Tummala P, Guzman E, Mali RS, Gregorski J, Swaroop A, Mitton KP. The transcription factor neural retina leucine zipper (NRL) controls photoreceptor-specific expression of myocyte enhancer factor Mef2c from an alternative promoter. J Biol Chem 2011; 286:34893-902. [PMID: 21849497 PMCID: PMC3186360 DOI: 10.1074/jbc.m111.271072] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 08/15/2011] [Indexed: 11/06/2022] Open
Abstract
Neural retina leucine zipper (NRL) is an essential transcription factor for cell fate specification and functional maintenance of rod photoreceptors in the mammalian retina. In the Nrl(-/-) mouse retina, photoreceptor precursors fail to produce rods and generate functional cone photoreceptors that predominantly express S-opsin. Previous global expression analysis using microarrays revealed dramatically reduced expression of myocyte enhancer factor Mef2c in the adult Nrl(-/-) retina. We undertook this study to examine the biological relevance of Mef2c expression in retinal rod photoreceptors. Bioinformatics analysis, rapid analysis of cDNA ends (5'-RACE), and reverse transcription coupled with qPCR using splice site-specific oligonucleotides suggested that Mef2c is expressed in the mature retina from an alternative promoter. Chromatin immunoprecipitation (ChIP) studies showed the association of active RNA polymerase II and acetylated histone H3 just upstream of Mef2c exon 4, providing additional evidence for the utilization of an alternative promoter in the retina. In concordance, we observed the binding of NRL to a putative NRL-response element (NRE) at this location by ChIP-seq and electrophoretic mobility shift assays. NRL also activated the Mef2c alternative promoter in vitro and in vivo. Notably, MEF2C could support Rhodopsin promoter activity in rod photoreceptors. We conclude that Mef2c expression from an alternative promoter in the retina is regulated by NRL. Our studies also implicate MEF2C as a transcriptional regulator of homeostasis in rod photoreceptor cells.
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Affiliation(s)
- Hong Hao
- From the Neurobiology Neurodegeneration & Repair Laboratory, NEI, National Institutes of Health, Bethesda, Maryland 20892 and
| | - Padmaja Tummala
- the Control of Gene Expression Laboratory, Eye Research Institute, Oakland University, Rochester, Michigan 48309
| | - Eduardo Guzman
- the Control of Gene Expression Laboratory, Eye Research Institute, Oakland University, Rochester, Michigan 48309
| | - Raghuveer S. Mali
- the Control of Gene Expression Laboratory, Eye Research Institute, Oakland University, Rochester, Michigan 48309
| | - Janina Gregorski
- From the Neurobiology Neurodegeneration & Repair Laboratory, NEI, National Institutes of Health, Bethesda, Maryland 20892 and
| | - Anand Swaroop
- From the Neurobiology Neurodegeneration & Repair Laboratory, NEI, National Institutes of Health, Bethesda, Maryland 20892 and
| | - Kenneth P. Mitton
- the Control of Gene Expression Laboratory, Eye Research Institute, Oakland University, Rochester, Michigan 48309
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Agarwal P, Verzi MP, Nguyen T, Hu J, Ehlers ML, McCulley DJ, Xu SM, Dodou E, Anderson JP, Wei ML, Black BL. The MADS box transcription factor MEF2C regulates melanocyte development and is a direct transcriptional target and partner of SOX10. Development 2011; 138:2555-65. [PMID: 21610032 PMCID: PMC3100711 DOI: 10.1242/dev.056804] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/31/2011] [Indexed: 12/24/2022]
Abstract
Waardenburg syndromes are characterized by pigmentation and autosensory hearing defects, and mutations in genes encoding transcription factors that control neural crest specification and differentiation are often associated with Waardenburg and related disorders. For example, mutations in SOX10 result in a severe form of Waardenburg syndrome, Type IV, also known as Waardenburg-Hirschsprung disease, characterized by pigmentation and other neural crest defects, including defective innervation of the gut. SOX10 controls neural crest development through interactions with other transcription factors. The MADS box transcription factor MEF2C is an important regulator of brain, skeleton, lymphocyte and cardiovascular development and is required in the neural crest for craniofacial development. Here, we establish a novel role for MEF2C in melanocyte development. Inactivation of Mef2c in the neural crest of mice results in reduced expression of melanocyte genes during development and a significant loss of pigmentation at birth due to defective differentiation and reduced abundance of melanocytes. We identify a transcriptional enhancer of Mef2c that directs expression to the neural crest and its derivatives, including melanocytes, in transgenic mouse embryos. This novel Mef2c neural crest enhancer contains three functional SOX binding sites and a single essential MEF2 site. We demonstrate that Mef2c is a direct transcriptional target of SOX10 and MEF2 via this evolutionarily conserved enhancer. Furthermore, we show that SOX10 and MEF2C physically interact and function cooperatively to activate the Mef2c gene in a feed-forward transcriptional circuit, suggesting that MEF2C might serve as a potentiator of the transcriptional pathways affected in Waardenburg syndromes.
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Affiliation(s)
- Pooja Agarwal
- Cardiovascular Research Institute, University of California, San Francisco, CA 94158-2517, USA
| | - Michael P. Verzi
- Cardiovascular Research Institute, University of California, San Francisco, CA 94158-2517, USA
| | - Thuyen Nguyen
- Department of Dermatology, Veterans Affairs Medical Center, University of California, San Francisco, CA 94143-0316, USA
| | - Jianxin Hu
- Cardiovascular Research Institute, University of California, San Francisco, CA 94158-2517, USA
| | - Melissa L. Ehlers
- Cardiovascular Research Institute, University of California, San Francisco, CA 94158-2517, USA
| | - David J. McCulley
- Cardiovascular Research Institute, University of California, San Francisco, CA 94158-2517, USA
| | - Shan-Mei Xu
- Cardiovascular Research Institute, University of California, San Francisco, CA 94158-2517, USA
| | - Evdokia Dodou
- Cardiovascular Research Institute, University of California, San Francisco, CA 94158-2517, USA
| | - Joshua P. Anderson
- Cardiovascular Research Institute, University of California, San Francisco, CA 94158-2517, USA
| | - Maria L. Wei
- Department of Dermatology, Veterans Affairs Medical Center, University of California, San Francisco, CA 94143-0316, USA
| | - Brian L. Black
- Cardiovascular Research Institute, University of California, San Francisco, CA 94158-2517, USA
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94158-2517, USA
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Vertebrate paralogous MEF2 genes: origin, conservation, and evolution. PLoS One 2011; 6:e17334. [PMID: 21394201 PMCID: PMC3048864 DOI: 10.1371/journal.pone.0017334] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2010] [Accepted: 01/31/2011] [Indexed: 01/04/2023] Open
Abstract
Background The myocyte enhancer factor 2 (MEF2) gene family is broadly expressed during the development and maintenance of muscle cells. Although a great deal has been elucidated concerning MEF2 transcription factors' regulation of specific gene expression in diverse programs and adaptive responses, little is known about the origin and evolution of the four members of the MEF2 gene family in vertebrates. Methodology/Principal Findings By phylogenetic analyses, we investigated the origin, conservation, and evolution of the four MEF2 genes. First, among the four MEF2 paralogous branches, MEF2B is clearly distant from the other three branches in vertebrates, mainly because it lacks the HJURP_C (Holliday junction recognition protein C-terminal) region. Second, three duplication events might have occurred to produce the four MEF2 paralogous genes and the latest duplication event occurred near the origin of vertebrates producing MEF2A and MEF2C. Third, the ratio (Ka/Ks) of non-synonymous to synonymous nucleotide substitution rates showed that MEF2B evolves faster than the other three MEF2 proteins despite purifying selection on all of the four MEF2 branches. Moreover, a pair model of M0 versus M3 showed that variable selection exists among MEF2 proteins, and branch-site analysis presented that sites 53 and 64 along the MEF2B branch are under positive selection. Finally, and interestingly, substitution rates showed that type II MADS genes (i.e., MEF2-like genes) evolve as slowly as type I MADS genes (i.e., SRF-like genes) in animals, which is inconsistent with the fact that type II MADS genes evolve much slower than type I MADS genes in plants. Conclusion Our findings shed light on the relationship of MEF2A, B, C, and D with functional conservation and evolution in vertebrates. This study provides a rationale for future experimental design to investigate distinct but overlapping regulatory roles of the four MEF2 genes in various tissues.
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Tsai ACH, Dossett CJ, Walton CS, Cramer AE, Eng PA, Nowakowska BA, Pursley AN, Stankiewicz P, Wiszniewska J, Cheung SW. Exon deletions of the EP300 and CREBBP genes in two children with Rubinstein-Taybi syndrome detected by aCGH. Eur J Hum Genet 2010; 19:43-9. [PMID: 20717166 DOI: 10.1038/ejhg.2010.121] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
We demonstrate the utility of an exon coverage microarray platform in detecting intragenic deletions: one in exons 24-27 of the EP300 gene and another in exons 27 and 28 of the CREBBP gene in two patients with Rubinstein-Taybi syndrome (RSTS). RSTS is a heterogeneous disorder in which approximately 45-55% of cases result from deletion or mutations in the CREBBP gene and an unknown portion of cases result from gene changes in EP300. The first case is a 3-year-old female with an exonic deletion of the EP300 gene who has classic facial features of RSTS without the thumb and great toe anomalies, consistent with the milder skeletal phenotype that has been described in other RSTS cases with EP300 mutations. In addition, the mother of this patient also had preeclampsia during pregnancy, which has been infrequently reported. The second case is a newborn male who has the classical features of RSTS. Our results illustrate that exon-targeted array comparative genomic hybridization (aCGH) is a powerful tool for detecting clinically significant intragenic rearrangements that would be otherwise missed by aCGH platforms lacking sufficient exonic coverage or sequencing of the gene of interest.
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Affiliation(s)
- Anne Chun-Hui Tsai
- The Children's Hospital, Section of Clinical Genetics and Metabolism, Denver, UC Denver, Aurora, CO, USA
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