151
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Epilessie generalizzate. Neurologia 2015. [DOI: 10.1016/s1634-7072(15)70512-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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152
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Chen ZH, Wang C, Wang LG, Zhuo MQ, Tang ZH, Zhai QX, Chen Q, Guo YX, Zhang YX. Analysis of the CHRNA7 gene mutation and polymorphism in Southern Han Chinese patients with nocturnal frontal epilepsy. ASIAN PAC J TROP MED 2015; 8:330-3. [DOI: 10.1016/s1995-7645(14)60340-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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153
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Bacchelli E, Battaglia A, Cameli C, Lomartire S, Tancredi R, Thomson S, Sutcliffe JS, Maestrini E. Analysis of CHRNA7 rare variants in autism spectrum disorder susceptibility. Am J Med Genet A 2015; 167A:715-23. [PMID: 25655306 DOI: 10.1002/ajmg.a.36847] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 09/30/2014] [Indexed: 11/11/2022]
Abstract
Chromosome 15q13.3 recurrent microdeletions are causally associated with a wide range of phenotypes, including autism spectrum disorder (ASD), seizures, intellectual disability, and other psychiatric conditions. Whether the reciprocal microduplication is pathogenic is less certain. CHRNA7, encoding for the alpha7 subunit of the neuronal nicotinic acetylcholine receptor, is considered the likely culprit gene in mediating neurological phenotypes in 15q13.3 deletion cases. To assess if CHRNA7 rare variants confer risk to ASD, we performed copy number variant analysis and Sanger sequencing of the CHRNA7 coding sequence in a sample of 135 ASD cases. Sequence variation in this gene remains largely unexplored, given the existence of a fusion gene, CHRFAM7A, which includes a nearly identical partial duplication of CHRNA7. Hence, attempts to sequence coding exons must distinguish between CHRNA7 and CHRFAM7A, making next-generation sequencing approaches unreliable for this purpose. A CHRNA7 microduplication was detected in a patient with autism and moderate cognitive impairment; while no rare damaging variants were identified in the coding region, we detected rare variants in the promoter region, previously described to functionally reduce transcription. This study represents the first sequence variant analysis of CHRNA7 in a sample of idiopathic autism.
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Affiliation(s)
- Elena Bacchelli
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
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154
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Lukic A, Uphill J, Brown CA, Beck J, Poulter M, Campbell T, Adamson G, Hummerich H, Whitfield J, Ponto C, Zerr I, Lloyd SE, Collinge J, Mead S. Rare structural genetic variation in human prion diseases. Neurobiol Aging 2015; 36:2004.e1-8. [PMID: 25726360 DOI: 10.1016/j.neurobiolaging.2015.01.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 12/22/2014] [Accepted: 01/13/2015] [Indexed: 10/24/2022]
Abstract
Prion diseases are a diverse group of neurodegenerative conditions, caused by the templated misfolding of prion protein. Aside from the strong genetic risk conferred by multiple variants of the prion protein gene (PRNP), several other variants have been suggested to confer risk in the most common type, sporadic Creutzfeldt-Jakob disease (sCJD) or in the acquired prion diseases. Large and rare copy number variants (CNVs) are known to confer risk in several related disorders including Alzheimer's disease (at APP), schizophrenia, epilepsy, mental retardation, and autism. Here, we report the first genome-wide analysis for CNV-associated risk using data derived from a recent international collaborative association study in sCJD (n = 1147 after quality control) and publicly available controls (n = 5427). We also investigated UK patients with variant Creutzfeldt-Jakob disease (n = 114) and elderly women from the Eastern Highlands of Papua New Guinea who proved highly resistant to the epidemic prion disease kuru, who were compared with healthy young Fore population controls (n = 395). There were no statistically significant alterations in the burden of CNVs >100, >500, or >1000 kb, duplications, or deletions in any disease group or geographic region. After correction for multiple testing, no statistically significant associations were found. A UK blood service control sample showed a duplication CNV that overlapped PRNP, but these were not found in prion disease. Heterozygous deletions of a 3' region of the PARK2 gene were found in 3 sCJD patients and no controls (p = 0.001, uncorrected). A cell-based prion infection assay did not provide supportive evidence for a role for PARK2 in prion disease susceptibility. These data are consistent with a modest impact of CNVs on risk of late-onset neurologic conditions and suggest that, unlike APP, PRNP duplication is not a causal high-risk mutation.
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Affiliation(s)
- Ana Lukic
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
| | - James Uphill
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
| | - Craig A Brown
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
| | - John Beck
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
| | - Mark Poulter
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
| | - Tracy Campbell
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
| | - Gary Adamson
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
| | - Holger Hummerich
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
| | - Jerome Whitfield
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
| | - Claudia Ponto
- Department of Neurology, Georg-August University Göttingen, Göttingen, Germany; German Center for Neurodegenrative Diseases (DZNE), Gottingen, Germany
| | - Inga Zerr
- Department of Neurology, Georg-August University Göttingen, Göttingen, Germany; German Center for Neurodegenrative Diseases (DZNE), Gottingen, Germany
| | - Sarah E Lloyd
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
| | - John Collinge
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
| | - Simon Mead
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK.
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155
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Naseer MI, Faheem M, Chaudhary AG, Kumosani TA, Al-Quaiti MM, Jan MM, Saleh Jamal H, Al-Qahtani MH. Genome wide analysis of novel copy number variations duplications/deletions of different epileptic patients in Saudi Arabia. BMC Genomics 2015; 16 Suppl 1:S10. [PMID: 25923336 PMCID: PMC4315149 DOI: 10.1186/1471-2164-16-s1-s10] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Background Epilepsy is genetically complex neurological disorder affecting millions of people of different age groups varying in its type and severity. Copy number variants (CNVs) are key players in the genetic etiology of numerous neurodevelopmental disorders and prior findings also revealed that chromosomal aberrations are more susceptible against the pathogenesis of epilepsy. Novel technologies, such as array comparative genomic hybridization (array-CGH), may help to uncover the pathogenic CNVs in patients with epilepsy. Results This study was carried out by high density whole genome array-CGH analysis with blood DNA samples from a cohort of 22 epilepsy patients to search for CNVs associated with epilepsy. Pathogenic rearrangements which include 6p12.1 microduplications in 5 patients covering a total region of 99.9kb and 7q32.3 microdeletions in 3 patients covering a total region of 63.9kb were detected. Two genes BMP5 and PODXL were located in the predicted duplicated and deleted regions respectively. Furthermore, these CNV findings were confirmed by qPCR. Conclusion We have described, for the first time, several novel CNVs/genes implicated in epilepsy in the Saudi population. These findings enable us to better describe the genetic variations in epilepsy, and could provide a foundation for understanding the critical regions of the genome which might be involved in the development of epilepsy.
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156
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Miteff CI, Smith RL, Bain NL, Subramanian G, Brown JE, Kamien B. 16p13.11 microdeletion in a patient with hemiconvulsion-hemiplegia-epilepsy syndrome: a case report. J Child Neurol 2015; 30:83-6. [PMID: 24453159 DOI: 10.1177/0883073813516382] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We describe a patient with hemiconvulsion-hemiplegia-epilepsy syndrome. The pathophysiology of hemiconvulsion-hemiplegia-epilepsy syndrome remains uncertain and there are probably multiple potential contributing factors. Our patient had a chromosomal 16p13.11 microdeletion that confers susceptibility to various types of epilepsy. This is the first report detailing an association of hemiconvulsion-hemiplegia-epilepsy syndrome with a 16p13.11 deletion and identifies another potential causal factor for hemiconvulsion-hemiplegia-epilepsy syndrome.
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Affiliation(s)
- Christina I Miteff
- John Hunter Children's Hospital, New Lambton Heights, New South Wales, Australia
| | - Robert L Smith
- John Hunter Children's Hospital, New Lambton Heights, New South Wales, Australia The University of Newcastle, School of Medicine and Public Health, Newcastle, New South Wales, Australia
| | - Nicole L Bain
- Department of Molecular Medicine, Hunter Area Pathology Service, John Hunter Hospital, Rankin Park, Australia
| | - Gopinath Subramanian
- John Hunter Children's Hospital, New Lambton Heights, New South Wales, Australia
| | - Janis E Brown
- John Hunter Children's Hospital, New Lambton Heights, New South Wales, Australia
| | - Ben Kamien
- The University of Newcastle, School of Medicine and Public Health, Newcastle, New South Wales, Australia Hunter Genetics, Newcastle, New South Wales, Australia
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157
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The developmental transcriptome of the human brain: implications for neurodevelopmental disorders. Curr Opin Neurol 2014; 27:149-56. [PMID: 24565942 DOI: 10.1097/wco.0000000000000069] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE OF REVIEW Recent characterizations of the transcriptome of the developing human brain by several groups have generated comprehensive datasets on coding and noncoding RNAs that will be instrumental for illuminating the underlying biology of complex neurodevelopmental disorders. This review summarizes recent studies successfully utilizing these data to increase our understanding of the molecular mechanisms of pathogenesis. RECENT FINDINGS Several approaches have successfully integrated developmental transcriptome data with gene discovery to generate testable hypotheses about when and where in the developing human brain disease-associated genes converge. Specifically, these include the projection neurons in the prefrontal and primary motor--somatosensory cortex during mid-fetal development in autism spectrum disorder and the frontal cortex during fetal development in schizophrenia. SUMMARY Developmental transcriptome data is a key to interpreting disease-associated mutations and transcriptional changes. Novel approaches integrating the spatial and temporal dimensions of these data have increased our understanding of when and where disease occurs. Refinement of spatial and temporal properties and expanding these findings to other neurodevelopmental disorders will provide critical insights for understanding disease biology.
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158
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Palindromic GOLGA8 core duplicons promote chromosome 15q13.3 microdeletion and evolutionary instability. Nat Genet 2014; 46:1293-302. [PMID: 25326701 PMCID: PMC4244265 DOI: 10.1038/ng.3120] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2014] [Accepted: 09/25/2014] [Indexed: 12/14/2022]
Abstract
Recurrent deletions of chromosome 15q13.3 associate with intellectual disability, schizophrenia, autism and epilepsy. To gain insight into its instability, we sequenced the region in patients, normal individuals and nonhuman primates. We discovered five structural configurations of the human chromosome 15q13.3 region ranging in size from 2 to 3 Mbp. These configurations arose recently (~0.5–0.9 million years ago) as a result of human-specific expansions of segmental duplications and two independent inversion events. All inversion breakpoints map near GOLGA8 core duplicons—a ~14 kbp primate-specific chromosome 15 repeat that became organized into larger palindromic structures. GOLGA8-flanked palindromes also demarcate the breakpoints of recurrent 15q13.3 microdeletions, the expansion of chromosome 15 segmental duplications in the human lineage, and independent structural changes in apes. The significant clustering (p=0.002) of breakpoints provides mechanistic evidence for the role of this core duplicon and its palindromic architecture in promoting evolutionary and disease-related instability of chromosome 15.
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159
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Chowdhury FA, Woldman W, FitzGerald THB, Elwes RDC, Nashef L, Terry JR, Richardson MP. Revealing a brain network endophenotype in families with idiopathic generalised epilepsy. PLoS One 2014; 9:e110136. [PMID: 25302690 PMCID: PMC4193864 DOI: 10.1371/journal.pone.0110136] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 09/17/2014] [Indexed: 12/16/2022] Open
Abstract
Idiopathic generalised epilepsy (IGE) has a genetic basis. The mechanism of seizure expression is not fully known, but is assumed to involve large-scale brain networks. We hypothesised that abnormal brain network properties would be detected using EEG in patients with IGE, and would be manifest as a familial endophenotype in their unaffected first-degree relatives. We studied 117 participants: 35 patients with IGE, 42 unaffected first-degree relatives, and 40 normal controls, using scalp EEG. Graph theory was used to describe brain network topology in five frequency bands for each subject. Frequency bands were chosen based on a published Spectral Factor Analysis study which demonstrated these bands to be optimally robust and independent. Groups were compared, using Bonferroni correction to account for nonindependent measures and multiple groups. Degree distribution variance was greater in patients and relatives than controls in the 6-9 Hz band (p = 0.0005, p = 0.0009 respectively). Mean degree was greater in patients than healthy controls in the 6-9 Hz band (p = 0.0064). Clustering coefficient was higher in patients and relatives than controls in the 6-9 Hz band (p = 0.0025, p = 0.0013). Characteristic path length did not differ between groups. No differences were found between patients and unaffected relatives. These findings suggest brain network topology differs between patients with IGE and normal controls, and that some of these network measures show similar deviations in patients and in unaffected relatives who do not have epilepsy. This suggests brain network topology may be an inherited endophenotype of IGE, present in unaffected relatives who do not have epilepsy, as well as in affected patients. We propose that abnormal brain network topology may be an endophenotype of IGE, though not in itself sufficient to cause epilepsy.
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Affiliation(s)
- Fahmida A. Chowdhury
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
- Centre for Epilepsy, King's College Hospital, London, United Kingdom
| | - Wessel Woldman
- College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, United Kingdom
| | - Thomas H. B. FitzGerald
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
- Wellcome Trust Centre for Neuroimaging, UCL, London, United Kingdom
| | | | - Lina Nashef
- Centre for Epilepsy, King's College Hospital, London, United Kingdom
| | - John R. Terry
- College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, United Kingdom
| | - Mark P. Richardson
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
- Centre for Epilepsy, King's College Hospital, London, United Kingdom
- * E-mail:
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160
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Moreira DP, Griesi-Oliveira K, Bossolani-Martins AL, Lourenço NCV, Takahashi VNO, da Rocha KM, Moreira ES, Vadasz E, Meira JGC, Bertola D, Halloran EO, Magalhães TR, Fett-Conte AC, Passos-Bueno MR. Investigation of 15q11-q13, 16p11.2 and 22q13 CNVs in autism spectrum disorder Brazilian individuals with and without epilepsy. PLoS One 2014; 9:e107705. [PMID: 25255310 PMCID: PMC4177849 DOI: 10.1371/journal.pone.0107705] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Accepted: 08/21/2014] [Indexed: 11/18/2022] Open
Abstract
Copy number variations (CNVs) are an important cause of ASD and those located at 15q11-q13, 16p11.2 and 22q13 have been reported as the most frequent. These CNVs exhibit variable clinical expressivity and those at 15q11-q13 and 16p11.2 also show incomplete penetrance. In the present work, through multiplex ligation-dependent probe amplification (MLPA) analysis of 531 ethnically admixed ASD-affected Brazilian individuals, we found that the combined prevalence of the 15q11-q13, 16p11.2 and 22q13 CNVs is 2.1% (11/531). Parental origin could be determined in 8 of the affected individuals, and revealed that 4 of the CNVs represent de novo events. Based on CNV prediction analysis from genome-wide SNP arrays, the size of those CNVs ranged from 206 kb to 2.27 Mb and those at 15q11-q13 were limited to the 15q13.3 region. In addition, this analysis also revealed 6 additional CNVs in 5 out of 11 affected individuals. Finally, we observed that the combined prevalence of CNVs at 15q13.3 and 22q13 in ASD-affected individuals with epilepsy (6.4%) was higher than that in ASD-affected individuals without epilepsy (1.3%; p<0.014). Therefore, our data show that the prevalence of CNVs at 15q13.3, 16p11.2 and 22q13 in Brazilian ASD-affected individuals is comparable to that estimated for ASD-affected individuals of pure or predominant European ancestry. Also, it suggests that the likelihood of a greater number of positive MLPA results might be found for the 15q13.3 and 22q13 regions by prioritizing ASD-affected individuals with epilepsy.
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MESH Headings
- Adolescent
- Base Sequence
- Brazil
- Child
- Child Development Disorders, Pervasive/complications
- Child Development Disorders, Pervasive/genetics
- Chromosomes, Human/genetics
- Chromosomes, Human, Pair 15/genetics
- Chromosomes, Human, Pair 16/genetics
- Chromosomes, Human, Pair 22/genetics
- DNA Copy Number Variations
- Epilepsy/complications
- Female
- Genomics
- Humans
- Male
- Pedigree
- Polymorphism, Single Nucleotide
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Affiliation(s)
- Danielle P. Moreira
- Centro de Pesquisas sobre o Genoma Humano e Células Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brasil
| | - Karina Griesi-Oliveira
- Centro de Pesquisas sobre o Genoma Humano e Células Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brasil
| | - Ana L. Bossolani-Martins
- Departamento de Biologia Molecular, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto, SP, Brasil
| | - Naila C. V. Lourenço
- Centro de Pesquisas sobre o Genoma Humano e Células Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brasil
| | - Vanessa N. O. Takahashi
- Centro de Pesquisas sobre o Genoma Humano e Células Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brasil
| | - Kátia M. da Rocha
- Centro de Pesquisas sobre o Genoma Humano e Células Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brasil
| | - Eloisa S. Moreira
- Centro de Pesquisas sobre o Genoma Humano e Células Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brasil
| | - Estevão Vadasz
- Instituto de Psiquiatria do Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brasil
| | - Joanna Goes Castro Meira
- Centro de Pesquisas sobre o Genoma Humano e Células Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brasil
| | - Debora Bertola
- Centro de Pesquisas sobre o Genoma Humano e Células Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brasil
- Instituto da Criança da Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brasil
| | - Eoghan O’ Halloran
- Academic Centre on Rare Diseases, School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Tiago R. Magalhães
- Academic Centre on Rare Diseases, School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
- National Children’s Research Centre, Our Lady’s Children’s Hospital, Dublin, Ireland
| | - Agnes C. Fett-Conte
- Departamento de Biologia Molecular, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto, SP, Brasil
| | - Maria Rita Passos-Bueno
- Centro de Pesquisas sobre o Genoma Humano e Células Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brasil
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161
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Fanciulli M, Pasini E, Malacrida S, Striano P, Striano S, Michelucci R, Ottman R, Nobile C. Copy number variations and susceptibility to lateral temporal epilepsy: A study of 21 pedigrees. Epilepsia 2014; 55:1651-8. [DOI: 10.1111/epi.12767] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/23/2014] [Indexed: 11/28/2022]
Affiliation(s)
| | - Elena Pasini
- Unit of Neurology; Bellaria Hospital; IRCCS of Neurological Sciences; Bologna Italy
| | | | - Pasquale Striano
- Pediatric Neurology and Neuromuscular Disease Unit; Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health; “G. Gaslini” Institute; University of Genoa; Genova Italy
| | - Salvatore Striano
- Department of Neurological Sciences; Federico II University; Napoli Italy
| | - Roberto Michelucci
- Unit of Neurology; Bellaria Hospital; IRCCS of Neurological Sciences; Bologna Italy
| | - Ruth Ottman
- Departments of Epidemiology and Neurology and the G.H. Sergievsky Center; Columbia University; New York New York U.S.A
- Division of Epidemiology; New York State Psychiatric Institute; New York New York U.S.A
| | - Carlo Nobile
- CNR-Neuroscience Institute; Section of Padua; Padova Italy
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162
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Olson HE, Poduri A, Pearl PL. Genetic forms of epilepsies and other paroxysmal disorders. Semin Neurol 2014; 34:266-79. [PMID: 25192505 DOI: 10.1055/s-0034-1386765] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Genetic mechanisms explain the pathophysiology of many forms of epilepsy and other paroxysmal disorders, such as alternating hemiplegia of childhood, familial hemiplegic migraine, and paroxysmal dyskinesias. Epilepsy is a key feature of well-defined genetic syndromes including tuberous sclerosis complex, Rett syndrome, Angelman syndrome, and others. There is an increasing number of single-gene causes or susceptibility factors associated with several epilepsy syndromes, including the early-onset epileptic encephalopathies, benign neonatal/infantile seizures, progressive myoclonus epilepsies, genetic generalized and benign focal epilepsies, epileptic aphasias, and familial focal epilepsies. Molecular mechanisms are diverse, and a single gene can be associated with a broad range of phenotypes. Additional features, such as dysmorphisms, head size, movement disorders, and family history may provide clues to a genetic diagnosis. Genetic testing can impact medical care and counseling. We discuss genetic mechanisms of epilepsy and other paroxysmal disorders, tools and indications for genetic testing, known genotype-phenotype associations, the importance of genetic counseling, and a look toward the future of epilepsy genetics.
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Affiliation(s)
- Heather E Olson
- Division of Epilepsy, Department of Neurology, Boston Children's Hospital, Boston, Massachusetts
| | - Annapurna Poduri
- Division of Epilepsy, Department of Neurology, Boston Children's Hospital, Boston, Massachusetts
| | - Phillip L Pearl
- Division of Epilepsy, Department of Neurology, Boston Children's Hospital, Boston, Massachusetts
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163
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Abstract
Copy number variants (CNVs; deletions or duplications of chromosomal regions) have emerged as an important cause of human disease. In a recent study, epilepsy could be attributed to a pathogenic CNV in 5% of patients, but understanding the implications of a CNV for an individual patient can be challenging.
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164
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Vadlamudi L, Milne RL, Lawrence K, Heron SE, Eckhaus J, Keay D, Connellan M, Torn-Broers Y, Howell RA, Mulley JC, Scheffer IE, Dibbens LM, Hopper JL, Berkovic SF. Genetics of epilepsy: The testimony of twins in the molecular era. Neurology 2014; 83:1042-8. [PMID: 25107880 DOI: 10.1212/wnl.0000000000000790] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVE Analysis of twins with epilepsy to explore the genetic architecture of specific epilepsies, to evaluate the applicability of the 2010 International League Against Epilepsy (ILAE) organization of epilepsy syndromes, and to integrate molecular genetics with phenotypic analyses. METHODS A total of 558 twin pairs suspected to have epilepsy were ascertained from twin registries (69%) or referral (31%). Casewise concordance estimates were calculated for epilepsy syndromes. Epilepsies were then grouped according to the 2010 ILAE organizational scheme. Molecular genetic information was utilized where applicable. RESULTS Of 558 twin pairs, 418 had confirmed seizures. A total of 534 twin individuals were affected. There were higher twin concordance estimates for monozygotic (MZ) than for dizygotic (DZ) twins for idiopathic generalized epilepsies (MZ = 0.77; DZ = 0.35), genetic epilepsy with febrile seizures plus (MZ = 0.85; DZ = 0.25), and focal epilepsies (MZ = 0.40; DZ = 0.03). Utilizing the 2010 ILAE scheme, the twin data clearly demonstrated genetic influences in the syndromes designated as genetic. Of the 384 tested twin individuals, 10.9% had mutations of large effect in known epilepsy genes or carried validated susceptibility alleles. CONCLUSIONS Twin studies confirm clear genetic influences for specific epilepsies. Analysis of the twin sample using the 2010 ILAE scheme strongly supported the validity of grouping the "genetic" syndromes together and shows this organizational scheme to be a more flexible and biologically meaningful system than previous classifications. Successful selected molecular testing applied to this cohort is the prelude to future large-scale next-generation sequencing of epilepsy research cohorts. Insights into genetic architecture provided by twin studies provide essential data for optimizing such approaches.
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Affiliation(s)
- Lata Vadlamudi
- From the Epilepsy Research Centre, Department of Medicine (Neurology) (L.V., K.L., J.E., D.K., M.C., Y.T.-B., R.A.H., I.E.S., S.F.B.), University of Melbourne, Austin Health; School of Medicine (L.V.), The University of Queensland, Brisbane; Department of Neurology (L.V.), Royal Brisbane and Women's Hospital; Centre for Molecular, Environmental, Analytic and Genetic Epidemiology (R.L.M., J.L.H.), University of Melbourne; School of Pharmacy and Medical Sciences and Sansom Institute for Health Research (S.E.H., L.M.D.), University of South Australia, Adelaide; and the Department of Genetic Medicine, SA Pathology (J.C.M.), Women's and Children's Hospital, North Adelaide, Australia
| | - Roger L Milne
- From the Epilepsy Research Centre, Department of Medicine (Neurology) (L.V., K.L., J.E., D.K., M.C., Y.T.-B., R.A.H., I.E.S., S.F.B.), University of Melbourne, Austin Health; School of Medicine (L.V.), The University of Queensland, Brisbane; Department of Neurology (L.V.), Royal Brisbane and Women's Hospital; Centre for Molecular, Environmental, Analytic and Genetic Epidemiology (R.L.M., J.L.H.), University of Melbourne; School of Pharmacy and Medical Sciences and Sansom Institute for Health Research (S.E.H., L.M.D.), University of South Australia, Adelaide; and the Department of Genetic Medicine, SA Pathology (J.C.M.), Women's and Children's Hospital, North Adelaide, Australia
| | - Kate Lawrence
- From the Epilepsy Research Centre, Department of Medicine (Neurology) (L.V., K.L., J.E., D.K., M.C., Y.T.-B., R.A.H., I.E.S., S.F.B.), University of Melbourne, Austin Health; School of Medicine (L.V.), The University of Queensland, Brisbane; Department of Neurology (L.V.), Royal Brisbane and Women's Hospital; Centre for Molecular, Environmental, Analytic and Genetic Epidemiology (R.L.M., J.L.H.), University of Melbourne; School of Pharmacy and Medical Sciences and Sansom Institute for Health Research (S.E.H., L.M.D.), University of South Australia, Adelaide; and the Department of Genetic Medicine, SA Pathology (J.C.M.), Women's and Children's Hospital, North Adelaide, Australia
| | - Sarah E Heron
- From the Epilepsy Research Centre, Department of Medicine (Neurology) (L.V., K.L., J.E., D.K., M.C., Y.T.-B., R.A.H., I.E.S., S.F.B.), University of Melbourne, Austin Health; School of Medicine (L.V.), The University of Queensland, Brisbane; Department of Neurology (L.V.), Royal Brisbane and Women's Hospital; Centre for Molecular, Environmental, Analytic and Genetic Epidemiology (R.L.M., J.L.H.), University of Melbourne; School of Pharmacy and Medical Sciences and Sansom Institute for Health Research (S.E.H., L.M.D.), University of South Australia, Adelaide; and the Department of Genetic Medicine, SA Pathology (J.C.M.), Women's and Children's Hospital, North Adelaide, Australia
| | - Jazmin Eckhaus
- From the Epilepsy Research Centre, Department of Medicine (Neurology) (L.V., K.L., J.E., D.K., M.C., Y.T.-B., R.A.H., I.E.S., S.F.B.), University of Melbourne, Austin Health; School of Medicine (L.V.), The University of Queensland, Brisbane; Department of Neurology (L.V.), Royal Brisbane and Women's Hospital; Centre for Molecular, Environmental, Analytic and Genetic Epidemiology (R.L.M., J.L.H.), University of Melbourne; School of Pharmacy and Medical Sciences and Sansom Institute for Health Research (S.E.H., L.M.D.), University of South Australia, Adelaide; and the Department of Genetic Medicine, SA Pathology (J.C.M.), Women's and Children's Hospital, North Adelaide, Australia
| | - Deborah Keay
- From the Epilepsy Research Centre, Department of Medicine (Neurology) (L.V., K.L., J.E., D.K., M.C., Y.T.-B., R.A.H., I.E.S., S.F.B.), University of Melbourne, Austin Health; School of Medicine (L.V.), The University of Queensland, Brisbane; Department of Neurology (L.V.), Royal Brisbane and Women's Hospital; Centre for Molecular, Environmental, Analytic and Genetic Epidemiology (R.L.M., J.L.H.), University of Melbourne; School of Pharmacy and Medical Sciences and Sansom Institute for Health Research (S.E.H., L.M.D.), University of South Australia, Adelaide; and the Department of Genetic Medicine, SA Pathology (J.C.M.), Women's and Children's Hospital, North Adelaide, Australia
| | - Mary Connellan
- From the Epilepsy Research Centre, Department of Medicine (Neurology) (L.V., K.L., J.E., D.K., M.C., Y.T.-B., R.A.H., I.E.S., S.F.B.), University of Melbourne, Austin Health; School of Medicine (L.V.), The University of Queensland, Brisbane; Department of Neurology (L.V.), Royal Brisbane and Women's Hospital; Centre for Molecular, Environmental, Analytic and Genetic Epidemiology (R.L.M., J.L.H.), University of Melbourne; School of Pharmacy and Medical Sciences and Sansom Institute for Health Research (S.E.H., L.M.D.), University of South Australia, Adelaide; and the Department of Genetic Medicine, SA Pathology (J.C.M.), Women's and Children's Hospital, North Adelaide, Australia
| | - Yvonne Torn-Broers
- From the Epilepsy Research Centre, Department of Medicine (Neurology) (L.V., K.L., J.E., D.K., M.C., Y.T.-B., R.A.H., I.E.S., S.F.B.), University of Melbourne, Austin Health; School of Medicine (L.V.), The University of Queensland, Brisbane; Department of Neurology (L.V.), Royal Brisbane and Women's Hospital; Centre for Molecular, Environmental, Analytic and Genetic Epidemiology (R.L.M., J.L.H.), University of Melbourne; School of Pharmacy and Medical Sciences and Sansom Institute for Health Research (S.E.H., L.M.D.), University of South Australia, Adelaide; and the Department of Genetic Medicine, SA Pathology (J.C.M.), Women's and Children's Hospital, North Adelaide, Australia
| | - R Anne Howell
- From the Epilepsy Research Centre, Department of Medicine (Neurology) (L.V., K.L., J.E., D.K., M.C., Y.T.-B., R.A.H., I.E.S., S.F.B.), University of Melbourne, Austin Health; School of Medicine (L.V.), The University of Queensland, Brisbane; Department of Neurology (L.V.), Royal Brisbane and Women's Hospital; Centre for Molecular, Environmental, Analytic and Genetic Epidemiology (R.L.M., J.L.H.), University of Melbourne; School of Pharmacy and Medical Sciences and Sansom Institute for Health Research (S.E.H., L.M.D.), University of South Australia, Adelaide; and the Department of Genetic Medicine, SA Pathology (J.C.M.), Women's and Children's Hospital, North Adelaide, Australia
| | - John C Mulley
- From the Epilepsy Research Centre, Department of Medicine (Neurology) (L.V., K.L., J.E., D.K., M.C., Y.T.-B., R.A.H., I.E.S., S.F.B.), University of Melbourne, Austin Health; School of Medicine (L.V.), The University of Queensland, Brisbane; Department of Neurology (L.V.), Royal Brisbane and Women's Hospital; Centre for Molecular, Environmental, Analytic and Genetic Epidemiology (R.L.M., J.L.H.), University of Melbourne; School of Pharmacy and Medical Sciences and Sansom Institute for Health Research (S.E.H., L.M.D.), University of South Australia, Adelaide; and the Department of Genetic Medicine, SA Pathology (J.C.M.), Women's and Children's Hospital, North Adelaide, Australia
| | - Ingrid E Scheffer
- From the Epilepsy Research Centre, Department of Medicine (Neurology) (L.V., K.L., J.E., D.K., M.C., Y.T.-B., R.A.H., I.E.S., S.F.B.), University of Melbourne, Austin Health; School of Medicine (L.V.), The University of Queensland, Brisbane; Department of Neurology (L.V.), Royal Brisbane and Women's Hospital; Centre for Molecular, Environmental, Analytic and Genetic Epidemiology (R.L.M., J.L.H.), University of Melbourne; School of Pharmacy and Medical Sciences and Sansom Institute for Health Research (S.E.H., L.M.D.), University of South Australia, Adelaide; and the Department of Genetic Medicine, SA Pathology (J.C.M.), Women's and Children's Hospital, North Adelaide, Australia
| | - Leanne M Dibbens
- From the Epilepsy Research Centre, Department of Medicine (Neurology) (L.V., K.L., J.E., D.K., M.C., Y.T.-B., R.A.H., I.E.S., S.F.B.), University of Melbourne, Austin Health; School of Medicine (L.V.), The University of Queensland, Brisbane; Department of Neurology (L.V.), Royal Brisbane and Women's Hospital; Centre for Molecular, Environmental, Analytic and Genetic Epidemiology (R.L.M., J.L.H.), University of Melbourne; School of Pharmacy and Medical Sciences and Sansom Institute for Health Research (S.E.H., L.M.D.), University of South Australia, Adelaide; and the Department of Genetic Medicine, SA Pathology (J.C.M.), Women's and Children's Hospital, North Adelaide, Australia
| | - John L Hopper
- From the Epilepsy Research Centre, Department of Medicine (Neurology) (L.V., K.L., J.E., D.K., M.C., Y.T.-B., R.A.H., I.E.S., S.F.B.), University of Melbourne, Austin Health; School of Medicine (L.V.), The University of Queensland, Brisbane; Department of Neurology (L.V.), Royal Brisbane and Women's Hospital; Centre for Molecular, Environmental, Analytic and Genetic Epidemiology (R.L.M., J.L.H.), University of Melbourne; School of Pharmacy and Medical Sciences and Sansom Institute for Health Research (S.E.H., L.M.D.), University of South Australia, Adelaide; and the Department of Genetic Medicine, SA Pathology (J.C.M.), Women's and Children's Hospital, North Adelaide, Australia
| | - Samuel F Berkovic
- From the Epilepsy Research Centre, Department of Medicine (Neurology) (L.V., K.L., J.E., D.K., M.C., Y.T.-B., R.A.H., I.E.S., S.F.B.), University of Melbourne, Austin Health; School of Medicine (L.V.), The University of Queensland, Brisbane; Department of Neurology (L.V.), Royal Brisbane and Women's Hospital; Centre for Molecular, Environmental, Analytic and Genetic Epidemiology (R.L.M., J.L.H.), University of Melbourne; School of Pharmacy and Medical Sciences and Sansom Institute for Health Research (S.E.H., L.M.D.), University of South Australia, Adelaide; and the Department of Genetic Medicine, SA Pathology (J.C.M.), Women's and Children's Hospital, North Adelaide, Australia.
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Subaran RL, Greenberg DA. The Genetics of Common Epilepsy Disorders: Lessons Learned from the Channelopathy Era. CURRENT GENETIC MEDICINE REPORTS 2014. [DOI: 10.1007/s40142-014-0040-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Lowther C, Costain G, Stavropoulos DJ, Melvin R, Silversides CK, Andrade DM, So J, Faghfoury H, Lionel AC, Marshall CR, Scherer SW, Bassett AS. Delineating the 15q13.3 microdeletion phenotype: a case series and comprehensive review of the literature. Genet Med 2014; 17:149-57. [PMID: 25077648 DOI: 10.1038/gim.2014.83] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 06/06/2014] [Indexed: 01/14/2023] Open
Abstract
PURPOSE Recurrent 15q13.3 deletions are enriched in multiple neurodevelopmental conditions including intellectual disability, autism, epilepsy, and schizophrenia. However, the 15q13.3 microdeletion syndrome remains ill-defined. METHODS We systematically compiled all cases of 15q13.3 deletion published before 2014. We also examined three locally available cohorts to identify new adults with 15q13.3 deletions. RESULTS We identified a total of 246 cases (133 children, 113 adults) with deletions overlapping or within the 15q13.3 (breakpoint (BP)4-BP5) region, including seven novel adult cases from local cohorts. No BP4-BP5 deletions were identified in 23,838 adult controls. Where known, 15q13.3 deletions were typically inherited (85.4%) and disproportionately of maternal origin (P < 0.0001). Overall, 198 cases (121 children, 77 adults; 80.5%) had at least one neuropsychiatric diagnosis. Accounting for ascertainment, developmental disability/intellectual disability was present in 57.7%, epilepsy/seizures in 28.0%, speech problems in 15.9%, autism spectrum disorder in 10.9%, schizophrenia in 10.2%, mood disorder in 10.2%, and attention deficit hyperactivity disorder in 6.5%. By contrast, major congenital malformations, including congenital heart disease (2.4%), were uncommon. Placenta previa occurred in the pregnancies of four cases. CONCLUSION The 15q13.3 microdeletion syndrome is predominantly characterized by neuropsychiatric expression. There are implications for pre- and postnatal detection, genetic counseling, and anticipatory care.
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Affiliation(s)
- Chelsea Lowther
- 1] Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto, Ontario, Canada [2] Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Gregory Costain
- Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Dimitri J Stavropoulos
- 1] Cytogenetics Laboratory, Department of Pediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada [2] Department of Laboratory Medicine and Pathology, University of Toronto, Toronto, Ontario, Canada
| | - Rebecca Melvin
- Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Candice K Silversides
- 1] Division of Cardiology, Department of Medicine, University Health Network, Toronto, Ontario, Canada [2] Division of Obstetric Medicine, Medical Disorders of Pregnancy Program, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Danielle M Andrade
- 1] Division of Neurology, Toronto Western Hospital, Toronto, Ontario, Canada [2] Krembil Neurosciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - Joyce So
- 1] Department of Laboratory Medicine and Pathology, University of Toronto, Toronto, Ontario, Canada [2] Department of Clinical Genetics, Lakeridge Health Oshawa, Oshawa, Ontario, Canada
| | - Hanna Faghfoury
- The Fred A. Litwin and Family Centre in Genetic Medicine, University Health Network and Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Anath C Lionel
- 1] The Centre for Applied Genomics and Program in Genomics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada [2] Department of Molecular Genetics and McLaughlin Centre, University of Toronto, Toronto, Ontario, Canada
| | - Christian R Marshall
- 1] The Centre for Applied Genomics and Program in Genomics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada [2] Department of Molecular Genetics and McLaughlin Centre, University of Toronto, Toronto, Ontario, Canada
| | - Stephen W Scherer
- 1] Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada [2] The Centre for Applied Genomics and Program in Genomics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada [3] Department of Molecular Genetics and McLaughlin Centre, University of Toronto, Toronto, Ontario, Canada
| | - Anne S Bassett
- 1] Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto, Ontario, Canada [2] Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada [3] Division of Cardiology, Department of Medicine, University Health Network, Toronto, Ontario, Canada [4] Department of Psychiatry, University of Toronto and University Health Network, Toronto, Ontario, Canada
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Abstract
Background The epilepsies are a clinically heterogeneous group of neurological disorders. Despite strong evidence for heritability, genome-wide association studies have had little success in identification of risk loci associated with epilepsy, probably because of relatively small sample sizes and insufficient power. We aimed to identify risk loci through meta-analyses of genome-wide association studies for all epilepsy and the two largest clinical subtypes (genetic generalised epilepsy and focal epilepsy). Methods We combined genome-wide association data from 12 cohorts of individuals with epilepsy and controls from population-based datasets. Controls were ethnically matched with cases. We phenotyped individuals with epilepsy into categories of genetic generalised epilepsy, focal epilepsy, or unclassified epilepsy. After standardised filtering for quality control and imputation to account for different genotyping platforms across sites, investigators at each site conducted a linear mixed-model association analysis for each dataset. Combining summary statistics, we conducted fixed-effects meta-analyses of all epilepsy, focal epilepsy, and genetic generalised epilepsy. We set the genome-wide significance threshold at p<1·66 × 10−8. Findings We included 8696 cases and 26 157 controls in our analysis. Meta-analysis of the all-epilepsy cohort identified loci at 2q24.3 (p=8·71 × 10−10), implicating SCN1A, and at 4p15.1 (p=5·44 × 10−9), harbouring PCDH7, which encodes a protocadherin molecule not previously implicated in epilepsy. For the cohort of genetic generalised epilepsy, we noted a single signal at 2p16.1 (p=9·99 × 10−9), implicating VRK2 or FANCL. No single nucleotide polymorphism achieved genome-wide significance for focal epilepsy. Interpretation This meta-analysis describes a new locus not previously implicated in epilepsy and provides further evidence about the genetic architecture of these disorders, with the ultimate aim of assisting in disease classification and prognosis. The data suggest that specific loci can act pleiotropically raising risk for epilepsy broadly, or can have effects limited to a specific epilepsy subtype. Future genetic analyses might benefit from both lumping (ie, grouping of epilepsy types together) or splitting (ie, analysis of specific clinical subtypes). Funding International League Against Epilepsy and multiple governmental and philanthropic agencies.
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A mouse model that recapitulates cardinal features of the 15q13.3 microdeletion syndrome including schizophrenia- and epilepsy-related alterations. Biol Psychiatry 2014; 76:128-37. [PMID: 24090792 DOI: 10.1016/j.biopsych.2013.08.014] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Revised: 08/06/2013] [Accepted: 08/06/2013] [Indexed: 01/19/2023]
Abstract
BACKGROUND Genome-wide scans have uncovered rare copy number variants conferring high risk of psychiatric disorders. The 15q13.3 microdeletion is associated with a considerably increased risk of idiopathic generalized epilepsy, intellectual disability, and schizophrenia. METHODS A 15q13.3 microdeletion mouse model (Df[h15q13]/+) was generated by hemizygous deletion of the orthologous region and characterized with focus on schizophrenia- and epilepsy-relevant parameters. RESULTS Df(h15q13)/+ mice showed marked changes in neuronal excitability in acute seizure assays, with increased propensity to develop myoclonic and absence-like seizures but decreased propensity for clonic and tonic seizures. Furthermore, they had impaired long-term spatial reference memory and a decreased theta frequency in hippocampus and prefrontal cortex. Electroencephalogram characterization revealed auditory processing deficits similar to those observed in schizophrenia. Gamma band power was increased during active state, but evoked gamma power following auditory stimulus (40 Hz) was dramatically reduced, mirroring observations in patients with schizophrenia. In addition, Df(h15q13)/+ mice showed schizophrenia-like decreases in amplitudes of auditory evoked potentials. Although displaying a grossly normal behavior, Df(h15q13)/+ mice are more aggressive following exposure to mild stressors, similar to what is described in human deletion carriers. Furthermore, Df(h15q13)/+ mice have increased body weight, and a similar increase in body weight was subsequently found in a sample of human subjects with 15q13.3 deletion. CONCLUSIONS The Df(h15q13)/+ mouse shows similarities to several alterations related to the 15q13.3 microdeletion syndrome, epilepsy, and schizophrenia, offering a novel tool for addressing the underlying biology of these diseases.
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Ekenstedt KJ, Oberbauer AM. Inherited epilepsy in dogs. Top Companion Anim Med 2014; 28:51-8. [PMID: 24070682 DOI: 10.1053/j.tcam.2013.07.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2013] [Accepted: 07/01/2013] [Indexed: 12/15/2022]
Abstract
Epilepsy is the most common neurologic disease in dogs and many forms are considered to have a genetic basis. In contrast, some seizure disorders are also heritable, but are not technically defined as epilepsy. Investigation of true canine epilepsies has uncovered genetic associations in some cases, however, many remain unexplained. Gene mutations have been described for 2 forms of canine epilepsy: primary epilepsy (PE) and progressive myoclonic epilepsies. To date, 9 genes have been described to underlie progressive myoclonic epilepsies in several dog breeds. Investigations into genetic PE have been less successful, with only 1 causative gene described. Genetic testing as an aid to diagnosis, prognosis, and breeding decisions is available for these 10 forms. Additional studies utilizing genome-wide tools have identified PE loci of interest; however, specific genetic tests are not yet developed. Many studies of dog breeds with PE have failed to identify genes or loci of interest, suggesting that, similar to what is seen in many human genetic epilepsies, inheritance is likely complex, involving several or many genes, and reflective of environmental interactions. An individual dog's response to therapeutic intervention for epilepsy may also be genetically complex. Although the field of inherited epilepsy has faced challenges, particularly with PE, newer technologies contribute to further advances.
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Affiliation(s)
- Kari J Ekenstedt
- Department of Animal and Food Science, College of Agriculture, Food, and Environmental Sciences, University of Wisconsin - River Falls, River Falls, WI, USA.
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Dejanovic B, Lal D, Catarino CB, Arjune S, Belaidi AA, Trucks H, Vollmar C, Surges R, Kunz WS, Motameny S, Altmüller J, Köhler A, Neubauer BA, EPICURE Consortium, Nürnberg P, Noachtar S, Schwarz G, Sander T. Exonic microdeletions of the gephyrin gene impair GABAergic synaptic inhibition in patients with idiopathic generalized epilepsy. Neurobiol Dis 2014; 67:88-96. [DOI: 10.1016/j.nbd.2014.02.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 01/09/2014] [Accepted: 02/10/2014] [Indexed: 12/29/2022] Open
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Abstract
Copy number variants (CNVs) are deletions or duplications of DNA. CNVs have been increasingly recognized as an important source of both normal genetic variation and pathogenic mutation. Technologies for genome-wide discovery of CNVs facilitate studies of large cohorts of patients and controls to identify CNVs that cause increased risk for disease. Over the past 5 years, studies of patients with epilepsy confirm that both recurrent and non-recurrent CNVs are an important source of mutation for patients with various forms of epilepsy. Here, we will review the latest findings and explore the clinical implications.
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Affiliation(s)
- Heather C. Mefford
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, RR349A, Box 356320, Seattle, WA USA
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Lin H, Hsu FC, Baumann BH, Coulter DA, Anderson SA, Lynch DR. Cortical parvalbumin GABAergic deficits with α7 nicotinic acetylcholine receptor deletion: implications for schizophrenia. Mol Cell Neurosci 2014; 61:163-75. [PMID: 24983521 DOI: 10.1016/j.mcn.2014.06.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 05/23/2014] [Accepted: 06/16/2014] [Indexed: 11/25/2022] Open
Abstract
Dysfunction of cortical parvalbumin (PV)-containing GABAergic interneurons has been implicated in cognitive deficits of schizophrenia. In humans microdeletion of the CHRNA7 (α7 nicotinic acetylcholine receptor, nAChR) gene is associated with cortical dysfunction in a broad spectrum of neurodevelopmental and neuropsychiatric disorders including schizophrenia while in mice similar deletion causes analogous abnormalities including impaired attention, working-memory and learning. However, the pathophysiological roles of α7 nAChRs in cortical PV GABAergic development remain largely uncharacterized. In both in vivo and in vitro models, we identify here that deletion of the α7 nAChR gene in mice impairs cortical PV GABAergic development and recapitulates many of the characteristic neurochemical deficits in PV-positive GABAergic interneurons found in schizophrenia. α7 nAChR null mice had decreased cortical levels of GABAergic markers including PV, glutamic acid decarboxylase 65/67 (GAD65/67) and the α1 subunit of GABAA receptors, particularly reductions of PV and GAD67 levels in cortical PV-positive interneurons during late postnatal life and adulthood. Cortical GABAergic synaptic deficits were identified in the prefrontal cortex of α7 nAChR null mice and α7 nAChR null cortical cultures. Similar disruptions in development of PV-positive GABAergic interneurons and perisomatic synapses were found in cortical cultures lacking α7 nAChRs. Moreover, NMDA receptor expression was reduced in GABAergic interneurons, implicating NMDA receptor hypofunction in GABAergic deficits in α7 nAChR null mice. Our findings thus demonstrate impaired cortical PV GABAergic development and multiple characteristic neurochemical deficits reminiscent of schizophrenia in cortical PV-positive interneurons in α7 nAChR gene deletion models. This implicates crucial roles of α7 nAChRs in cortical PV GABAergic development and dysfunction in schizophrenia and other neuropsychiatric disorders.
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Affiliation(s)
- Hong Lin
- Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States; Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States
| | - Fu-Chun Hsu
- Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States; Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States
| | - Bailey H Baumann
- Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States; Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States
| | - Douglas A Coulter
- Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States; Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Stewart A Anderson
- Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States; Department of Child Psychiatry, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - David R Lynch
- Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States; Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States.
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Reinthaler EM, Lal D, Lebon S, Hildebrand MS, Dahl HHM, Regan BM, Feucht M, Steinböck H, Neophytou B, Ronen GM, Roche L, Gruber-Sedlmayr U, Geldner J, Haberlandt E, Hoffmann P, Herms S, Gieger C, Waldenberger M, Franke A, Wittig M, Schoch S, Becker AJ, Hahn A, Männik K, Toliat MR, Winterer G, Lerche H, Nürnberg P, Mefford H, Scheffer IE, Berkovic SF, Beckmann JS, Sander T, Jacquemont S, Reymond A, Zimprich F, Neubauer BA. 16p11.2 600 kb Duplications confer risk for typical and atypical Rolandic epilepsy. Hum Mol Genet 2014; 23:6069-80. [PMID: 24939913 DOI: 10.1093/hmg/ddu306] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Rolandic epilepsy (RE) is the most common idiopathic focal childhood epilepsy. Its molecular basis is largely unknown and a complex genetic etiology is assumed in the majority of affected individuals. The present study tested whether six large recurrent copy number variants at 1q21, 15q11.2, 15q13.3, 16p11.2, 16p13.11 and 22q11.2 previously associated with neurodevelopmental disorders also increase risk of RE. Our association analyses revealed a significant excess of the 600 kb genomic duplication at the 16p11.2 locus (chr16: 29.5-30.1 Mb) in 393 unrelated patients with typical (n = 339) and atypical (ARE; n = 54) RE compared with the prevalence in 65,046 European population controls (5/393 cases versus 32/65,046 controls; Fisher's exact test P = 2.83 × 10(-6), odds ratio = 26.2, 95% confidence interval: 7.9-68.2). In contrast, the 16p11.2 duplication was not detected in 1738 European epilepsy patients with either temporal lobe epilepsy (n = 330) and genetic generalized epilepsies (n = 1408), suggesting a selective enrichment of the 16p11.2 duplication in idiopathic focal childhood epilepsies (Fisher's exact test P = 2.1 × 10(-4)). In a subsequent screen among children carrying the 16p11.2 600 kb rearrangement we identified three patients with RE-spectrum epilepsies in 117 duplication carriers (2.6%) but none in 202 carriers of the reciprocal deletion. Our results suggest that the 16p11.2 duplication represents a significant genetic risk factor for typical and atypical RE.
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Affiliation(s)
| | - Dennis Lal
- Cologne Center for Genomics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany, Department of Neuropediatrics, University Medical Faculty Giessen and Marburg, Giessen, Germany
| | - Sebastien Lebon
- Unit of Pediatric Neurology and Neurorehabilitation, Department of Pediatrics
| | - Michael S Hildebrand
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Australia
| | - Hans-Henrik M Dahl
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Australia
| | - Brigid M Regan
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Australia
| | - Martha Feucht
- Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | | | - Birgit Neophytou
- Department of Neuropediatrics, St. Anna Children's Hospital, Vienna, Austria
| | - Gabriel M Ronen
- Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
| | - Laurian Roche
- Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
| | | | - Julia Geldner
- Department of Pediatrics, Hospital SMZ Süd Kaiser-Franz-Josef Spital, Vienna, Austria
| | - Edda Haberlandt
- Department of Pediatrics, Medical University of Innsbruck, Innsbruck, Austria
| | - Per Hoffmann
- Institute of Human Genetics, University of Bonn, Bonn, Germany, Division of Medical Genetics, University Hospital and Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Stefan Herms
- Institute of Human Genetics, University of Bonn, Bonn, Germany, Division of Medical Genetics, University Hospital and Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Christian Gieger
- Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Institute of Genetic Epidemiology, Neuherberg, Germany
| | - Melanie Waldenberger
- Research Unit of Molecular Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Andre Franke
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Michael Wittig
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Susanne Schoch
- Department of Neuropathology, University of Bonn Medical Center, Bonn, Germany
| | - Albert J Becker
- Department of Neuropathology, University of Bonn Medical Center, Bonn, Germany
| | - Andreas Hahn
- Department of Neuropediatrics, University Medical Faculty Giessen and Marburg, Giessen, Germany
| | - Katrin Männik
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland, Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | | | - Georg Winterer
- Experimental and Clinical Research Center (ECRC) Charité, University Medicine Berlin, Berlin, Germany
| | | | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute of Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Peter Nürnberg
- Cologne Center for Genomics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Heather Mefford
- Division of Genetic Medicine, University of Washington, Seattle, Washington, USA
| | - Ingrid E Scheffer
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Australia, Florey Institute and Department of Pediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia
| | - Samuel F Berkovic
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Australia
| | - Jacques S Beckmann
- Service of Medical Genetics, Lausanne University Hospital, Lausanne, Switzerland, Swiss Institute of Bioinformatics, Lausanne, Switzerland and
| | | | | | | | - Sebastien Jacquemont
- Service of Medical Genetics, Lausanne University Hospital, Lausanne, Switzerland
| | - Alexandre Reymond
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | | | - Bernd A Neubauer
- Department of Neuropediatrics, University Medical Faculty Giessen and Marburg, Giessen, Germany
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174
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Olson H, Shen Y, Avallone J, Sheidley BR, Pinsky R, Bergin AM, Berry GT, Duffy FH, Eksioglu Y, Harris DJ, Hisama FM, Ho E, Irons M, Jacobsen CM, James P, Kothare S, Khwaja O, Lipton J, Loddenkemper T, Markowitz J, Maski K, Megerian JT, Neilan E, Raffalli PC, Robbins M, Roberts A, Roe E, Rollins C, Sahin M, Sarco D, Schonwald A, Smith SE, Soul J, Stoler JM, Takeoka M, Tan WH, Torres AR, Tsai P, Urion DK, Weissman L, Wolff R, Wu BL, Miller DT, Poduri A. Copy number variation plays an important role in clinical epilepsy. Ann Neurol 2014; 75:943-58. [PMID: 24811917 DOI: 10.1002/ana.24178] [Citation(s) in RCA: 120] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 05/07/2014] [Accepted: 05/07/2014] [Indexed: 01/13/2023]
Abstract
OBJECTIVE To evaluate the role of copy number abnormalities detectable using chromosomal microarray (CMA) testing in patients with epilepsy at a tertiary care center. METHODS We identified patients with International Classification of Diseases, ninth revision (ICD-9) codes for epilepsy or seizures and clinical CMA testing performed between October 2006 and February 2011 at Boston Children's Hospital. We reviewed medical records and included patients who met criteria for epilepsy. We phenotypically characterized patients with epilepsy-associated abnormalities on CMA. RESULTS Of 973 patients who had CMA and ICD-9 codes for epilepsy or seizures, 805 patients satisfied criteria for epilepsy. We observed 437 copy number variants (CNVs) in 323 patients (1-4 per patient), including 185 (42%) deletions and 252 (58%) duplications. Forty (9%) were confirmed de novo, 186 (43%) were inherited, and parental data were unavailable for 211 (48%). Excluding full chromosome trisomies, CNV size ranged from 18kb to 142Mb, and 34% were >500kb. In at least 40 cases (5%), the epilepsy phenotype was explained by a CNV, including 29 patients with epilepsy-associated syndromes and 11 with likely disease-associated CNVs involving epilepsy genes or "hotspots." We observed numerous recurrent CNVs including 10 involving loss or gain of Xp22.31, a region described in patients with and without epilepsy. INTERPRETATION Copy number abnormalities play an important role in patients with epilepsy. Because the diagnostic yield of CMA for epilepsy patients is similar to the yield in autism spectrum disorders and in prenatal diagnosis, for which published guidelines recommend testing with CMA, we recommend the implementation of CMA in the evaluation of unexplained epilepsy.
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Affiliation(s)
- Heather Olson
- Epilepsy Genetics Program, Division of Epilepsy and Clinical Neurophysiology and Neurogenetics Program, Department of Neurology, Boston Children's Hospital, and Harvard Medical School, Boston, MA
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175
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Du X, An Y, Yu L, Liu R, Qin Y, Guo X, Sun D, Zhou S, Wu B, Jiang YH, Wang Y. A genomic copy number variant analysis implicates the MBD5 and HNRNPU genes in Chinese children with infantile spasms and expands the clinical spectrum of 2q23.1 deletion. BMC MEDICAL GENETICS 2014; 15:62. [PMID: 24885232 PMCID: PMC4061518 DOI: 10.1186/1471-2350-15-62] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 05/13/2014] [Indexed: 02/06/2023]
Abstract
Background Infantile spasms (IS) is a specific type of epileptic encephalopathy associated with severe developmental disabilities. Genetic factors are strongly implicated in IS, however, the exact genetic defects remain unknown in the majority of cases. Rare mutations in a single gene or in copy number variants (CNVs) have been implicated in IS of children in Western countries. The objective of this study was to dissect the role of copy number variations in Chinese children with infantile spasms. Methods We used the Agilent Human Genome CGH microarray 180 K for genome-wide detection of CNVs. Real-time qPCR was used to validate the CNVs. We performed genomic and medical annotations for individual CNVs to determine the pathogenicity of CNVs related to IS. Results We report herein the first genome-wide CNV analysis in children with IS, detecting a total of 14 CNVs in a cohort of 47 Chinese children with IS. Four CNVs (4/47 = 8.5%) (1q21.1 gain; 1q44, 2q31.1, and 17p13 loss) are considered to be pathogenic. The CNV loss at 17p13.3 contains PAFAH1B1 (LIS1), a causative gene for lissencephaly. Although the CNVs at 1q21.1, 1q44, and 2q23.1 have been previously implicated in a wide spectrum of clinical features including autism spectrum disorders (ASD) and generalized seizure, our study is the first report identifying them in individuals with a primary diagnosis of IS. The CNV loss in the 1q44 region contains HNRNPU, a strong candidate gene recently suggested in IS by the whole exome sequencing of children with IS. The CNV loss at 2q23.1 includes MBD5, a methyl-DNA binding protein that is a causative gene of ASD and a candidate gene for epileptic encephalopathy. We also report a distinct clinical presentation of IS, microcephaly, intellectual disability, and absent hallux in a case with the 2q23.1 deletion. Conclusion Our findings strongly support the role of CNVs in infantile spasms and expand the clinical spectrum associate with 2q23.1 deletion. In particular, our study implicates the HNRNPU and MBD5 genes in Chinese children with IS. Our study also supports that the molecular mechanisms of infantile spasms appear conserved among different ethnic backgrounds.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Yong-Hui Jiang
- Division of Neurology, Children's Hospital of Fudan University, 399 Wan Yuan Road, Shanghai 201102, China.
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176
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Clinical utility gene card for: 15q13.3 microdeletion syndrome. Eur J Hum Genet 2014; 22:ejhg201488. [PMID: 24824131 DOI: 10.1038/ejhg.2014.88] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 04/04/2014] [Accepted: 04/09/2014] [Indexed: 12/20/2022] Open
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177
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Bates RC, Stith BJ, Stevens KE, Adams CE. Reduced CHRNA7 expression in C3H mice is associated with increases in hippocampal parvalbumin and glutamate decarboxylase-67 (GAD67) as well as altered levels of GABA(A) receptor subunits. Neuroscience 2014; 273:52-64. [PMID: 24836856 DOI: 10.1016/j.neuroscience.2014.05.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 04/23/2014] [Accepted: 05/02/2014] [Indexed: 12/14/2022]
Abstract
Decreased expression of CHRNA7, the gene encoding the α7(∗) subtype of nicotinic receptor, may contribute to the cognitive dysfunction observed in schizophrenia by disrupting the inhibitory/excitatory balance in the hippocampus. C3H mice with reduced Chrna7 expression have significant reductions in hippocampal α7(∗) receptor density, deficits in hippocampal auditory gating, increased hippocampal activity as well as significant decreases in hippocampal glutamate decarboxylase-65 (GAD65) and γ-aminobutyric acid-A (GABAA) receptor levels. The current study investigated whether altered Chrna7 expression is associated with changes in the levels of parvalbumin, GAD67 and/or GABAA receptor subunits in the hippocampus from male and female C3H Chrna7 wildtype, C3H Chrna7 heterozygous and C3H Chrna7 knockout (KO) mice using quantitative Western immunoblotting. Reduced Chrna7 expression was associated with significant increases in hippocampal parvalbumin and GAD67 and with complex alterations in GABAA receptor subunits. A decrease in α3 subunit protein was seen in both female C3H Chrna7 Het and KO mice while a decrease in α4 subunit protein was also detected in C3H Chrna7 KO mice with no sex difference. In contrast, an increase in δ subunit protein was observed in C3H Chrna7 Het mice while a decrease in this subunit was observed in C3H Chrna7 KO mice, with δ subunit protein levels being greater in males than in females. Finally, an increase in γ2 subunit protein was found in C3H Chrna7 KO mice with the levels of this subunit again being greater in males than in females. The increases in hippocampal parvalbumin and GAD67 observed in C3H Chrna7 mice are contrary to reports of reductions in these proteins in the postmortem hippocampus from schizophrenic individuals. We hypothesize that the disparate results may occur because of the influence of factors other than CHRNA7 that have been found to be abnormal in schizophrenia.
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Affiliation(s)
- R C Bates
- Medical Research, Veterans Affairs Medical Center, Denver, CO 80220, United States; Department of Psychiatry, University of Colorado Denver Anschutz Medical Campus, Aurora, CO 80045, United States; Department of Integrative Biology, University of Colorado Denver Downtown Denver Campus, Denver, CO 80217, United States
| | - B J Stith
- Department of Integrative Biology, University of Colorado Denver Downtown Denver Campus, Denver, CO 80217, United States
| | - K E Stevens
- Medical Research, Veterans Affairs Medical Center, Denver, CO 80220, United States; Department of Psychiatry, University of Colorado Denver Anschutz Medical Campus, Aurora, CO 80045, United States
| | - C E Adams
- Medical Research, Veterans Affairs Medical Center, Denver, CO 80220, United States; Department of Psychiatry, University of Colorado Denver Anschutz Medical Campus, Aurora, CO 80045, United States.
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178
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High rate of disease-related copy number variations in childhood onset schizophrenia. Mol Psychiatry 2014; 19:568-72. [PMID: 23689535 PMCID: PMC5157161 DOI: 10.1038/mp.2013.59] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 03/20/2013] [Accepted: 04/02/2013] [Indexed: 12/15/2022]
Abstract
Copy number variants (CNVs) are risk factors in neurodevelopmental disorders, including autism, epilepsy, intellectual disability (ID) and schizophrenia. Childhood onset schizophrenia (COS), defined as onset before the age of 13 years, is a rare and severe form of the disorder, with more striking array of prepsychotic developmental disorders and abnormalities in brain development. Because of the well-known phenotypic variability associated with pathogenic CNVs, we conducted whole genome genotyping to detect CNVs and then focused on a group of 46 rare CNVs that had well-documented risk for adult onset schizophrenia (AOS), autism, epilepsy and/or ID. We evaluated 126 COS probands, 69 of which also had a healthy full sibling. When COS probands were compared with their matched related controls, significantly more affected individuals carried disease-related CNVs (P=0.017). Moreover, COS probands showed a higher rate than that found in AOS probands (P<0.0001). A total of 15 (11.9%) subjects exhibited at least one such CNV and four of these subjects (26.7%) had two. Five of 15 (4.0% of the sample) had a 2.5-3 Mb deletion mapping to 22q11.2, a rate higher than that reported for adult onset (0.3-1%) (P<0.001) or autism spectrum disorder and, indeed, the highest rate reported for any clinical population to date. For one COS subject, a duplication found at 22q13.3 had previously only been associated with autism, and for four patients CNVs at 8q11.2, 10q22.3, 16p11.2 and 17q21.3 had only previously been associated with ID. Taken together, these findings support the well-known pleiotropic effects of these CNVs suggesting shared abnormalities early in brain development. Clinically, broad CNV-based population screening is needed to assess their overall clinical burden.
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179
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Michaud JL, Lachance M, Hamdan FF, Carmant L, Lortie A, Diadori P, Major P, Meijer IA, Lemyre E, Cossette P, Mefford HC, Rouleau GA, Rossignol E. The genetic landscape of infantile spasms. Hum Mol Genet 2014; 23:4846-58. [PMID: 24781210 DOI: 10.1093/hmg/ddu199] [Citation(s) in RCA: 136] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Infantile spasms (IS) is an early-onset epileptic encephalopathy of unknown etiology in ∼40% of patients. We hypothesized that unexplained IS cases represent a large collection of rare single-gene disorders. We investigated 44 children with unexplained IS using comparative genomic hybridisation arrays (aCGH) (n = 44) followed by targeted sequencing of 35 known epilepsy genes (n = 8) or whole-exome sequencing (WES) of familial trios (n = 18) to search for rare inherited or de novo mutations. aCGH analysis revealed de novo variants in 7% of patients (n = 3/44), including a distal 16p11.2 duplication, a 15q11.1q13.1 tetrasomy and a 2q21.3-q22.2 deletion. Furthermore, it identified a pathogenic maternally inherited Xp11.2 duplication. Targeted sequencing was informative for ARX (n = 1/14) and STXBP1 (n = 1/8). In contrast, sequencing of a panel of 35 known epileptic encephalopathy genes (n = 8) did not identify further mutations. Finally, WES (n = 18) was very informative, with an excess of de novo mutations identified in genes predicted to be involved in neurodevelopmental processes and/or known to be intolerant to functional variations. Several pathogenic mutations were identified, including de novo mutations in STXBP1, CASK and ALG13, as well as recessive mutations in PNPO and ADSL, together explaining 28% of cases (5/18). In addition, WES identified 1-3 de novo variants in 64% of remaining probands, pointing to several interesting candidate genes. Our results indicate that IS are genetically heterogeneous with a major contribution of de novo mutations and that WES is significantly superior to targeted re-sequencing in identifying detrimental genetic variants involved in IS.
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Affiliation(s)
- Jacques L Michaud
- Department of Pediatrics and Department of Neurosciences, Université de Montréal, Montréal, QC, Canada, CHU Ste-Justine Research Center, Montréal, QC, Canada
| | | | - Fadi F Hamdan
- CHU Ste-Justine Research Center, Montréal, QC, Canada
| | - Lionel Carmant
- Department of Pediatrics and Department of Neurosciences, Université de Montréal, Montréal, QC, Canada, CHU Ste-Justine Research Center, Montréal, QC, Canada
| | - Anne Lortie
- Department of Pediatrics and Department of Neurosciences, Université de Montréal, Montréal, QC, Canada, CHU Ste-Justine Research Center, Montréal, QC, Canada
| | - Paola Diadori
- Department of Pediatrics and Department of Neurosciences, Université de Montréal, Montréal, QC, Canada, CHU Ste-Justine Research Center, Montréal, QC, Canada
| | - Philippe Major
- Department of Pediatrics and Department of Neurosciences, Université de Montréal, Montréal, QC, Canada, CHU Ste-Justine Research Center, Montréal, QC, Canada
| | - Inge A Meijer
- CHU Ste-Justine Research Center, Montréal, QC, Canada
| | - Emmanuelle Lemyre
- Department of Pediatrics and CHU Ste-Justine Research Center, Montréal, QC, Canada
| | - Patrick Cossette
- Department of Neurosciences, Université de Montréal, Montréal, QC, Canada, CHUM, Montréal, QC, Canada
| | - Heather C Mefford
- Department of Pediatrics, University of Washington, Seattle, WA, USA and
| | - Guy A Rouleau
- Department of Neurosciences, Montreal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Elsa Rossignol
- Department of Pediatrics and Department of Neurosciences, Université de Montréal, Montréal, QC, Canada, CHU Ste-Justine Research Center, Montréal, QC, Canada,
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180
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Watson CT, Marques-Bonet T, Sharp AJ, Mefford HC. The genetics of microdeletion and microduplication syndromes: an update. Annu Rev Genomics Hum Genet 2014; 15:215-244. [PMID: 24773319 DOI: 10.1146/annurev-genom-091212-153408] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Chromosomal abnormalities, including microdeletions and microduplications, have long been associated with abnormal developmental outcomes. Early discoveries relied on a common clinical presentation and the ability to detect chromosomal abnormalities by standard karyotype analysis or specific assays such as fluorescence in situ hybridization. Over the past decade, the development of novel genomic technologies has allowed more comprehensive, unbiased discovery of microdeletions and microduplications throughout the human genome. The ability to quickly interrogate large cohorts using chromosome microarrays and, more recently, next-generation sequencing has led to the rapid discovery of novel microdeletions and microduplications associated with disease, including very rare but clinically significant rearrangements. In addition, the observation that some microdeletions are associated with risk for several neurodevelopmental disorders contributes to our understanding of shared genetic susceptibility for such disorders. Here, we review current knowledge of microdeletion/duplication syndromes, with a particular focus on recurrent rearrangement syndromes.
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Affiliation(s)
- Corey T Watson
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029.,Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Tomas Marques-Bonet
- Institut de Biologia Evolutiva, Universitat Pompeu Fabra/CSIC, 08003 Barcelona, Spain.,Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain.,Centro Nacional de Análisis Genómico, 08023 Barcelona, Spain
| | - Andrew J Sharp
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Heather C Mefford
- Department of Pediatrics, University of Washington, Seattle, Washington 98195
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181
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Chowdhury FA, Elwes RDC, Koutroumanidis M, Morris RG, Nashef L, Richardson MP. Impaired cognitive function in idiopathic generalized epilepsy and unaffected family members: An epilepsy endophenotype. Epilepsia 2014; 55:835-40. [DOI: 10.1111/epi.12604] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/20/2014] [Indexed: 01/28/2023]
Affiliation(s)
- Fahmida A. Chowdhury
- Department of Clinical Neuroscience; Institute of Psychiatry; King's College London; London United Kingdom
| | | | | | - Robin G. Morris
- Department of Psychology; Institute of Psychiatry; King's College London; London United Kingdom
| | - Lina Nashef
- Centre for Epilepsy; King's College Hospital; London United Kingdom
| | - Mark P. Richardson
- Department of Clinical Neuroscience; Institute of Psychiatry; King's College London; London United Kingdom
- Centre for Epilepsy; King's College Hospital; London United Kingdom
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182
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Pardo CA, Nabbout R, Galanopoulou AS. Mechanisms of epileptogenesis in pediatric epileptic syndromes: Rasmussen encephalitis, infantile spasms, and febrile infection-related epilepsy syndrome (FIRES). Neurotherapeutics 2014; 11:297-310. [PMID: 24639375 PMCID: PMC3996116 DOI: 10.1007/s13311-014-0265-2] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The mechanisms of epileptogenesis in pediatric epileptic syndromes are diverse, and may involve disturbances of neurodevelopmental trajectories, synaptic homeostasis, and cortical connectivity, which may occur during brain development, early infancy, or childhood. Although genetic or structural/metabolic factors are frequently associated with age-specific epileptic syndromes, such as infantile spasms and West syndrome, other syndromes may be determined by the effect of immunopathogenic mechanisms or energy-dependent processes in response to environmental challenges, such as infections or fever in normally-developed children during early or late childhood. Immune-mediated mechanisms have been suggested in selected pediatric epileptic syndromes in which acute and rapidly progressive encephalopathies preceded by fever and/or infections, such as febrile infection-related epilepsy syndrome, or in chronic progressive encephalopathies, such as Rasmussen encephalitis. A definite involvement of adaptive and innate immune mechanisms driven by cytotoxic CD8(+) T lymphocytes and neuroglial responses has been demonstrated in Rasmussen encephalitis, although the triggering factor of these responses remains unknown. Although the beneficial response to steroids and adrenocorticotropic hormone of infantile spasms, or preceding fever or infection in FIRES, may support a potential role of neuroinflammation as pathogenic factor, no definite demonstration of such involvement has been achieved, and genetic or metabolic factors are suspected. A major challenge for the future is discovering pathogenic mechanisms and etiological factors that facilitate the introduction of novel targets for drug intervention aimed at interfering with the disease mechanisms, therefore providing putative disease-modifying treatments in these pediatric epileptic syndromes.
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Affiliation(s)
- Carlos A Pardo
- Department of Neurology, Division of Neuroimmunology and Neuroinfectious Disorders, Center for Pediatric Rasmussen Syndrome, Johns Hopkins University School of Medicine, Baltimore, MD, USA,
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183
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Heithaus JL, Davenport S, Twyman KA, Torti EE, Batanian JR. An intragenic deletion of the gene MNAT1 in a family with pectus deformities. Am J Med Genet A 2014; 164A:1293-7. [PMID: 24664931 DOI: 10.1002/ajmg.a.36445] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 12/26/2013] [Indexed: 11/07/2022]
Abstract
Pectus carinatum and excavatum have multiple genetic associations. We report on a novel association of these deformities in a 34-month-old male and his father, likely due to a small intragenic deletion of MNAT1 (ménage a trois 1 gene). Both individuals share a deletion of MNAT1 located at 14q23.1 and an interstitial duplication of CHRNA7 located at 15q13.3. Deletion of MNAT1 has been associated with connective tissue abnormalities and is likely the etiology of the malformations, whereas the duplication of CHNRA7 is unlikely related due to the lack of association with any such connective tissue abnormalities.
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Affiliation(s)
- Jennifer L Heithaus
- Department of Pediatrics, Genetics Division, Saint Louis University School of Medicine, St. Louis, Missouri
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184
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Masurel-Paulet A, Drumare I, Holder M, Cuisset JM, Vallée L, Defoort S, Bourgois B, Pernes P, Cuvellier JC, Huet F, Chehadeh SE, Thevenon J, Callier P, Thauvin C, Faivre L, Andrieux J. Further delineation of eye manifestations in homozygous 15q13.3 microdeletions including TRPM1: a differential diagnosis of ceroid lipofuscinosis. Am J Med Genet A 2014; 164A:1537-44. [PMID: 24668847 DOI: 10.1002/ajmg.a.36471] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Accepted: 12/31/2013] [Indexed: 11/11/2022]
Abstract
The 15q13.3 heterozygous microdeletion is a fairly common microdeletion syndrome with marked clinical variability and incomplete penetrance. The average size of the deletion, which comprises six genes including CHRNA7, is 1.5 Mb. CHRNA7 has been identified as the gene responsible for the neurological phenotype in this microdeletion syndrome. Only seven patients with a homozygous microdeletion that includes at least CHRNA7, and is inherited from both parents have been described in the literature. The aim of this study was to further describe the distinctive eye manifestations from the analysis in the three French patients diagnosed with the classical 1.5 Mb homozygous microdeletion. Patients' ages ranged from 30 months to 9 years, and included one sib pair. They all displayed a remarkably severe identifiable clinical phenotype that included congenital blindness and convulsive encephalopathy with inconstant abnormal movements. The ophthalmological examination revealed a lack of eye tracking, optic nerve pallor, an immature response with increased latencies with no response to the checkerboard stimulations at the visual evoked potential examination, and a distinctive retina dystrophy with a negative electroretinogram in which the "b" wave was smaller than the "a" wave after a dark adapted pupil and bright flash in all patients. Clear genotype-phenotype correlations emerged, showing that this eye phenotype was secondary to homozygous deletion of TRPM1, the gene responsible for autosomal recessive congenital stationary night blindness. The main differential diagnosis is ceroid lipofuscinosis.
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Affiliation(s)
- Alice Masurel-Paulet
- Centre de Génétique et Centre de Référence Anomalies du Développement et Syndromes Malformatifs, Hôpital d'Enfants, CHU Dijon, France
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185
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Clancy MJ, Clarke MC, Connor DJ, Cannon M, Cotter DR. The prevalence of psychosis in epilepsy; a systematic review and meta-analysis. BMC Psychiatry 2014; 14:75. [PMID: 24625201 PMCID: PMC3995617 DOI: 10.1186/1471-244x-14-75] [Citation(s) in RCA: 169] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Accepted: 02/12/2014] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Epilepsy has long been considered to be a risk factor for psychosis. However there is a lack of consistency in findings across studies on the effect size of this risk which reflects methodological differences in studies and changing diagnostic classifications within neurology and psychiatry. The aim of this study was to assess the prevalence of psychosis in epilepsy and to estimate the risk of psychosis among individuals with epilepsy compared with controls. METHODS A systematic review and meta-analysis was conducted of all published literature pertaining to prevalence rates of psychosis in epilepsy using electronic databases PUBMED, OVIDMEDLINE, PsychINFO and Embase from their inception until September 2010 with the following search terms: prevalence, incidence, rate, rates, psychosis, schizophrenia, schizophreniform illness, epilepsy, seizures, temporal lobe epilepsy. RESULTS The literature search and search of reference lists yielded 215 papers. Of these, 58 (27%) had data relevant to the review and 157 were excluded following a more detailed assessment. 10% of the included studies were population based studies. The pooled odds ratio for risk of psychosis among people with epilepsy compared with controls was 7.8. The pooled estimate of prevalence of psychosis in epilepsy was found to be 5.6% (95% CI: 4.8-6.4). There was a high level of heterogeneity. The prevalence of psychosis in temporal lobe epilepsy was 7% (95% CI: 4.9-9.1). The prevalence of interictal psychosis in epilepsy was 5.2% (95% CI: 3.3-7.2). The prevalence of postictal psychosis in epilepsy was 2% (95% CI: 1.2-2.8). CONCLUSIONS Our systematic review found that up to 6% of individuals with epilepsy have a co-morbid psychotic illness and that patients have an almost eight fold increased risk of psychosis. The prevalence rate of psychosis is higher in temporal lobe epilepsy (7%). We suggest that further investigation of this association could give clues to the aetiology of psychosis.
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Affiliation(s)
- Maurice J Clancy
- Department of Psychiatry, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin 9, Ireland
- Department of Psychiatry, Beaumont Hospital, Dublin 9, Ireland
| | - Mary C Clarke
- Department of Psychiatry, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin 9, Ireland
- Department of Psychology, Division of Population Health Sciences, Royal College of Surgeons in Ireland, Beaux Lane House, Dublin 2, Ireland
| | - Dearbhla J Connor
- Department of Psychiatry, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin 9, Ireland
| | - Mary Cannon
- Department of Psychiatry, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin 9, Ireland
- Department of Psychiatry, Beaumont Hospital, Dublin 9, Ireland
| | - David R Cotter
- Department of Psychiatry, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin 9, Ireland
- Department of Psychiatry, Beaumont Hospital, Dublin 9, Ireland
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186
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Lo-Castro A, Curatolo P. Epilepsy associated with autism and attention deficit hyperactivity disorder: is there a genetic link? Brain Dev 2014; 36:185-93. [PMID: 23726375 DOI: 10.1016/j.braindev.2013.04.013] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 04/28/2013] [Accepted: 04/30/2013] [Indexed: 12/26/2022]
Abstract
Autism Spectrum Disorders (ASDs) and Attention Deficit and Hyperactivity Disorder (ADHD) are the most common comorbid conditions associated with childhood epilepsy. The co-occurrence of an epilepsy/autism phenotype or an epilepsy/ADHD phenotype has a complex and heterogeneous pathogenesis, resulting from several altered neurobiological mechanisms involved in early brain development, and influencing synaptic plasticity, neurotransmission and functional connectivity. Rare clinically relevant chromosomal aberrations, in addition to environmental factors, may confer an increased risk for ASDs/ADHD comorbid with epilepsy. The majority of the candidate genes are involved in synaptic formation/remodeling/maintenance (NRX1, CNTN4, DCLK2, CNTNAP2, TRIM32, ASTN2, CTNTN5, SYN1), neurotransmission (SYNGAP1, GABRG1, CHRNA7), or DNA methylation/chromatin remodeling (MBD5). Two genetic disorders, such as Tuberous sclerosis and Fragile X syndrome may serve as models for understanding the common pathogenic pathways leading to ASDs and ADHD comorbidities in children with epilepsy, offering the potential for new biologically focused treatment options.
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Affiliation(s)
- Adriana Lo-Castro
- Neuroscience Department, Pediatric Neurology and Psychiatry Unit, Tor Vergata University of Rome, Italy.
| | - Paolo Curatolo
- Neuroscience Department, Pediatric Neurology and Psychiatry Unit, Tor Vergata University of Rome, Italy
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187
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Kirov G, Rees E, Walters JTR, Escott-Price V, Georgieva L, Richards AL, Chambert KD, Davies G, Legge SE, Moran JL, McCarroll SA, O'Donovan MC, Owen MJ. The penetrance of copy number variations for schizophrenia and developmental delay. Biol Psychiatry 2014; 75:378-85. [PMID: 23992924 PMCID: PMC4229045 DOI: 10.1016/j.biopsych.2013.07.022] [Citation(s) in RCA: 247] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 07/03/2013] [Accepted: 07/17/2013] [Indexed: 12/26/2022]
Abstract
BACKGROUND Several recurrent copy number variants (CNVs) have been shown to increase the risk of developing schizophrenia (SCZ), developmental delay (DD), autism spectrum disorders (ASD), and various congenital malformations (CM). Their penetrance for SCZ has been estimated to be modest. However, comparisons between their penetrance for SCZ or DD/ASD/CM, or estimates of the total penetrance for any of these disorders have not yet been made. METHODS We use data from the largest available studies on SCZ and DD/ASD/CM, including a new sample of 6882 cases and 6316 controls, to estimate the frequencies of 70 implicated CNVs in carriers with these disorders, healthy control subjects, and the general population. On the basis of these frequencies, we estimate their penetrance. We also estimate the strength of the selection pressure against CNVs and correlate this against their overall penetrance. RESULTS The rates of nearly all CNVs are higher in DD/ASD/CM compared with SCZ. The penetrance of CNVs is at least several times higher for the development of a disorder from the group of DD/ASD/CM. The overall penetrance of SCZ-associated CNVs for developing any disorder is high, ranging between 10.6% and 100%. CONCLUSIONS CNVs associated with SCZ have high pathogenicity. The majority of the increased risk conferred by CNVs is toward the development of an earlier-onset disorder, such as DD/ASD/CM, rather than SCZ. The penetrance of CNVs correlates strongly with their selection coefficients. The improved estimates of penetrance will provide crucial information for genetic counselling.
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Affiliation(s)
- George Kirov
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Institute of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, United Kingdom.
| | - Elliott Rees
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Institute of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, United Kingdom
| | - James T R Walters
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Institute of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, United Kingdom
| | - Valentina Escott-Price
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Institute of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, United Kingdom
| | - Lyudmila Georgieva
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Institute of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, United Kingdom
| | - Alexander L Richards
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Institute of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, United Kingdom
| | - Kimberly D Chambert
- Stanley Center for Psychiatric Research, The Broad Institute of MIT and Harvard, Cambridge, Massachusetts
| | - Gerwyn Davies
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Institute of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, United Kingdom
| | - Sophie E Legge
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Institute of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, United Kingdom
| | - Jennifer L Moran
- Stanley Center for Psychiatric Research, The Broad Institute of MIT and Harvard, Cambridge, Massachusetts
| | - Steven A McCarroll
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Institute of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, United Kingdom
| | - Michael C O'Donovan
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Institute of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, United Kingdom
| | - Michael J Owen
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Institute of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, United Kingdom
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188
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Schaaf CP. Nicotinic acetylcholine receptors in human genetic disease. Genet Med 2014; 16:649-56. [DOI: 10.1038/gim.2014.9] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 01/13/2014] [Indexed: 01/26/2023] Open
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189
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Abstract
Bipolar disorder is a common, complex genetic disorder, but the mode of transmission remains to be discovered. Many researchers assume that common genomic variants carry some risk for manifesting the disease. The research community has celebrated the first genome-wide significant associations between common single nucleotide polymorphisms (SNPs) and bipolar disorder. Currently, attempts are under way to translate these findings into clinical practice, genetic counseling, and predictive testing. However, some experts remain cautious. After all, common variants explain only a very small percentage of the genetic risk, and functional consequences of the discovered SNPs are inconclusive. Furthermore, the associated SNPs are not disease specific, and the majority of individuals with a "risk" allele are healthy. On the other hand, population-based genome-wide studies in psychiatric disorders have rediscovered rare structural variants and mutations in genes, which were previously known to cause genetic syndromes and monogenic Mendelian disorders. In many Mendelian syndromes, psychiatric symptoms are prevalent. Although these conditions do not fit the classic description of any specific psychiatric disorder, they often show nonspecific psychiatric symptoms that cross diagnostic boundaries, including intellectual disability, behavioral abnormalities, mood disorders, anxiety disorders, attention deficit, impulse control deficit, and psychosis. Although testing for chromosomal disorders and monogenic Mendelian disorders is well established, testing for common variants is still controversial. The standard concept of genetic testing includes at least three broad criteria that need to be fulfilled before new genetic tests should be introduced: analytical validity, clinical validity, and clinical utility. These criteria are currently not fulfilled for common genomic variants in psychiatric disorders. Further work is clearly needed before genetic testing for common variants in psychiatric disorders should be established.
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Affiliation(s)
- Berit Kerner
- Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA
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190
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CHRNA7 triplication associated with cognitive impairment and neuropsychiatric phenotypes in a three-generation pedigree. Eur J Hum Genet 2014; 22:1071-6. [PMID: 24424125 DOI: 10.1038/ejhg.2013.302] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 10/30/2013] [Accepted: 11/27/2013] [Indexed: 01/27/2023] Open
Abstract
Although deletions of CHRNA7 have been associated with intellectual disability (ID), seizures and neuropsychiatric phenotypes, the pathogenicity of CHRNA7 duplications has been uncertain. We present the first report of CHRNA7 triplication. Three generations of a family affected with various neuropsychiatric phenotypes, including anxiety, bipolar disorder, developmental delay and ID, were studied with array comparative genomic hybridization (aCGH). High-resolution aCGH revealed a 650-kb triplication at chromosome 15q13.3 encompassing the CHRNA7 gene, which encodes the alpha7 subunit of the neuronal nicotinic acetylcholine receptor. A small duplication precedes the triplication at the proximal breakpoint junction, and analysis of the breakpoint indicates that the triplicated segment is in an inverted orientation with respect to the duplication. CHRNA7 triplication appears to occur by a replication-based mechanism that produces inverted triplications embedded within duplications. Co-segregation of the CHRNA7 triplication with neuropsychiatric and cognitive phenotypes provides further evidence for dosage sensitivity of CHRNA7.
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191
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Weiss LA. Autism genetics: emerging data from genome-wide copy-number and single nucleotide polymorphism scans. Expert Rev Mol Diagn 2014; 9:795-803. [DOI: 10.1586/erm.09.59] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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192
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Nieratschker V, Meyer-Lindenberg A, Witt SH. Genome-wide investigation of rare structural variants identifiesVIPR2as a new candidate gene for schizophrenia. Expert Rev Neurother 2014; 11:937-41. [DOI: 10.1586/ern.11.84] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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193
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Remind me again what disease we are studying? A population genetics, genetic analysis, and real data perspective on why progress on identifying genetic influences on common epilepsies has been so slow. PROGRESS IN BRAIN RESEARCH 2014; 213:199-221. [DOI: 10.1016/b978-0-444-63326-2.00011-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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194
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Szigeti K, Kellermayer B, Lentini JM, Trummer B, Lal D, Doody RS, Yan L, Liu S, Ma C. Ordered subset analysis of copy number variation association with age at onset of Alzheimer's disease. J Alzheimers Dis 2014; 41:1063-71. [PMID: 24787912 PMCID: PMC4866488 DOI: 10.3233/jad-132693] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Genetic heterogeneity is a common problem for genome-wide association studies of complex human diseases. Ordered-subset analysis (OSA) reduces genetic heterogeneity and optimizes the use of phenotypic information, thus improving power under some disease models. We hypothesized that in a genetically heterogeneous disorder such as Alzheimer's disease (AD), utilizing OSA by age at onset (AAO) of AD may increase the power to detect relevant loci. Using this approach, 8 loci were detected, including the chr15 : 30,44 region harboring CHRFAM7A. The association was replicated in the NIA-LOAD Familial Study dataset. CHRFAM7A is a dominant negative regulator of CHRNA7 function, the receptor that facilitates amyloid-β1-42 internalization through endocytosis and has been implicated in AD. OSA, using AAO as a quantitative trait, optimized power and detected replicable signals suggesting that AD is genetically heterogeneous between AAO subsets.
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Affiliation(s)
- Kinga Szigeti
- Department of Neurology, University at Buffalo, SUNY, Buffalo, NY, USA,Correspondence to: Kinga Szigeti, MD, PhD, University of Buffalo SUNY, 100 High Street, Buffalo, NY 14203, USA. Tel.: +1 716 859 3484; Fax: +1 716 859 7833;
| | | | - Jenna M. Lentini
- Department of Neurology, University at Buffalo, SUNY, Buffalo, NY, USA
| | - Brian Trummer
- Department of Neurology, University at Buffalo, SUNY, Buffalo, NY, USA
| | - Deepika Lal
- Department of Neurology, University at Buffalo, SUNY, Buffalo, NY, USA
| | - Rachelle S. Doody
- Alzheimer’s Disease and Memory Disorders Center, Department of Neurology, Baylor College of Medicine, Houston, TX, USA
| | - Li Yan
- Department of Bioinformatics, University at Buffalo, SUNY, Buffalo, NY, USA
| | - Song Liu
- Roswell Park Cancer Institute, Buffalo, NY, USA
| | - Changxing Ma
- Department of Bioinformatics, University at Buffalo, SUNY, Buffalo, NY, USA
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195
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Żmieńko A, Samelak A, Kozłowski P, Figlerowicz M. Copy number polymorphism in plant genomes. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2014; 127:1-18. [PMID: 23989647 PMCID: PMC4544587 DOI: 10.1007/s00122-013-2177-7] [Citation(s) in RCA: 120] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 08/12/2013] [Indexed: 05/18/2023]
Abstract
Copy number variants (CNVs) are genomic rearrangements resulting from gains or losses of DNA segments. Typically, the term refers to rearrangements of sequences larger than 1 kb. This type of polymorphism has recently been shown to be a key contributor to intra-species genetic variation, along with single-nucleotide polymorphisms and short insertion-deletion polymorphisms. Over the last decade, a growing number of studies have highlighted the importance of copy number variation (CNV) as a factor affecting human phenotype and individual CNVs have been linked to risks for severe diseases. In plants, the exploration of the extent and role of CNV is still just beginning. Initial genomic analyses indicate that CNVs are prevalent in plants and have greatly affected plant genome evolution. Many CNV events have been observed in outcrossing and autogamous species. CNVs are usually found on all chromosomes, with CNV hotspots interspersed with regions of very low genetic variation. Although CNV is mainly associated with intergenic regions, many CNVs encompass protein-coding genes. The collected data suggest that CNV mainly affects the members of large families of functionally redundant genes. Thus, the effects of individual CNV events on phenotype are usually modest. Nevertheless, there are many cases in which CNVs for specific genes have been linked to important traits such as flowering time, plant height and resistance to biotic and abiotic stress. Recent reports suggest that CNVs may form rapidly in response to stress.
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Affiliation(s)
- Agnieszka Żmieńko
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, Poznan, Poland
| | - Anna Samelak
- Institute of Computing Science, Poznan University of Technology, Piotrowo 2, 60-965 Poznan, Poland
| | - Piotr Kozłowski
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, Poznan, Poland
| | - Marek Figlerowicz
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, Poznan, Poland
- Institute of Computing Science, Poznan University of Technology, Piotrowo 2, 60-965 Poznan, Poland
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196
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Krumm N, O'Roak BJ, Shendure J, Eichler EE. A de novo convergence of autism genetics and molecular neuroscience. Trends Neurosci 2013; 37:95-105. [PMID: 24387789 PMCID: PMC4077788 DOI: 10.1016/j.tins.2013.11.005] [Citation(s) in RCA: 327] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 10/07/2013] [Accepted: 11/21/2013] [Indexed: 12/19/2022]
Abstract
Autism spectrum disorder (ASD) and intellectual disability (ID) are neurodevelopmental disorders with large genetic components, but identification of pathogenic genes has proceeded slowly because hundreds of loci are involved. New exome sequencing technology has identified novel rare variants and has found that sporadic cases of ASD/ID are enriched for disruptive de novo mutations. Targeted large-scale resequencing studies have confirmed the significance of specific loci, including chromodomain helicase DNA binding protein 8 (CHD8), sodium channel, voltage-gated, type II, alpha subunit (SCN2A), dual specificity tyrosine-phosphorylation-regulated kinase 1A (DYRK1A), and catenin (cadherin-associated protein), beta 1, 88 kDa (CTNNB1, beta-catenin). We review recent studies and suggest that they have led to a convergence on three functional pathways: (i) chromatin remodeling; (ii) wnt signaling during development; and (iii) synaptic function. These pathways and genes significantly expand the neurobiological targets for study, and suggest a path for future genetic and functional studies.
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Affiliation(s)
- Niklas Krumm
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Brian J O'Roak
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Jay Shendure
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Evan E Eichler
- Department of Genome Sciences, University of Washington, Seattle, WA, USA; Howard Hughes Medical Institute, University of Washington School of Medicine, Seattle, WA, USA.
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197
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Dimassi S, Labalme A, Lesca G, Rudolf G, Bruneau N, Hirsch E, Arzimanoglou A, Motte J, de Saint Martin A, Boutry-Kryza N, Cloarec R, Benitto A, Ameil A, Edery P, Ryvlin P, De Bellescize J, Szepetowski P, Sanlaville D. A subset of genomic alterations detected in rolandic epilepsies contains candidate or known epilepsy genes includingGRIN2AandPRRT2. Epilepsia 2013; 55:370-8. [DOI: 10.1111/epi.12502] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/31/2013] [Indexed: 01/08/2023]
Affiliation(s)
- Sarra Dimassi
- Department of Genetics; Lyon University Hospital; Lyon France
- Claude Bernard Lyon I University; Lyon France
- CRNL; CNRS UMR 5292; INSERM U1028; Lyon France
| | - Audrey Labalme
- Department of Genetics; Lyon University Hospital; Lyon France
- The French EPILAND (Epilepsy, Language and Development) Consortium; Marseille France
| | - Gaetan Lesca
- Department of Genetics; Lyon University Hospital; Lyon France
- Claude Bernard Lyon I University; Lyon France
- CRNL; CNRS UMR 5292; INSERM U1028; Lyon France
- The French EPILAND (Epilepsy, Language and Development) Consortium; Marseille France
| | - Gabrielle Rudolf
- The French EPILAND (Epilepsy, Language and Development) Consortium; Marseille France
- Department of Neurology; Strasbourg University Hospital; Strasbourg France
- UMR_S; INSERM U1119; Strasbourg France
| | - Nadine Bruneau
- The French EPILAND (Epilepsy, Language and Development) Consortium; Marseille France
- INSERM Unit U901; Marseille France
- Mediterranean Institute of Neurobiology (INMED); Marseille France
- UMR_S901; Aix-Marseille University; Marseille France
| | - Edouard Hirsch
- The French EPILAND (Epilepsy, Language and Development) Consortium; Marseille France
- Department of Neurology; Strasbourg University Hospital; Strasbourg France
| | - Alexis Arzimanoglou
- CRNL; CNRS UMR 5292; INSERM U1028; Lyon France
- The French EPILAND (Epilepsy, Language and Development) Consortium; Marseille France
- Departments of Epilepsy, Sleep and Pediatric Neurophysiology (ESEFNP); University Hospitals of Lyon (HCL); Lyon France
| | - Jacques Motte
- The French EPILAND (Epilepsy, Language and Development) Consortium; Marseille France
- Department of Pediatry A; American Memorial Hospital; Reims University Hospital; Reims France
| | - Anne de Saint Martin
- The French EPILAND (Epilepsy, Language and Development) Consortium; Marseille France
- Department of Pediatry I; Strasbourg University Hospital; Strasbourg France
| | - Nadia Boutry-Kryza
- Claude Bernard Lyon I University; Lyon France
- CRNL; CNRS UMR 5292; INSERM U1028; Lyon France
- The French EPILAND (Epilepsy, Language and Development) Consortium; Marseille France
- Department of Molecular Genetics; Lyon University Hospital; Lyon France
| | - Robin Cloarec
- The French EPILAND (Epilepsy, Language and Development) Consortium; Marseille France
- INSERM Unit U901; Marseille France
- Mediterranean Institute of Neurobiology (INMED); Marseille France
- UMR_S901; Aix-Marseille University; Marseille France
| | - Afaf Benitto
- Department of Pediatry A; American Memorial Hospital; Reims University Hospital; Reims France
| | - Agnès Ameil
- Department of Pediatry A; American Memorial Hospital; Reims University Hospital; Reims France
| | - Patrick Edery
- Department of Genetics; Lyon University Hospital; Lyon France
- Claude Bernard Lyon I University; Lyon France
- CRNL; CNRS UMR 5292; INSERM U1028; Lyon France
| | - Philippe Ryvlin
- Claude Bernard Lyon I University; Lyon France
- CRNL; CNRS UMR 5292; INSERM U1028; Lyon France
- The French EPILAND (Epilepsy, Language and Development) Consortium; Marseille France
- Department of Neurology; Lyon University Hospital; Lyon France
| | - Julitta De Bellescize
- The French EPILAND (Epilepsy, Language and Development) Consortium; Marseille France
- Departments of Epilepsy, Sleep and Pediatric Neurophysiology (ESEFNP); University Hospitals of Lyon (HCL); Lyon France
| | - Pierre Szepetowski
- The French EPILAND (Epilepsy, Language and Development) Consortium; Marseille France
- INSERM Unit U901; Marseille France
- Mediterranean Institute of Neurobiology (INMED); Marseille France
- UMR_S901; Aix-Marseille University; Marseille France
| | - Damien Sanlaville
- Department of Genetics; Lyon University Hospital; Lyon France
- Claude Bernard Lyon I University; Lyon France
- CRNL; CNRS UMR 5292; INSERM U1028; Lyon France
- The French EPILAND (Epilepsy, Language and Development) Consortium; Marseille France
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198
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Abstract
A number of rare copy number variants (CNVs), including both deletions and duplications, have been associated with developmental disorders, including schizophrenia, autism, intellectual disability, and epilepsy. Pathogenicity may derive from dosage sensitivity of one or more genes contained within the CNV locus. To understand pathophysiology, the specific disease-causing gene(s) within each CNV need to be identified. In the present study, we test the hypothesis that ohnologs (genes retained after ancestral whole-genome duplication events, which are frequently dosage sensitive) are overrepresented in pathogenic CNVs. We selected three sets of genes implicated in copy number pathogenicity: (i) genes mapping within rare disease-associated CNVs, (ii) genes within de novo CNVs under negative genetic selection, and (iii) genes identified by clinical array comparative genome hybridization studies as potentially pathogenic. We compared the proportion of ohnologs between these gene sets and control genes, mapping to CNVs not known to be disease associated. We found that ohnologs are significantly overrepresented in genes mapping to pathogenic CNVs, irrespective of how CNVs were identified, with over 90% containing an ohnolog, compared with control CNVs >100 kb, where only about 30% contained an ohnolog. In some CNVs, such as del15p11.2 (CYFIP1) and dup/del16p13.11 (NDE1), the most plausible prior candidate gene was also an ohnolog, as were the genes VIPR2 and NRXN1, each found in short CNVs containing no other genes. Our results support the hypothesis that ohnologs represent critical dosage-sensitive elements of the genome, possibly responsible for some of the deleterious phenotypes observed for pathogenic CNVs and as such are readily identifiable candidate genes for further study.
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199
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Cortical synaptic NMDA receptor deficits in α7 nicotinic acetylcholine receptor gene deletion models: implications for neuropsychiatric diseases. Neurobiol Dis 2013; 63:129-40. [PMID: 24326163 DOI: 10.1016/j.nbd.2013.11.021] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 11/21/2013] [Accepted: 11/26/2013] [Indexed: 01/06/2023] Open
Abstract
Microdeletion of the human CHRNA7 gene (α7 nicotinic acetylcholine receptor, nAChR) as well as dysfunction in N-methyl-d-aspartate receptors (NMDARs) have been associated with cortical dysfunction in a broad spectrum of neurodevelopmental and neuropsychiatric disorders including schizophrenia. However, the pathophysiological roles of synaptic vs. extrasynaptic NMDARs and their interactions with α7 nAChRs in cortical dysfunction remain largely uncharacterized. Using a combination of in vivo and in vitro models, we demonstrate that α7 nAChR gene deletion leads to specific loss of synaptic NMDARs and their coagonist, d-serine, as well as glutamatergic synaptic deficits in mouse cortex. α7 nAChR null mice had decreased cortical NMDAR expression and glutamatergic synapse formation during postnatal development. Similar reductions in NMDAR expression and glutamatergic synapse formation were revealed in cortical cultures lacking α7 nAChRs. Interestingly, synaptic, but not extrasynaptic, NMDAR currents were specifically diminished in cultured cortical pyramidal neurons as well as in acute prefrontal cortical slices of α7 nAChR null mice. Moreover, d-serine responsive synaptic NMDAR-mediated currents and levels of the d-serine synthetic enzyme serine racemase were both reduced in α7 nAChR null cortical pyramidal neurons. Our findings thus identify specific loss of synaptic NMDARs and their coagonist, d-serine, as well as glutamatergic synaptic deficits in α7 nAChR gene deletion models of cortical dysfunction, thereby implicating α7 nAChR-mediated control of synaptic NMDARs and serine racemase/d-serine pathways in cortical dysfunction underlying many neuropsychiatric and neurodevelopmental disorders, particularly those associated with deletion of human CHRNA7.
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200
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Amiet C, Gourfinkel-An I, Laurent C, Bodeau N, Génin B, Leguern E, Tordjman S, Cohen D. Does epilepsy in multiplex autism pedigrees define a different subgroup in terms of clinical characteristics and genetic risk? Mol Autism 2013; 4:47. [PMID: 24289166 PMCID: PMC4176303 DOI: 10.1186/2040-2392-4-47] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 09/13/2013] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Autism spectrum disorders (ASD) and epilepsy frequently occur together. Prevalence rates are variable, and have been attributed to age, gender, comorbidity, subtype of pervasive developmental disorder (PDD) and risk factors. Recent studies have suggested disparate clinical and genetic settings depending on simplex or multiplex autism. The aim of this study was to assess: 1) the prevalence of epilepsy in multiplex autism and its association with genetic and non-genetic risk factors of major effect, intellectual disability and gender; and 2) whether autism and epilepsy cosegregate within multiplex autism families. METHODS We extracted from the Autism Genetic Resource Exchange (AGRE) database (n = 3,818 children from 1,264 families) all families with relevant medical data (n = 664 children from 290 families). The sample included 478 children with ASD and 186 siblings without ASD. We analyzed the following variables: seizures, genetic and non-genetic risk factors, gender, and cognitive functioning as assessed by Raven's Colored Progressive Matrices (RCPM) and Vineland Adaptive Behavior Scales (VABS). RESULTS The prevalence of epilepsy was 12.8% in cases with ASD and 2.2% in siblings without ASD (P <10-5). With each RCPM or VABS measure, the risk of epilepsy in multiplex autism was significantly associated with intellectual disability, but not with gender. Identified risk factors (genetic or non-genetic) of autism tended to be significantly associated with epilepsy (P = 0.052). When children with prematurity, pre- or perinatal insult, or cerebral palsy were excluded, a genetic risk factor was reported for 6/59 (10.2%) of children with epilepsy and 12/395 (3.0%) of children without epilepsy (P = 0.002). Finally, using a permutation test, there was significant evidence that the epilepsy phenotype co-segregated within families (P <10-4). CONCLUSIONS Epilepsy in multiplex autism may define a different subgroup in terms of clinical characteristics and genetic risk.
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Affiliation(s)
| | | | | | | | | | | | | | - David Cohen
- Department of Child and Adolescent Psychiatry, Assistance Publique-Hôpitaux de Paris (AP-HP), Groupe Hospitalier Pitié-Salpêtrière, Université Pierre et Marie Curie, 47 bd de l'Hôpital, 75013 Paris, France.
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