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Lin ZJ, He JW, Zhu SY, Xue LH, Zheng JF, Zheng LQ, Huang BX, Chen GZ, Lin PX. Gene-gene interaction network analysis indicates CNTN2 is a candidate gene for idiopathic generalized epilepsy. Neurogenetics 2024; 25:131-139. [PMID: 38460076 DOI: 10.1007/s10048-024-00748-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 01/19/2024] [Indexed: 03/11/2024]
Abstract
Twin and family studies have established the genetic contribution to idiopathic generalized epilepsy (IGE). The genetic architecture of IGE is generally complex and heterogeneous, and the majority of the genetic burden in IGE remains unsolved. We hypothesize that gene-gene interactions contribute to the complex inheritance of IGE. CNTN2 (OMIM* 615,400) variants have been identified in cases with familial adult myoclonic epilepsy and other epilepsies. To explore the gene-gene interaction network in IGE, we took the CNTN2 gene as an example and investigated its co-occurrent genetic variants in IGE cases. We performed whole-exome sequencing in 114 unrelated IGE cases and 296 healthy controls. Variants were qualified with sequencing quality, minor allele frequency, in silico prediction, genetic phenotype, and recurrent case numbers. The STRING_TOP25 gene interaction network analysis was introduced with the bait gene CNTN2 (denoted as A). The gene-gene interaction pair mode was presumed to be A + c, A + d, A + e, with a leading gene A, or A + B + f, A + B + g, A + B + h, with a double-gene A + B, or other combinations. We compared the number of gene interaction pairs between the case and control groups. We identified three pairs in the case group, CNTN2 + PTPN18, CNTN2 + CNTN1 + ANK2 + ANK3 + SNTG2, and CNTN2 + PTPRZ1, while we did not discover any pairs in the control group. The number of gene interaction pairs in the case group was much more than in the control group (p = 0.021). Taking together the genetic bioinformatics, reported epilepsy cases, and statistical evidence in the study, we supposed CNTN2 as a candidate pathogenic gene for IGE. The gene interaction network analysis might help screen candidate genes for IGE or other complex genetic disorders.
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Affiliation(s)
- Zhi-Jian Lin
- Department of Neurology, School of Clinical Medicine, the Affiliated Hospital of Putian UniversityFujian Medical UniversityBrain Science Institute of Putian University, 999 Dongzhen East Road, Licheng District, Putian, 351100, China
| | - Jun-Wei He
- Department of Neurology, School of Clinical Medicine, the Affiliated Hospital of Putian UniversityFujian Medical UniversityBrain Science Institute of Putian University, 999 Dongzhen East Road, Licheng District, Putian, 351100, China
| | - Sheng-Yin Zhu
- Department of Neurology, School of Clinical Medicine, the Affiliated Hospital of Putian UniversityFujian Medical UniversityBrain Science Institute of Putian University, 999 Dongzhen East Road, Licheng District, Putian, 351100, China
| | - Li-Hong Xue
- Department of Neurology, School of Clinical Medicine, the Affiliated Hospital of Putian UniversityFujian Medical UniversityBrain Science Institute of Putian University, 999 Dongzhen East Road, Licheng District, Putian, 351100, China
| | - Jian-Feng Zheng
- Department of Neurology, School of Clinical Medicine, the Affiliated Hospital of Putian UniversityFujian Medical UniversityBrain Science Institute of Putian University, 999 Dongzhen East Road, Licheng District, Putian, 351100, China
| | - Li-Qin Zheng
- Department of Neurology, School of Clinical Medicine, the Affiliated Hospital of Putian UniversityFujian Medical UniversityBrain Science Institute of Putian University, 999 Dongzhen East Road, Licheng District, Putian, 351100, China
| | - Bi-Xia Huang
- Department of Neurology, School of Clinical Medicine, the Affiliated Hospital of Putian UniversityFujian Medical UniversityBrain Science Institute of Putian University, 999 Dongzhen East Road, Licheng District, Putian, 351100, China
| | - Guo-Zhang Chen
- Department of Neurology, School of Clinical Medicine, the Affiliated Hospital of Putian UniversityFujian Medical UniversityBrain Science Institute of Putian University, 999 Dongzhen East Road, Licheng District, Putian, 351100, China
| | - Peng-Xing Lin
- Department of Neurology, School of Clinical Medicine, the Affiliated Hospital of Putian UniversityFujian Medical UniversityBrain Science Institute of Putian University, 999 Dongzhen East Road, Licheng District, Putian, 351100, China.
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Lin ZJ, Huang BX, Su LF, Zhu SY, He JW, Chen GZ, Lin PX. Sub-region analysis of DMD gene in cases with idiopathic generalized epilepsy. Neurogenetics 2023; 24:161-169. [PMID: 37022522 DOI: 10.1007/s10048-023-00715-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 03/24/2023] [Indexed: 04/07/2023]
Abstract
Gene sub-region encoded protein domain is the basic unit for protein structure and function. The DMD gene is the largest coding gene in humans, with its phenotype relevant to idiopathic generalized epilepsy. We hypothesized variants clustered in sub-regions of idiopathic generalized epilepsy genes and investigated the relationship between the DMD gene and idiopathic generalized epilepsy. Whole exome sequencing was performed in 106 idiopathic generalized epilepsy individuals. DMD variants were filtered with variant type, allele frequency, in silico prediction, hemizygous or homozygous status in the population, inheritance mode, and domain location. Variants located at the sub-regions were selected by the subRVIS software. The pathogenicity of variants was evaluated by the American College of Medical Genetics and Genomics criteria. Articles on functional studies related to epilepsy for variants clustered protein domains were reviewed. In sub-regions of the DMD gene, two variants were identified in two unrelated cases with juvenile absence epilepsy or juvenile myoclonic epilepsy. The pathogenicity of both variants was uncertain significance. Allele frequency of both variants in probands with idiopathic generalized epilepsy reached statistical significance compared with the population (Fisher's test, p = 2.02 × 10-6, adjusted α = 4.52 × 10-6). The variants clustered in the spectrin domain of dystrophin, which binds to glycoprotein complexes and indirectly affects ion channels contributing to epileptogenesis. Gene sub-region analysis suggests a weak association between the DMD gene and idiopathic generalized epilepsy. Functional analysis of gene sub-region helps infer the pathogenesis of idiopathic generalized epilepsy.
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Affiliation(s)
- Zhi-Jian Lin
- Department of Neurology, The Affiliated Hospital of Putian University, Brain Science Institute of Putian University, 999 Dongzhen East Road, Licheng District, Putian, 351100, China
| | - Bi-Xia Huang
- Department of Neurology, The Affiliated Hospital of Putian University, Brain Science Institute of Putian University, 999 Dongzhen East Road, Licheng District, Putian, 351100, China
| | - Li-Fang Su
- Department of Neurology, The Affiliated Hospital of Putian University, Brain Science Institute of Putian University, 999 Dongzhen East Road, Licheng District, Putian, 351100, China
| | - Sheng-Yin Zhu
- Department of Neurology, The Affiliated Hospital of Putian University, Brain Science Institute of Putian University, 999 Dongzhen East Road, Licheng District, Putian, 351100, China
| | - Jun-Wei He
- Department of Neurology, The Affiliated Hospital of Putian University, Brain Science Institute of Putian University, 999 Dongzhen East Road, Licheng District, Putian, 351100, China
| | - Guo-Zhang Chen
- Department of Neurology, The Affiliated Hospital of Putian University, Brain Science Institute of Putian University, 999 Dongzhen East Road, Licheng District, Putian, 351100, China
| | - Peng-Xing Lin
- Department of Neurology, The Affiliated Hospital of Putian University, Brain Science Institute of Putian University, 999 Dongzhen East Road, Licheng District, Putian, 351100, China.
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Gonsales MC, Ribeiro PAO, Betting LE, Alvim MKM, Guerreiro CM, Yasuda CL, Gitaí DLG, Cendes F, Lopes-Cendes I. Revisiting the clinical impact of variants in EFHC1 in patients with different phenotypes of genetic generalized epilepsy. Epilepsy Behav 2020; 112:107469. [PMID: 33181902 DOI: 10.1016/j.yebeh.2020.107469] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 08/20/2020] [Accepted: 08/30/2020] [Indexed: 01/27/2023]
Abstract
The most common form of genetic generalized epilepsy (GGE) is juvenile myoclonic epilepsy (JME), which accounts for 5 to 10% of all epilepsy cases. The gene EFHC1 has been implicated as a putative cause of JME. However, it remains debatable whether testing for EFHC1 mutations should be included in the diagnostic epilepsy gene panels. To investigate the clinical utility of EFHC1 testing, we studied 125 individuals: 100 with JME and 25 with other GGEs. We amplified and sequenced all EFHC1 coding exons. Then, we predicted the pathogenicity or benign impact of the variants using the analyses proposed by the American College of Medical Genetics and Genomics (ACMG)/Association for Molecular Pathology (AMP). Mutation screening revealed 11 missense variants in 44 probands with JME (44%) and one of the seven individuals with generalized tonic-clonic seizures on awakening (14%). Six of the 11 variants (54%) were classified as 'benign,' and the remaining variants were considered variants of uncertain significance (VUS). There is currently a limitation to test for genes that predispose an individual to complex, nonmonogenic phenotypes. Thus, we show suggestive evidence that EFHC1 testing lacks a scientific foundation based on the disputed nature of the gene-disease relationship and should be currently limited to research purposes.
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Affiliation(s)
- Marina C Gonsales
- Department of Medical Genetics and Genomic Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil; The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
| | - Patrícia A O Ribeiro
- Department of Medical Genetics and Genomic Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil; The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
| | - Luiz E Betting
- Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil; The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
| | - Marina K M Alvim
- Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil; The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
| | - Carlos M Guerreiro
- Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil; The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
| | - Clarissa L Yasuda
- Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil; The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
| | - Daniel L G Gitaí
- Institute of Biological Sciences and Health, Federal University of Alagoas (UFAL), Maceió, AL, Brazil
| | - Fernando Cendes
- Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil; The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
| | - Iscia Lopes-Cendes
- Department of Medical Genetics and Genomic Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil; The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil.
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Almane DN, Jones JE, McMillan T, Stafstrom CE, Hsu DA, Seidenberg M, Hermann BP, Oyegbile TO. The Timing, Nature, and Range of Neurobehavioral Comorbidities in Juvenile Myoclonic Epilepsy. Pediatr Neurol 2019; 101:47-52. [PMID: 31122836 PMCID: PMC6752993 DOI: 10.1016/j.pediatrneurol.2019.03.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 03/05/2019] [Accepted: 03/10/2019] [Indexed: 11/26/2022]
Abstract
BACKGROUND Accumulating evidence suggests that considerable cognitive and psychiatric comorbidity is associated with juvenile myoclonic epilepsy, for which the etiology remains controversial. Our goal was to comprehensively characterize the status of multiple neurobehavioral comorbidities in youth with new- or recent-onset juvenile myoclonic epilepsy, before effects of chronic seizures and medications. METHODS A total of 111 children aged eight to 18 years (41 new- or recent-onset juvenile myoclonic epilepsy and 70 first-degree cousin controls) underwent neuropsychological assessment (attention, executive, verbal, perceptual, speed), structured review of need for supportive academic services, parent reports of behavior and executive function (Child Behavior Checklist and Behavior Rating Inventory of Executive Function), and formal structured psychiatric interview and diagnosis (Kiddie Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version). RESULTS Children with juvenile myoclonic epilepsy performed worse than controls across all tested cognitive domains (F(1,105) = 3.85, P < 0.01), utilized more academic services (47% versus 19%, P = 0.002), had more parent-reported behavioral problems and dysexecutive function with lower competence (P < 0.001), and had a higher prevalence of current Axis I diagnoses (attention-deficit/hyperactivity disorder, depression, and anxiety; 54% versus 23%, P = 0.001). Academic and psychiatric problems occurred antecedent to epilepsy onset compared with comparable timeline in controls. CONCLUSION Comprehensive assessment of cognitive, academic, behavioral, and psychiatric comorbidities in youth with new- or recent-onset juvenile myoclonic epilepsy reveals a pattern of significantly increased neurobehavioral comorbidities across a broad spectrum of areas. These early evident comorbidities are of clear clinical importance with worrisome implications for future cognitive, behavioral, and social function. It is important for health care providers to avoid delays in intervention by assessing potential comorbidities early in the course of the disorder to optimize their patients' social, academic and behavioral progress.
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Affiliation(s)
- Dace N Almane
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison Wisconsin
| | - Jana E Jones
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison Wisconsin
| | - Taylor McMillan
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison Wisconsin
| | - Carl E Stafstrom
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore Maryland
| | - David A Hsu
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison Wisconsin
| | | | - Bruce P Hermann
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison Wisconsin
| | - Temitayo O Oyegbile
- Department of Pediatrics and Neurology, Georgetown University, Washington District of Columbia.
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Wang M, Greenberg DA, Stewart WCL. In Response: ME2 association analysis in adolescent-onset genetic generalized epilepsy. Epilepsia 2019; 60:2001-2002. [PMID: 31353459 DOI: 10.1111/epi.16303] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 07/08/2019] [Indexed: 11/27/2022]
Affiliation(s)
- Meng Wang
- The Research Institute at Nationwide Children's Hospital, Nationwide Children's Hospital, Columbus, Ohio
| | | | - William C L Stewart
- The Research Institute at Nationwide Children's Hospital, Nationwide Children's Hospital, Columbus, Ohio.,Department of Pediatrics, The Ohio State University, Columbus, Ohio.,Departments of Statistics, The Ohio State University, Columbus, Ohio
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Pathak S, Miller J, Morris EC, Stewart WCL, Greenberg DA. DNA methylation of the BRD2 promoter is associated with juvenile myoclonic epilepsy in Caucasians. Epilepsia 2018; 59:1011-1019. [PMID: 29608786 DOI: 10.1111/epi.14058] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/22/2018] [Indexed: 12/24/2022]
Abstract
OBJECTIVE Juvenile myoclonic epilepsy (JME) is a common adolescent-onset genetic generalized epilepsy (GGE) syndrome. Multiple linkage and association studies have found that BRD2 influences the expression of JME. The BRD2-JME connection is further corroborated by our murine model; Brd2 haploinsufficiency produces characteristics that typify the clinical hallmarks of JME. Neither we, nor several large-scale studies of JME, found JME-related BRD2 coding mutations. Therefore, we investigated noncoding BRD2 regions, seeking the origin of BRD2's JME influence. BRD2's promoter harbors a JME-associated single nucleotide polymorphism (rs3918149) and a CpG (C-phosphate-G dinucleotides) island (CpG76), making it a potential "hotspot" for JME-associated epigenetic variants. Methylating promoter CpG sites causes gene silencing, often resulting in reduced gene expression. We tested for differences in DNA methylation at CpG76 in 3 different subgroups: (1) JME patients versus their unaffected family members, (2) JME versus patients with other forms of GGE, and (3) Caucasian versus non-Caucasian JME patients. METHODS We used DNA pyrosequencing to analyze the methylation status of 10 BRD2 promoter CpG sites in lymphoblastoid cells from JME patients of Caucasian and non-Caucasian origin, unaffected family members, and also non-JME GGE patients. We also measured global methylation levels and DNA methyl transferase 1 (DNMT1) transcript expression in JME families by standard methods. RESULTS CpG76 is highly methylated in JME patients compared to unaffected family members. In families with non-JME GGE, we found no relationship between promoter methylation and epilepsy. In non-Caucasian JME families, promoter methylation was mostly not associated with epilepsy. This makes the BRD2 promoter a JME-specific, ethnicity-specific, differentially methylated region. Global methylation was constant across groups. SIGNIFICANCE BRD2 promoter methylation in JME, and the lack of methylation in unaffected relatives, in non-JME GGE patients, and in non-Caucasian JME, demonstrate that methylation specificity is a possible seizure susceptibility motif in JME risk and suggests JME therapeutics targeting BRD2.
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Affiliation(s)
- Shilpa Pathak
- Battelle Center for Mathematical Medicine, Research Institute, Nationwide Children's Hospital, Columbus, OH, USA
| | - James Miller
- Battelle Center for Mathematical Medicine, Research Institute, Nationwide Children's Hospital, Columbus, OH, USA
| | - Emily C Morris
- Battelle Center for Mathematical Medicine, Research Institute, Nationwide Children's Hospital, Columbus, OH, USA
| | - William C L Stewart
- Battelle Center for Mathematical Medicine, Research Institute, Nationwide Children's Hospital, Columbus, OH, USA
| | - David A Greenberg
- Battelle Center for Mathematical Medicine, Research Institute, Nationwide Children's Hospital, Columbus, OH, USA
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Baykan B, Wolf P. Juvenile myoclonic epilepsy as a spectrum disorder: A focused review. Seizure 2017; 49:36-41. [PMID: 28544889 DOI: 10.1016/j.seizure.2017.05.011] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 05/12/2017] [Accepted: 05/15/2017] [Indexed: 01/11/2023] Open
Abstract
In consequence of newer research juvenile myoclonic epilepsy (JME) is no longer seen as a homogeneous disease. The causes of the existing variance are only partially known yet. We discuss to what extent the phenotypical spectrum of this polygenetically determined disorder expresses genetically defined endophenotypes, or is due to mere quantitative differences in the expression of the core phenotype. Of the three common seizure types of JME, myoclonic, generalized tonic-clonic and absences, absences also occur independently and are strong candidates for an endophenotype. Focal features may in some patients be seen in clinical seizures or the EEG but rarely in both. They have no morphological correlates. In a system epilepsy, local manifestations are possible, and some are due to reflex mechanisms. Of the four reflex epileptic traits common in JME, photosensitivity and praxis induction appear related to basic mechanisms of the core syndrome, whereas language-induced orofacial reflex myocloni and eye closure sensitivity are also seen in other clinical contexts and therefore seem to represent endophenotypes. Cognitive abnormalities indicating slight frontal lobe dysfunction seem to be ubiquitous in JME and are also seen in unaffected siblings of patients. Cluster B personality disorder is found in 1/3 of patients, representing a more severe expression of the underlying pathology. Treatment response and prognosis seem to be affected by an interplay of the described factors producing the severest end of the JME spectrum. The spectrum appears to be due to an interaction of stronger or weaker expression of the core phenotype with various endophenotypes.
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Affiliation(s)
- Betül Baykan
- Istanbul University, Istanbul Faculty of Medicine, Departments of Neurology and Clinical Neurophysiology, Turkey.
| | - Peter Wolf
- Danish Epilepsy Centre, Kolonivej 1, 4293 Dianalund, Denmark; Programa de Pós-Graduação em Ciências Médicas, Universidad Federal de Santa Catarina, Florianópolis, SC, Brazil.
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