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Aslan-Kara K, Dündar-Yenilmez E, Ateş E, Alparslan MM, Peköz T, Bozdemir H, Tuli A. EFHC1 gene mutation profile of Turkish JME patients and its association with disease risk. Seizure 2024; 114:79-83. [PMID: 38088014 DOI: 10.1016/j.seizure.2023.12.002] [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: 08/13/2023] [Revised: 11/28/2023] [Accepted: 12/01/2023] [Indexed: 01/23/2024] Open
Abstract
OBJECTIVES Juvenile myoclonic epilepsy (JME) is a common form of generalized epilepsy with an important genetic component. This cohort study aimed to examine the frequency of EFHC1 gene variants in Turkish JME patients and a healthy control group and evaluate the association between these mutations and disease risk. METHODS We screened 72 JME patients with a mean age of 31.8 ± 9.9 (20-65) years and 35 controls with a mean age of 29.1 ± 7.6 (17-50) years from southern Turkey using direct sequencing analyses. RESULTS EFCH1 single nucleotide variants were detected in 24 of 72 JME patients and 3 of 35 controls. The most common mutations were R182H in JME patients (p = 0.010) and 3'UTR in the control group (p < 0.001). The R182H mutation is a common variant in JME (95 % CI: 1.232-76.580, p = 0.031) and the 3'UTR mutation may be associated with lower risk of JME in the Turkish population (95 % CI: 13.89-166.67, p < 0.001). SIGNIFICANCE Our results indicate that EFHC1 gene variants carry a risk for JME and the 3'UTR variant may have a protective role against JME in the Turkish population. Screening for other genes is needed to further clarify the genetic inheritance of JME in Turkish patients.
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Affiliation(s)
- Kezban Aslan-Kara
- Department of Neurology, School of Medicine, Çukurova University Faculty of Medicine, Sarıçam-Adana 01330, Türkiye.
| | - Ebru Dündar-Yenilmez
- Department of Medical Biochemistry, Çukurova University Faculty of Medicine, Türkiye
| | - Elçin Ateş
- Department of Neurology, School of Medicine, Çukurova University Faculty of Medicine, Sarıçam-Adana 01330, Türkiye
| | | | - Taylan Peköz
- Department of Neurology, School of Medicine, Çukurova University Faculty of Medicine, Sarıçam-Adana 01330, Türkiye
| | - Hacer Bozdemir
- Department of Neurology, School of Medicine, Çukurova University Faculty of Medicine, Sarıçam-Adana 01330, Türkiye
| | - Abdullah Tuli
- Department of Medical Biochemistry, Çukurova University Faculty of Medicine, Türkiye
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Ithal D, Sukumaran SK, Bhattacharjee D, Vemula A, Nadella R, Mahadevan J, Sud R, Viswanath B, Purushottam M, Jain S. Exome hits demystified: The next frontier. Asian J Psychiatr 2021; 59:102640. [PMID: 33892377 DOI: 10.1016/j.ajp.2021.102640] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 03/26/2021] [Indexed: 12/13/2022]
Abstract
Severe mental illnesses such as schizophrenia and bipolar disorder have complex inheritance patterns, involving both common and rare variants. Whole exome sequencing is a promising approach to find out the rare genetic variants. We had previously reported several rare variants in multiplex families with severe mental illnesses. The current article tries to summarise the biological processes and pattern of expression of genes harbouring the aforementioned variants, linking them to known clinical manifestations through a methodical narrative review. Of the 28 genes considered for this review from 7 families with multiple affected individuals, 6 genes are implicated in various neuropsychiatric manifestations including some variations in the brain morphology assessed by magnetic resonance imaging. Another 15 genes, though associated with neuropsychiatric manifestations, did not have established brain morphological changes whereas the remaining 7 genes did not have any previously recorded neuropsychiatric manifestations at all. Wnt/b-catenin signaling pathway was associated with 6 of these genes and PI3K/AKT, calcium signaling, ERK, RhoA and notch signaling pathways had at least 2 gene associations. We present a comprehensive review of biological and clinical knowledge about the genes previously reported in multiplex families with severe mental illness. A 'disease in dish approach' can be helpful to further explore the fundamental mechanisms.
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Affiliation(s)
- Dhruva Ithal
- Department of Psychiatry, National Institute of Mental Health and Neuro Sciences, Bengaluru, Karnataka, India
| | - Salil K Sukumaran
- Department of Psychiatry, National Institute of Mental Health and Neuro Sciences, Bengaluru, Karnataka, India
| | - Debanjan Bhattacharjee
- Department of Psychiatry, National Institute of Mental Health and Neuro Sciences, Bengaluru, Karnataka, India
| | - Alekhya Vemula
- Department of Psychiatry, National Institute of Mental Health and Neuro Sciences, Bengaluru, Karnataka, India
| | - Ravi Nadella
- Department of Psychiatry, National Institute of Mental Health and Neuro Sciences, Bengaluru, Karnataka, India
| | - Jayant Mahadevan
- Department of Psychiatry, National Institute of Mental Health and Neuro Sciences, Bengaluru, Karnataka, India
| | - Reeteka Sud
- Department of Psychiatry, National Institute of Mental Health and Neuro Sciences, Bengaluru, Karnataka, India
| | - Biju Viswanath
- Department of Psychiatry, National Institute of Mental Health and Neuro Sciences, Bengaluru, Karnataka, India
| | - Meera Purushottam
- Department of Psychiatry, National Institute of Mental Health and Neuro Sciences, Bengaluru, Karnataka, India.
| | - Sanjeev Jain
- Department of Psychiatry, National Institute of Mental Health and Neuro Sciences, Bengaluru, Karnataka, India
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Mutational Analysis of Myoclonin1 Gene in Pakistani Juvenile Myoclonic Epilepsy Patients. BIOMED RESEARCH INTERNATIONAL 2021; 2021:7509825. [PMID: 33969125 PMCID: PMC8081613 DOI: 10.1155/2021/7509825] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 02/03/2021] [Accepted: 04/10/2021] [Indexed: 02/06/2023]
Abstract
Juvenile myoclonic epilepsy (JME) is the most prevalent and genetically heterogeneous form of epilepsy and accounts for 10–30% of all the cases worldwide. Ef-hand domain- (c-terminal-) containing protein 1 (EFHC1) encodes for a nonion channel protein and mutations in this gene have been extensively reported in different populations to play a causative role in JME. Linkage between JME and 6p11-12 locus has already been confirmed in Mexican and Dutch families. A case-control study was conducted on Pakistani JME patients for the first time, aimed at finding out EFHC1 mutations that have been reported in different populations. For this purpose, 66 clinically diagnosed JME patients and 108 control subjects were included in the study. Blood samples were collected from all the participants, and DNA was isolated from the lymphocytes by the modified organic method. Total 3 exons of EFHC1, harboring extensively reported mutations, were selected for genotypic analysis. We identified three heterozygous variants, R159W, V460A, P436P, and one insertion in the current study. V460A, an uncommon variant identified herein, has recently been reported in public databases in an unphenotyped American individual. This missense variant was found in 3 Pakistani JME patients from 2 unrelated families. However, in silico analysis showed that V460A may possibly be a neutral variant. While the absence of a majority of previously reported mutations in our population suggests that most of the mutations of EFHC1 are confined to particular ethnicities and are not evenly distributed across the world. However, to imply the causation, the whole gene and larger number of JME patients should be screened in this understudied population.
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Suzuki T, Inoue I, Yamakawa K. Epilepsy protein Efhc1/myoclonin1 is expressed in cells with motile cilia but not in neurons or mitotic apparatuses in brain. Sci Rep 2020; 10:22076. [PMID: 33328576 PMCID: PMC7744795 DOI: 10.1038/s41598-020-79202-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 12/04/2020] [Indexed: 11/09/2022] Open
Abstract
EFHC1 gene encodes the myoclonin1 protein, also known as Rib72-1. Pathogenic variants in EFHC1 have been reported in patients with juvenile myoclonic epilepsy (JME). Although several studies of immunohistological investigations reproducibly showed that the myoclonin1 is expressed in cells with flagella and motile cilia such as sperm, trachea and ependymal cells lining the brain ventricles, whether myoclonin1 is also expressed in neurons still remains controversial. Here we investigated myoclonin1 expression using widely-used polyclonal (mRib72-pAb) and self-made monoclonal (6A3-mAb) anti-myoclonin1 antibodies together with Efhc1 homozygous knock-out (Efhc1-/-) mice. All of the western blot, immunocytochemical, and immunohistochemical analyses showed that mRib72-pAb crossreacts with several mouse proteins besides myoclonin1, while 6A3-mAb specifically recognized myoclonin1 and detected it only in cells with motile cilia but not in neurons. In dividing cells, mRib72-pAb signals were observed at the midbody (intercellular bridge) and mitotic spindle, but 6A3-mAb did not show any signals at these apparatuses. We further found that the complete elimination of myoclonin1 in Efhc1-/- mouse did not critically affect cell division and migration of neurons in cerebral cortex. These results indicate that myoclonin1 is not expressed in neurons, not a regulator of cell division or neuronal migration during cortical development, but expressed in choroid plexus and ependymal cells and suggest that EFHC1 mutation-dependent JME is a motile ciliopathy.
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Affiliation(s)
- Toshimitsu Suzuki
- Department of Neurodevelopmental Disorder Genetics, Institute of Brain Science, Nagoya City University Graduate School of Medical Science, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi, 467-8601, Japan.,Laboratory for Neurogenetics, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan
| | - Ikuyo Inoue
- Laboratory for Neurogenetics, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan
| | - Kazuhiro Yamakawa
- Department of Neurodevelopmental Disorder Genetics, Institute of Brain Science, Nagoya City University Graduate School of Medical Science, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi, 467-8601, Japan. .,Laboratory for Neurogenetics, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan.
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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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Whole exome sequencing identifies a novel SCN1A mutation in genetic (idiopathic) generalized epilepsy and juvenile myoclonic epilepsy subtypes. Neurol Sci 2019; 41:591-598. [DOI: 10.1007/s10072-019-04122-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 10/22/2019] [Indexed: 12/30/2022]
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Gilsoul M, Grisar T, Delgado-Escueta AV, de Nijs L, Lakaye B. Subtle Brain Developmental Abnormalities in the Pathogenesis of Juvenile Myoclonic Epilepsy. Front Cell Neurosci 2019; 13:433. [PMID: 31611775 PMCID: PMC6776584 DOI: 10.3389/fncel.2019.00433] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 09/09/2019] [Indexed: 12/17/2022] Open
Abstract
Juvenile myoclonic epilepsy (JME), a lifelong disorder that starts during adolescence, is the most common of genetic generalized epilepsy syndromes. JME is characterized by awakening myoclonic jerks and myoclonic-tonic-clonic (m-t-c) grand mal convulsions. Unfortunately, one third of JME patients have drug refractory m-t-c convulsions and these recur in 70-80% who attempt to stop antiepileptic drugs (AEDs). Behavioral studies documented impulsivity, but also impairment of executive functions relying on organization and feedback, which points to prefrontal lobe dysfunction. Quantitative voxel-based morphometry (VBM) revealed abnormalities of gray matter (GM) volumes in cortical (frontal and parietal) and subcortical structures (thalamus, putamen, and hippocampus). Proton magnetic resonance spectroscopy (MRS) found evidence of dysfunction of thalamic neurons. White matter (WM) integrity was disrupted in corpus callosum and frontal WM tracts. Magnetic resonance imaging (MRI) further unveiled anomalies in both GM and WM structures that were already present at the time of seizure onset. Aberrant growth trajectories of brain development occurred during the first 2 years of JME diagnosis. Because of genetic origin, disease causing variants were sought, first by positional cloning, and most recently, by next generation sequencing. To date, only six genes harboring pathogenic variants (GABRA1, GABRD, EFHC1, BRD2, CASR, and ICK) with Mendelian and complex inheritance and covering a limited proportion of the world population, are considered as major susceptibility alleles for JME. Evidence on the cellular role, developmental and cell-type expression profiles of these six diverse JME genes, point to their pathogenic variants driving the first steps of brain development when cell division, expansion, axial, and tangential migration of progenitor cells (including interneuron cortical progenitors) sculpture subtle alterations in brain networks and microcircuits during development. These alterations may explain "microdysgenesis" neuropathology, impulsivity, executive dysfunctions, EEG polyspike waves, and awakening m-t-c convulsions observed in JME patients.
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Affiliation(s)
- Maxime Gilsoul
- GIGA-Stem Cells, University of Liège, Liège, Belgium
- GIGA-Neurosciences, University of Liège, Liège, Belgium
- GENESS International Consortium, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Thierry Grisar
- GENESS International Consortium, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Antonio V. Delgado-Escueta
- GENESS International Consortium, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Epilepsy Genetics/Genomics Lab, Neurology and Research Services, VA Greater Los Angeles Healthcare System, Los Angeles, CA, United States
| | - Laurence de Nijs
- GENESS International Consortium, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- School for Mental Health and Neuroscience, Department of Psychiatry and Neuropsychology, Maastricht University, Maastricht, Netherlands
| | - Bernard Lakaye
- GIGA-Stem Cells, University of Liège, Liège, Belgium
- GIGA-Neurosciences, University of Liège, Liège, Belgium
- GENESS International Consortium, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
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