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Jara-Prado A, Guerrero-Camacho JL, Ángeles-López QD, Ochoa-Morales A, Dávila-Ortiz de Montellano DJ, Ramírez-García MÁ, Breda-Yepes M, Durón RM, Delgado-Escueta AV, Barrios-González DA, Martínez-Juárez IE. Association of variants in the ABCB1, CYP2C19 and CYP2C9 genes for Juvenile Myoclonic Epilepsy. Neurol Sci 2024; 45:1635-1643. [PMID: 37875597 DOI: 10.1007/s10072-023-07124-w] [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: 06/15/2023] [Accepted: 10/06/2023] [Indexed: 10/26/2023]
Abstract
Juvenile myoclonic epilepsy (JME) is the most common of the generalized genetic epilepsies, with multiple causal and susceptibility genes; however, its etiopathogenesis is mainly unknown. The toxic effects caused by xenobiotics in cells occur during their metabolic transformation, mainly by enzymes belonging to cytochrome P450. The elimination of these compounds by transporters of the ABC type protects the central nervous system, but their accumulation causes neuronal damage, resulting in neurological diseases. The present study has sought the association between single nucleotide genetic variants of the CYP2C9, CYP2C19, and ABCB1 genes and the development of JME in patients compared to healthy controls. The CC1236 and GG2677 genotypes of ABCB1 in women; allele G 2677, genotypes GG 2677 and CC 3435 in men; the CYP2C19*2A allele, and the CYP2C19*3G/A genotype in both sexes were found to be risk factors for JME. Furthermore, carriers of the TTGGCC genotype combination of the ABCB1 gene (1236/2677/3435) have a 10.5 times higher risk of developing JME than non-carriers. Using the STRING database, we found an interaction between the proteins encoded by these genes and other possible proteins. These findings indicate that the CYP450 system and ABC transporters could interact with other genes in the JME.
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Affiliation(s)
- Aurelio Jara-Prado
- Genetics Department, National Institute of Neurology and Neurosurgery, Mexico City, Mexico
| | | | | | - Adriana Ochoa-Morales
- Genetics Department, National Institute of Neurology and Neurosurgery, Mexico City, Mexico
| | | | | | - Michelle Breda-Yepes
- National Institute of Neurology and Neurosurgery, Epilepsy Clinic, Mexico City, Mexico
| | - Reyna M Durón
- Universidad Tecnológica Centroamericana (UNITEC), Tegucigalpa, Honduras
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2
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Lin ZJ, Li B, Lin PX, Song W, Yan LM, Meng H, He N. Clinical application of trio-based whole-exome sequencing in idiopathic generalized epilepsy. Seizure 2024; 116:24-29. [PMID: 36842888 DOI: 10.1016/j.seizure.2023.02.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/07/2023] [Accepted: 02/10/2023] [Indexed: 02/13/2023] Open
Abstract
PURPOSE Idiopathic generalized epilepsies (IGEs) are a common group of genetic generalized epilepsies with high genetic heterogeneity and complex inheritance. However, the genetic basis is still largely unknown. This study aimed to explore the genetic etiologies in IGEs. METHODS Trio-based whole-exome sequencing was performed in 60 cases with IGEs. The pathogenicity of candidate genetic variants was evaluated by the criteria of the American College of Medical Genetics and Genomics (ACMG), and the clinical causality was assessed by concordance between the observed phenotype and the reported phenotype. RESULTS Seven candidate variants were detected in seven unrelated cases with IGE (11.7%, 7/60). According to ACMG, a de novo SLC2A1 (c.376C>T/p.Arg126Cys) variant identified in childhood absence epilepsy was evaluated as pathogenic with clinical concordance. Six variants were assessed to be uncertain significance by ACMG, but then considered causative after evaluation of clinical concordance. These variants included CLCN4 hemizygous variant (c.2044G>A/p.Glu682Lys) and IQSEC2 heterozygous variant (c.4315C>T/p.Pro1439Ser) in juvenile absence epilepsy, EFHC1 variant (c.1504C>T/p.Arg502Trp) and CACNA1H (c.589G>T/p.Ala197Ser) both with incomplete penetrance in juvenile myoclonic epilepsy, and GRIN2A variant (c.2011C>G/p.Gln671Glu) and GABRB1 variant (c.1075G>A/p.Val359Ile) both co-segregated with juvenile myoclonic epilepsy. Among them, GABRB1 was for the first time identified as potential novel causative gene for IGE. SIGNIFICANCE Considering the genetic heterogeneity and complex inheritance of IGEs, a comprehensive evaluation combined the ACMG scoring and assessment of clinical concordance is suggested for the pathogenicity analysis of variants identified in clinical screening. GABRB1 is probably a novel causative gene for IGE, which warrants further studies.
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Affiliation(s)
- Zhi-Jian Lin
- Department of Neurology, the Affiliated Hospital of Putian University, Putian 351100, Fujian Province, China; Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China
| | - Bin Li
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China
| | - Peng-Xing Lin
- Department of Neurology, the Affiliated Hospital of Putian University, Putian 351100, Fujian Province, China
| | - Wang Song
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China
| | - Li-Min Yan
- Department of Neurology, The Second Affiliated Hospital of Hainan Medical University, 570311 Haikou, Hainan, China
| | - Heng Meng
- Department of Neurology, the First Affiliated Hospital of Jinan University, Guangzhou 510632, China.
| | - Na He
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China.
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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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Alobaidi A, Alsamarai A, Alsamarai MA. Inflammation in Asthma Pathogenesis: Role of T cells, Macrophages, Epithelial Cells and Type 2 Inflammation. Antiinflamm Antiallergy Agents Med Chem 2021; 20:317-332. [PMID: 34544350 DOI: 10.2174/1871523020666210920100707] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 06/06/2021] [Accepted: 06/15/2021] [Indexed: 11/22/2022]
Abstract
Asthma is a chronic disease with abnormal inflammatory and immunological responses. The disease initiated by antigens in subjects with genetic susceptibility. However, environmental factors play a role in the initiation and exacerbation of asthma attack. Asthma is T helper 2 (Th2)-cell-mediated disease. Recent studies indicated that asthma is not a single disease entity, but it is with multiple phenotypes and endotypes. The pathophysiological changes in asthma included a series of subsequent continuous vicious circle of cellular activation contributed to induction of chemokines and cytokines that potentiate inflammation. The heterogeneity of asthma influenced the treatment response. The asthma pathogenesis driven by varied set of cells such as eosinophils, basophils, neutrophils, mast cells, macrophages, epithelial cells and T cells. In this review the role of T cells, macrophage, and epithelial cells are discussed.
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Affiliation(s)
- Amina Alobaidi
- Kirkuk University College of Veterinary Medicine, Kirkuk. Iraq
| | - Abdulghani Alsamarai
- Aalborg Academy College of Medicine [AACOM], Denmark. Tikrit University College of Medicine, [TUCOM], Tikrit. Iraq
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Ascoli M, Mastroianni G, Gasparini S, Striano P, Cianci V, Neri S, Bova V, Mammì A, Gambardella A, Labate A, Aguglia U, Ferlazzo E. Diagnostic and therapeutic approach to drug-resistant juvenile myoclonic epilepsy. Expert Rev Neurother 2021; 21:1265-1273. [PMID: 33993822 DOI: 10.1080/14737175.2021.1931126] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Juvenile myoclonic epilepsy (JME), also known as Janz syndrome, is a common form of generalized epilepsy of presumed genetic origin representing up to 10% of all epilepsy cases. Despite adequate anti-seizure medication (ASM) treatment, seizures persist in one-third of JME patients. AREAS COVERED A literature search was conducted using Pubmed search on the topics of drug-resistant JME. EXPERT OPINION About 30% of JME patients are drug-resistant. Valproate (VPA) is considered the first-choice drug. In women of childbearing potential, levetiracetam (LEV) should represent the first-choice treatment. Alternative monotherapy or add-on therapy should be considered in subjects with resistant seizures after the exclusion of pseudo-drug resistance. The choice of the add-on ASM depends on the predominant seizure type. In subjects with persistent bilateral tonic-clonic seizures, LEV or lamotrigine should be firstly considered. In patients with difficult-to-treat myoclonic seizures, clonazepam or LEV are recommended. In case of persistent absences, ethosuximide should be considered. With appropriate selection and safeguards in place, VPA should remain available as an option in women of childbearing potential whose seizures are resistant to other treatments.
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Affiliation(s)
- Michele Ascoli
- Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy.,Regional Epilepsy Centre, Great Metropolitan Hospital, Via Melacrino, Reggio, Calabria, Italy
| | - Giovanni Mastroianni
- Regional Epilepsy Centre, Great Metropolitan Hospital, Via Melacrino, Reggio, Calabria, Italy
| | - Sara Gasparini
- Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy.,Regional Epilepsy Centre, Great Metropolitan Hospital, Via Melacrino, Reggio, Calabria, Italy
| | - Pasquale Striano
- Paediatric Neurology and Muscular Disease Unit, IRCCS Institute "Giannina Gaslini", Genova, Italy.,Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genova, Genova, Italy
| | - Vittoria Cianci
- Regional Epilepsy Centre, Great Metropolitan Hospital, Via Melacrino, Reggio, Calabria, Italy
| | - Sabrina Neri
- Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy
| | - Valentina Bova
- Regional Epilepsy Centre, Great Metropolitan Hospital, Via Melacrino, Reggio, Calabria, Italy
| | - Anna Mammì
- Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy
| | - Antonio Gambardella
- Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy
| | - Angelo Labate
- Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy
| | - Umberto Aguglia
- Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy.,Regional Epilepsy Centre, Great Metropolitan Hospital, Via Melacrino, Reggio, Calabria, Italy.,Institute of Molecular Bioimaging and Physiology, National Research Council, Viale Europa, Catanzaro, Italy
| | - Edoardo Ferlazzo
- Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy.,Regional Epilepsy Centre, Great Metropolitan Hospital, Via Melacrino, Reggio, Calabria, Italy.,Institute of Molecular Bioimaging and Physiology, National Research Council, Viale Europa, Catanzaro, Italy
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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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8
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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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Heijink IH, Kuchibhotla VNS, Roffel MP, Maes T, Knight DA, Sayers I, Nawijn MC. Epithelial cell dysfunction, a major driver of asthma development. Allergy 2020; 75:1902-1917. [PMID: 32460363 PMCID: PMC7496351 DOI: 10.1111/all.14421] [Citation(s) in RCA: 151] [Impact Index Per Article: 37.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 05/04/2020] [Accepted: 05/12/2020] [Indexed: 12/13/2022]
Abstract
Airway epithelial barrier dysfunction is frequently observed in asthma and may have important implications. The physical barrier function of the airway epithelium is tightly interwoven with its immunomodulatory actions, while abnormal epithelial repair responses may contribute to remodelling of the airway wall. We propose that abnormalities in the airway epithelial barrier play a crucial role in the sensitization to allergens and pathogenesis of asthma. Many of the identified susceptibility genes for asthma are expressed in the airway epithelium, supporting the notion that events at the airway epithelial surface are critical for the development of the disease. However, the exact mechanisms by which the expression of epithelial susceptibility genes translates into a functionally altered response to environmental risk factors of asthma are still unknown. Interactions between genetic factors and epigenetic regulatory mechanisms may be crucial for asthma susceptibility. Understanding these mechanisms may lead to identification of novel targets for asthma intervention by targeting the airway epithelium. Moreover, exciting new insights have come from recent studies using single‐cell RNA sequencing (scRNA‐Seq) to study the airway epithelium in asthma. This review focuses on the role of airway epithelial barrier function in the susceptibility to develop asthma and novel insights in the modulation of epithelial cell dysfunction in asthma.
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Affiliation(s)
- Irene H. Heijink
- Department of Pathology & Medical Biology GRIAC Research Institute University Medical Center Groningen University of Groningen Groningen The Netherlands
- Department of Pulmonology University Medical Center Groningen University of Groningen Groningen The Netherlands
| | - Virinchi N. S. Kuchibhotla
- Department of Pathology & Medical Biology GRIAC Research Institute University Medical Center Groningen University of Groningen Groningen The Netherlands
- School of Biomedical Sciences and Pharmacy University of Newcastle Callaghan NSW Australia
| | - Mirjam P. Roffel
- Department of Pathology & Medical Biology GRIAC Research Institute University Medical Center Groningen University of Groningen Groningen The Netherlands
- Department of Respiratory Medicine Laboratory for Translational Research in Obstructive Pulmonary Diseases Ghent University Hospital Ghent University Ghent Belgium
| | - Tania Maes
- Department of Respiratory Medicine Laboratory for Translational Research in Obstructive Pulmonary Diseases Ghent University Hospital Ghent University Ghent Belgium
| | - Darryl A. Knight
- School of Biomedical Sciences and Pharmacy University of Newcastle Callaghan NSW Australia
- UBC Providence Health Care Research Institute Vancouver BC Canada
- Department of Anesthesiology, Pharmacology and Therapeutics University of British Columbia Vancouver BC Canada
| | - Ian Sayers
- Division of Respiratory Medicine National Institute for Health Research Nottingham Biomedical Research Centre University of Nottingham Biodiscovery Institute University of Nottingham Nottingham UK
| | - Martijn C. Nawijn
- Department of Pathology & Medical Biology GRIAC Research Institute University Medical Center Groningen University of Groningen Groningen The Netherlands
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Crippa M, Malatesta P, Bonati MT, Trapasso F, Fortunato F, Annesi G, Larizza L, Labate A, Finelli P, Perrotti N, Gambardella A. A familial t(4;8) translocation segregates with epilepsy and migraine with aura. Ann Clin Transl Neurol 2020; 7:855-859. [PMID: 32315120 PMCID: PMC7261755 DOI: 10.1002/acn3.51040] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 03/11/2020] [Indexed: 01/03/2023] Open
Abstract
Three relatives carrying a t(4;8)(p15.2;p23.2) translocation had juvenile myoclonic epilepsy, self‐limited photosensitive occipital epilepsy and migraine with aura. The t(4;8) translocation interrupted the coding sequence of CSMD1 gene and occurred immediately to the 3’UTR of STIM2 gene. STIM2 was overexpressed in the patient carrying the unbalanced translocation, and all three individuals had a single functional copy of CSMD1. Array CGH study disclosed that these three individuals also carried a deletion at 5q12.3 that involves the RGS7BP gene. The overall results favor the view that CSMD1, STIM2, and RGS7BP genes could contribute to epilepsy and migraine phenotypes in our family.
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Affiliation(s)
- Milena Crippa
- Research Laboratory of Medical Cytogenetics and Molecular Genetics, IRCCS Istituto Auxologico Italiano, Milan, Italy.,Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Paola Malatesta
- Institute of Medical Genetics, University Magna Graecia, Catanzaro, Italy
| | - Maria Teresa Bonati
- Clinic of Medical Genetics, IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - Francesco Trapasso
- Institute of Medical Genetics, University Magna Graecia, Catanzaro, Italy
| | | | - Grazia Annesi
- Institute of Molecular Bioimaging and Physiology, National Research Council, Catanzaro, Italy
| | - Lidia Larizza
- Research Laboratory of Medical Cytogenetics and Molecular Genetics, IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - Angelo Labate
- Institute of Neurology, University Magna Graecia, Catanzaro, Italy.,Institute of Molecular Bioimaging and Physiology, National Research Council, Catanzaro, Italy
| | - Palma Finelli
- Research Laboratory of Medical Cytogenetics and Molecular Genetics, IRCCS Istituto Auxologico Italiano, Milan, Italy.,Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Nicola Perrotti
- Institute of Medical Genetics, University Magna Graecia, Catanzaro, Italy
| | - Antonio Gambardella
- Institute of Neurology, University Magna Graecia, Catanzaro, Italy.,Institute of Molecular Bioimaging and Physiology, National Research Council, Catanzaro, Italy
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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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The genetic basis of juvenile myoclonic epilepsy. Lancet Neurol 2018; 17:493-495. [DOI: 10.1016/s1474-4422(18)30173-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 04/24/2018] [Indexed: 02/06/2023]
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13
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Raju PK, Satishchandra P, Nayak S, Iyer V, Sinha S, Anand A. Microtubule-associated defects caused by EFHC1
mutations in juvenile myoclonic epilepsy. Hum Mutat 2017; 38:816-826. [DOI: 10.1002/humu.23221] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 03/21/2017] [Accepted: 03/21/2017] [Indexed: 01/06/2023]
Affiliation(s)
- Praveen K Raju
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research; Jakkur Bangalore Karnataka India
| | | | - Sourav Nayak
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research; Jakkur Bangalore Karnataka India
| | - Vishwanathan Iyer
- Department of Neurology; National Institute of Mental Health and Neurosciences; Bangalore Karnataka India
| | - Sanjib Sinha
- Department of Neurology; National Institute of Mental Health and Neurosciences; Bangalore Karnataka India
| | - Anuranjan Anand
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research; Jakkur Bangalore Karnataka India
- Neuroscience Unit; Jawaharlal Nehru Centre for Advanced Scientific Research; Jakkur Bangalore Karnataka India
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Thounaojam R, Langbang L, Itisham K, Sobhani R, Srivastava S, Ramanujam B, Verma R, Tripathi M, Aguan K. EFHC1 mutation in Indian juvenile myoclonic epilepsy patient. Epilepsia Open 2017; 2:84-89. [PMID: 29750216 PMCID: PMC5939392 DOI: 10.1002/epi4.12037] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/12/2016] [Indexed: 12/21/2022] Open
Abstract
Objective Juvenile myoclonic epilepsy (JME) is the most common form of idiopathic generalized epilepsies (IGEs) and is genetically heterogeneous. Mutations in EFHC1 cause JME. Because about 2 million people in India are affected by JME alone, we investigated the prevalence of mutations in the EFHC1 gene in the Indian population with JME. We studied 63 patients with JME and 80 healthy controls. Methods Clinical identification of JME was evaluated using established criteria. Following clinical evaluation of the patients and confirming presence of JME, blood samples were collected from each patient and healthy individual. Subsequently, genomic DNA was extracted from the blood samples. Eleven exons of the EFHC1 gene were individually amplified by polymerase chain reaction (PCR) for each DNA sample. The PCR products were then purified and sequenced commercially. The identified DNA variants were sequenced at least twice in both the forward and reverse directions and compared with the Exome Aggregation Consortium (ExAC) database. Results We found five heterozygous and one homozygous variant. We found three novel coding variants 661C→T, 779 G →A, and 730 C→T, which lead to R221C, R260Q, and R244STOP amino acid substitutions, respectively. The coding variant 475 C→T, resulting in the amino acid substitution R159W, reported earlier as polymorphism, was also identified in both patient and control populations. Significance Detection of these three novel variants, excluding R159W, which is considered polymorphism, expands the range of possible mutations in the EFHC1 gene. The novel variants that we are reporting herein have not been mentioned before as occurring in JME patients of other ethnic population. Therefore, these novel coding variants may be confined to the Indian JME population. Further studies on the mutational spectrum of EFHC1 in a larger number of Indian JME patients concurrent with their mode of inheritance and underlying functional assays should establish whether EFHC1 could be a panethnic gene for JME.
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Affiliation(s)
- Romita Thounaojam
- Department of Biotechnology and Bioinformatics North Eastern Hill University (NEHU) Shillong India
| | - Leader Langbang
- Department of Biotechnology and Bioinformatics North Eastern Hill University (NEHU) Shillong India
| | - Kavish Itisham
- Department of Neurology Neurosciences Centre All India Institute of Medical Sciences (AIIMS) New Delhi India
| | - Roohollah Sobhani
- Department of Biotechnology and Bioinformatics North Eastern Hill University (NEHU) Shillong India
| | - Shivani Srivastava
- Department of Neurology Neurosciences Centre All India Institute of Medical Sciences (AIIMS) New Delhi India
| | - Bhargavi Ramanujam
- Department of Neurology Neurosciences Centre All India Institute of Medical Sciences (AIIMS) New Delhi India
| | - Ramesh Verma
- Department of Neurology Neurosciences Centre All India Institute of Medical Sciences (AIIMS) New Delhi India
| | - Manjari Tripathi
- Department of Neurology Neurosciences Centre All India Institute of Medical Sciences (AIIMS) New Delhi India
| | - Kripamoy Aguan
- Department of Biotechnology and Bioinformatics North Eastern Hill University (NEHU) Shillong India
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EFHC1 variants in juvenile myoclonic epilepsy: reanalysis according to NHGRI and ACMG guidelines for assigning disease causality. Genet Med 2016; 19:144-156. [PMID: 27467453 DOI: 10.1038/gim.2016.86] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 05/09/2016] [Indexed: 12/12/2022] Open
Abstract
PURPOSE EFHC1 variants are the most common mutations in inherited myoclonic and grand mal clonic-tonic-clonic (CTC) convulsions of juvenile myoclonic epilepsy (JME). We reanalyzed 54 EFHC1 variants associated with epilepsy from 17 cohorts based on National Human Genome Research Institute (NHGRI) and American College of Medical Genetics and Genomics (ACMG) guidelines for interpretation of sequence variants. METHODS We calculated Bayesian LOD scores for variants in coinheritance, unconditional exact tests and odds ratios (OR) in case-control associations, allele frequencies in genome databases, and predictions for conservation/pathogenicity. We reviewed whether variants damage EFHC1 functions, whether efhc1-/- KO mice recapitulate CTC convulsions and "microdysgenesis" neuropathology, and whether supernumerary synaptic and dendritic phenotypes can be rescued in the fly model when EFHC1 is overexpressed. We rated strengths of evidence and applied ACMG combinatorial criteria for classifying variants. RESULTS Nine variants were classified as "pathogenic," 14 as "likely pathogenic," 9 as "benign," and 2 as "likely benign." Twenty variants of unknown significance had an insufficient number of ancestry-matched controls, but ORs exceeded 5 when compared with racial/ethnic-matched Exome Aggregation Consortium (ExAC) controls. CONCLUSIONS NHGRI gene-level evidence and variant-level evidence establish EFHC1 as the first non-ion channel microtubule-associated protein whose mutations disturb R-type VDCC and TRPM2 calcium currents in overgrown synapses and dendrites within abnormally migrated dislocated neurons, thus explaining CTC convulsions and "microdysgenesis" neuropathology of JME.Genet Med 19 2, 144-156.
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Wight JE, Nguyen V, Medina MT, Patterson C, Durón RM, Molina Y, Lin Y, Martínez‐Juárez IE, Ochoa A, Jara‐Prado A, Tanaka M, Bai D, Aftab S, Bailey JN, Delgado‐Escueta AV. Chromosome loci vary by juvenile myoclonic epilepsy subsyndromes: linkage and haplotype analysis applied to epilepsy and EEG 3.5-6.0 Hz polyspike waves. Mol Genet Genomic Med 2016; 4:197-210. [PMID: 27066514 PMCID: PMC4799870 DOI: 10.1002/mgg3.195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 11/09/2015] [Accepted: 11/12/2015] [Indexed: 12/15/2022] Open
Abstract
Juvenile myoclonic epilepsy (JME), the most common genetic epilepsy, remains enigmatic because it is considered one disease instead of several diseases. We ascertained three large multigenerational/multiplex JME pedigrees from Honduras with differing JME subsyndromes, including Childhood Absence Epilepsy evolving to JME (CAE/JME; pedigree 1), JME with adolescent onset pyknoleptic absence (JME/pA; pedigree 2), and classic JME (cJME; pedigree 3). All phenotypes were validated, including symptomatic persons with various epilepsies, asymptomatic persons with EEG 3.5-6.0 Hz polyspike waves, and asymptomatic persons with normal EEGs. Two-point parametric linkage analyses were performed with 5185 single-nucleotide polymorphisms on individual pedigrees and pooled pedigrees using four diagnostic models based on epilepsy/EEG diagnoses. Haplotype analyses of the entire genome were also performed for each individual. In pedigree 1, haplotyping identified a 34 cM region in 2q21.2-q31.1 cosegregating with all affected members, an area close to 2q14.3 identified by linkage (Z max = 1.77; pedigree 1). In pedigree 2, linkage and haplotyping identified a 44 cM cosegregating region in 13q13.3-q31.2 (Z max = 3.50 at 13q31.1; pooled pedigrees). In pedigree 3, haplotyping identified a 6 cM cosegregating region in 17q12. Possible cosegregation was also identified in 13q14.2 and 1q32 in pedigree 3, although this could not be definitively confirmed due to the presence of uninformative markers in key individuals. Differing chromosome regions identified in specific JME subsyndromes may contain separate JME disease-causing genes, favoring the concept of JME as several distinct diseases. Whole-exome sequencing will likely identify a CAE/JME gene in 2q21.2-2q31.1, a JME/pA gene in 13q13.3-q31.2, and a cJME gene in 17q12.
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Affiliation(s)
- Jenny E. Wight
- Epilepsy Genetics/Genomics LaboratoriesVA GLAHS – West Los AngelesLos AngelesCalifornia
- GENESS International ConsortiumLos AngelesCalifornia
| | - Viet‐Huong Nguyen
- Epilepsy Genetics/Genomics LaboratoriesVA GLAHS – West Los AngelesLos AngelesCalifornia
- GENESS International ConsortiumLos AngelesCalifornia
| | - Marco T. Medina
- GENESS International ConsortiumLos AngelesCalifornia
- National Autonomous University of HondurasTegucigalpaHonduras
| | - Christopher Patterson
- Epilepsy Genetics/Genomics LaboratoriesVA GLAHS – West Los AngelesLos AngelesCalifornia
- GENESS International ConsortiumLos AngelesCalifornia
| | - Reyna M. Durón
- Epilepsy Genetics/Genomics LaboratoriesVA GLAHS – West Los AngelesLos AngelesCalifornia
- GENESS International ConsortiumLos AngelesCalifornia
- National Autonomous University of HondurasTegucigalpaHonduras
- Universidad Tecnológica Centroamericana (UNITEC)TegucigalpaHonduras
- Department of NeurologyDavid Geffen School of Medicine at UCLALos AngelesCalifornia
| | - Yolly Molina
- GENESS International ConsortiumLos AngelesCalifornia
- National Autonomous University of HondurasTegucigalpaHonduras
| | - Yu‐Chen Lin
- Epilepsy Genetics/Genomics LaboratoriesVA GLAHS – West Los AngelesLos AngelesCalifornia
- GENESS International ConsortiumLos AngelesCalifornia
| | - Iris E. Martínez‐Juárez
- GENESS International ConsortiumLos AngelesCalifornia
- National Institute of Neurology and NeurosurgeryMexico CityMexico
| | - Adriana Ochoa
- GENESS International ConsortiumLos AngelesCalifornia
- National Institute of Neurology and NeurosurgeryMexico CityMexico
| | - Aurelio Jara‐Prado
- GENESS International ConsortiumLos AngelesCalifornia
- National Institute of Neurology and NeurosurgeryMexico CityMexico
| | - Miyabi Tanaka
- Epilepsy Genetics/Genomics LaboratoriesVA GLAHS – West Los AngelesLos AngelesCalifornia
- GENESS International ConsortiumLos AngelesCalifornia
- Department of NeurologyDavid Geffen School of Medicine at UCLALos AngelesCalifornia
| | - Dongsheng Bai
- Epilepsy Genetics/Genomics LaboratoriesVA GLAHS – West Los AngelesLos AngelesCalifornia
- GENESS International ConsortiumLos AngelesCalifornia
- Department of NeurologyDavid Geffen School of Medicine at UCLALos AngelesCalifornia
| | - Sumaya Aftab
- Epilepsy Genetics/Genomics LaboratoriesVA GLAHS – West Los AngelesLos AngelesCalifornia
- GENESS International ConsortiumLos AngelesCalifornia
- Department of NeurologyDavid Geffen School of Medicine at UCLALos AngelesCalifornia
| | - Julia N. Bailey
- Epilepsy Genetics/Genomics LaboratoriesVA GLAHS – West Los AngelesLos AngelesCalifornia
- GENESS International ConsortiumLos AngelesCalifornia
- Department of EpidemiologyFielding School of Public Health at UCLALos AngelesCalifornia
| | - Antonio V. Delgado‐Escueta
- Epilepsy Genetics/Genomics LaboratoriesVA GLAHS – West Los AngelesLos AngelesCalifornia
- GENESS International ConsortiumLos AngelesCalifornia
- Department of NeurologyDavid Geffen School of Medicine at UCLALos AngelesCalifornia
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Meta-analysis identifies seven susceptibility loci involved in the atopic march. Nat Commun 2015; 6:8804. [PMID: 26542096 PMCID: PMC4667629 DOI: 10.1038/ncomms9804] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 10/06/2015] [Indexed: 12/20/2022] Open
Abstract
Eczema often precedes the development of asthma in a disease course called the ‘atopic march'. To unravel the genes underlying this characteristic pattern of allergic disease, we conduct a multi-stage genome-wide association study on infantile eczema followed by childhood asthma in 12 populations including 2,428 cases and 17,034 controls. Here we report two novel loci specific for the combined eczema plus asthma phenotype, which are associated with allergic disease for the first time; rs9357733 located in EFHC1 on chromosome 6p12.3 (OR 1.27; P=2.1 × 10−8) and rs993226 between TMTC2 and SLC6A15 on chromosome 12q21.3 (OR 1.58; P=5.3 × 10−9). Additional susceptibility loci identified at genome-wide significance are FLG (1q21.3), IL4/KIF3A (5q31.1), AP5B1/OVOL1 (11q13.1), C11orf30/LRRC32 (11q13.5) and IKZF3 (17q21). We show that predominantly eczema loci increase the risk for the atopic march. Our findings suggest that eczema may play an important role in the development of asthma after eczema. The development of asthma following eczema is known as the atopic march. Here the authors conduct a GWAS on affected children and identify two novel loci associated with the disease phenotype.
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Lesca G, Depienne C. Epilepsy genetics: the ongoing revolution. Rev Neurol (Paris) 2015; 171:539-57. [PMID: 26003806 DOI: 10.1016/j.neurol.2015.01.569] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 12/24/2014] [Accepted: 01/20/2015] [Indexed: 01/04/2023]
Abstract
Epilepsies have long remained refractory to gene identification due to several obstacles, including a highly variable inter- and intrafamilial expressivity of the phenotypes, a high frequency of phenocopies, and a huge genetic heterogeneity. Recent technological breakthroughs, such as array comparative genomic hybridization and next generation sequencing, have been leading, in the past few years, to the identification of an increasing number of genomic regions and genes in which mutations or copy-number variations cause various epileptic disorders, revealing an enormous diversity of pathophysiological mechanisms. The field that has undergone the most striking revolution is that of epileptic encephalopathies, for which most of causing genes have been discovered since the year 2012. Some examples are the continuous spike-and-waves during slow-wave sleep and Landau-Kleffner syndromes for which the recent discovery of the role of GRIN2A mutations has finally confirmed the genetic bases. These new technologies begin to be used for diagnostic applications, and the main challenge now resides in the interpretation of the huge mass of variants detected by these methods. The identification of causative mutations in epilepsies provides definitive confirmation of the clinical diagnosis, allows accurate genetic counselling, and sometimes permits the development of new appropriate and specific antiepileptic therapies. Future challenges include the identification of the genetic or environmental factors that modify the epileptic phenotypes caused by mutations in a given gene and the understanding of the role of somatic mutations in sporadic epilepsies.
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Affiliation(s)
- G Lesca
- Service de génétique, groupement hospitalier Est, hospices civils de Lyon, 59, boulevard Pinel, 69677 Bron, France; Université Claude-Bernard Lyon 1, 43, boulevard du 11-Novembre-1918, 69100 Villeurbanne, France; CRNL, CNRS UMR 5292, Inserm U1028, bâtiment IMBL, 11, avenue Jean-Capelle, 69621 Villeurbanne cedex, France.
| | - C Depienne
- Département de génétique et cytogénétique, hôpital Pitié-Salpêtrière, AP-HP, 47-83, boulevard de l'Hôpital, 75651 Paris cedex 13, France; Sorbonne universités, UPMC université Paris 06, 4, place Jussieu, 75005 Paris, France; ICM, CNRS UMR 7225, Inserm U1127, 47, boulevard de l'Hôpital, 75651 Paris cedex 13, France
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Mumoli L, Tarantino P, Michelucci R, Bianchi A, Labate A, Franceschetti S, Marini C, Striano P, Gagliardi M, Ferlazzo E, Sofia V, Pennese L, Annesi G, Aguglia U, Guerrini R, Zara F, Gambardella A. No evidence of a role for cystatin B gene in juvenile myoclonic epilepsy. Epilepsia 2015; 56:e40-3. [DOI: 10.1111/epi.12944] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/20/2015] [Indexed: 11/30/2022]
Affiliation(s)
- Laura Mumoli
- Institute of Neurology; University Magna Graecia Catanzaro; Catanzaro Italy
| | - Patrizia Tarantino
- Institute of Molecular Bioimaging and Physiology; Section of Germaneto; National Research Council; Catanzaro Italy
| | - Roberto Michelucci
- Division of Neurology; IRCCS-Institute of Neurological Sciences of Bologna; Bellaria Hospital; Bologna Italy
| | - Amedeo Bianchi
- Division of Neurology; Hospital San Donato Arezzo; Arezzo Italy
| | - Angelo Labate
- Institute of Neurology; University Magna Graecia Catanzaro; Catanzaro Italy
- Institute of Molecular Bioimaging and Physiology; Section of Germaneto; National Research Council; Catanzaro Italy
| | - Silvana Franceschetti
- Department of Neurophysiopathology and Epilepsy Centre; IRCCS Foundation C. Besta Neurological Institute; Milan Italy
| | - Carla Marini
- Pediatric Neurology Unit; Neuroscience Department; Children's Hospital A. Meyer-University of Florence; Firenze Italy
| | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit; Department of Neurosciences Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health; G. Gaslini Institute; University of Genoa; Genoa Italy
| | - Monica Gagliardi
- Institute of Neurology; University Magna Graecia Catanzaro; Catanzaro Italy
- Institute of Molecular Bioimaging and Physiology; Section of Germaneto; National Research Council; Catanzaro Italy
| | - Edoardo Ferlazzo
- Institute of Neurology; University Magna Graecia Catanzaro; Catanzaro Italy
- Regional Epilepsy Center; Hospital of Reggio Calabria; Reggio Calabria; Italy
| | - Vito Sofia
- Section of Neurosciences; Department GF Ingrassia; University of Catania; Catania Italy
| | - Loredana Pennese
- Pediatric Neurology and Muscular Diseases Unit; Department of Neurosciences Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health; G. Gaslini Institute; University of Genoa; Genoa Italy
| | - Grazia Annesi
- Institute of Molecular Bioimaging and Physiology; Section of Germaneto; National Research Council; Catanzaro Italy
| | - Umberto Aguglia
- Institute of Neurology; University Magna Graecia Catanzaro; Catanzaro Italy
- Regional Epilepsy Center; Hospital of Reggio Calabria; Reggio Calabria; Italy
| | - Renzo Guerrini
- Pediatric Neurology Unit; Neuroscience Department; Children's Hospital A. Meyer-University of Florence; Firenze Italy
| | - Federico Zara
- Pediatric Neurology and Muscular Diseases Unit; Department of Neurosciences Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health; G. Gaslini Institute; University of Genoa; Genoa Italy
| | - Antonio Gambardella
- Institute of Neurology; University Magna Graecia Catanzaro; Catanzaro Italy
- Institute of Molecular Bioimaging and Physiology; Section of Germaneto; National Research Council; Catanzaro Italy
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von Podewils F, Kowoll V, Schroeder W, Geithner J, Wang ZI, Gaida B, Bombach P, Kessler C, Felbor U, Runge U. Predictive value of EFHC1 variants for the long-term seizure outcome in juvenile myoclonic epilepsy. Epilepsy Behav 2015; 44:61-6. [PMID: 25625532 DOI: 10.1016/j.yebeh.2014.12.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 12/12/2014] [Accepted: 12/13/2014] [Indexed: 11/30/2022]
Abstract
OBJECTIVE This study aimed to determine the contribution of EFHC1 variants to the phenotypic variability of juvenile myoclonic epilepsy (JME) and to evaluate their diagnostic value regarding previously identified clinical long-term seizure outcome predictors in a consecutive cohort of patients with JME. METHODS Thirty-eight probands and three family members affected with JME were studied at a tertiary epilepsy center with a review of their medical records and a subsequent face-to-face interview. All coding EFHC1 exons and adjacent exon/intron boundaries were directly sequenced. RESULTS The previously reported EFHC1 mutation F229L was found in two cases who presented with early generalized tonic-clonic seizure (GTCS) onset and appeared to be associated with milder subtypes of JME. Variant R294H was identified in two further probands who had a subtype of JME developing from childhood absence epilepsy. However, segregation of the phenotype with this variant could not be confirmed in one family. CONCLUSIONS Our findings corroborate the heterogeneity of JME as an electroclinical epilepsy syndrome and provide evidence that genetic factors may influence and help predict the long-term seizure outcome in patients with JME.
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Affiliation(s)
- Felix von Podewils
- Department of Neurology, Epilepsy Center, University of Greifswald, Greifswald, Germany.
| | - Victoria Kowoll
- Department of Neurology, Epilepsy Center, University of Greifswald, Greifswald, Germany
| | - Winnie Schroeder
- Department of Human Genetics, University Medicine Greifswald and Interfaculty Institute of Genetics and Functional Genomics, Ernst Moritz Arndt University, Greifswald, Germany
| | - Julia Geithner
- Department of Neurology, Epilepsy Center, University of Greifswald, Greifswald, Germany; Epilepsy Center Berlin-Brandenburg, Berlin, Germany
| | - Zhong I Wang
- Epilepsy Center, Neurological Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Bernadette Gaida
- Department of Neurology, Epilepsy Center, University of Greifswald, Greifswald, Germany
| | - Paula Bombach
- Department of Neurology, Epilepsy Center, University of Greifswald, Greifswald, Germany
| | - Christof Kessler
- Department of Neurology, Epilepsy Center, University of Greifswald, Greifswald, Germany
| | - Ute Felbor
- Department of Human Genetics, University Medicine Greifswald and Interfaculty Institute of Genetics and Functional Genomics, Ernst Moritz Arndt University, Greifswald, Germany
| | - Uwe Runge
- Department of Neurology, Epilepsy Center, University of Greifswald, Greifswald, Germany
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van Luijtelaar G, Onat FY, Gallagher MJ. Animal models of absence epilepsies: what do they model and do sex and sex hormones matter? Neurobiol Dis 2014; 72 Pt B:167-79. [PMID: 25132554 DOI: 10.1016/j.nbd.2014.08.014] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 08/05/2014] [Accepted: 08/07/2014] [Indexed: 11/28/2022] Open
Abstract
While epidemiological data suggest a female prevalence in human childhood- and adolescence-onset typical absence epilepsy syndromes, the sex difference is less clear in adult-onset syndromes. In addition, although there are more females than males diagnosed with typical absence epilepsy syndromes, there is a paucity of studies on sex differences in seizure frequency and semiology in patients diagnosed with any absence epilepsy syndrome. Moreover, it is unknown if there are sex differences in the prevalence or expression of atypical absence epilepsy syndromes. Surprisingly, most studies of animal models of absence epilepsy either did not investigate sex differences, or failed to find sex-dependent effects. However, various rodent models for atypical syndromes such as the AY9944 model (prepubertal females show a higher incidence than prepubertal males), BN model (also with a higher prevalence in males) and the Gabra1 deletion mouse in the C57BL/6J strain offer unique possibilities for the investigation of the mechanisms involved in sex differences. Although the mechanistic bases for the sex differences in humans or these three models are not yet known, studies of the effects of sex hormones on seizures have offered some possibilities. The sex hormones progesterone, estradiol and testosterone exert diametrically opposite effects in genetic absence epilepsy and pharmacologically-evoked convulsive types of epilepsy models. In addition, acute pharmacological effects of progesterone on absence seizures during proestrus are opposite to those seen during pregnancy. 17β-Estradiol has anti-absence seizure effects, but it is only active in atypical absence models. It is speculated that the pro-absence action of progesterone, and perhaps also the delayed pro-absence action of testosterone, are mediated through the neurosteroid allopregnanolone and its structural and functional homolog, androstanediol. These two steroids increase extrasynaptic thalamic tonic GABAergic inhibition by selectively targeting neurosteroid-selective subunits of GABAA receptors (GABAARs). Neurosteroids also modulate the expression of GABAAR containing the γ2, α4, and δ subunits. It is hypothesized that differences in subunit expression during pregnancy and ovarian cycle contribute to the opposite effects of progesterone in these two hormonal states.
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Affiliation(s)
- Gilles van Luijtelaar
- Donders Centre of Cognition, Radboud University Nijmegen, Nijmegen, The Netherlands.
| | - Filiz Yilmaz Onat
- Department of Pharmacology, School of Medicine, Marmara University, Istanbul, Turkey
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Koepp MJ, Thomas RH, Wandschneider B, Berkovic SF, Schmidt D. Concepts and controversies of juvenile myoclonic epilepsy: still an enigmatic epilepsy. Expert Rev Neurother 2014; 14:819-31. [DOI: 10.1586/14737175.2014.928203] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Abstract
Epileptic myoclonus can be defined as an elementary electroclinical manifestation of epilepsy involving descending neurons, whose spatial (spread) or temporal (self-sustained repetition) amplification can trigger overt epileptic activity and can be classified as cortical (positive and negative), secondarily generalized, thalamo-cortical, and reticular. Cortical epileptic myoclonus represents a fragment of partial or symptomatic generalized epilepsy; thalamo-cortical epileptic myoclonus is a fragment of idiopathic generalized epilepsy. Reflex reticular myoclonus represents the clinical counterpart of fragments of hypersynchronous epileptic activity of neurons in the brainstem reticular formation. Epileptic myoclonus, in the setting of an epilepsy syndrome, can be only one component of a seizure, the only seizure manifestations, one of the multiple seizure types or a more stable condition that is manifested in a nonparoxysmal fashion and mimics a movement disorder. This complex correlation is more obvious in patients with epilepsia partialis continua in which cortical myoclonus and overt focal motor seizures usually start in the same somatic (and cortical) region. In patients with cortical tremor this correlation is less obvious and requires neurophysiological studies to be demonstrated.
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Affiliation(s)
- Renzo Guerrini
- Pediatric Neurology Unit and Laboratories, Children's Hospital A. Meyer - University of Florence, Florence, Italy.
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de Nijs L, Wolkoff N, Coumans B, Delgado-Escueta AV, Grisar T, Lakaye B. Mutations of EFHC1, linked to juvenile myoclonic epilepsy, disrupt radial and tangential migrations during brain development. Hum Mol Genet 2012; 21:5106-17. [PMID: 22926142 DOI: 10.1093/hmg/dds356] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Heterozygous mutations in Myoclonin1/EFHC1 cause juvenile myoclonic epilepsy (JME), the most common form of genetic generalized epilepsies, while homozygous F229L mutation is associated with primary intractable epilepsy in infancy. Heterozygous mutations in adolescent JME patients produce subtle malformations of cortical and subcortical architecture, whereas homozygous F229L mutation in infancy induces severe brain pathology and death. However, the underlying pathological mechanisms for these observations remain unknown. We had previously demonstrated that EFHC1 is a microtubule-associated protein (MAP) involved in cell division and radial migration during cerebral corticogenesis. Here, we show that JME mutations, including F229L, do not alter the ability of EFHC1 to colocalize with the centrosome and the mitotic spindle, but act in a dominant-negative manner to impair mitotic spindle organization. We also found that mutants EFHC1 expression disrupted radial and tangential migration by affecting the morphology of radial glia and migrating neurons. These results show how Myoclonin1/EFHC1 mutations disrupt brain development and potentially produce structural brain abnormalities on which epileptogenesis is established.
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Jara-Prado A, Martínez-Juárez IE, Ochoa A, González VM, Fernández-González-Aragón MDC, López-Ruiz M, Medina MT, Bailey JN, Delgado-Escueta AV, Alonso ME. Novel Myoclonin1/EFHC1 mutations in Mexican patients with juvenile myoclonic epilepsy. Seizure 2012; 21:550-4. [PMID: 22727576 DOI: 10.1016/j.seizure.2012.05.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 05/28/2012] [Accepted: 05/29/2012] [Indexed: 11/25/2022] Open
Abstract
PURPOSE The purpose of this study was to identify the prevalence of mutations in the Myoclonin1/EFHC1 gene in Mexican patients with juvenile myoclonic epilepsy (JME). METHOD We studied forty-one patients at the National Institute of Neurology and Neurosurgery in Mexico City and 100 healthy controls. DNA was extracted from the peripheral venous blood of all participants. The exons of EFHC1 were then amplified and sequenced. RESULTS We found three new putative mutations, all of which were heterozygous missense mutations located in exon 3. The first identified mutation, 352C>T, produces a R118C change in the protein and cosegregated in the patient's affected father and brother. The second identified mutation, 544C>T, produces a R182L change in the protein and was found in the patient's asymptomatic father. The third identified mutation, 458>A, produces a R153Q change in the protein and was also found in the patient's father. These mutations were not found in controls. CONCLUSIONS The frequency of Myoclonin1/EFHC1 mutations in our sample is 7.3%. Thus, we conclude that mutations in the Myoclonin1/EFHC1 gene are an important cause of JME in Mexican patients.
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Affiliation(s)
- Aurelio Jara-Prado
- Neurogenetics and Molecular Biology Department, National Institute of Neurology and Neurosurgery of Mexico, Insurgentes Sur 3877, Col. La Fama, Tlalpan, México D.F. 14269, Mexico.
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Rossetto MG, Zanarella E, Orso G, Scorzeto M, Megighian A, Kumar V, Delgado-Escueta AV, Daga A. Defhc1.1, a homologue of the juvenile myoclonic gene EFHC1, modulates architecture and basal activity of the neuromuscular junction in Drosophila. Hum Mol Genet 2011; 20:4248-57. [PMID: 21835885 DOI: 10.1093/hmg/ddr352] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Mutations in the EFHC1 gene have been linked to juvenile myoclonic epilepsy. To understand EFHC1 function in vivo, we generated knockout Drosophila for the fly homolog Defhc1.1. We found that the neuromuscular junction synapse of Defhc1.1 mutants displays an increased number of satellite boutons resulting in increased spontaneous neurotransmitter release. Defhc1.1 binds to microtubules in vitro and overlaps in vivo with axonal and synaptic microtubules. Elimination of Defhc1.1 from synaptic terminals reduces the number of microtubule loops, suggesting that Defhc1.1 is a negative regulator of microtubule dynamics. In fact, pharmacological treatment of Defhc1.1 mutants with vinblastine, an inhibitor of microtubule dynamics, suppresses the satellite bouton phenotype. Furthermore, Defhc1.1 mutants display overgrowth of the dendritic arbor and Defhc1.1 overexpression reduces dendrite elaboration. These results suggest that Defhc1.1 functions as an inhibitor of neurite growth by finely tuning the microtubule cytoskeleton dynamics and that EFHC1-dependent juvenile myoclonic epilepsy may result from augmented spontaneous neurotransmitter release due to overgrowth of neuronal processes.
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Layouni S, Salzmann A, Guipponi M, Mouthon D, Chouchane L, Dogui M, Malafosse A. Genetic linkage study of an autosomal recessive form of juvenile myoclonic epilepsy in a consanguineous Tunisian family. Epilepsy Res 2010; 90:33-8. [PMID: 20378313 DOI: 10.1016/j.eplepsyres.2010.03.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2009] [Revised: 03/01/2010] [Accepted: 03/07/2010] [Indexed: 11/15/2022]
Abstract
Juvenile myoclonic epilepsy (JME) is the most common idiopathic generalized epilepsies (IGEs), affecting 12-30% of all epilepsies in medical centers. To date genetic linkage studies have revealed putative loci on different chromosomes, but these findings are still inconclusive about which gene precisely is responsible for the disease. Here, we report the genetic and clinical analysis of a (JME) consanguineous Tunisian family with four affected children out of eight. A genome-wide search was carried out by using the Affymetrix GeneChip Mapping 500K NspI chip. Pairewise logarithm of the odds (LOD) scores were calculated with MERLIN (1.1) assuming an autosomal recessive model, and a complementary homozygous mapping analysis was performed with AutoSNPa software. The genome-wide parametric linkage analysis showed suggestive linkage to chromosome 2q. Interactive visual analysis of SNP data using AutoSNPa revealed two large regions of shared homozygosity by descent on 2q23.3 and on 2q24.1. We decided to sequence the exons of the two genes coding for such proteins located in 2q23.3, CACNB4 and 2q24.1, KCNJ3. No nucleotide variation--comprising the previously reported mutations--was detected.
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Affiliation(s)
- Samia Layouni
- Department of Physiology, Faculty of Medicine, Monastir, Tunisia.
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de Nijs L, Léon C, Nguyen L, Loturco JJ, Delgado-Escueta AV, Grisar T, Lakaye B. EFHC1 interacts with microtubules to regulate cell division and cortical development. Nat Neurosci 2009; 12:1266-74. [PMID: 19734894 DOI: 10.1038/nn.2390] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2009] [Accepted: 08/04/2009] [Indexed: 12/29/2022]
Abstract
Mutations in the EFHC1 gene are linked to juvenile myoclonic epilepsy (JME), one of the most frequent forms of idiopathic generalized epilepsies. JME is associated with subtle alterations of cortical and subcortical architecture, but the underlying pathological mechanism remains unknown. We found that EFHC1 is a microtubule-associated protein involved in the regulation of cell division. In vitro, EFHC1 loss of function disrupted mitotic spindle organization, impaired M phase progression, induced microtubule bundling and increased apoptosis. EFHC1 impairment in the rat developing neocortex by ex vivo and in utero electroporation caused a marked disruption of radial migration. We found that this effect was a result of cortical progenitors failing to exit the cell cycle and defects in the radial glia scaffold organization and in the locomotion of postmitotic neurons. Therefore, we propose that EFHC1 is a regulator of cell division and neuronal migration during cortical development and that disruption of its functions leads to JME.
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Bai D, Bailey JN, Durón RM, Alonso ME, Medina MT, Martínez-Juárez IE, Suzuki T, Machado-Salas J, Ramos-Ramírez R, Tanaka M, Ortega RHC, López-Ruiz M, Rasmussen A, Ochoa A, Jara-Prado A, Yamakawa K, Delgado-Escueta AV. DNA variants in coding region of EFHC1: SNPs do not associate with juvenile myoclonic epilepsy. Epilepsia 2009; 50:1184-90. [PMID: 18823326 DOI: 10.1111/j.1528-1167.2008.01762.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE Juvenile myoclonic epilepsy (JME) accounts for 3 to 12% of all epilepsies. In 2004, we identified a mutation-harboring Mendelian gene that encodes a protein with one EF-hand motif (EFHC1) in chromosome 6p12. We observed one doubly heterozygous and three heterozygous missense mutations in EFHC1 segregating as an autosomal dominant gene with 21 affected members of six Hispanic JME families from California and Mexico. In 2006, similar and three novel missense mutations were reported in sporadic and familial Caucasian JME from Italy and Austria. In this study, we asked if coding single nucleotide polymorphisms (SNPs) of EFHC1 also contribute as susceptibility alleles to JME with complex genetics. METHODS We screened using denaturing high-performance liquid chromatography (DHPLC) and then directly sequenced the 11 exons of EFHC1 in 130 unrelated JME probands, their 352 family members, and seven exons of EFHC1 in 400-614 ethnically matched controls. We carried out case-control association studies between 124 unrelated Hispanic JME probands and 552-614 ethnically matched controls using four SNPs, rs3804506, rs3804505, rs1266787, and rs17851770. We also performed family-based association on SNPs rs3804506 and rs3804505 in 84 complete JME families using the Family-Based Association Test (FBAT) program. RESULTS We found no statistically significant differences between JME probands and controls in case-control association and no genetic transmission disequilibria in family-based association for the tested SNPs. In addition, we identified four new DNA variants in the coding region of EFHC1. CONCLUSION The four coding SNPs, rs3804506, rs3804505, rs1266787, and rs17851770, of EFHC1 may not be susceptibility alleles for JME.
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Affiliation(s)
- Dongsheng Bai
- Epilepsy Genetics/Genomics Lab, CEP, UCLA & VA GLAHS, Los Angeles, California 90073, USA
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Abstract
OBJECTIVE This article aimed to review the latest genes associated with idiopathic focal and generalized epilepsies. METHODS PubMed and Entrez Gene searches pertaining to this work was conducted using specific keyword search terms related to genes and various listed subtopics related to idiopathic epilepsy syndromes. RESULTS Mutations in the cholinergic receptor, neuronal nicotinic, alpha2, alpha4 and beta2 subunit genes have been found in autosomal dominant nocturnal frontal lobe epilepsy. Mutations of potassium voltage-gated channel, KQT-like subfamily, members 2 and 3 genes were identified to be responsible for benign familial neonatal seizures. The voltage-gated sodium channel genes and gamma-aminobutyric acid receptor alpha subunit genes may be involved in the pathogenesis of generalized epilepsy with febrile seizure plus. Mutations of gamma-aminobutyric acid receptor alpha1, gamma-aminobutyric acid receptor delta, calcium channel voltage-dependent beta4 subunit and chloride channel 2 gene are associated with juvenile myoclonic epilepsy. In addition, mutations of leucine-rich, glioma-inactivated 1 gene leads to genetic abnormalities of familial lateral temporal lobe epilepsy. EF-hand domain (C-terminal)-containing 1 gene can cause some patterns of juvenile myoclonic and juvenile absence epilepsies. DISCUSSION Genetic factors play an important role in idiopathic epilepsy syndromes. Ion channel genes and some non-ion channel genes contribute to the pathogenesis of idiopathic epilepsies. Based on these findings, genetic diagnosis and new treatment strategies to part of idiopathic epilepsies become possible in the future.
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Affiliation(s)
- Yang Lu
- The First Affiliated Hospital, Chongqing Medical University, Chongqing, China
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Suzuki T, Miyamoto H, Nakahari T, Inoue I, Suemoto T, Jiang B, Hirota Y, Itohara S, Saido TC, Tsumoto T, Sawamoto K, Hensch TK, Delgado-Escueta AV, Yamakawa K. Efhc1 deficiency causes spontaneous myoclonus and increased seizure susceptibility. Hum Mol Genet 2009; 18:1099-109. [PMID: 19147686 DOI: 10.1093/hmg/ddp006] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Mutations in EFHC1 gene have been previously reported in patients with epilepsies, including those with juvenile myoclonic epilepsy. Myoclonin1, also known as mRib72-1, is encoded by the mouse Efhc1 gene. Myoclonin1 is dominantly expressed in embryonic choroid plexus, post-natal ependymal cilia, tracheal cilia and sperm flagella. In this study, we generated viable Efhc1-deficient mice. Most of the mice were normal in outward appearance, and both sexes were found to be fertile. However, the ventricles of the brains were significantly enlarged in the null mutants, but not in the heterozygotes. Although the ciliary structure was found intact, the ciliary beating frequency was significantly reduced in null mutants. In adult stages, both the heterozygous and null mutants developed frequent spontaneous myoclonus. Furthermore, the threshold of seizures induced by pentylenetetrazol was significantly reduced in both heterozygous and null mutants. These observations seem to further suggest that decrease or loss of function of myoclonin1 may be the molecular basis for epilepsies caused by EFHC1 mutations.
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Affiliation(s)
- Toshimitsu Suzuki
- Laboratory for Neurogenetics, RIKEN Brain Science Institute (BSI), Wako-shi, 351-0198 Saitama, Japan
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Mechanisms of human inherited epilepsies. Prog Neurobiol 2009; 87:41-57. [DOI: 10.1016/j.pneurobio.2008.09.016] [Citation(s) in RCA: 155] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2008] [Revised: 08/25/2008] [Accepted: 09/29/2008] [Indexed: 12/19/2022]
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Suzuki T, Inoue I, Yamagata T, Morita N, Furuichi T, Yamakawa K. Sequential expression of Efhc1/myoclonin1 in choroid plexus and ependymal cell cilia. Biochem Biophys Res Commun 2007; 367:226-33. [PMID: 18164683 DOI: 10.1016/j.bbrc.2007.12.126] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2007] [Accepted: 12/19/2007] [Indexed: 11/19/2022]
Abstract
EFHC1 is a gene mutated in patients with idiopathic epilepsies, and encodes the myoclonin1 protein. We here report the distribution of myoclonin1 in mouse. Immunohistochemical analyses revealed that the myoclonin1 first appeared at the roof of hindbrain at embryonic day 10 (E10), and moved on to choroid plexus at E14. At E18, it moved to ventricle walls and disappeared from choroid plexus. From neonatal to adult stages, myoclonin1 was concentrated in the cilia of ependymal cells at ventricle walls. At adult stages, myoclonin1 expression was also observed at tracheal epithelial cilia in lung and at sperm flagella in testis. Specificities of these immunohistochemical signals were verified by using Efhc1-deficient mice as negative controls. Results of Efhc1 mRNA in situ hybridization were also consistent with the immunohistochemical observations. Our findings raise "choroid plexusopathy" or "ciliopathy" as intriguing candidate cascades for the molecular pathology of epilepsies caused by the EFHC1 mutations.
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Affiliation(s)
- Toshimitsu Suzuki
- Laboratory for Neurogenetics, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako-Shi, Saitama 351-0198, Japan
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