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Chengyan L, Chupeng X, You W, Yinhui C, Binglong H, Dang A, Ling L, Chuan T. Identification of genetic causes in children with unexplained epilepsy based on trio-whole exome sequencing. Clin Genet 2024; 106:140-149. [PMID: 38468460 DOI: 10.1111/cge.14519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 02/25/2024] [Accepted: 02/26/2024] [Indexed: 03/13/2024]
Abstract
Genotype and clinical phenotype analyses of 128 children were performed based on whole exome sequencing (WES), providing a reference for the provision of genetic counseling and the precise diagnosis and treatment of epilepsy. A total of 128 children with unexplained epilepsy were included in this study, and all their clinical data were analyzed. The children's treatments, epilepsy control, and neurodevelopmental levels were regularly followed up every 3 months. The genetic diagnostic yield of the 128 children with epilepsy is 50.8%, with an SNV diagnostic yield of 39.8% and a CNV diagnostic yield of 12.5%. Among the 128 children with epilepsy, 57.0% had onset of epilepsy in infancy, 25.8% have more than two clinical seizure forms, 62.5% require two or more anti-epileptic drug treatments, and 72.7% of the children have varying degrees of psychomotor development retardation. There are significant differences between ages of onset, neurodevelopmental levels and the presence of drug resistance in the genetic diagnostic yield (all p < 0.05). The 52 pathogenic/likely pathogenic SNVs involve 31 genes, with genes encoding ion channels having the largest number of mutations (30.8%). There were 16 cases of pathogenic/possibly pathogenic CNVs, among which the main proportions of CNVs were located in chromosome 15 and chromosome 16. Trio-WES is an essential tool for the genetic diagnosis of unexplained epilepsy, with a genetic diagnostic yield of up to 50.8%. Early genetic testing can provide an initiate appropriate therapies and accurate molecular diagnosis.
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Affiliation(s)
- Li Chengyan
- Department of Pediatrics, Affiliated Hospital of Guangdong Medical University, Zhanjiang, People's Republic of China
| | - Xue Chupeng
- Department of Pediatrics, Affiliated Hospital of Guangdong Medical University, Zhanjiang, People's Republic of China
- Department of Pediatrics, Shantou Central Hospital, Shantou, People's Republic of China
| | - Wang You
- Department of Pediatrics, Affiliated Hospital of Guangdong Medical University, Zhanjiang, People's Republic of China
| | - Chen Yinhui
- Department of Pediatrics, Affiliated Hospital of Guangdong Medical University, Zhanjiang, People's Republic of China
| | - Huang Binglong
- Department of Pediatrics, Affiliated Hospital of Guangdong Medical University, Zhanjiang, People's Republic of China
| | - Ao Dang
- Department of Pediatrics, Affiliated Hospital of Guangdong Medical University, Zhanjiang, People's Republic of China
| | - Liu Ling
- Department of Pediatrics, Affiliated Hospital of Guangdong Medical University, Zhanjiang, People's Republic of China
| | - Tian Chuan
- Department of Pediatrics, Affiliated Hospital of Guangdong Medical University, Zhanjiang, People's Republic of China
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Muthaffar OY, Alqarni A, Shafei JA, Bahowarth SY, Alyazidi AS, Naseer MI. Childhood-related neural genotype-phenotype in ATP1A3 mutations: comprehensive analysis. Genes Genomics 2024; 46:475-487. [PMID: 38243045 DOI: 10.1007/s13258-023-01481-8] [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: 09/10/2023] [Accepted: 12/07/2023] [Indexed: 01/21/2024]
Abstract
BACKGROUND ATP1A3 is a gene that encodes the ATPase Na + /K + transporting subunit alpha-3 isoenzyme that is widely expressed in GABAergic neurons. It maintains metabolic balance and neurotransmitter movement. These pathways are essential for the proper functioning of the nervous system. A mutation in the ATP1A3 gene demonstrates remarkable genotype-phenotype heterogeneity. OBJECTIVES To provide insight into patients with ATP1A3 mutation. MATERIAL AND METHODS These cases were identified using next generation sequencing. The patients' clinical and genetic data were retrieved. Detailed revision of the literature was conducted to illustrate and compare findings. The clinical, genetical, neuroimaging, and electrophysiological data of all pediatric patients were extracted. RESULTS The study included 14 females and 12 males in addition to two novel females cases. Their mean current age is 6.3 ± 4.24 years. There were 11.54% preterm pregnancies with 5 cases reporting pregnancy complications. Mean age of seizure onset was 1.07 ± 1.06 years. Seizure semiology included generalized tonic-clonic, staring spells, tonic-clonic, and others. Levetiracetam was the most frequently used Anti-seizure medication. The three most frequently reported classical symptoms included alternating hemiplegia of childhood (50%), cerebellar ataxia (50%), and optic atrophy (23.08%). Non-classical symptoms included dystonia (73.08%), paroxysmal dyskinesias (34.62%), and encephalopathy (26.92%). Developmental delay was reported among 84.62% in cognitive, 92.31% in sensorimotor, 80.77% in speech, and 76.92% in socioemotional. EEG and MRI were non-specific. CONCLUSION Our study demonstrated high heterogeneity among patients with pathogenic variants in the ATP1A3 gene. Such variation is multifactorial and can be a predisposition of wide genetic and clinical variables. Many patients shared few similarities in their genetic map including repeatedly reported de novo, heterozygous, mutations in the gene. Clinically, higher females prevalence of atypical presentation was noted. These findings are validated with prior evidence and the comprehensive analysis in this study.
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Affiliation(s)
- Osama Y Muthaffar
- Department of Pediatrics, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Asma Alqarni
- Department of Neurology, Neuroscience Centre, King Faisal Specialist Hospital & Research Centre, 21313, Jeddah, Saudi Arabia
| | - Jumana A Shafei
- Faculty of Medicine, King Abdulaziz University, 23446, Jeddah, Saudi Arabia
| | - Sarah Y Bahowarth
- Faculty of Medicine, King Abdulaziz University, 23446, Jeddah, Saudi Arabia
| | - Anas S Alyazidi
- Faculty of Medicine, King Abdulaziz University, 23446, Jeddah, Saudi Arabia
| | - Muhammad Imran Naseer
- Center of Excellence in Genomic Medicine Research (CEGMR), King Abdulaziz University, 21589, Jeddah, Saudi Arabia.
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, 21589, Jeddah, Saudi Arabia.
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Zuo RR, Jin M, Sun SZ. Etiological analysis of 167 cases of drug-resistant epilepsy in children. Ital J Pediatr 2024; 50:50. [PMID: 38481309 PMCID: PMC10938754 DOI: 10.1186/s13052-024-01619-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 02/24/2024] [Indexed: 03/17/2024] Open
Abstract
BACKGROUND To analyze the etiological distribution characteristics of drug-resistant epilepsy (DRE) in children, with the aim of providing valuable perspectives to enhance clinical practice. METHODS In this retrospective study, clinical data were collected on 167 children with DRE who were hospitalized between January 2020 and December 2022, including gender, age of onset, seizure types, video electroencephalogram(VEEG) recordings, neuroimaging, and genetic testing results. Based on the etiology of epilepsy, the enrolled children were categorized into different groups. The rank-sum test was conducted to compare the age of onset for different etiologies. RESULTS Of the 167 cases, 89 (53.3%) had a clear etiology. Among them, structural factors account for 23.4%, genetic factors for 19.2%, multiple factors for 7.2%, and immunological factors for 3.6%. The age of onset was significantly earlier in children with genetic causes than those with structural (P < 0.001) or immunological (P = 0.001) causes. CONCLUSIONS More than half of children with DRE have a distinct underlying cause, predominantly attributed to structural factors, followed by genetic factors. Genetic etiology primarily manifests at an early age, especially among children aged less than one year. This underscores the need for proactive enhancements in genetic testing to unveil the underlying causes and subsequently guide treatment protocols.
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Affiliation(s)
- Ran-Ran Zuo
- Department of Neurology, Hebei Childrens Hospital, 133, Jianhua South Street, 050000, Shijiazhuang, Hebei Province, China
| | - Mei Jin
- Department of Neurology, Hebei Childrens Hospital, 133, Jianhua South Street, 050000, Shijiazhuang, Hebei Province, China
- The Key Laboratory of Pediatric Epilepsy and Neurological Disorders of Hebei Province, 050000, Shijiazhuang, Hebei, China
| | - Su-Zhen Sun
- Department of Neurology, Hebei Childrens Hospital, 133, Jianhua South Street, 050000, Shijiazhuang, Hebei Province, China.
- The Key Laboratory of Pediatric Epilepsy and Neurological Disorders of Hebei Province, 050000, Shijiazhuang, Hebei, China.
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Liang Y, Wan L, Liu X, Zhang J, Zhu G, Yang G. Infantile epileptic spasm syndrome as a new NR2F1 gene phenotype. Int J Dev Neurosci 2024; 84:75-83. [PMID: 38010976 DOI: 10.1002/jdn.10309] [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: 09/18/2023] [Revised: 11/03/2023] [Accepted: 11/06/2023] [Indexed: 11/29/2023] Open
Abstract
INTRODUCTION NR2F1 pathogenetic variants are associated with the Bosch-Boonstra-Schaaf optic atrophy syndrome (BBSOAS). Recent studies indicate that BBSOAS patients not only have visual impairments but may also have developmental delays, hypotonia, thin corpus callosum and epileptic seizures. However, reports of BBSOAS occurrence along with infantile epileptic spasm syndrome (IESS) are rare. METHODS Here, we report three cases involving children with IESS and BBSOAS caused by de novo NR2F1 pathogenetic variants and summarize the genotype, clinical characteristics, diagnosis and treatment of them. RESULTS All three children experienced epileptic spasms and global developmental delays, with brain Magnetic Resonance Imaging (MRI) suggesting abnormalities (thinning of the corpus callosum or widened extracerebral spaces) and two of the children exhibiting abnormal visual evoked potentials. CONCLUSIONS Our findings indicate that new missense NR2F1 pathogenetic variants may lead to IESS with abnormal visual evoked potentials. Thus, clinicians should be aware of the Bosch-Boonstra-Schaaf optic atrophy syndrome and regular monitoring of the fundus, and the optic nerve is necessary during follow-up.
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Affiliation(s)
- Yan Liang
- Senior Department of Pediatrics, Seventh Medical Center of PLA General Hospital, Beijing, China
- Department of Pediatrics, First Medical Centre, Chinese PLA General Hospital, Beijing, China
- Medical School of Chinese People's Liberation Army, Beijing, China
| | - Lin Wan
- Senior Department of Pediatrics, Seventh Medical Center of PLA General Hospital, Beijing, China
- Department of Pediatrics, First Medical Centre, Chinese PLA General Hospital, Beijing, China
- Medical School of Chinese People's Liberation Army, Beijing, China
| | - Xinting Liu
- Senior Department of Pediatrics, Seventh Medical Center of PLA General Hospital, Beijing, China
- Department of Pediatrics, First Medical Centre, Chinese PLA General Hospital, Beijing, China
- Medical School of Chinese People's Liberation Army, Beijing, China
| | - Jing Zhang
- Senior Department of Pediatrics, Seventh Medical Center of PLA General Hospital, Beijing, China
- Department of Pediatrics, First Medical Centre, Chinese PLA General Hospital, Beijing, China
- Medical School of Chinese People's Liberation Army, Beijing, China
| | - Gang Zhu
- Senior Department of Pediatrics, Seventh Medical Center of PLA General Hospital, Beijing, China
- Department of Pediatrics, First Medical Centre, Chinese PLA General Hospital, Beijing, China
- Medical School of Chinese People's Liberation Army, Beijing, China
| | - Guang Yang
- Senior Department of Pediatrics, Seventh Medical Center of PLA General Hospital, Beijing, China
- Department of Pediatrics, First Medical Centre, Chinese PLA General Hospital, Beijing, China
- Medical School of Chinese People's Liberation Army, Beijing, China
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Chaudhuri T, Hosur MV. Molecular modelling reveals how abundance of α4 sub-type in synaptic GABAR A receptor can lead to refractoriness toward GABA and BZ-type drugs. J Biomol Struct Dyn 2023:1-8. [PMID: 37948195 DOI: 10.1080/07391102.2023.2277858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 10/25/2023] [Indexed: 11/12/2023]
Abstract
Epilepsy is a complex neurological disorder with genetic and acquired causes, and the drugs presently used to treat epilepsy are not effective in about 30% of the cases. Identification of the molecular mechanisms of resistance will help in the development of newer molecules for treatment. Recent clinical data indicate increased expression of α4- and γ2-containing synaptic GABARA receptors in patients of focal cortical dysplasia (FCD), which is associated with refractory epilepsy pathology. We have investigated, by molecular modelling and docking, the structure and ligand-binding efficiency of the α4-containing hetero-pentameric synaptic GABARA receptor. Though the overall conformation is similar to that of the α1-containing receptor, local conformational changes are seen due to differences between aligned α1 and α4 sub-type residues. The overlaps ALA209(α1)/PRO215(α4) and PHE73(α1)/TYR79(α4) have together caused conformational changes in ARG100(α4) (aligned with ARG94 in α1) thereby affecting key hydrogen bonding interactions with the inhibitory neurotransmitter GABA. This may influence the nature of seizures as strength of GABA-binding is known to affect the nature of Inhibitory Post-Synaptic Currents (IPSCs) from GABAergic neurons. The residue ARG135 (α4) aligns with the residue HIS129 (α1) in the benzodiazapine binding pocket. Molecular modelling also shows that a steric clash between benzodiazapine-type (BZ-type) drugs and ARG135 would reduce the binding of BZ-type drugs to α4-containing receptor. These two findings rationalize the observed association between over-expression of α4-containing synaptic GABARA receptors and refractory epilepsy pathology in FCD. The accurate three-dimensional geometry of the receptor-drug complex made available by these modelling studies will help in designing effective drugs.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Tanusree Chaudhuri
- Department of Natural Sciences and Engineering, National Institute of Advanced Studies, Bangalore, India
| | - M V Hosur
- Department of Natural Sciences and Engineering, National Institute of Advanced Studies, Bangalore, India
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Dai L, Ding C, Tian X, Liu M, Ma Y, Chen C, Ren X, Li H. The clinical spectrum associated with ATP1A2 variants in Chinese pediatric patients. Brain Dev 2023; 45:422-431. [PMID: 37142513 DOI: 10.1016/j.braindev.2023.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 04/17/2023] [Accepted: 04/18/2023] [Indexed: 05/06/2023]
Abstract
PURPOSE To evaluate the clinical spectrum associated with ATP1A2 variants in Chinese children with hemiplegia, migraines, encephalopathy or seizures. METHODS Sixteen children (12 males and 4 females), including ten patients with ATP1A2 variants whose cases had been published previously, were identified using next-generation sequencing. RESULTS Fifteen patients had FHM2 (familial hemiplegic migraine type 2), including three who had AHC (alternating hemiplegia of childhood) and one who had drug-resistant focal epilepsy. Thirteen patients had DD (developmental delay). The onset of febrile seizures, which occurred between 5 months and 2 years 5 months (median 1 year 3 months) was earlier than the onset of HM (hemiplegic migraine), which occurred between 1 year 5 months and 13 years (median 3 years 11 months). Disturbance of consciousness subsided first, at 40 h to 9 days (median 4.5 days); hemiplegia and aphasia were resolved slowly, taking 30 min to 6 months (median 17.5 days) for the former and 24 h to over 1 year (median 14.5 days) for the latter. Cranial MRI showed edema in the cerebral hemispheres, mainly the left hemisphereacute attacks. All thirteen FHM2 patients recovered to baseline in 30 min to 6 months. Fifteen patients had between 1 and 7 (median 2) total attacks between the baseline and follow-up timepoints. We report twelve missense variants, including a novel variant ATP1A2 variant, p.G855E. CONCLUSIONS The known genotypic and phenotypic spectra of Chinese patients with ATP1A2-related disorders were further expanded. Recurrent febrile seizures and DD combined with paroxysmal hemiplegia and encephalopathy should raise the clinical suspicion of FHM2. The avoidance of triggers and thus the prevention of attacks may be the most effective therapy for FHM2.
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Affiliation(s)
- Lifang Dai
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, 100045, China
| | - Changhong Ding
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, 100045, China; Department of Neurology, Baoding Children's Hospital, Baoding, Hebei 071000, China.
| | - Xiaojuan Tian
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, 100045, China
| | - Ming Liu
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, 100045, China
| | - Yuping Ma
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, 100045, China
| | - Chunhong Chen
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, 100045, China
| | - Xiaotun Ren
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, 100045, China
| | - Hua Li
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, 100045, China
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Absalom NL, Lin SXN, Liao VWY, Chua HC, Møller RS, Chebib M, Ahring PK. GABA A receptors in epilepsy: Elucidating phenotypic divergence through functional analysis of genetic variants. J Neurochem 2023. [PMID: 37621067 DOI: 10.1111/jnc.15932] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 07/27/2023] [Accepted: 08/01/2023] [Indexed: 08/26/2023]
Abstract
Normal brain function requires a tightly regulated balance between excitatory and inhibitory neurotransmissions. γ-Aminobutyric acid type A (GABAA ) receptors represent the major class of inhibitory ion channels in the mammalian brain. Dysregulation of these receptors and/or their associated pathways is strongly implicated in the pathophysiology of epilepsy. To date, hundreds of different GABAA receptor subunit variants have been associated with epilepsy, making them a prominent cause of genetically linked epilepsy. While identifying these genetic variants is crucial for accurate diagnosis and effective genetic counselling, it does not necessarily lead to improved personalised treatment options. This is because the identification of a variant does not reveal how the function of GABAA receptors is affected. Genetic variants in GABAA receptor subunits can cause complex changes to receptor properties resulting in various degrees of gain-of-function, loss-of-function or a combination of both. Understanding how variants affect the function of GABAA receptors therefore represents an important first step in the ongoing development of precision therapies. Furthermore, it is important to ensure that functional data are produced using methodologies that allow genetic variants to be classified using clinical guidelines such as those developed by the American College of Medical Genetics and Genomics. This article will review the current knowledge in the field and provide recommendations for future functional analysis of genetic GABAA receptor variants.
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Affiliation(s)
- Nathan L Absalom
- School of Science, University of Western Sydney, Sydney, New South Wales, Australia
- Brain and Mind Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Susan X N Lin
- Brain and Mind Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Vivian W Y Liao
- Brain and Mind Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Han C Chua
- Brain and Mind Centre, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Rikke S Møller
- Department of Epilepsy Genetics and Personalized Medicine, The Danish Epilepsy Centre, Filadelfia, Dianalund, Denmark
- Department of Regional Health Research, University of Southern Denmark, Odense, Denmark
| | - Mary Chebib
- Brain and Mind Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Philip K Ahring
- Brain and Mind Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
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Brock DC, Abbott M, Reed L, Kammeyer R, Gibbons M, Angione K, Bernard TJ, Gaskell A, Demarest S. Epilepsy panels in clinical practice: Yield, variants of uncertain significance, and treatment implications. Epilepsy Res 2023; 193:107167. [PMID: 37230012 DOI: 10.1016/j.eplepsyres.2023.107167] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 05/09/2023] [Accepted: 05/11/2023] [Indexed: 05/27/2023]
Abstract
OBJECTIVE There has been increasing utilization of genetic testing for pediatric epilepsy in recent years. Little systematic data is available examining how practice changes have impacted testing yields, diagnostic pace, incidence of variants of uncertain significance (VUSs), or therapeutic management. METHODS A retrospective chart review was performed at Children's Hospital Colorado from February 2016 through February 2020. All patients under 18 years for whom an epilepsy gene panel was sent were included. RESULTS A total of 761 epilepsy gene panels were sent over the study period. During the study period, there was a 292% increase in the average number of panels sent per month. The time from seizure onset to panel result decreased over the study period from a median of 2.9 years to 0.7 years. Despite the increase in testing, the percentage of panels yielding a disease-causing result remained stable at 11-13%. A total of 90 disease-causing results were identified, > 75% of which provided guidance in management. Children were more likely to have a disease-causing result if they were < 3 years old at seizure onset (OR 4.4, p < 0.001), had neurodevelopmental concerns (OR 2.2, p = 0.002), or had a developmentally abnormal MRI (OR 3.8, p < 0.001). A total of 1417 VUSs were identified, equating to 15.7 VUSs per disease-causing result. Non-Hispanic white patients had a lower average number of VUSs than patients of all other races/ethnicities (1.7 vs 2.1, p < 0.001). SIGNIFICANCE Expansion in the volume of genetic testing corresponded to a decrease in the time from seizure onset to testing result. Diagnostic yield remained stable, resulting in an increase in the absolute number of disease-causing results annually-most of which have implications for management. However, there has also been an increase in total VUSs, which likely resulted in additional clinical time spent on VUS resolution.
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Affiliation(s)
- Dylan C Brock
- Children's Hospital Colorado Anschutz Medical Campus, Aurora 13123 East 16th Avenue, Aurora, CO 80045; University of Colorado, Anschutz Medical Campus School of Medicine, Department of Pediatrics, Section of Neurology Anschutz Medical Campus, Aurora 13001 E 17th Pl, Aurora, CO 80045.
| | - Megan Abbott
- Children's Hospital Colorado Anschutz Medical Campus, Aurora 13123 East 16th Avenue, Aurora, CO 80045; University of Colorado, Anschutz Medical Campus School of Medicine, Department of Pediatrics, Section of Neurology Anschutz Medical Campus, Aurora 13001 E 17th Pl, Aurora, CO 80045.
| | - Laurel Reed
- Children's Hospital Colorado Anschutz Medical Campus, Aurora 13123 East 16th Avenue, Aurora, CO 80045; University of Colorado, Anschutz Medical Campus School of Medicine, Department of Pediatrics, Section of Neurology Anschutz Medical Campus, Aurora 13001 E 17th Pl, Aurora, CO 80045.
| | - Ryan Kammeyer
- Children's Hospital Colorado Anschutz Medical Campus, Aurora 13123 East 16th Avenue, Aurora, CO 80045; University of Colorado, Anschutz Medical Campus School of Medicine, Department of Pediatrics, Section of Neurology Anschutz Medical Campus, Aurora 13001 E 17th Pl, Aurora, CO 80045.
| | - Melissa Gibbons
- Children's Hospital Colorado Anschutz Medical Campus, Aurora 13123 East 16th Avenue, Aurora, CO 80045; University of Colorado, Anschutz Medical Campus School of Medicine, Department of Pediatrics, Section of Neurology Anschutz Medical Campus, Aurora 13001 E 17th Pl, Aurora, CO 80045.
| | - Katie Angione
- Precision Medicine Institute, Children's Hospital Colorado Anschutz Medical Campus, Aurora 1312 East 16th Avenue, Aurora, CO 80045, USA; University of Colorado, Anschutz Medical Campus School of Medicine, Department of Pediatrics, Section of Neurology Anschutz Medical Campus, Aurora 13001 E 17th Pl, Aurora, CO 80045.
| | - Timothy J Bernard
- Children's Hospital Colorado Anschutz Medical Campus, Aurora 13123 East 16th Avenue, Aurora, CO 80045; University of Colorado, Anschutz Medical Campus School of Medicine, Department of Pediatrics, Section of Neurology Anschutz Medical Campus, Aurora 13001 E 17th Pl, Aurora, CO 80045.
| | - Alisa Gaskell
- Precision Medicine Institute, Children's Hospital Colorado Anschutz Medical Campus, Aurora 1312 East 16th Avenue, Aurora, CO 80045, USA; University of Colorado, Anschutz Medical Campus School of Medicine, Department of Pediatrics, Section of Neurology Anschutz Medical Campus, Aurora 13001 E 17th Pl, Aurora, CO 80045.
| | - Scott Demarest
- Precision Medicine Institute, Children's Hospital Colorado Anschutz Medical Campus, Aurora 1312 East 16th Avenue, Aurora, CO 80045, USA; University of Colorado, Anschutz Medical Campus School of Medicine, Department of Pediatrics, Section of Neurology Anschutz Medical Campus, Aurora 13001 E 17th Pl, Aurora, CO 80045.
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Zou S, Lan YL, Gong Y, Chen Z, Xu C. The role of ATP1A3 gene in epilepsy: We need to know more. Front Cell Neurosci 2023; 17:1143956. [PMID: 36866063 PMCID: PMC9972585 DOI: 10.3389/fncel.2023.1143956] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 01/23/2023] [Indexed: 02/16/2023] Open
Abstract
The ATP1A3 gene, which encodes the Na+/K+-ATPase α3 catalytic subunit, plays a crucial role in both physiological and pathological conditions in the brain, and mutations in this gene have been associated with a wide variety of neurological diseases by impacting the whole infant development stages. Cumulative clinical evidence suggests that some severe epileptic syndromes have been linked to mutations in ATP1A3, among which inactivating mutation of ATP1A3 has been intriguingly found to be a candidate pathogenesis for complex partial and generalized seizures, proposing ATP1A3 regulators as putative targets for the rational design of antiepileptic therapies. In this review, we introduced the physiological function of ATP1A3 and summarized the findings about ATP1A3 in epileptic conditions from both clinical and laboratory aspects at first. Then, some possible mechanisms of how ATP1A3 mutations result in epilepsy are provided. We think this review timely introduces the potential contribution of ATP1A3 mutations in both the genesis and progression of epilepsy. Taken that both the detailed mechanisms and therapeutic significance of ATP1A3 for epilepsy are not yet fully illustrated, we think that both in-depth mechanisms investigations and systematic intervention experiments targeting ATP1A3 are needed, and by doing so, perhaps a new light can be shed on treating ATP1A3-associated epilepsy.
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Affiliation(s)
- Shuang Zou
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Yu-Long Lan
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China,*Correspondence: Yu-Long Lan ✉
| | - Yiwei Gong
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Zhong Chen
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Cenglin Xu
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China,Cenglin Xu ✉
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Esterhuizen AI, Tiffin N, Riordan G, Wessels M, Burman RJ, Aziz MC, Calhoun JD, Gunti J, Amiri EE, Ramamurthy A, Bamshad MJ, Mefford HC, Ramesar R, Wilmshurst JM, Carvill GL, Leal SM, Nickerson DA, Anderson P, Bacus TJ, Blue EE, Brower K, Buckingham KJ, Chong JX, Cornejo Sánchez D, Davis CP, Davis CJ, Frazar CD, Gomeztagle-Burgess K, Gordon WW, Horike-Pyne M, Hurless JR, Jarvik GP, Johanson E, Thomas Kolar J, Marvin CT, McGee S, McGoldrick DJ, Mekonnen B, Nielsen PM, Patterson K, Radhakrishnan A, Richardson MA, Roote GT, Ryke EL, Schrauwen I, Shively KM, Smith JD, Tackett M, Wang G, Weiss JM, Wheeler MM, Yi Q, Zhang X. Precision medicine for developmental and epileptic encephalopathies in Africa-strategies for a resource-limited setting. Genet Med 2023; 25:100333. [PMID: 36480001 DOI: 10.1016/j.gim.2022.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 10/31/2022] [Accepted: 11/01/2022] [Indexed: 12/13/2022] Open
Abstract
PURPOSE Sub-Saharan Africa bears the highest burden of epilepsy worldwide. A presumed proportion is genetic, but this etiology is buried under the burden of infections and perinatal insults in a setting of limited awareness and few options for testing. Children with developmental and epileptic encephalopathies (DEEs) are most severely affected by this diagnostic gap in Africa, because the rate of actionable findings is highest in DEE-associated genes. METHODS We tested 234 genetically naive South African children diagnosed with/possible DEE using gene panels, exome sequencing, and chromosomal microarray. Statistical comparison of electroclinical features in children with and children without candidate variants was performed to identify characteristics most likely predictive of a positive genetic finding. RESULTS Of the 41 (of 234) children with likely/pathogenic variants, 26 had variants supporting precision therapy. Multivariate regression modeling highlighted neonatal or infantile-onset seizures and movement abnormalities as predictive of a positive genetic finding. We used this, coupled with an emphasis on precision medicine outcomes, to propose the pragmatic "Think-Genetics" strategy for early recognition of a possible genetic etiology. CONCLUSION Our findings emphasize the importance of an early genetic diagnosis in DEE. We designed the Think-Genetics strategy for early recognition, appropriate interim management, and genetic testing for DEE in resource-constrained settings.
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Affiliation(s)
- Alina I Esterhuizen
- The South African MRC/UCT Genomic and Precision Medicine Research Unit, Division of Human Genetics, Institute of Infectious Diseases and Molecular Medicine, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa; National Health Laboratory Service, Groote Schuur Hospital, Cape Town, South Africa
| | - Nicki Tiffin
- South African National Bioinformatics Institute, University of the Western Cape, Bellville, Western Cape, South Africa
| | - Gillian Riordan
- Department of Paediatric Neurology, Red Cross War Memorial Children's Hospital, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
| | - Marie Wessels
- Department of Paediatric Neurology, Red Cross War Memorial Children's Hospital, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
| | - Richard J Burman
- Division of Clinical Neurology, Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Miriam C Aziz
- Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Jeffrey D Calhoun
- Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Jonathan Gunti
- Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Ezra E Amiri
- Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Aishwarya Ramamurthy
- Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Michael J Bamshad
- Department of Pediatrics, University of Washington, Seattle, WA; Department of Genome Sciences, University of Washington, Seattle, WA; Brotman Baty Institute, Seattle, WA
| | | | - Heather C Mefford
- Centre for Pediatric Neurological Disease Research, St. Jude Children's Research Hospital, Memphis, TN
| | - Raj Ramesar
- The South African MRC/UCT Genomic and Precision Medicine Research Unit, Division of Human Genetics, Institute of Infectious Diseases and Molecular Medicine, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa; National Health Laboratory Service, Groote Schuur Hospital, Cape Town, South Africa
| | - Jo M Wilmshurst
- Department of Paediatric Neurology, Red Cross War Memorial Children's Hospital, Neuroscience Institute, University of Cape Town, Cape Town, South Africa.
| | - Gemma L Carvill
- Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Northwestern University, Chicago, IL; Department of Pharmacology, Northwestern University Feinberg School of Medicine, Northwestern University, Chicago, IL; Department of Pediatrics, Northwestern University Feinberg School of Medicine, Northwestern University, Chicago, IL.
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11
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Ghosh A, Nadella N, Monaghan-Nichols AP, Chu XP. Gene Therapy as an Emerging Treatment for Scn2a Mutation-Induced Autism Spectrum Disorders. FUNDAMENTAL RESEARCH 2023. [DOI: 10.1016/j.fmre.2023.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
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12
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Arystarkhova E, Toustrup-Jensen MS, Holm R, Ko JK, Lee KE, Feschenko P, Ozelius LJ, Brashear A, Vilsen B, Sweadner KJ. Temperature instability of a mutation at a multidomain junction in Na,K-ATPase isoform ATP1A3 (p.Arg756His) produces a fever-induced neurological syndrome. J Biol Chem 2023; 299:102758. [PMID: 36462665 PMCID: PMC9860391 DOI: 10.1016/j.jbc.2022.102758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 11/18/2022] [Accepted: 11/19/2022] [Indexed: 12/02/2022] Open
Abstract
ATP1A3 encodes the α3 isoform of Na,K-ATPase. In the brain, it is expressed only in neurons. Human ATP1A3 mutations produce a wide spectrum of phenotypes, but particular syndromes are associated with unique substitutions. For arginine 756, at the junction of membrane and cytoplasmic domains, mutations produce encephalopathy during febrile infections. Here we tested the pathogenicity of p.Arg756His (R756H) in isogenic mammalian cells. R756H protein had sufficient transport activity to support cells when endogenous ATP1A1 was inhibited. It had half the turnover rate of wildtype, reduced affinity for Na+, and increased affinity for K+. There was modest endoplasmic reticulum retention during biosynthesis at 37 °C but little benefit from the folding drug phenylbutyrate (4-PBA), suggesting a tolerated level of misfolding. When cells were incubated at just 39 °C, however, α3 protein level dropped without loss of β subunit, paralleled by an increase of endogenous α1. Elevated temperature resulted in internalization of α3 from the surface along with some β subunit, accompanied by cytoplasmic redistribution of a marker of lysosomes and endosomes, lysosomal-associated membrane protein 1. After return to 37 °C, α3 protein levels recovered with cycloheximide-sensitive new protein synthesis. Heating in vitro showed activity loss at a rate 20- to 30-fold faster than wildtype, indicating a temperature-dependent destabilization of protein structure. Arg756 appears to confer thermal resistance as an anchor, forming hydrogen bonds among four linearly distant parts of the Na,K-ATPase structure. Taken together, our observations are consistent with fever-induced symptoms in patients.
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Affiliation(s)
- Elena Arystarkhova
- Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts, USA.
| | | | - Rikke Holm
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark
| | - Jae-Kyun Ko
- Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Kyung Eun Lee
- Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Polina Feschenko
- Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Laurie J Ozelius
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Allison Brashear
- Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, Buffalo, New York, USA
| | - Bente Vilsen
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark
| | - Kathleen J Sweadner
- Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts, USA.
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Luo S, Ye XG, Jin L, Li H, He YY, Guan BZ, Gao LD, Liang XY, Wang PY, Lu XG, Yan HJ, Li BM, Chen YJ, Liu ZG. SZT2 variants associated with partial epilepsy or epileptic encephalopathy and the genotype-phenotype correlation. Front Mol Neurosci 2023; 16:1162408. [PMID: 37213690 PMCID: PMC10198435 DOI: 10.3389/fnmol.2023.1162408] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 04/10/2023] [Indexed: 05/23/2023] Open
Abstract
Background Recessive SZT2 variants are reported to be associated with developmental and epileptic encephalopathy 18 (DEE-18) and occasionally neurodevelopment abnormalities (NDD) without seizures. This study aims to explore the phenotypic spectrum of SZT2 and the genotype-phenotype correlation. Methods Trios-based whole-exome sequencing was performed in patients with epilepsy. Previously reported SZT2 mutations were systematically reviewed to analyze the genotype-phenotype correlations. Results SZT2 variants were identified in six unrelated cases with heterogeneous epilepsy, including one de novo null variant and five pairs of biallelic variants. These variants had no or low frequencies in controls. All missense variants were predicted to alter the hydrogen bonds with surrounding residues and/or protein stability. The three patients with null variants exhibited DEE. The patients with biallelic null mutations presented severe DEE featured by frequent spasms/tonic seizures and diffuse cortical dysplasia/periventricular nodular heterotopia. The three patients with biallelic missense variants presented mild partial epilepsy with favorable outcomes. Analysis of previously reported cases revealed that patients with biallelic null mutations presented significantly higher frequency of refractory seizures and earlier onset age of seizure than those with biallelic non-null mutations or with biallelic mutations containing one null variant. Significance This study suggested that SZT2 variants were potentially associated with partial epilepsy with favorable outcomes without NDD, expanding the phenotypic spectrum of SZT2. The genotype-phenotype correlation helps in understanding the underlying mechanism of phenotypic variation.
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Affiliation(s)
- Sheng Luo
- 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
| | - Xing-Guang Ye
- Department of Pediatrics, Affiliated Foshan Maternity and Child Healthcare Hospital, Southern Medical University, Foshan, China
| | - Liang Jin
- 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
- Department of Neurology, The Affiliated Nanhua Hospital, Hengyang Medical School, University of South China, Hengyang, China
| | - Huan 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
| | - Yun-Yan 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
| | - Bao-Zhu Guan
- 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
| | - Liang-Di Gao
- 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
| | - Xiao-Yu Liang
- 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-Yu Wang
- 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
| | - Xin-Guo Lu
- Epilepsy Center and Department of Neurology, Shenzhen Children's Hospital, Shenzhen, China
| | - Hong-Jun Yan
- Epilepsy Center, Guangdong 999 Brain Hospital, Guangzhou, China
| | - Bing-Mei 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
| | - Yong-Jun Chen
- Department of Neurology, The Affiliated Nanhua Hospital, Hengyang Medical School, University of South China, Hengyang, China
- *Correspondence: Yong-Jun Chen
| | - Zhi-Gang Liu
- Department of Pediatrics, Affiliated Foshan Maternity and Child Healthcare Hospital, Southern Medical University, Foshan, China
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
- Zhi-Gang Liu
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14
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He Z, Li Y, Zhao X, Li B. Dravet Syndrome: Advances in Etiology, Clinical Presentation, and Treatment. Epilepsy Res 2022; 188:107041. [DOI: 10.1016/j.eplepsyres.2022.107041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 10/08/2022] [Accepted: 10/26/2022] [Indexed: 11/16/2022]
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15
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Zhang L, Liu X. Clinical phenotype and genotype of children with GABAA receptor α1 subunit gene-related epilepsy. Front Neurol 2022; 13:941054. [PMID: 35937053 PMCID: PMC9350551 DOI: 10.3389/fneur.2022.941054] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 06/27/2022] [Indexed: 12/03/2022] Open
Abstract
Objective This study aimed to summarize the clinical phenotype and genotype of children with epilepsy caused by GABRA1 gene variants. Methods Eight epilepsy patients, who were admitted to Qilu Hospital of Shandong University from 2015 to 2021, were enrolled in the study. GABRA1 gene variants were detected by whole-exome sequencing. Epilepsy clinical manifestations, electroencephalography, neuroimaging characteristics and treatment methods were retrospectively analyzed. Results Among the eight patients, four were males and four were females. Epilepsy onset age was between 3 and 8 months of age. Two patients had a family history of epilepsy. Six cases were de novo variants, and two were hereditary variants. Two children carried the same pathogenic variants, and five carried novel pathogenic variants that had not been reported internationally. The types of seizures were diverse, including focal seizures in five cases, generalized tonic-clonic seizures in five cases, and spasms in two cases. Electroencephalography of seven cases showed abnormal background rhythms, and six cases showed abnormal discharge during the interictal period. No obvious abnormalities were found on magnetic resonance imaging in five cases. All eight children had different degrees of developmental retardation. Conclusion De novo pathogenic variants in GABRA1 are more common than inherited pathogenic variants, and most epilepsy symptoms begin in the first year of life, manifesting with a variety of seizure types and developmental delays. Conventional treatment usually involves one or more drugs; although drug treatment can control seizures in some cases, cognitive and developmental deficits often exist. The five newly discovered pathogenic variants enrich the GABRA1 gene pathogenic variant spectrum.
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Phenotypic and Genotypic Spectrum of Early-Onset Developmental and Epileptic Encephalopathies-Data from a Romanian Cohort. Genes (Basel) 2022; 13:genes13071253. [PMID: 35886038 PMCID: PMC9322987 DOI: 10.3390/genes13071253] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 07/11/2022] [Accepted: 07/12/2022] [Indexed: 02/01/2023] Open
Abstract
Early-onset developmental epileptic encephalopathy (DEE) refers to an age-specific, diverse group of epilepsy syndromes with electroclinical anomalies that are associated with severe cognitive, behavioral, and developmental impairments. Genetic DEEs have heterogeneous etiologies. This study includes 36 Romanian patients referred to the Regional Centre for Medical Genetics Dolj for genetic testing between 2017 and 2020. The patients had been admitted to and clinically evaluated at Doctor Victor Gomoiu Children’s Hospital and Prof. Dr. Alexandru Obregia Psychiatry Hospital in Bucharest. Panel testing was performed using the Illumina® TruSight™ One “clinical exome” (4811 genes), and the analysis focused on the known genes reported in DEEs and clinical concordance. The overall diagnostic rate was 25% (9/36 cases). Seven cases were diagnosed with Dravet syndrome (likely pathogenic/pathogenic variants in SCN1A) and two with Genetic Epilepsy with Febrile Seizures Plus (SCN1B). For the diagnosed patients, seizure onset was <1 year, and the seizure type was generalized tonic-clonic. Four additional plausible variants of unknown significance in SCN2A, SCN9A, and SLC2A1 correlated with the reported phenotype. Overall, we are reporting seven novel variants. Comprehensive clinical phenotyping is crucial for variant interpretation. Genetic assessment of patients with severe early-onset DEE can be a powerful diagnostic tool for clinicians, with implications for the management and counseling of the patients and their families.
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Zhao X, Ning H, Wang Y, Zhao G, Mei S, Liu N, Wang C, Cai A, Wei E, Kong X. Genetic analysis and identification of novel variations in Chinese patients with pediatric epilepsy by whole-exome sequencing. Neurol Sci 2022; 43:4439-4451. [DOI: 10.1007/s10072-022-05953-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 02/12/2022] [Indexed: 11/28/2022]
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18
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Duan R, Li HM, Hu WB, Hong CG, Chen ML, Cao J, Wang ZX, Chen CY, Yin F, Hu ZH, Li JD, Xie H, Liu ZZ. Recurrent de novo single point variant on the gene encoding Na +/K + pump results in epilepsy. Prog Neurobiol 2022; 216:102310. [PMID: 35724808 DOI: 10.1016/j.pneurobio.2022.102310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 04/28/2022] [Accepted: 06/15/2022] [Indexed: 10/18/2022]
Abstract
The etiology of epilepsy remains undefined in two-thirds of patients. Here, we identified a de novo variant of ATP1A2 (c.2426 T > G, p.Leu809Arg), which encodes the α2 subunit of Na+/K+-ATPase, from a family with idiopathic epilepsy. This variant caused epilepsy with hemiplegic migraine in the study patients. We generated the point variant mouse model Atp1a2L809R, which recapitulated the epilepsy observed in the study patients. In Atp1a2L809R/WT mice, convulsions were observed and cognitive and memory function was impaired. This variant affected the potassium binding function of the protein, disabling its ion transport ability, thereby increasing the frequency of nerve impulses. Valproate (VPA) and Carbamazepine (CBZ) have limited therapeutic efficacy in ameliorating the epileptic syndromes of Atp1a2L809R/WT mice. Our work revealed that ATP1A2L809R variants cause a predisposition to epilepsy. Moreover, we provide a point variant mouse model for epilepsy research and drug screening.
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Affiliation(s)
- Ran Duan
- Department of Sports Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Movement System Injury and Repair Research Center, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Hong-Ming Li
- Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Movement System Injury and Repair Research Center, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Wen-Bao Hu
- Institute of Molecular Precision Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Chun-Gu Hong
- Movement System Injury and Repair Research Center, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Meng-Lu Chen
- Department of Sports Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Movement System Injury and Repair Research Center, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Jia Cao
- Movement System Injury and Repair Research Center, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Zhen-Xing Wang
- Movement System Injury and Repair Research Center, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Chun-Yuan Chen
- Department of Sports Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Movement System Injury and Repair Research Center, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Zhong-Hua Hu
- Institute of Molecular Precision Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Jia-Da Li
- State Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan 410078, China
| | - Hui Xie
- Department of Sports Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Movement System Injury and Repair Research Center, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Hunan Key Laboratory of Organ Injury, Aging and Regenerative Medicine, Changsha, Hunan 410008, China; Hunan Key Laboratory of Bone Joint Degeneration and Injury, Changsha, Hunan 410008, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Changsha, Hunan 410008, China.
| | - Zheng-Zhao Liu
- Department of Sports Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Movement System Injury and Repair Research Center, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Hunan Key Laboratory of Organ Injury, Aging and Regenerative Medicine, Changsha, Hunan 410008, China.
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Baez-Nieto D, Allen A, Akers-Campbell S, Yang L, Budnik N, Pupo A, Shin YC, Genovese G, Liao M, Pérez-Palma E, Heyne H, Lal D, Lipscombe D, Pan JQ. Analysing an allelic series of rare missense variants of CACNA1I in a Swedish schizophrenia cohort. Brain 2022; 145:1839-1853. [PMID: 34919654 PMCID: PMC9166571 DOI: 10.1093/brain/awab443] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 10/23/2021] [Accepted: 11/11/2021] [Indexed: 11/14/2022] Open
Abstract
CACNA1I is implicated in the susceptibility to schizophrenia by large-scale genetic association studies of single nucleotide polymorphisms. However, the channelopathy of CACNA1I in schizophrenia is unknown. CACNA1I encodes CaV3.3, a neuronal voltage-gated calcium channel that underlies a subtype of T-type current that is important for neuronal excitability in the thalamic reticular nucleus and other regions of the brain. Here, we present an extensive functional characterization of 57 naturally occurring rare and common missense variants of CACNA1I derived from a Swedish schizophrenia cohort of more than 10 000 individuals. Our analysis of this allelic series of coding CACNA1I variants revealed that reduced CaV3.3 channel current density was the dominant phenotype associated with rare CACNA1I coding alleles derived from control subjects, whereas rare CACNA1I alleles from schizophrenia patients encoded CaV3.3 channels with altered responses to voltages. CACNA1I variants associated with altered current density primarily impact the ionic channel pore and those associated with altered responses to voltage impact the voltage-sensing domain. CaV3.3 variants associated with altered voltage dependence of the CaV3.3 channel and those associated with peak current density deficits were significantly segregated across affected and unaffected groups (Fisher's exact test, P = 0.034). Our results, together with recent data from the SCHEMA (Schizophrenia Exome Sequencing Meta-Analysis) cohort, suggest that reduced CaV3.3 function may protect against schizophrenia risk in rare cases. We subsequently modelled the effect of the biophysical properties of CaV3.3 channel variants on thalamic reticular nucleus excitability and found that compared with common variants, ultrarare CaV3.3-coding variants derived from control subjects significantly decreased thalamic reticular nucleus excitability (P = 0.011). When all rare variants were analysed, there was a non-significant trend between variants that reduced thalamic reticular nucleus excitability and variants that either had no effect or increased thalamic reticular nucleus excitability across disease status. Taken together, the results of our functional analysis of an allelic series of >50 CACNA1I variants in a schizophrenia cohort reveal that loss of function of CaV3.3 is a molecular phenotype associated with reduced disease risk burden, and our approach may serve as a template strategy for channelopathies in polygenic disorders.
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Affiliation(s)
- David Baez-Nieto
- Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Andrew Allen
- Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Seth Akers-Campbell
- Carney Institute for Brain Science & Department of Neuroscience, Brown University, Providence, RI 02912, USA
| | - Lingling Yang
- Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Nikita Budnik
- Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Amaury Pupo
- Department of Biology, West Virginia University, Morgantown, West Virginia 26506, USA
| | - Young-Cheul Shin
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Giulio Genovese
- Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Maofu Liao
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Eduardo Pérez-Palma
- Genomic Medicine Institute, Lerner Research institute, Cleveland Clinic, OH 44195, USA
- Centro de Genética y Genómica, Universidad del Desarrollo, Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana, Chile
| | - Henrike Heyne
- Genomic Medicine, Hasso Plattner Institute, Potsdam, 14482, Germany
| | - Dennis Lal
- Genomic Medicine Institute, Lerner Research institute, Cleveland Clinic, OH 44195, USA
- Cologne Center for Genomics, University of Cologne, Cologne 50931, Germany
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Diane Lipscombe
- Carney Institute for Brain Science & Department of Neuroscience, Brown University, Providence, RI 02912, USA
| | - Jen Q. Pan
- Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
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Yang Y, Zeng Q, Cheng M, Niu X, Xiangwei W, Gong P, Li W, Ma J, Zhang X, Yang X, Yang Z, Sun D, Zhou S, Liao J, Jiang Y, Zhang Y. GABRB3-related epilepsy: novel variants, clinical features and therapeutic implications. J Neurol 2022; 269:2649-2665. [PMID: 34698933 DOI: 10.1007/s00415-021-10834-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 09/28/2021] [Accepted: 09/29/2021] [Indexed: 02/08/2023]
Abstract
OBJECTIVE This study aimed to comprehensively examine the genetic and phenotypic aspects of GABRB3-related epilepsy and to explore the potential prospects of personalized medicine. METHODS Genetic testing was conducted in all epilepsy patients without acquired factors for epilepsy. Through the collaboration of multicenter in China, we analyzed the genotype-phenotype correlation and antiepileptic therapy of 26 patients with GABRB3-related epilepsy. RESULTS Thirteen GABRB3 variants were novel, and 25 were de novo. The seizure onset age ranged from 1 to 21 months (median age 3.75 months). Seizure types predominated including focal seizures (92.3%), generalized tonic-clonic seizures (23.1%), and epileptic spasms (15.4%). Clinical features included cluster seizures (80.8%), fever sensitivity (53.8%), and developmental delay (96.2%). Neuroimaging was abnormal in 10 patients, including dysplasia of the cerebral cortex, dysplasia of the frontal and temporal cortex, delayed myelination, and corpus callosum dysplasia. Eleven patients were diagnosed with developmental and epileptic encephalopathy (DEE), four with West syndrome, three with epilepsy of infancy with migrating focal seizures (EIMFS), one with epilepsy with myoclonic-atonic seizures (EMAS), one with Dravet syndrome, and one with febrile seizures plus (FS+). Seizures were controlled in 57.7% of patients by valproate, levetiracetam, or perampanel in the majority. CONCLUSIONS The clinical features of GABRB3-related epilepsy included seizure onset in early infancy, cluster seizures and fever sensitivity. Most patients manifest severe epilepsy phenotypes. Valproate, levetiracetam and perampanel seem to have positive effects on seizure control for patients with GABRB3 variants.
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Affiliation(s)
- Ying Yang
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Qi Zeng
- Department of Neurology, Shenzhen Children's Hospital, Shenzhen, 518038, China
| | - Miaomiao Cheng
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Xueyang Niu
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Wenshu Xiangwei
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Pan Gong
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Wenhui Li
- Department of Neurology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, 201102, China
| | - Jiehui Ma
- Department of Neurology, Wuhan Children's Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430015, China
| | - Xiaoli Zhang
- Department of Pediatrics, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Xiaoling Yang
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Zhixian Yang
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Dan Sun
- Department of Neurology, Wuhan Children's Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430015, China
| | - Shuizhen Zhou
- Department of Neurology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, 201102, China
| | - Jianxiang Liao
- Department of Neurology, Shenzhen Children's Hospital, Shenzhen, 518038, China
| | - Yuwu Jiang
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Yuehua Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China.
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21
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Johannesen KM, Iqbal S, Guazzi M, Mohammadi NA, Pérez-Palma E, Schaefer E, De Saint Martin A, Abiwarde MT, McTague A, Pons R, Piton A, Kurian MA, Ambegaonkar G, Firth H, Sanchis-Juan A, Deprez M, Jansen K, De Waele L, Briltra EH, Verbeek NE, van Kempen M, Fazeli W, Striano P, Zara F, Visser G, Braakman HMH, Haeusler M, Elbracht M, Vaher U, Smol T, Lemke JR, Platzer K, Kennedy J, Klein KM, Au PYB, Smyth K, Kaplan J, Thomas M, Dewenter MK, Dinopoulos A, Campbell AJ, Lal D, Lederer D, Liao VWY, Ahring PK, Møller RS, Gardella E. Structural mapping of GABRB3 variants reveals genotype-phenotype correlations. Genet Med 2022; 24:681-693. [PMID: 34906499 DOI: 10.1016/j.gim.2021.11.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 09/30/2021] [Accepted: 11/05/2021] [Indexed: 12/27/2022] Open
Abstract
PURPOSE Pathogenic variants in GABRB3 have been associated with a spectrum of phenotypes from severe developmental disorders and epileptic encephalopathies to milder epilepsy syndromes and mild intellectual disability (ID). In this study, we analyzed a large cohort of individuals with GABRB3 variants to deepen the phenotypic understanding and investigate genotype-phenotype correlations. METHODS Through an international collaboration, we analyzed electro-clinical data of unpublished individuals with variants in GABRB3, and we reviewed previously published cases. All missense variants were mapped onto the 3-dimensional structure of the GABRB3 subunit, and clinical phenotypes associated with the different key structural domains were investigated. RESULTS We characterized 71 individuals with GABRB3 variants, including 22 novel subjects, expressing a wide spectrum of phenotypes. Interestingly, phenotypes correlated with structural locations of the variants. Generalized epilepsy, with a median age at onset of 12 months, and mild-to-moderate ID were associated with variants in the extracellular domain. Focal epilepsy with earlier onset (median: age 4 months) and severe ID were associated with variants in both the pore-lining helical transmembrane domain and the extracellular domain. CONCLUSION These genotype-phenotype correlations will aid the genetic counseling and treatment of individuals affected by GABRB3-related disorders. Future studies may reveal whether functional differences underlie the phenotypic differences.
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Affiliation(s)
- Katrine M Johannesen
- Department of Epilepsy Genetics and Personalized Treatment, The Danish Epilepsy Centre "Filadelfia", Dianalund, Denmark; Department of Regional Health Research, University of Southern Denmark, Odense, Denmark
| | - Sumaiya Iqbal
- The Center for the Development of Therapeutics (CDOT), Broad Institute of MIT and Harvard, Cambridge, MA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA; Analytic & Translational Genetics Unit (ATGU), Department of Medicine, Massachusetts General Hospital, Boston, MA
| | - Milena Guazzi
- Department of Medicine, University of Genoa, Genoa, Italy; Department of Clinical Neurophysiology, The Danish Epilepsy Centre "Filadelfia", Dianalund, Denmark
| | - Nazanin A Mohammadi
- Department of Epilepsy Genetics and Personalized Treatment, The Danish Epilepsy Centre "Filadelfia", Dianalund, Denmark; Department of Regional Health Research, University of Southern Denmark, Odense, Denmark
| | - Eduardo Pérez-Palma
- Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
| | - Elise Schaefer
- Service de Génétique Médicale, Institut de Génétique Médicale d'Alsace, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Anne De Saint Martin
- Department of Pediatric Neurology, Strasbourg University Hospital, Strasbourg, France
| | | | - Amy McTague
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, London, United Kingdom; Department of Neurology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | - Roser Pons
- First Department of Pediatrics, "I Agia Sofia" Children Hospital, National & Kapodistrian University of Athens, Athens, Greece
| | - Amelie Piton
- Laboratoire de diagnostic génétique, Hôpital Civil, CHRU de Strasburg, Strasbourg, France
| | - Manju A Kurian
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, London, United Kingdom; Department of Neurology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | - Gautam Ambegaonkar
- Department of Paediatric Neurology, Child Development Centre, Addenbrookes Hospital, Cambridge, United Kingdom
| | - Helen Firth
- Department of Clinical Genetics, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom
| | - Alba Sanchis-Juan
- NIHR BioResource, Department of Haematology, University of Cambridge, United Kingdom
| | - Marie Deprez
- CNRS, IPMC, Université Côte d'Azur, Sophia-Antipolis, France
| | - Katrien Jansen
- Department of Pediatric Neurology, University Hospitals KU Leuven, Leuven, Belgium
| | - Liesbeth De Waele
- Department of Pediatric Neurology, University Hospitals KU Leuven, Leuven, Belgium; Department of Development and Regeneration, Kulak Kortrijk Campus, Kortrijk, Belgium
| | - Eva H Briltra
- Department of Genetics, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Nienke E Verbeek
- Department of Genetics, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Marjan van Kempen
- Department of Genetics, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Walid Fazeli
- Department of Pediatric Neurology, University Hospital Bonn, Bonn, Germany
| | - Pasquale Striano
- IRCCS Giannina Gaslini Institute, Genova, Italy; Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genova, Genova, Italy
| | - Federico Zara
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genova, Genova, Italy; Laboratory of Neurogenetics and Neuroscience, IRCCS Giannina Gaslini Institute, Genova, Italy
| | - Gerhard Visser
- Stichting Epilepsie Instellingen Nederland (SEIN), Hoofddorp, The Netherlands
| | - Hilde M H Braakman
- Department of Pediatric Neurology, Amalia Children's Hospital, Radboud University Medical Center, Nijmegen, The Netherlands; Department of Neurology, Academic Center for Epileptology Kempenhaeghe & Maastricht University Medical Center, Heeze, The Netherlands
| | - Martin Haeusler
- Division of Neuropediatrics and Social Pediatrics, Department of Pediatrics, University Hospital RWTH Aachen, Aachen, Germany
| | - Miriam Elbracht
- Institute of Human Genetics, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
| | - Ulvi Vaher
- Children's Clinic of Tartu University Hospital, Tartu, Estonia; ERN EpiCARE, Tartu, Estonia
| | - Thomas Smol
- Institut de Genetique Medicale, CHU Lille, Universite de Lille, Lille, France
| | - Johannes R Lemke
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
| | - Konrad Platzer
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
| | - Joanna Kennedy
- Clinical Genetics Service, University Hospitals Bristol NHS Foundation Trust, St Michael's Hospital, Bristol, United Kingdom
| | - Karl Martin Klein
- Department of Clinical Neurosciences, Hotchkiss Brain Institute & Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; Department of Medical Genetics, Hotchkiss Brain Institute & Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; Department of Community Health Sciences, Hotchkiss Brain Institute & Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Center of Neurology and Neurosurgery, University Hospital, Goethe-University Frankfurt, Frankfurt, Germany; Center for Personalized Translational Epilepsy Research (CePTER), Goethe University Frankfurt, Frankfurt, Germany
| | - Ping Yee Billie Au
- Department of Medical Genetics, Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Kimberly Smyth
- Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Julie Kaplan
- Division of Medical Genetics, Nemours A.I. duPont Hospital for Children, Wilmington, DE
| | - Morgan Thomas
- Precision Medicine/Genetic Testing Stewardship Program, Nemours A.I. duPont Hospital for Children, Wilmington, DE
| | - Malin K Dewenter
- Institute of Human Genetics, Universitätsmedizin, Johannes Gutenberg-University, Mainz Institut für Humangenetik, Mainz, Germany
| | - Argirios Dinopoulos
- Third Department of Pediatrics, Attiko University Hospital, University of Athens, Haidari, Greece
| | - Arthur J Campbell
- The Center for the Development of Therapeutics (CDOT), Broad Institute of MIT and Harvard, Cambridge, MA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA
| | - Dennis Lal
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA; Genomic Medicine Institute, Cleveland Clinic Lerner Research Institute, Cleveland, OH; Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH; Cologne Center for Genomics (CCG), University of Cologne, Cologne, Germany
| | - Damien Lederer
- Centre de Génétique Humaine, Institut de Pathologie et de Génétique, Charleroi, Belgium
| | - Vivian W Y Liao
- Brain and Mind Centre, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Philip K Ahring
- Brain and Mind Centre, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Rikke S Møller
- Department of Epilepsy Genetics and Personalized Treatment, The Danish Epilepsy Centre "Filadelfia", Dianalund, Denmark; Department of Regional Health Research, University of Southern Denmark, Odense, Denmark
| | - Elena Gardella
- Department of Epilepsy Genetics and Personalized Treatment, The Danish Epilepsy Centre "Filadelfia", Dianalund, Denmark; Department of Regional Health Research, University of Southern Denmark, Odense, Denmark; Department of Medicine, University of Genoa, Genoa, Italy; Department of Clinical Neurophysiology, The Danish Epilepsy Centre "Filadelfia", Dianalund, Denmark.
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22
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Distinct Functional Alterations and Therapeutic Options of Two Pathological De Novo Variants of the T292 Residue of GABRA1 Identified in Children with Epileptic Encephalopathy and Neurodevelopmental Disorders. Int J Mol Sci 2022; 23:ijms23052723. [PMID: 35269865 PMCID: PMC8911174 DOI: 10.3390/ijms23052723] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/25/2022] [Accepted: 02/27/2022] [Indexed: 11/17/2022] Open
Abstract
Mutations of GABAAR have reportedly led to epileptic encephalopathy and neurodevelopmental disorders. We have identified a novel de novo T292S missense variant of GABRA1 from a pediatric patient with grievous global developmental delay but without obvious epileptic activity. This mutation coincidentally occurs at the same residue as that of a previously reported GABRA1 variant T292I identified from a pediatric patient with severe epilepsy. The distinct phenotypes of these two patients prompted us to compare the impacts of the two mutants on the receptor function and to search for suitable therapeutics. In this study, we used biochemical techniques and patch-clamp recordings in HEK293 cells overexpressing either wild-type or mutated rat recombinant GABAARs. We found that the α1T292S variant significantly increased GABA-evoked whole-cell currents, shifting the dose-response curve to the left without altering the maximal response. In contrast, the α1T292I variant significantly reduced GABA-evoked currents, shifting the dose-response curve to the right with a severely diminished maximum response. Single-channel recordings further revealed that the α1T292S variant increased, while the α1T292I variant decreased the GABAAR single-channel open time and open probability. Importantly, we found that the T292S mutation-induced increase in GABAAR function could be fully normalized by the negative GABAAR modulator thiocolchicoside, whereas the T292I mutation-induced impairment of GABAAR function was largely rescued with a combination of the GABAAR positive modulators diazepam and verapamil. Our study demonstrated that α1T292 is a critical residue for controlling GABAAR channel gating, and mutations at this residue may produce opposite impacts on the function of the receptors. Thus, the present work highlights the importance of functionally characterizing each individual GABAAR mutation for ensuring precision medicine.
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23
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Cali E, Rocca C, Salpietro V, Houlden H. Epileptic Phenotypes Associated With SNAREs and Related Synaptic Vesicle Exocytosis Machinery. Front Neurol 2022; 12:806506. [PMID: 35095745 PMCID: PMC8792400 DOI: 10.3389/fneur.2021.806506] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 11/16/2021] [Indexed: 01/29/2023] Open
Abstract
SNAREs (soluble N-ethylmaleimide sensitive factor attachment protein receptor) are an heterogeneous family of proteins that, together with their key regulators, are implicated in synaptic vesicle exocytosis and synaptic transmission. SNAREs represent the core component of this protein complex. Although the specific mechanisms of the SNARE machinery is still not completely uncovered, studies in recent years have provided a clearer understanding of the interactions regulating the essential fusion machinery for neurotransmitter release. Mutations in genes encoding SNARE proteins or SNARE complex associated proteins have been associated with a variable spectrum of neurological conditions that have been recently defined as “SNAREopathies.” These include neurodevelopmental disorder, autism spectrum disorder (ASD), movement disorders, seizures and epileptiform abnormalities. The SNARE phenotypic spectrum associated with seizures ranges from simple febrile seizures and infantile spasms, to severe early-onset epileptic encephalopathies. Our study aims to review and delineate the epileptic phenotypes associated with dysregulation of synaptic vesicle exocytosis and transmission, focusing on the main proteins of the SNARE core complex (STX1B, VAMP2, SNAP25), tethering complex (STXBP1), and related downstream regulators.
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Affiliation(s)
- Elisa Cali
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Clarissa Rocca
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Vincenzo Salpietro
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Henry Houlden
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, United Kingdom
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24
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Umeda R, Teranishi H, Hada K, Shimizu N, Shiraishi H, Urushibata H, Shaohong L, Shide M, Apolinario MEC, Higa R, Shikano K, Shin T, Mimata H, Hikida T, Hanada T, Hanada R. Vrk2 deficiency elicits aggressive behavior in female zebrafish. Genes Cells 2022; 27:254-265. [DOI: 10.1111/gtc.12924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 01/25/2022] [Accepted: 01/25/2022] [Indexed: 11/29/2022]
Affiliation(s)
- Ryohei Umeda
- Department of Neurophysiology Faculty of Medicine Oita University Oita Japan
| | - Hitoshi Teranishi
- Department of Neurophysiology Faculty of Medicine Oita University Oita Japan
| | - Kazumasa Hada
- Department of Cell Biology Faculty of Medicine Oita University Oita Japan
| | - Nobuyuki Shimizu
- Department of Cell Biology Faculty of Medicine Oita University Oita Japan
| | - Hiroshi Shiraishi
- Department of Cell Biology Faculty of Medicine Oita University Oita Japan
| | | | - Lai Shaohong
- Department of Cell Biology Faculty of Medicine Oita University Oita Japan
| | - Masahito Shide
- Department of Neurophysiology Faculty of Medicine Oita University Oita Japan
| | | | - Ryoko Higa
- Department of Neurophysiology Faculty of Medicine Oita University Oita Japan
| | - Kenshiro Shikano
- Department of Neurophysiology Faculty of Medicine Oita University Oita Japan
| | - Toshitaka Shin
- Department of Urology Faculty of Medicine Oita University Oita Japan
| | - Hiromitsu Mimata
- Department of Urology Faculty of Medicine Oita University Oita Japan
| | - Takatoshi Hikida
- Laboratory for Advanced Brain Functions Institute for Protein Research Osaka University Osaka Japan
| | - Toshikatsu Hanada
- Department of Cell Biology Faculty of Medicine Oita University Oita Japan
| | - Reiko Hanada
- Department of Neurophysiology Faculty of Medicine Oita University Oita Japan
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25
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Su T, Chen ML, Liu LH, Meng H, Tang B, Liu XR, Liao WP. Critical Role of E1623 Residue in S3-S4 Loop of Nav1.1 Channel and Correlation Between Nature of Substitution and Functional Alteration. Front Mol Neurosci 2022; 14:797628. [PMID: 35082603 PMCID: PMC8785683 DOI: 10.3389/fnmol.2021.797628] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 12/15/2021] [Indexed: 12/24/2022] Open
Abstract
Objective: An overwhelming majority of the genetic variants associated with genetic disorders are missense. The association between the nature of substitution and the functional alteration, which is critical in determining the pathogenicity of variants, remains largely unknown. With a novel missense variant (E1623A) identified from two epileptic cases, which occurs in the extracellular S3-S4 loop of Nav1.1, we studied functional changes of all latent mutations at residue E1623, aiming to understand the relationship between substitution nature and functional alteration. Methods: Six latent mutants with amino acid substitutions at E1623 were generated, followed by measurements of their electrophysiological alterations. Different computational analyses were used to parameterize the residue alterations. Results: Structural modeling indicated that the E1623 was located in the peripheral region far from the central pore, and contributed to the tight turn of the S3-S4 loop. The E1623 residue exhibited low functional tolerance to the substitutions with the most remarkable loss-of-function found in E1623A, including reduced current density, less steady-state availability of activation and inactivation, and slower recovery from fast inactivation. Correlation analysis between electrophysiological parameters and the parameterized physicochemical properties of different residues suggested that hydrophilicity of side-chain at E1623 might be a crucial contributor for voltage-dependent kinetics. However, none of the established algorithms on the physicochemical variations of residues could well predict changes in the channel conductance property indicated by peak current density. Significance: The results established the important role of the extracellular S3-S4 loop in Nav1.1 channel gating and proposed a possible effect of local conformational loop flexibility on channel conductance and kinetics. Site-specific knowledge of protein will be a fundamental task for future bioinformatics.
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Affiliation(s)
- Tao Su
- Department of Neurology, Institute of Neuroscience, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies of the Ministry of Education of China, Guangzhou, China
| | - Meng-Long Chen
- Department of Neurology, Institute of Neuroscience, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies of the Ministry of Education of China, Guangzhou, China
| | - Li-Hong Liu
- Department of Neurology, Institute of Neuroscience, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies of the Ministry of Education of China, Guangzhou, China
| | - Hen Meng
- Department of Neurology, Institute of Neuroscience, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies of the Ministry of Education of China, Guangzhou, China
| | - Bin Tang
- Department of Neurology, Institute of Neuroscience, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies of the Ministry of Education of China, Guangzhou, China
| | - Xiao-Rong Liu
- Department of Neurology, Institute of Neuroscience, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies of the Ministry of Education of China, Guangzhou, China
| | - Wei-Ping Liao
- Department of Neurology, Institute of Neuroscience, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies of the Ministry of Education of China, Guangzhou, China
- *Correspondence: Wei-Ping Liao
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26
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Dong M, Zhang T, Hu R, Li M, Wang G, Liu X. Genotype and phenotype spectrum of 10 children with STXBP1 gene-related encephalopathy and epilepsy. Front Pediatr 2022; 10:1010886. [PMID: 36440324 PMCID: PMC9695404 DOI: 10.3389/fped.2022.1010886] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 10/26/2022] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVE STXBP1 mutations are associated with early onset epileptic encephalopathy (EOEE). Our aim was to explore the phenotype spectrum, clinical treatment and prognosis of STXBP1-related encephalopathy (STXBP1-E). METHODS Clinical and genetic data were collected from 10 patients with STXBP1 mutations. These patients were examined and diagnosed from 2015 to 2021 at the Pediatric Department of Qilu Hospital. Blood samples were collected and sequenced by next generation sequencing and Candidate pathogenic variants were identified using Sanger sequencing in all family members. RESULTS All of the patients showed severe epilepsy, varying degrees of intellectual disability and delayed motor. The patients developed multiple seizure types and abnormal electroencephalography (EEG) results at onset, and focal seizures were the most frequent seizure type. Among the patients, 2 were diagnosed with Ohtahara syndrome, 2 patient was diagnosed with West syndrome. The other 6 patients could not be diagnosed with any specifically recognized epilepsy syndrome. Five of the 10 patients had a history of fever with seizures, 4 of whom had eliminated intracranial infection according to the results of cerebrospinal fluid (CSF) examinations, and the other patient was diagnosed with anti-myelin oligodendrocyte glycoprotein (MOG) -associated encephalitis. We identified one patient with a complete deletion of STXBP1 and 9 patients with de novo heterozygous mutations of STXBP1. Among those mutations, 4 were novel (c.56°C > T, c.1315A > T, c.751G > C, and c.554_559del), and 5 had been previously reported [c.364C > T, c.569G > A (2 cases), c.748C > T, and c.1651C > T]. For 8 of our patients, different combinations of anti-seizure medications (ASMs) led to seizure freedom. One patient with MOG antibodies in his serum obtained a poor therapeutic effect from the traditional ASMs treatment, so he had to achieve seizure-free status through vagus nerve stimulation (VNS), which had little effect on his psychomotor ability. Fortunately, in one case, patient psychomotor ability was improved through VNS. CONCLUSION Our study shows that STXBP1 screening should be considered in patients with neonatal seizures with intellectual disability, and frequent seizures with fever should also be considered with the STXBP1 mutation when intracranial infection is eliminated. VNS has expanded outcome measures to include behavioral and developmental function as well as seizure control.
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Affiliation(s)
- Meng Dong
- Department of Pediatrics, Qilu Hospital, Shandong University, Jinan, China
| | - Tianyu Zhang
- Department of Pediatrics, Qilu Hospital, Shandong University, Jinan, China
| | - Ruimei Hu
- Department of Pediatrics, Qilu Hospital, Shandong University, Jinan, China
| | - Meng Li
- Department of Pediatrics, Qilu Hospital, Shandong University, Jinan, China
| | - Guan Wang
- Department of Pediatrics, Qilu Hospital, Shandong University, Jinan, China
| | - Xinjie Liu
- Department of Pediatrics, Qilu Hospital, Shandong University, Jinan, China
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27
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Lan Y, Yi S, Li M, Wang J, Yang Q, Yi S, Chen F, Huang L, Ruan Y, Shen Y, Luo J, Qin Z. Case Report: Christianson Syndrome Caused by SLC9A6 Mutation: From Case to Genotype-Phenotype Analysis. Front Genet 2021; 12:783841. [PMID: 34987551 PMCID: PMC8721738 DOI: 10.3389/fgene.2021.783841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 11/30/2021] [Indexed: 11/13/2022] Open
Abstract
Christianson syndrome (CS) is an X-linked neurodevelopmental syndrome characterized by microcephaly, epilepsy, ataxia, and severe generalized developmental delay. Pathogenic mutations in the SLC9A6 gene, which encodes the Na+/H+ exchanger protein member 6 (NHE6), are associated with CS and autism spectrum disorder in males. In this study, whole exome sequencing (WES) and Sanger sequencing revealed a novel de novo frameshift variant c.1548_1549insT of SLC9A6 in a 14-month-old boy with early-onset seizures. According to The American College of Medical Genetics and Genomics (ACMG)/the Association for Molecular Pathology (AMP) guidelines, the variant was classified as pathogenic. The proband presented with several core symptoms of typical epilepsy, including microcephaly, motor delay, distal muscle weakness, micrognathia, occasional unprovoked laughter, swallowing and speech difficulties. Electroencephalography (EEG) showed spikes-slow waves in frontal pole, frontal, anterior temporal and frontal midline point areas. Gesell development schedules (GDS) indicated generalized developmental delay. We also summarized all the reported variants and analyzed the correlation of genotype and phenotype of CS. Our study extends the mutation spectrum of the SLC9A6 gene, and it might imply that the phenotypes of CS are not correlated with SLC9A6 genotypes.
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Affiliation(s)
- Yueyun Lan
- Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Guangxi Key Laboratory of Precision Medicine for Genetic Diseases, Guangxi Key Laboratory of Birth Defects and Stem Cell Biobank, Guangxi Key Laboratory of Birth Defects Research and Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Genetic and Metabolic Central Laboratory, Guangxi Birth Defects Research and Prevention Institute, Nanning, China
| | - Sheng Yi
- Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Guangxi Key Laboratory of Precision Medicine for Genetic Diseases, Guangxi Key Laboratory of Birth Defects and Stem Cell Biobank, Guangxi Key Laboratory of Birth Defects Research and Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Genetic and Metabolic Central Laboratory, Guangxi Birth Defects Research and Prevention Institute, Nanning, China
| | - Mengting Li
- Genetic and Metabolic Central Laboratory, Guangxi Birth Defects Research and Prevention Institute, Nanning, China
- The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Jinqiu Wang
- Pediatrics Department, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Qi Yang
- Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Guangxi Key Laboratory of Precision Medicine for Genetic Diseases, Guangxi Key Laboratory of Birth Defects and Stem Cell Biobank, Guangxi Key Laboratory of Birth Defects Research and Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Genetic and Metabolic Central Laboratory, Guangxi Birth Defects Research and Prevention Institute, Nanning, China
| | - Shang Yi
- Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Guangxi Key Laboratory of Precision Medicine for Genetic Diseases, Guangxi Key Laboratory of Birth Defects and Stem Cell Biobank, Guangxi Key Laboratory of Birth Defects Research and Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Genetic and Metabolic Central Laboratory, Guangxi Birth Defects Research and Prevention Institute, Nanning, China
| | - Fei Chen
- Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Guangxi Key Laboratory of Precision Medicine for Genetic Diseases, Guangxi Key Laboratory of Birth Defects and Stem Cell Biobank, Guangxi Key Laboratory of Birth Defects Research and Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Genetic and Metabolic Central Laboratory, Guangxi Birth Defects Research and Prevention Institute, Nanning, China
| | - Limei Huang
- Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Guangxi Key Laboratory of Precision Medicine for Genetic Diseases, Guangxi Key Laboratory of Birth Defects and Stem Cell Biobank, Guangxi Key Laboratory of Birth Defects Research and Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Genetic and Metabolic Central Laboratory, Guangxi Birth Defects Research and Prevention Institute, Nanning, China
| | - Yiyan Ruan
- Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Guangxi Key Laboratory of Precision Medicine for Genetic Diseases, Guangxi Key Laboratory of Birth Defects and Stem Cell Biobank, Guangxi Key Laboratory of Birth Defects Research and Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Yiping Shen
- Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Guangxi Key Laboratory of Precision Medicine for Genetic Diseases, Guangxi Key Laboratory of Birth Defects and Stem Cell Biobank, Guangxi Key Laboratory of Birth Defects Research and Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Genetic and Metabolic Central Laboratory, Guangxi Birth Defects Research and Prevention Institute, Nanning, China
- Department of Genetics, Harvard Medical School, Boston, MA, United States
| | - Jingsi Luo
- Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Guangxi Key Laboratory of Precision Medicine for Genetic Diseases, Guangxi Key Laboratory of Birth Defects and Stem Cell Biobank, Guangxi Key Laboratory of Birth Defects Research and Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Genetic and Metabolic Central Laboratory, Guangxi Birth Defects Research and Prevention Institute, Nanning, China
- *Correspondence: Jingsi Luo, ; Zailong Qin,
| | - Zailong Qin
- Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Guangxi Key Laboratory of Precision Medicine for Genetic Diseases, Guangxi Key Laboratory of Birth Defects and Stem Cell Biobank, Guangxi Key Laboratory of Birth Defects Research and Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Genetic and Metabolic Central Laboratory, Guangxi Birth Defects Research and Prevention Institute, Nanning, China
- *Correspondence: Jingsi Luo, ; Zailong Qin,
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Hu K, Liang P. Transcriptome Analysis Reveals Higher Levels of Mobile Element-Associated Abnormal Gene Transcripts in Temporal Lobe Epilepsy Patients. Front Genet 2021; 12:767341. [PMID: 34868252 PMCID: PMC8640520 DOI: 10.3389/fgene.2021.767341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 10/25/2021] [Indexed: 11/13/2022] Open
Abstract
Mesial temporal lobe epilepsy (MTLE) is the most common form of epilepsy, and temporal lobe epilepsy patients with hippocampal sclerosis (TLE-HS) show worse drug treatment effects and prognosis. TLE has been shown to have a genetic component, but its genetic research has been mostly limited to coding sequences of genes with known association to epilepsy. Representing a major component of the genome, mobile elements (MEs) are believed to contribute to the genetic etiology of epilepsy despite limited research. We analyzed publicly available human RNA-seq-based transcriptome data to determine the role of mobile elements in epilepsy by performing de novo transcriptome assembly, followed by identification of spliced gene transcripts containing mobile element (ME) sequences (ME-transcripts), to compare their frequency across different sample groups. Significantly higher levels of ME-transcripts in hippocampal tissues of epileptic patients, particularly in TLE-HS, were observed. Among ME classes, short interspersed nuclear elements (SINEs) were shown to be the most frequent contributor to ME-transcripts, followed by long interspersed nuclear elements (LINEs) and DNA transposons. These ME sequences almost in all cases represent older MEs normally located in the intron sequences. For protein coding genes, ME sequences were mostly found in the 3'-UTR regions, with a significant portion also in the coding sequences (CDSs), leading to reading frame disruption. Genes associated with ME-transcripts showed enrichment for the mRNA splicing process and an apparent bias in epileptic transcriptomes toward neural- and epilepsy-associated genes. The findings of this study suggest that abnormal splicing involving MEs, leading to loss of functions in critical genes, plays a role in epilepsy, particularly in TLE-HS, thus providing a novel insight into the molecular mechanisms underlying epileptogenesis.
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Affiliation(s)
- Kai Hu
- Department of Biological Sciences, Brock University, St. Catharines, ON, Canada.,Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Ping Liang
- Department of Biological Sciences, Brock University, St. Catharines, ON, Canada
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Zhang X, Wu X, Liu H, Song T, Jiang Y, He H, Yang S, Xie Y. Christianson syndrome: A novel splicing variant of SLC9A6 causes exon skipping in a Chinese boy and a literature review. J Clin Lab Anal 2021; 36:e24123. [PMID: 34791706 PMCID: PMC8761434 DOI: 10.1002/jcla.24123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/26/2021] [Accepted: 10/27/2021] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Variants in the endosomal solute carrier family 9 member A6 (SLC9A6)/(Na+ ,K+ )/H+ exchanger 6 (NHE6) gene have been linked to epilepsy, speech loss, truncal ataxia, hyperkinesia, and postnatal microcephaly. METHODS In the present study, we evaluated genetic alterations in a 3-year-old Chinese boy displayed features of epilepsy, psychomotor retardation, microcephaly, low body weight, difficulty in feeding, excessive movement, attention loss, ataxia, and cerebellar atrophy and his healthy family using WES method. The identified variant was further confirmed by Sanger sequencing method. Finally, minigene assays were used to verify whether the novel SLC9A6 intronic variant influenced the normal splicing of mRNA. RESULTS We identified a novel hemizygous splicing variant [NM_001042537.1: c.1463-1G>A] in SLC9A6 by trio-based exome sequencing. The minigene expression in vitro confirmed the splicing variant altered a consensus splice acceptor site of SLC9A6 intron 11, resulting in skipping over exon 12. CONCLUSIONS Our finding extends the catalog of pathogenic intronic variants affecting SLC9A6 pre-mRNA splicing and provides a basis for the genetic diagnosis of CS.
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Affiliation(s)
- Xiaoge Zhang
- Department of pediatrics, Northwest Women's and Children's Hospital, Xi'an, China
| | - Xiaofang Wu
- Department of pediatrics, Northwest Women's and Children's Hospital, Xi'an, China
| | - Hongli Liu
- Department of pediatrics, Northwest Women's and Children's Hospital, Xi'an, China
| | - Tingting Song
- Department of pediatrics, Northwest Women's and Children's Hospital, Xi'an, China
| | - Yongsheng Jiang
- Department of pediatrics, Northwest Women's and Children's Hospital, Xi'an, China
| | - Hanhan He
- Department of pediatrics, Northwest Women's and Children's Hospital, Xi'an, China
| | - Shaoqing Yang
- State Key Laboratory of Military Stomatology, Department of Oral Biology, School of Stomatology, Clinic of Oral Rare and Genetic Diseases, National Clinical Research Center for Oral Diseases, The Fourth Military Medical University, Xi'an, China
| | - Yun Xie
- Department of clinical laboratory, Northwest Women's and Children's Hospital, Xi'an, China
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Riikonen R. Could prevention of infantile spasms have been possible in a historical cohort of 31 tuberous sclerosis patients? Eur J Paediatr Neurol 2021; 35:153-157. [PMID: 34731702 DOI: 10.1016/j.ejpn.2021.10.010] [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: 05/24/2021] [Revised: 10/07/2021] [Accepted: 10/23/2021] [Indexed: 10/20/2022]
Abstract
UNLABELLED Efforts to prevent epilepsy in infants with tuberous sclerosis complex (TSC) has been the focus of EPISTOP. PURPOSE The present study was carried out to evaluate whether prevention could have been realistic. METHODS A retrospective analysis by hospital chart review of 31 patients with TSC and infantile spasms (practically all patients) admitted to two tertiary hospitals, Children's Hospital, University of Helsinki and Kuopio in 1980-2000. Clinical history, early cognitive development, early clinical signs of TSC, clinical signs of suspicious seizures, first seizures and EEG, response to adrenocorticotropic hormone (ACTH) therapy, EEG and brain imaging were evaluated. RESULTS Early development prior the spasms was apparently normal in 25 (80%). The first EEG ever performed for a child showed hypsarrhythmia in 16 (51%) or modified hypsarrhythmia in 10 (32%). Treatment lag was short (0-4, mean 2 weeks) and the primary response to ACTH favorable in 19 (64%). Etiological diagnostic workup of IS revealed TSC. In one single case (3%) the diagnosis of TSC could be made at birth due to a congenital cardiac rhabdomyoma. Three other rhabomyomas were diagnosed later. In brain imaging, subependymal periventricular calcifications or hypodense areas were seen in every patient at onset of IS. Other organ manifestations of TSC were retinal phakomas (6), polycystic kidneys (2), and renal angiolipomatosis (1). CONCLUSIONS Preventive treatment of epileptic discharges could have been possible in a single case of neonatal rhabdomyoma suggesting that preventive treatment is challenging in everyday practice. The main obstacle is the delay of TSC diagnosis.
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Affiliation(s)
- Raili Riikonen
- University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland, Postal Address: Yliopistonranta 1, FI-70110, Kuopio, Finland.
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Xiang R, Xu J, Yu H, Chen Q, Huang Y, Li Z, Yu C, Cui R. Effects of carbamazepine and sodium valproate on efficacy, cognitive function and uric acid in epileptic patients with first generalized seizure. Am J Transl Res 2021; 13:9778-9783. [PMID: 34540109 PMCID: PMC8430124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 03/29/2021] [Indexed: 06/13/2023]
Abstract
OBJECTIVE To investigate the effects of carbamazepine and sodium valproate on efficacy, cognitive function and uric acid in epileptic patients with first generalized seizure. METHODS 120 epilepsy patients with first generalized seizure who admitted to our hospital from March 2017 to March 2019, were selected and randomly divided into carbamazepine-group and sodium valproate-group, with 60 objects in each group. Both groups of patients received medication for one year. Subsequently, the changes in clinical efficacy, cognitive function, and blood uric acid of the two groups of patients 1 year after treatment were compared, and the correlation between blood uric acid and cognitive function was analyzed between the two groups. RESULTS The two groups had statistically insignificant difference in the total effective rate (P>0.05). The cognitive function scores of the two groups after 6 months and 1 year of treatment were critically higher than those before treatment (P<0.05), and the comparison of cognitive function and blood uric acid degree between groups before treatment, 6 months after treatment and 1 year after treatment had statistically insignificant difference (P>0.05). There was a significant positive correlation between Mini-mental State Examination (MMSE) score of cognitive function and level of blood uric acid in patients with epilepsy (r=0.279, P=0.012). CONCLUSION Both carbamazepine and valproate can effectively improve the cognitive function of patients with first generalized seizure, and the two medications have similar clinical efficacy. Patient's blood uric acid level increases after treatment, and there is a affirmative relationship between blood uric acid level and cognitive function of patients.
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Affiliation(s)
- Ruping Xiang
- Department of Neurology, The Affiliated Changsha Hospital of Hunan Normal UniversityChangsha 410006, Hunan, China
| | - Juan Xu
- Department of Rehabilitation Medicine, The Affiliated Changsha Hospital of Hunan Normal UniversityChangsha 410006, Hunan, China
| | - Huiyun Yu
- Department of Neurology, The Affiliated Changsha Hospital of Hunan Normal UniversityChangsha 410006, Hunan, China
| | - Qiong Chen
- Department of Neurology, The Affiliated Changsha Hospital of Hunan Normal UniversityChangsha 410006, Hunan, China
| | - Yujuan Huang
- Department of Neurology, The Affiliated Changsha Hospital of Hunan Normal UniversityChangsha 410006, Hunan, China
| | - Zhi Li
- Department of Neurology, The Affiliated Changsha Hospital of Hunan Normal UniversityChangsha 410006, Hunan, China
| | - Cheng Yu
- Department of Neurology, The Affiliated Changsha Hospital of Hunan Normal UniversityChangsha 410006, Hunan, China
| | - Rong Cui
- Department of Intensive Care Unit, The Affiliated Changsha Hospital of Hunan Normal UniversityChangsha 410006, Hunan, China
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Khair AM, Salvucci AE. Phenotype Expression Variability in Children with GABRB3 Heterozygous Mutations. Oman Med J 2021; 36:e240. [PMID: 33854792 PMCID: PMC8019580 DOI: 10.5001/omj.2021.27] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 03/09/2020] [Indexed: 11/21/2022] Open
Abstract
GABRB3 gene is a recently identified gene located in 15q12 chromosome and encodes for gamma-aminobutyric acid (GABA) receptor subunit beta-3 protein, which is linked to the GABAA receptor. The gene is believed to share a role in inhibitory GABAergic synapses, GABA iron-gated channel function, and possible cellular response to histamine. The β3 subunit is expressed in cerebral grey matter, thalami, hippocampi, and cerebellum, among other structures. Faulty GABRB3 function is linked to several neurological disorders and clinical syndromes. However, the spectrum of such disorders is not yet well known. We present three case reports highlighting the potentially expanding clinical phenotype and variable expression in children with mutated GABRB3 gene.
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Affiliation(s)
- Abdulhafeez M Khair
- Thomas Jefferson University, Sidney Kimmel Medical College, duPont Hospital for Children, Wilmington DE, USA
| | - Alana E Salvucci
- Thomas Jefferson University, Sidney Kimmel Medical College, duPont Hospital for Children, Wilmington DE, USA
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Fontana A, Consentino MC, Motta M, Costanza G, Lo Bianco M, Marino S, Falsaperla R, Praticò AD. Syntaxin Binding Protein 1 Related Epilepsies. JOURNAL OF PEDIATRIC NEUROLOGY 2021. [DOI: 10.1055/s-0041-1727259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
AbstractSyntaxin binding protein 1 (STXBP1), commonly known as MUNC18–1, is a member of SEC1 family membrane trafficking proteins; their function consists in controlling the soluble N-ethylmaleimide-sensitive factor attachment protein receptors complex assembly, making them essentials regulators of vesicle fusion. The precise function and molecular mechanism through which Munc18–1 contributes to neurotransmitter releasing is not entirely understood, but several evidences suggest its probable role in exocytosis. In 2008, heterozygous de novo mutations in neuronal protein Munc18–1 were first referred as a cause of Ohtahara syndrome development. Currently, a wide examination of the published data proved that 3.1% of patients with severe epilepsy carry a pathogenic de novo mutation including STXBP1 and approximately 10.2% of early onset epileptic encephalopathy is due to an aberrant STXBP1 form codified by the mutated gene. STXBP1 mutations can be associated to a wide clinical heterogeneity. All affected individuals show developmental delay and approximately the 95% of cases have seizures and early onset epileptic encephalopathy, characterized by infantile spasms as the main consistent feature. Burst suppression pattern and hypsarrhythmia are the most frequent EEG anomalies. Other neuronal disorders include Rett syndrome and behavioral and movement disorders. Mild dysmorphic features have been detected in a small number of cases. No genotype–phenotype correlation has been reported. Management of STXBP1 encephalopathy requires a multidisciplinary approach, including epilepsy control and neurological rehabilitation. About 25% of patients are refractory to standard therapy. A single or combined antiepileptic drugs may be required. Several studies described vigabatrin, valproic acid, levetiracetam, topiramate, clobazam, and oxcarbazepine as effective in seizure control. Lamotrigine, zonisamide, and phenobarbital are also commonly used. To date, it remains unclear which therapy is the most effective. Severe morbidity and high mortality are inevitable consequences in some of these patients.
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Affiliation(s)
- Alessandra Fontana
- Pediatrics Postgraduate Residency Program, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, Catania, Italy
| | - Maria Chiara Consentino
- Pediatrics Postgraduate Residency Program, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, Catania, Italy
| | - Milena Motta
- Pediatrics Postgraduate Residency Program, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, Catania, Italy
| | - Giuseppe Costanza
- Pediatrics Postgraduate Residency Program, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, Catania, Italy
| | - Manuela Lo Bianco
- Pediatrics Postgraduate Residency Program, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, Catania, Italy
| | - Simona Marino
- Unit of Pediatrics and Pediatric Emergency, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
| | - Raffaele Falsaperla
- Unit of Pediatrics and Pediatric Emergency, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
- Unit of Neonatal Intensive Care and Neonatology, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
| | - Andrea D. Praticò
- Unit of Rare Diseases of the Nervous System in Childhood, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, Catania, Italy
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Brafa Musicoro V, Sortino V, Pecora G, Tosto M, Lo Bianco M, Soma R, Romano C, Falsaperla R, Praticò AD. Gamma-Aminobutyric Acid Type A Receptor Genes and Their Related Epilepsies. JOURNAL OF PEDIATRIC NEUROLOGY 2021. [DOI: 10.1055/s-0041-1727269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
AbstractGamma-aminobutyric acid type A (GABA-A) receptor subunit gene mutations, which include GABRA1, GABRB3, GABRD, and GABRG2, are often involved in several genetic epilepsy syndromes and other neuropsychiatric diseases like autism spectrum disorder, schizophrenia, and anxiety. GABA-A are ligand-gated ionic channels, and are involved firstly in the fast inhibitory synaptic transmission of the central nervous system. The GABA receptors include the ionotropic GABA-A and GABA-C receptors and the metabotropic GABA-B receptors. According to the site in which mutations occur, they cause disorders in channel opening, “lock-and-pull” receptor system functioning, and capable of causing a specific epilepsy phenotype. The aim of this article is to summarize the most recent literature findings, considering genetic mutations, clinical features, genotype/phenotype correlation, and therapy about neurodevelopment diseases correlated to GABA receptors dysfunction, in particular epilepsy. According to our findings, we conclude that further mutation analysis could permit genotype–phenotype correlation and give more information about the best efficient treatment, even if—at present—more clinical and genetic studies are necessary.
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Affiliation(s)
- Viviana Brafa Musicoro
- Pediatric Postgraduate Residency Program, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, Catania, Italy
| | - Vincenzo Sortino
- Pediatric Postgraduate Residency Program, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, Catania, Italy
| | - Giulia Pecora
- Pediatric Postgraduate Residency Program, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, Catania, Italy
| | - Monica Tosto
- Pediatric Postgraduate Residency Program, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, Catania, Italy
| | - Manuela Lo Bianco
- Pediatric Postgraduate Residency Program, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, Catania, Italy
| | - Rachele Soma
- Unit of Rare Diseases of the Nervous System in Childhood, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, Catania, Italy
| | | | - Raffaele Falsaperla
- Unit of Pediatrics and Pediatric Emergency, University Hospital “Policlinico Rodolico-San Marco”, Catania, Italy
- Unit of Neonatal Intensive Care and Neonatology, University Hospital “Policlinico Rodolico-San Marco”, Catania, Italy
| | - Andrea D. Praticò
- Unit of Rare Diseases of the Nervous System in Childhood, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, Catania, Italy
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Portale A, Comella M, Salomone G, Di Nora A, Marino L, Leonardi R, Praticò AD, Falsaperla R. The Spectrum of KCNQ2- and KCNQ3-Related Epilepsy. JOURNAL OF PEDIATRIC NEUROLOGY 2021. [DOI: 10.1055/s-0041-1727099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Abstract
KCNQ genes encode for a family of six transmembrane domains, single pore-loop, and K+ channel α-subunits that have a wide range of physiological correlates. In the brain, KCNQ2 and KCNQ3 heteromultimers are thought to underlie the M-current which is essential in raising the threshold for firing an action potential; mutations in these genes may cause several types of infantile epilepsies. KCNQ2-related disorders represent a continuum of overlapping neonatal epileptic phenotypes that range from KCNQ2 benign familial neonatal epilepsy (BFNE), a seizure disorder that occur in children who typically have a normal psychomotor development and are inherited as an autosomal dominant trait, to KCNQ2 early-onset epileptic encephalopathy (EOEE) as the result of a de novo pathogenic variant. KCNQ3-related disorders are rarer and include BFNE, benign familial infantile epilepsy and KCNQ3-related epileptic encephalopathy with intellectual disability with or without seizures and/or cortical visual impairment. For both KCNQ2- and KCNQ3-related disorders, it is possible to use several drugs for different classes of mutations (i.e., gain of function vs. loss of function), and usually their effects vary in relation to the clinical presentation and the phenotype of the patient. However, KCNQ2-EOEE patients have a worse response to treatment than KCNQ2-BFNE patients and usually become drug resistant with multiple daily seizures.
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Affiliation(s)
- Anna Portale
- Unit of Pediatrics, Avola Hospital, Siracusa, Italy
| | - Mattia Comella
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Giulia Salomone
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Alessandra Di Nora
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Lidia Marino
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Roberta Leonardi
- Unit of Rare Diseases of the Nervous System in Childhood, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, Catania, Italy
| | - Andrea D. Praticò
- Unit of Rare Diseases of the Nervous System in Childhood, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, Catania, Italy
| | - Raffaele Falsaperla
- Unit of Pediatrics and Pediatric Emergency, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
- Unit of Neonatal Intensive Care and Neonatology, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
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Lin CH, Chou IC, Hong SY. Genetic factors and the risk of drug-resistant epilepsy in young children with epilepsy and neurodevelopment disability: A prospective study and updated meta-analysis. Medicine (Baltimore) 2021; 100:e25277. [PMID: 33761731 PMCID: PMC8049163 DOI: 10.1097/md.0000000000025277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 03/03/2021] [Indexed: 11/26/2022] Open
Abstract
Drug-resistant epilepsy (DRE) affects 7% to 20% of children with epilepsy. Although some risk factors for DRE have been identified, the results have not been consistent. Moreover, data regarding the risk factors for epilepsy and its seizure outcome in the first 2 years of life are limited.We analyzed data for children aged 0 to 2 years with epilepsy and neurodevelopmental disability from January, 2013, through December, 2017. These patients were followed up to compare the risk of DRE in patients with genetic defect (genetic group) with that without genetic defect (nongenetic group). Additionally, we conducted a meta-analysis to identify the pooled prevalence of genetic factors in children with DRE.A total of 96 patients were enrolled. A total of 68 patients were enrolled in the nongenetic group, whereas 28 patients were enrolled in the genetic group. The overall DRE risk in the genetic group was 6.5 times (95% confidence interval [CI], 2.15-19.6; p = 0.03) higher than that in the nongenetic group. Separately, a total of 1308 DRE patients were participated in the meta-analysis. The pooled prevalence of these patients with genetic factors was 22.8% (95% CI 17.4-29.3).The genetic defect plays a crucial role in the development of DRE in younger children with epilepsy and neurodevelopmental disability. The results can serve as a reference for further studies of epilepsy panel design and may also assist in the development of improved treatments and prevention strategies for DRE.
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Affiliation(s)
- Chien-Heng Lin
- Division of Pediatrics Pulmonology, China Medical University, Children's Hospital, Taichung, Taiwan
- Department of Biomedical Imaging and Radiological Science, College of Medicine, China Medical University
| | - I-Ching Chou
- Division of Pediatrics Neurology, China Medical University, Children's Hospital
- Graduate Institute of Integrated Medicine, College of Chinese Medicine, China Medical University, Taichung, Taiwan
| | - Syuan-Yu Hong
- Division of Pediatrics Neurology, China Medical University, Children's Hospital
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37
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Rodriguez-Acevedo AJ, Gordon LG, Waddell N, Hollway G, Vadlamudi L. Developing a gene panel for pharmacoresistant epilepsy: a review of epilepsy pharmacogenetics. Pharmacogenomics 2021; 22:225-234. [PMID: 33666520 DOI: 10.2217/pgs-2020-0145] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Evaluating genes involved in the pharmacodynamics and pharmacokinetics of epilepsy drugs is critical to better understand pharmacoresistant epilepsy. We reviewed the pharmacogenetics literature on six antiseizure medicines (carbamazepine, perampanel, lamotrigine, levetiracetam, sodium valproate and zonisamide) and compared the genes found with those present on epilepsy gene panels using a functional annotation pathway analysis. Little overlap was found between the two gene lists; pharmacogenetic genes are mainly involved in detoxification processes, while epilepsy panel genes are involved in cell signaling and gene expression. Our work provides support for a specific pharmacoresistant epilepsy gene panel to assist antiseizure medicine selection, enabling personalized approaches to treatment. Future efforts will seek to include this panel in genomic analyses of pharmacoresistant patients, to determine clinical utility and patient treatment responses.
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Affiliation(s)
- Astrid J Rodriguez-Acevedo
- Department of Population Health, QIMR Berghofer Medical Research Institute, 300 Herston Road, Brisbane, QLD, 4006, Australia
| | - Louisa G Gordon
- Department of Population Health, QIMR Berghofer Medical Research Institute, 300 Herston Road, Brisbane, QLD, 4006, Australia.,School of Nursing, Queensland University of Technology, Kelvin Grove, Brisbane, QLD, 4059, Australia.,School of Public Health, The University of Queensland, Brisbane, QLD, Australia
| | - Nicola Waddell
- Department of Population Health, QIMR Berghofer Medical Research Institute, 300 Herston Road, Brisbane, QLD, 4006, Australia.,GenomiQa Pty Ltd, Brisbane, QLD, Australia
| | - Georgina Hollway
- Department of Population Health, QIMR Berghofer Medical Research Institute, 300 Herston Road, Brisbane, QLD, 4006, Australia.,GenomiQa Pty Ltd, Brisbane, QLD, Australia
| | - Lata Vadlamudi
- The University of Queensland, UQ Centre for Clinical Research, Herston, Brisbane, QLD, 4029, Australia.,Department of Neurology, Royal Brisbane & Women's Hospital, Herston, Brisbane, QLD, 4029, Australia
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Kaminiów K, Kozak S, Paprocka J. Neonatal Seizures Revisited. CHILDREN-BASEL 2021; 8:children8020155. [PMID: 33670692 PMCID: PMC7922511 DOI: 10.3390/children8020155] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 02/02/2021] [Accepted: 02/12/2021] [Indexed: 12/29/2022]
Abstract
Seizures are the most common neurological disorder in newborns and are most prevalent in the neonatal period. They are mostly caused by severe disorders of the central nervous system (CNS). However, they can also be a sign of the immaturity of the infant’s brain, which is characterized by the presence of specific factors that increase excitation and reduce inhibition. The most common disorders which result in acute brain damage and can manifest as seizures in neonates include hypoxic-ischemic encephalopathy (HIE), ischemic stroke, intracranial hemorrhage, infections of the CNS as well as electrolyte and biochemical disturbances. The therapeutic management of neonates and the prognosis are different depending on the etiology of the disorders that cause seizures which can lead to death or disability. Therefore, establishing a prompt diagnosis and implementing appropriate treatment are significant, as they can limit adverse long-term effects and improve outcomes. In this review paper, we present the latest reports on the etiology, pathomechanism, clinical symptoms and guidelines for the management of neonates with acute symptomatic seizures.
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Affiliation(s)
- Konrad Kaminiów
- Students’ Scientific Society, Department of Pediatric Neurology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, 40-752 Katowice, Poland; (K.K.); (S.K.)
| | - Sylwia Kozak
- Students’ Scientific Society, Department of Pediatric Neurology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, 40-752 Katowice, Poland; (K.K.); (S.K.)
| | - Justyna Paprocka
- Department of Pediatric Neurology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, 40-752 Katowice, Poland
- Correspondence:
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Decreased content of ascorbic acid (vitamin C) in the brain of knockout mouse models of Na+,K+-ATPase-related neurologic disorders. PLoS One 2021; 16:e0246678. [PMID: 33544780 PMCID: PMC7864419 DOI: 10.1371/journal.pone.0246678] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Accepted: 01/23/2021] [Indexed: 12/21/2022] Open
Abstract
Na+,K+-ATPase is a crucial protein responsible for maintaining the electrochemical gradients across the cell membrane. The Na+,K+-ATPase is comprised of catalytic α, β, and γ subunits. In adult brains, the α3 subunit, encoded by ATP1A3, is predominantly expressed in neurons, whereas the α2 subunit, encoded by ATP1A2, is expressed in glial cells. In foetal brains, the α2 is expressed in neurons as well. Mutations in α subunits cause a variety of neurologic disorders. Notably, the onset of symptoms in ATP1A2- and ATP1A3-related neurologic disorders is usually triggered by physiological or psychological stressors. To gain insight into the distinct roles of the α2 and α3 subunits in the developing foetal brain, whose developmental dysfunction may be a predisposing factor of neurologic disorders, we compared the phenotypes of mouse foetuses with double homozygous knockout of Atp1a2 and Atp1a3 (α2α3-dKO) to those with single knockout. The brain haemorrhage phenotype of α2α3-dKO was similar to that of homozygous knockout of the gene encoding ascorbic acid (ASC or vitamin C) transporter, SVCT2. The α2α3-dKO brain showed significantly decreased level of ASC compared with the wild-type (WT) and single knockout. We found that the ASC content in the basal ganglia and cerebellum was significantly lower in the adult Atp1a3 heterozygous knockout mouse (α3-HT) than in the WT. Interestingly, we observed a significant decrease in the ASC level in the basal ganglia and cerebellum of α3-HT in the peripartum period, during which mice are under physiological stress. These observations indicate that the α2 and α3 subunits independently contribute to the ASC level in the foetal brain and that the α3 subunit contributes to ASC transport in the adult basal ganglia and cerebellum. We propose that decreases in ASC levels may affect neural network development and are linked to the pathophysiology of ATP1A2- and ATP1A3-related neurologic disorders.
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40
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Paprocka J, Jezela-Stanek A, Tylki-Szymańska A, Grunewald S. Congenital Disorders of Glycosylation from a Neurological Perspective. Brain Sci 2021; 11:brainsci11010088. [PMID: 33440761 PMCID: PMC7827962 DOI: 10.3390/brainsci11010088] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 01/01/2021] [Accepted: 01/04/2021] [Indexed: 12/11/2022] Open
Abstract
Most plasma proteins, cell membrane proteins and other proteins are glycoproteins with sugar chains attached to the polypeptide-glycans. Glycosylation is the main element of the post-translational transformation of most human proteins. Since glycosylation processes are necessary for many different biological processes, patients present a diverse spectrum of phenotypes and severity of symptoms. The most frequently observed neurological symptoms in congenital disorders of glycosylation (CDG) are: epilepsy, intellectual disability, myopathies, neuropathies and stroke-like episodes. Epilepsy is seen in many CDG subtypes and particularly present in the case of mutations in the following genes: ALG13, DOLK, DPAGT1, SLC35A2, ST3GAL3, PIGA, PIGW, ST3GAL5. On brain neuroimaging, atrophic changes of the cerebellum and cerebrum are frequently seen. Brain malformations particularly in the group of dystroglycanopathies are reported. Despite the growing number of CDG patients in the world and often neurological symptoms dominating in the clinical picture, the number of performed screening tests eg transferrin isoforms is systematically decreasing as broadened genetic testing is recently more favored. The aim of the review is the summary of selected neurological symptoms in CDG described in the literature in one paper. It is especially important for pediatric neurologists not experienced in the field of metabolic medicine. It may help to facilitate the diagnosis of this expanding group of disorders. Biochemically, this paper focuses on protein glycosylation abnormalities.
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Affiliation(s)
- Justyna Paprocka
- Department of Pediatric Neurology, Faculty of Medical Science in Katowice, Medical University of Silesia, 40-752 Katowice, Poland
- Correspondence: ; Tel.: +48-606-415-888
| | - Aleksandra Jezela-Stanek
- Department of Genetics and Clinical Immunology, National Institute of Tuberculosis and Lung Diseases, 01-138 Warsaw, Poland;
| | - Anna Tylki-Szymańska
- Department of Pediatrics, Nutrition and Metabolic Diseases, The Children’s Memorial Health Institute, W 04-730 Warsaw, Poland;
| | - Stephanie Grunewald
- NIHR Biomedical Research Center (BRC), Metabolic Unit, Great Ormond Street Hospital and Institute of Child Health, University College London, London SE1 9RT, UK;
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41
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Chow CK, Luk HM, Wong SN. KCNQ2 Encephalopathy and Responsiveness to Pyridoxal-5'-Phosphate. J Pediatr Genet 2020; 12:90-94. [PMID: 36684546 PMCID: PMC9848766 DOI: 10.1055/s-0040-1721384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 10/25/2020] [Indexed: 01/25/2023]
Abstract
KCNQ2 mutations encompass a wide range of phenotypes, ranging from benign familial neonatal seizure to a clinical spectrum of early-onset epileptic encephalopathy that occurs in the early neonatal period. We report an infant with KCNQ2 encephalopathy presenting as neonatal seizure, initially controlled by two anticonvulsants. Electroencephalogram (EEG) showed repetitive multifocal epileptiform discharges, which remained similar after administration of intravenous pyridoxine injection. Seizure recurred at the age of 3 months preceded by an episode of minor viral infection, which occurred multiple times per day. No significant change in seizure frequency was observed after 5-day oral pyridoxine trial, but subsequently, there was dramatic seizure improvement with oral pyridoxal-5'-phosphate (PLP). We hope to alert clinicians that in patients with neonatal epileptic encephalopathy, particularly with known KCNQ2 mutations, intravenous injection of pyridoxine (preferably with EEG monitoring), followed by both oral trial of pyridoxine and PLP should be considered. KCNQ2 mutations should also be considered in vitamin B6-responsive patients.
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Affiliation(s)
- Chit Kwong Chow
- Department of Paediatrics and Adolescent Medicine, United Christian Hospital, HKSAR, Hong Kong,Address for correspondence Chit Kwong Chow, MBBS (HK), FHKC (Paed), FHKAM (Paediatrics) Department of Paediatrics and Adolescent Medicine, United Christian Hospital130 Hip Wo Street, Kwun Tong, Kowloon, HKSARHong Kong
| | - Ho Ming Luk
- Clinical Genetic Service, Department of Health, HKSAR, Hong Kong
| | - Suet Na Wong
- Department of Paediatrics and Adolescent Medicine, Hong Kong Children's Hospital, HKSAR, Hong Kong
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42
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Abstract
Neonates presenting with seizures are frequently assessed and managed by neonatologists in the NICU. Although hypoxic-ischemic encephalopathy and infection are common underlying causes of neonatal seizures, many patients with neonatal epilepsy will have an identifiable genetic etiology. Often these cases will be evaluated in collaboration with a geneticist. The categories of genetic causes of neonatal seizures include 1) structural brain malformations; 2) inborn errors of metabolism; 3) syndromic; and 4) nonsyndromic, single gene. Evaluation of these patients involves a comprehensive history and examination, followed by appropriate investigations and diagnostic genetic testing. Components of the diagnostic process will vary based on the clinical suspicion and differential diagnoses. In certain cases, syndromic surveillance for evaluation of other congenital anomalies may be recommended. Determination of the underlying genetic diagnosis, when present, will have important implications for treatment. Targeted therapies are currently available for specific genetic syndromes, and outcomes may improve with earlier initiation of therapy. Certain genetic diagnoses may also have guideline-based management involving screening for other manifestations of the disorder.
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Affiliation(s)
- Shagun Kaur
- Division of Genetic, Genomic, and Metabolic Disorders, Children's Hospital of Michigan, Detroit, MI
| | - Kara Pappas
- Division of Genetic, Genomic, and Metabolic Disorders, Children's Hospital of Michigan, Detroit, MI.,Department of Pediatrics, Central Michigan University, Mt Pleasant, MI
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43
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Hinokuma N, Nakashima M, Asai H, Nakamura K, Akaboshi S, Fukuoka M, Togawa M, Oana S, Ohno K, Kasai M, Ogawa C, Yamamoto K, Okumiya K, Chong PF, Kira R, Uchino S, Fukuyama T, Shinagawa T, Miyata Y, Abe Y, Hojo A, Kobayashi K, Maegaki Y, Ishikawa N, Ikeda H, Amamoto M, Mizuguchi T, Iwama K, Itai T, Miyatake S, Saitsu H, Matsumoto N, Kato M. Clinical and genetic characteristics of patients with Doose syndrome. Epilepsia Open 2020; 5:442-450. [PMID: 32913952 PMCID: PMC7469791 DOI: 10.1002/epi4.12417] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 06/19/2020] [Accepted: 06/28/2020] [Indexed: 01/04/2023] Open
Abstract
OBJECTIVE To elucidate the genetic background and genotype-phenotype correlations for epilepsy with myoclonic-atonic seizures, also known as myoclonic-astatic epilepsy (MAE) or Doose syndrome. METHODS We collected clinical information and blood samples from 29 patients with MAE. We performed whole-exome sequencing for all except one MAE case in whom custom capture sequencing identified a variant. RESULTS We newly identified four variants: SLC6A1 and HNRNPU missense variants and microdeletions at 2q24.2 involving SCN1A and Xp22.31 involving STS. Febrile seizures preceded epileptic or afebrile seizures in four patients, of which two patients had gene variants. Myoclonic-atonic seizures occurred at onset in four patients, of which two had variants, and during the course of disease in three patients. Variants were more commonly identified in patients with a developmental delay or intellectual disability (DD/ID), but genetic status was not associated with the severity of DD/ID. Attention-deficit/hyperactivity disorder and autistic spectrum disorder were less frequently observed in patients with variants than in those with unknown etiology. SIGNIFICANCE MAE patients had genetic heterogeneity, and HNRNPU and STS emerged as possible candidate causative genes. Febrile seizures prior to epileptic seizures and myoclonic-atonic seizure at onset indicate a genetic predisposition to MAE. Comorbid conditions were not related to genetic predisposition to MAE.
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Affiliation(s)
- Nodoka Hinokuma
- Department of PediatricsShowa University School of MedicineTokyoJapan
| | - Mitsuko Nakashima
- Department of BiochemistryHamamatsu University School of MedicineHamamatsuJapan
- Department of Human GeneticsYokohama City University Graduate School of MedicineYokohamaJapan
| | - Hideyuki Asai
- Department of PediatricsShowa University School of MedicineTokyoJapan
| | - Kazuyuki Nakamura
- Department of PediatricsYamagata University Faculty of MedicineYamagataJapan
| | | | - Masataka Fukuoka
- Shizuoka Institute of Epilepsy and Neurological DisordersShizuokaJapan
| | - Masami Togawa
- Department of PediatricsTottori Prefectural Central HospitalTottoriJapan
| | - Shingo Oana
- Department of PediatricsTokyo Medical UniversityTokyoJapan
| | - Koyo Ohno
- Division of Child NeurologyInstitute of Neurological SciencesFaculty of MedicineTottori UniversityYonagoJapan
| | - Mariko Kasai
- Department of Developmental Medical Sciences Graduate School of MedicineThe University of TokyoTokyoJapan
| | - Chikako Ogawa
- Department of PediatricsNagoya University Graduate School of MedicineAichiJapan
| | - Kazuna Yamamoto
- Department of PediatricsTeikyo University School of MedicineTokyoJapan
| | - Kiyohito Okumiya
- Department of Pediatrics and Child HealthKurume University School of MedicineFukuokaJapan
| | - Pin Fee Chong
- Department of Pediatric NeurologyFukuoka Children's HospitalFukuokaJapan
| | - Ryutaro Kira
- Department of Pediatric NeurologyFukuoka Children's HospitalFukuokaJapan
| | - Shumpei Uchino
- Department of NeuropediatricsTokyo Metropolitan Neurological HospitalTokyoJapan
- Department of PediatricsThe University of TokyoTokyoJapan
| | - Tetsuhiro Fukuyama
- Department of PediatricsShinshu University School of MedicineMatsumotoJapan
| | | | - Yohane Miyata
- Department of PediatricsKyorin University Faculty of MedicineTokyoJapan
| | - Yuichi Abe
- Department of PediatricsSaitama Medical UniversityMoroyamaJapan
- Division of NeurologyNational Center for Child Health and DevelopmentTokyoJapan
| | - Akira Hojo
- Department of PediatricsShowa University School of MedicineTokyoJapan
| | - Kozue Kobayashi
- Department of PediatricsShowa University School of MedicineTokyoJapan
| | - Yoshihiro Maegaki
- Division of Child NeurologyInstitute of Neurological SciencesFaculty of MedicineTottori UniversityYonagoJapan
| | | | - Hiroko Ikeda
- Shizuoka Institute of Epilepsy and Neurological DisordersShizuokaJapan
| | - Masano Amamoto
- Kitakyushu City Yahata Hospital Pediatric Emergency/Children’s Medical CenterFukuokaJapan
| | - Takeshi Mizuguchi
- Department of Human GeneticsYokohama City University Graduate School of MedicineYokohamaJapan
| | - Kazuhiro Iwama
- Department of Human GeneticsYokohama City University Graduate School of MedicineYokohamaJapan
| | - Toshiyuki Itai
- Department of Human GeneticsYokohama City University Graduate School of MedicineYokohamaJapan
| | - Satoko Miyatake
- Department of Human GeneticsYokohama City University Graduate School of MedicineYokohamaJapan
| | - Hirotomo Saitsu
- Department of BiochemistryHamamatsu University School of MedicineHamamatsuJapan
- Department of Human GeneticsYokohama City University Graduate School of MedicineYokohamaJapan
| | - Naomichi Matsumoto
- Department of Human GeneticsYokohama City University Graduate School of MedicineYokohamaJapan
| | - Mitsuhiro Kato
- Department of PediatricsShowa University School of MedicineTokyoJapan
- Department of PediatricsYamagata University Faculty of MedicineYamagataJapan
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44
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Menezes LFS, Sabiá Júnior EF, Tibery DV, Carneiro LDA, Schwartz EF. Epilepsy-Related Voltage-Gated Sodium Channelopathies: A Review. Front Pharmacol 2020; 11:1276. [PMID: 33013363 PMCID: PMC7461817 DOI: 10.3389/fphar.2020.01276] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 07/31/2020] [Indexed: 12/29/2022] Open
Abstract
Epilepsy is a disease characterized by abnormal brain activity and a predisposition to generate epileptic seizures, leading to neurobiological, cognitive, psychological, social, and economic impacts for the patient. There are several known causes for epilepsy; one of them is the malfunction of ion channels, resulting from mutations. Voltage-gated sodium channels (NaV) play an essential role in the generation and propagation of action potential, and malfunction caused by mutations can induce irregular neuronal activity. That said, several genetic variations in NaV channels have been described and associated with epilepsy. These mutations can affect channel kinetics, modifying channel activation, inactivation, recovery from inactivation, and/or the current window. Among the NaV subtypes related to epilepsy, NaV1.1 is doubtless the most relevant, with more than 1500 mutations described. Truncation and missense mutations are the most observed alterations. In addition, several studies have already related mutated NaV channels with the electrophysiological functioning of the channel, aiming to correlate with the epilepsy phenotype. The present review provides an overview of studies on epilepsy-associated mutated human NaV1.1, NaV1.2, NaV1.3, NaV1.6, and NaV1.7.
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Affiliation(s)
- Luis Felipe Santos Menezes
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília, Brasília, Brazil
| | - Elias Ferreira Sabiá Júnior
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília, Brasília, Brazil
| | - Diogo Vieira Tibery
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília, Brasília, Brazil
| | - Lilian Dos Anjos Carneiro
- Faculdade de Medicina, Centro Universitário Euro Americano, Brasília, Brazil.,Faculdade de Medicina, Centro Universitário do Planalto Central, Brasília, Brazil
| | - Elisabeth Ferroni Schwartz
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília, Brasília, Brazil
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Gudenkauf FJ, Azamian MS, Hunter JV, Nayak A, Lalani SR. A novel CACNA1A variant in a child with early stroke and intractable epilepsy. Mol Genet Genomic Med 2020; 8:e1383. [PMID: 32692472 PMCID: PMC7549575 DOI: 10.1002/mgg3.1383] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 05/28/2020] [Indexed: 12/20/2022] Open
Abstract
Background CACNA1A variants have been described in several disorders that encompass a wide range of neurologic phenotypes, including hemiplegic migraine, ataxia, cognitive delay, and epilepsy. To date, ischemic stroke caused by a CACNA1A variant has only been reported once in the literature. Methods We describe a 4‐year‐old female with recurrent ischemic strokes beginning at 6 weeks of age, intractable epilepsy, and significant global developmental delay. Exome sequencing (ES) was completed for her evaluation. Results We found a novel de novo, likely pathogenic variant, p.Leu1692Gln in CACNA1A by ES. The substitution affects a leucine residue that is highly conserved in species from fish to primates. Conclusion We present the second case of recurrent ischemic strokes in a patient with CACNA1A mutation. Our findings expand the phenotypic heterogeneity related to Cav2.1 (P/Q‐type) calcium channel dysfunction and suggest consideration of CACNA1A disorder in evaluation of pediatric strokes.
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Affiliation(s)
| | - Mahshid S Azamian
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Jill V Hunter
- Department of Radiology, Baylor College of Medicine, Houston, TX, USA
| | - Anuranjita Nayak
- Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Seema R Lalani
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
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46
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Lee J, Lee C, Ki CS, Lee J. Determining the best candidates for next-generation sequencing-based gene panel for evaluation of early-onset epilepsy. Mol Genet Genomic Med 2020; 8:e1376. [PMID: 32613771 PMCID: PMC7507365 DOI: 10.1002/mgg3.1376] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 05/01/2020] [Accepted: 06/01/2020] [Indexed: 12/21/2022] Open
Abstract
Background Genetic testing is an emerging diagnostic approach in early‐onset epilepsy. Identification of the heterogeneous genetic causes of epilepsy may mitigate unnecessary evaluations and allow more accurate diagnosis and therapy. We aimed to uncover genetic causes of early‐onset epilepsy using next‐generation sequencing (NGS) to elucidate the diagnostic candidates and evaluate the diagnostic yield of targeted gene panel testing. Methods We evaluated 116 patients with early‐onset epilepsy developed before 2 years old and normal brain imaging using a NGS‐based targeted gene panel. Variants were classified according to their pathogenicity, and the diagnostic yield of the targeted genes and associated clinical factors were determined. Results We detected 40 disease‐causing variants with diagnostic yield of 34.5% (19 pathogenic, 21 likely pathogenic). Twelve variants were novel. The most commonly detected genes were SCN1A, associated with Dravet syndrome, and PRRT2, associated with benign familial infantile epilepsy. Other variants were identified in ARX, SCN2A, KCNQ2, PCDH19, STXBP1, DEPDC5, and SCN8A. The age of seizure onset and family history were associated with disease‐causing variants. Conclusion Next‐generation sequencing‐based targeted testing is an effective diagnostic test, with 30%–40% comparable diagnostic yield. Patients with earlier seizure onset and family history of epilepsy were the best candidates for testing. For pediatric patients with early‐onset epilepsy, genetic diagnosis is important for accurate prognosis and treatment.
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Affiliation(s)
- Jiwon Lee
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Chung Lee
- Samsung Genome Institute, Samsung Medical Center, Seoul, Korea
| | | | - Jeehun Lee
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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47
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Almarzooq S, Kwon J, Willis A, Craig J, Morris BJ. Novel alternatively-spliced exons of the VRK2 gene in mouse brain and microglial cells. Mol Biol Rep 2020; 47:5127-5136. [PMID: 32583282 PMCID: PMC7417415 DOI: 10.1007/s11033-020-05584-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 06/04/2020] [Accepted: 06/11/2020] [Indexed: 12/12/2022]
Abstract
Common sequence variations in the VRK2 gene contribute to genetic risk for various psychiatric diseases including schizophrenia and major depressive disorder. Despite the clear importance of studying the regulation and function of VRK2 for understanding the causes of these diseases, the organisation and expression of the gene remain poorly characterised. Using reverse-transcriptase-PCR, we have amplifed exons of Vrk2 mRNA from regions of mouse brain, and from different cell classes comprising neurones, astrocytes and microglial cells. We find that Vrk2 mRNA is expressed in all cell types, and that the splicing of the mouse Vrk2 gene is much more complex than previously appreciated. In addition to the predicted alternative splicing (absence/presence) of the penultimate 3 prime exon, we also detected a variety of 5 prime structures, including two novel exons spanning the first characterised exon (exon 1), which we term exons 1a and 1b. While expressed in neurones and astrocytes, exon 1b was not expressed in microglial cells. Expression of transcripts containing exon 1a in microglia was increased by immune stimulation. An additional truncated transcript lacking 7 central exons was also identified. As with the human gene, the results confirm complex patterns of alternative splicing which are likely to be relevant for understanding the physiological and pathological function of the gene in the CNS.
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Affiliation(s)
- Salsabil Almarzooq
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Sir James Black Building, G12 8QQ, Glasgow, UK
| | - Jaedeok Kwon
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Sir James Black Building, G12 8QQ, Glasgow, UK
| | - Ashleigh Willis
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Sir James Black Building, G12 8QQ, Glasgow, UK
| | - John Craig
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Sir James Black Building, G12 8QQ, Glasgow, UK
| | - Brian J Morris
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Sir James Black Building, G12 8QQ, Glasgow, UK.
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Targeted gene panel sequencing in early infantile onset developmental and epileptic encephalopathy. Brain Dev 2020; 42:438-448. [PMID: 32139178 DOI: 10.1016/j.braindev.2020.02.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 02/13/2020] [Accepted: 02/16/2020] [Indexed: 01/06/2023]
Abstract
BACKGROUND Early-onset developmental and epileptic encephalopathy (DEE) is characterized by repeated seizures beginning within 3 months of birth and severe interictal epileptiform discharge, including burst suppression. This study assessed the utility of targeted gene panel sequencing in the genetic diagnosis of this disease. MATERIALS AND METHODS Targeted gene panel sequencing was performed in 150 early infantile-onset DEE patients (≤3 months of age), and we extensively reviewed their clinical characteristics, including therapeutic efficacy, according to genotype. RESULTS Of the early infantile-onset DEE patients, 70 were neonatal-onset DEE and the other 80 patients began experiencing seizures from 1 to 3 months after birth. There were 11 different pathogenic or likely pathogenic variants among 34.7% (52/150) of patients with early infantile-onset DEE, in whom KCNQ2, STXBP1, CDKL5, and SCN1A were the major pathogenic variants. Among the neonatal-onset DEE patients, pathological genes were identified in 42.9% (30/70), indicating a significantly higher diagnostic yield than in 27.5% (22/80) of patients who experienced seizure onset 1 to 3 months after birth (p = 0.048). Among the neonatal-onset DEE group, variants in KCNQ2, STXBP1, and CDKL5 were detected at high frequencies, accounting for 66.7% (20/30) of the pathogenic or likely pathogenic variants found in this study. CONCLUSION Targeted gene panel sequencing demonstrated a high yield of pathogenic variants in the diagnosis of early-onset epileptic encephalopathy, especially in those with neonatal-onset DEE. Early diagnosis of early-onset epileptic encephalopathy may improve the prognosis of patients by earlier selection of appropriate treatment based on pathogenic variant.
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Naumova AA, Oleynik EA, Chernigovskaya EV, Glazova MV. Glutamatergic Fate of Neural Progenitor Cells of Rats with Inherited Audiogenic Epilepsy. Brain Sci 2020; 10:brainsci10050311. [PMID: 32455746 PMCID: PMC7288135 DOI: 10.3390/brainsci10050311] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 05/15/2020] [Accepted: 05/19/2020] [Indexed: 01/08/2023] Open
Abstract
Epilepsy is associated with aberrant neurogenesis in the hippocampus and may underlie the development of hereditary epilepsy. In the present study, we analyzed the differentiation fate of neural progenitor cells (NPC), which were isolated from the hippocampus of embryos of Krushinsky-Molodkina (KM) rats genetically prone to audiogenic epilepsy. NPCs from embryos of Wistar rats were used as the control. We found principal differences between Wistar and KM NPC in unstimulated controls: Wistar NPC culture contained both gamma-aminobutyric acid (GABA) and glutamatergic neurons; KM NPC culture was mainly represented by glutamatergic cells. The stimulation of glutamatergic differentiation of Wistar NPC resulted in a significant increase in glutamatergic cell number that was accompanied by the activation of protein kinase A. The stimulation of KM NPC led to a decrease in immature glutamatergic cell number and was associated with the activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) and protein kinase B/ glycogen synthase kinase 3 beta (Akt/GSK3β), which indicates the activation of glutamatergic cell maturation. These results suggest genetically programmed abnormalities in KM rats that determine the glutamatergic fate of NPC and contribute to the development of audiogenic epilepsy.
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Ilie A, Boucher A, Park J, Berghuis AM, McKinney RA, Orlowski J. Assorted dysfunctions of endosomal alkali cation/proton exchanger SLC9A6 variants linked to Christianson syndrome. J Biol Chem 2020; 295:7075-7095. [PMID: 32277048 PMCID: PMC7242699 DOI: 10.1074/jbc.ra120.012614] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 04/07/2020] [Indexed: 12/15/2022] Open
Abstract
Genetic screening has identified numerous variants of the endosomal solute carrier family 9 member A6 (SLC9A6)/(Na+,K+)/H+ exchanger 6 (NHE6) gene that cause Christianson syndrome, a debilitating X-linked developmental disorder associated with a range of neurological, somatic, and behavioral symptoms. Many of these variants cause complete loss of NHE6 expression, but how subtler missense substitutions or nonsense mutations that partially truncate its C-terminal cytoplasmic regulatory domain impair NHE6 activity and endosomal function are poorly understood. Here, we describe the molecular and cellular consequences of six unique mutations located in the N-terminal cytoplasmic segment (A9S), the membrane ion translocation domain (L188P and G383D), and the C-terminal regulatory domain (E547*, R568Q, and W570*) of human NHE6 that purportedly cause disease. Using a heterologous NHE6-deficient cell expression system, we show that the biochemical, catalytic, and cellular properties of the A9S and R568Q variants were largely indistinguishable from those of the WT transporter, which obscured their disease significance. By contrast, the L188P, G383D, E547*, and W570* mutants exhibited variable deficiencies in biosynthetic post-translational maturation, membrane sorting, pH homeostasis in recycling endosomes, and cargo trafficking, and they also triggered apoptosis. These findings broaden our understanding of the molecular dysfunctions of distinct NHE6 variants associated with Christianson syndrome.
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Affiliation(s)
- Alina Ilie
- Department of Physiology, McGill University, Montreal, Quebec H3G 0B1, Canada
| | - Annie Boucher
- Department of Physiology, McGill University, Montreal, Quebec H3G 0B1, Canada
| | - Jaeok Park
- Department of Biochemistry, McGill University, Montreal, Quebec H3G 0B1, Canada
| | | | - R Anne McKinney
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec H3G 0B1, Canada
| | - John Orlowski
- Department of Physiology, McGill University, Montreal, Quebec H3G 0B1, Canada
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