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Tao M, Li Z, Liu M, Ma H, Liu W. Association analysis of polymorphisms in SLK, ARHGEF9, WWC2, GAB3, and FSHR genes with reproductive traits in different sheep breeds. Front Genet 2024; 15:1371872. [PMID: 38680425 PMCID: PMC11045898 DOI: 10.3389/fgene.2024.1371872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 04/01/2024] [Indexed: 05/01/2024] Open
Abstract
The aim was to investigate the relationship between polymorphisms of gene mutation loci and reproductive traits in local sheep breeds (Duolang Sheep) and introduced sheep breeds (Suffolk, Hu Sheep) in Xinjiang to provide new molecular markers for the selection and breeding of high fecundity sheep. The expression pattern of typing successful genes in sheep tissues was investigated by RT-qPCR technology, providing primary data for subsequent verification of gene function. The 26 mutation loci of WWC2, ARHGEF9, SLK, GAB3, and FSHR genes were typed using KASP. Association analyses were performed using SPSS 25.0, and the typing results showed that five genes with six loci, WWC2 (g.14962207 C>T), ARHGEF9 (g.48271079 C>A), SLK (g.27107842 T>C, g.27108855 G>A), GAB3 (g.86134602 G>A), and FSHR (g.80789180 T>G) were successfully typed. The results of the association analyses showed that WWC2 (g.14962207 C>T), SLK (g.27108855 G>A), ARHGEF9 (g.48271079 C>A), and FSHR (g.80789180 T>G) caused significant or extremely significant effects on the litter size in Duolang, Suffolk and Hu Sheep populations. The expression distribution pattern of the five genes in 12 sheep reproduction-related tissues was examined by RT-qPCR. The results showed that the expression of the SLK gene in the uterus, the FSHR gene in the ovary, and the ARHGEF9 gene in hypothalamic-pituitary-gonadal axis-related tissues were significantly higher than in the tissues of other parts of the sheep. WWC2 and GAB3 genes were highly expressed both in reproductive organs and visceral tissues. In summary, the WWC2 (g.14962207 C>T), SLK (g.27108855 G>A), ARHGEF9 (g.48271079 C>A), and FSHR (g.80789180 T>G) loci can be used as potential molecular markers for detecting differences in reproductive performance in sheep. Due to variations in typing results, the SLK (g.27107842 T>C) and GAB3 (g.86134602 G>A) loci need further validation.
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Affiliation(s)
- Meini Tao
- College of Animal Science, Xinjiang Agricultural University, Urumqi, China
- Adsen Biotechnology Co., Ltd., Urumchi, China
| | - Zhiqiang Li
- Adsen Biotechnology Co., Ltd., Urumchi, China
| | - Meng Liu
- College of Animal Science, Xinjiang Agricultural University, Urumqi, China
| | - Haiyu Ma
- College of Animal Science, Xinjiang Agricultural University, Urumqi, China
| | - Wujun Liu
- College of Animal Science, Xinjiang Agricultural University, Urumqi, China
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Jin L, Li Y, Luo S, Peng Q, Zhai QX, Zhai JX, Gao LD, Guo JJ, Song W, Yi YH, He N, Chen YJ. Reprint of: Recessive APC2 missense variants associated with epilepsies without neurodevelopmental disorders. Seizure 2024; 116:87-92. [PMID: 38523034 DOI: 10.1016/j.seizure.2024.03.006] [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: 05/22/2023] [Revised: 08/10/2023] [Accepted: 08/17/2023] [Indexed: 03/26/2024] Open
Abstract
OBJECTIVES The APC2 gene, encoding adenomatous polyposis coli protein-2, is involved in cytoskeletal regulation in neurons responding to endogenous extracellular signals and plays an important role in brain development. Previously, the APC2 variants have been reported to be associated with cortical dysplasia and intellectual disability. This study aims to explore the association between APC2 variants and epilepsy. METHODS Whole-exome sequencing (WES) was performed in cases (trios) with epilepsies of unknown causes. The damaging effects of variants were predicted by protein modeling and in silico tools. Previously reported APC2 variants were reviewed to analyze the genotype-phenotype correlations. RESULTS Four pairs of compound heterozygous missense variants were identified in four unrelated patients with epilepsy without brain malformation/intellectual disability. All variants presented no or low allele frequencies in the controls. The missense variants were predicted to be damaging by silico tools, and affect hydrogen bonding with surrounding amino acids or decreased protein stability. Patients with variants that resulted in significant changes in protein stability exhibited more severe and intractable epilepsy, whereas patients with variants that had minor effect on protein stability exhibited relatively mild phenotypes. The previously reported APC2 variants in patients with complex cortical dysplasia with other brain malformations-10 (CDCBM10; MIM: 618677) were all truncating variants; in contrast, the variants identified in epilepsy in this study were all missense variants, suggesting a potential genotype-phenotype correlation. SIGNIFICANCE This study suggests that APC2 is potentially associated with epilepsy without brain malformation/intellectual disability. The genotype-phenotype correlation helps to understand the underlying mechanisms of phenotypic heterogeneity.
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Affiliation(s)
- Liang Jin
- Department of Neurology, the Affiliated Nanhua Hospital, Hengyang Medical School, University of South China, Hengyang, China
| | - Yun Li
- Department of Brain Function and Neuroelectrophysiology, the Affiliated Nanhua Hospital, Hengyang Medical School, University of South China, Hengyang, China
| | - 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
| | - Qian Peng
- Department of Pediatrics, Dongguan Maternal and Child Health Hospital, Southern Medical University Affiliated, Dongguang, China
| | - Qiong-Xiang Zhai
- Department of Pediatrics, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Jin-Xia Zhai
- Department of Neurology, the Affiliated Nanhua Hospital, Hengyang Medical School, University of South China, Hengyang, 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
| | - Jia-Jun Guo
- 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
| | - Wang Song
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China
| | - Yong-Hong Yi
- 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
| | - Na He
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China.
| | - Yong-Jun Chen
- Department of Neurology, the Affiliated Nanhua Hospital, Hengyang Medical School, University of South China, Hengyang, China.
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Li B, Lan S, Liu XR, Ji JJ, He YY, Zhang DM, Xu J, Sun H, Shi Z, Wang J, Tian Y. ATP6V1A variants are associated with childhood epilepsy with favorable outcome. Seizure 2024; 116:81-86. [PMID: 37574426 DOI: 10.1016/j.seizure.2023.08.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 08/03/2023] [Accepted: 08/06/2023] [Indexed: 08/15/2023] Open
Abstract
PURPOSE ATP6V1A variants have been identified in patients with highly variable phenotypes such as autosomal dominant epileptic encephalopathy and autosomal recessive cutis laxa. However, the mechanism underlying phenotype variation is unknown. We screened ATP6V1A variants in patients with epilepsy and analyzed the genotype-phenotype correlation to explain the mechanism underlying phenotypic variations. METHODS We performed trio-based whole-exome sequencing in people with epilepsy without acquired causes. All previously reported ATP6V1A variants were systematically retrieved from the HGMD and PubMed databases. RESULTS Three novel de novo ATP6V1A variants, including c.749G>C/p.Gly250Ala, c.782A>G/p.Gln261Arg, and c.1103T>C/p.Met368Thr, were identified in three unrelated cases with childhood focal (partial) epilepsy. None of the variants were listed in any public population database and evaluated as likely pathogenic according to the criteria of the American College of Medical Genetics and Genomics (ACMG). All persons showed good responses to anti-seizure medication and psychomotor development was normal. Further analysis showed that monoallelic missense variants were associated with epilepsy with variable severity, whereas biallelic variants resulted in developmental abnormalities of multisystem that may result in early lethality. CONCLUSION Childhood focal epilepsy with favorable outcome was probably a novel phenotype of ATP6V1A. ATP6V1A variants are associated with a range of phenotypes that correlate with genotypes. The relationship between phenotype severity and the genotype (genetic impairment) of ATP6V1A variants helps explain the phenotypic variations.
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Affiliation(s)
- Bin Li
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Song Lan
- Department of Neurology, Maoming People's Hospital, Maoming, China
| | - Xiao-Rong Liu
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Jing-Jing Ji
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Yun-Yan He
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Dong-Ming Zhang
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Jie Xu
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Hui Sun
- Department of Neurology, the First Affiliated Hospital of Guangzhou Medical University
| | - Zhen Shi
- Department of Neurology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangdong Provincial Clinical Research Center for Child Health, Guangzhou, China
| | - Jie Wang
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China.
| | - Yang Tian
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China; Department of Neurology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangdong Provincial Clinical Research Center for Child Health, Guangzhou, China.
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Hu Y, Zhang B, Chen L, He J, Yang L, Chen X. SCAF4 variants are associated with epilepsy with neurodevelopmental disorders. Seizure 2024; 116:113-118. [PMID: 37891035 DOI: 10.1016/j.seizure.2023.10.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 10/17/2023] [Accepted: 10/20/2023] [Indexed: 10/29/2023] Open
Abstract
AIMS The genetic causes of epilepsy with unknown etiology in most patients remain unknown. The aim of this study was to elucidate the phenotype of SCAF4-related epilepsy. METHODS Trio-based whole-exome sequencing was performed in patients with epilepsy. Silico programs and protein modeling were employed to predict the damaging of variants. Previously reported SCAF4 variants were systematically reviewed to analyze the genotype-phenotype correlations. RESULTS Three heterozygous variants in the SCAF4 were detected in three cases, including one missense variant and two frameshift variants. All variants were de novo. None of these variants is present in gnomAD controls. The missense variant was predicted to be damaging in silico tools. Protein modeling showed that two frameshift variants resulted in loss of domains, and the missense variant may disrupt a nearby phosphorylation site and alter the hydrogen bonds around 54C and the stability of the SCAF4 protein. Intellectual development was mildly delayed for all patients except for one with whom contact was lost. All probands experienced epilepsy as infrequent seizures, responded well to antiseizure drugs, and had a median [IQR] seizure onset age of 4 [1.75, 7.5] years. The variants in the domain-encoding exons and upstream exons exhibited a strong association with epilepsy. CONCLUSIONS SCAF4 is a potential causative gene of epilepsy with neurodevelopmental disorders.
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Affiliation(s)
- Yuanyuan Hu
- Epilepsy Center and Neurology Department of Children's Hospital of Soochow University, Suzhou 215000, China
| | - Bingbing Zhang
- Epilepsy Center and Neurology Department of Children's Hospital of Soochow University, Suzhou 215000, China
| | - Li Chen
- Neurogenetic Group, Department of Neurology, Shenzhen Children's Hospital, Shenzhen 518000, China
| | - Jing He
- Department of Neurology, Yuquan Hospital, Tsinghua University, Beijing 100000, China
| | - Letian Yang
- Epilepsy Center and Neurology Department of Children's Hospital of Soochow University, Suzhou 215000, China
| | - Xuqin Chen
- Epilepsy Center and Neurology Department of Children's Hospital of Soochow University, Suzhou 215000, China.
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Liu WH, Luo S, Zhang DM, Lin ZS, Lan S, Li X, Shi YW, Su T, Yi YH, Zhou P, Li BM. De novo GABRA1 variants in childhood epilepsies and the molecular subregional effects. Front Mol Neurosci 2024; 16:1321090. [PMID: 38269327 PMCID: PMC10806124 DOI: 10.3389/fnmol.2023.1321090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 12/13/2023] [Indexed: 01/26/2024] Open
Abstract
Background The GABRA1 gene, encoding the GABRAR subunit α1, plays vital roles in inhibitory neurons. Previously, the GABRA1 gene has been identified to be associated with developmental and epileptic encephalopathy (DEE) and idiopathic generalized epilepsy (IGE). This study aims to explore the phenotypic spectrum of GABRA1 and molecular subregional effect analysis. Methods Trios-based whole-exome sequencing was performed in patients with epilepsy. Previously reported GABRA1 mutations were systematically reviewed to analyze the molecular subregional effects. Results De novo GABRA1 mutations were identified in six unrelated patients with heterogeneous epilepsy, including three missense mutations (p.His83Asn, p.Val207Phe, and p.Arg214Cys) and one frameshift mutation (p.Thr453Hisfs*47). The two missense mutations, p.His83Asn and p.Val207Phe, were predicted to decrease the protein stability but no hydrogen bond alteration, with which the two patients also presented with mild genetic epilepsy with febrile seizures plus and achieved seizure-free status by monotherapy. The missense variant p.Arg214Cys was predicted to decrease protein stability and destroy hydrogen bonds with surrounding residues, which was recurrently identified in three cases with severe DEE. The frameshift variant p.Thr453Hisfs*47 was located in the last fifth residue of the C-terminus and caused an extension of 47 amino acids, with which the patients presented with moderated epilepsy with generalized tonic-clonic seizures alone (GTCA) but achieved seizure-free status by four drugs. The four variants were not presented in gnomAD and were evaluated as "pathogenic/likely pathogenic" according to ACMG criteria. Analysis of all reported cases indicated that patients with mutations in the N-terminal extracellular region presented a significantly higher percentage of FS and DEE, and the patients with variants in the transmembrane region presented earlier seizure onset ages. Significance This study suggested that GABRA1 variants were potentially associated with a spectrum of epilepsies, including EFS+, DEE, and GTCA. Phenotypic severity may be associated with the damaging effect of variants. The molecular subregional effects help in understanding the underlying mechanism of phenotypic variation.
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Affiliation(s)
- Wen-Hui Liu
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Sheng Luo
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Dong-Ming Zhang
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Zi-Sheng Lin
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Song Lan
- Department of Neurology, Maoming People’s Hospital, Maoming, China
| | - Xin Li
- Department of Pediatrics, The Second Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Yi-Wu Shi
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Tao Su
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Yong-Hong Yi
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Peng Zhou
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Bing-Mei Li
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
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He YY, Luo S, Jin L, Wang PY, Xu J, Jiao HL, Yan HJ, Wang Y, Zhai QX, Ji JJ, Zhang WJ, Zhou P, Li H, Liao WP, Lan S, Xu L. DLG3 variants caused X-linked epilepsy with/without neurodevelopmental disorders and the genotype-phenotype correlation. Front Mol Neurosci 2024; 16:1290919. [PMID: 38249294 PMCID: PMC10796462 DOI: 10.3389/fnmol.2023.1290919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 11/28/2023] [Indexed: 01/23/2024] Open
Abstract
Background The DLG3 gene encodes disks large membrane-associated guanylate kinase scaffold protein 3, which plays essential roles in the clustering of N-methyl-D-aspartate receptors (NMDARs) at excitatory synapses. Previously, DLG3 has been identified as the causative gene of X-linked intellectual developmental disorder-90 (XLID-90; OMIM# 300850). This study aims to explore the phenotypic spectrum of DLG3 and the genotype-phenotype correlation. Methods Trios-based whole-exome sequencing was performed in patients with epilepsy of unknown causes. To analyze the genotype-phenotype correlations, previously reported DLG3 variants were systematically reviewed. Results DLG3 variants were identified in seven unrelated cases with epilepsy. These variants had no hemizygous frequencies in controls. All variants were predicted to be damaging by silico tools and alter the hydrogen bonds with surrounding residues and/or protein stability. Four cases mainly presented with generalized seizures, including generalized tonic-clonic and myoclonic seizures, and the other three cases exhibited secondary generalized tonic-clonic seizures and focal seizures. Multifocal discharges were recorded in all cases during electroencephalography monitoring, including the four cases with generalized discharges initially but multifocal discharges after drug treating. Protein-protein interaction network analysis revealed that DLG3 interacts with 52 genes with high confidence, in which the majority of disease-causing genes were associated with a wide spectrum of neurodevelopmental disorder (NDD) and epilepsy. Three patients with variants locating outside functional domains all achieved seizure-free, while the four patients with variants locating in functional domains presented poor control of seizures. Analysis of previously reported cases revealed that patients with non-null variants presented higher percentages of epilepsy than those with null variants, suggesting a genotype-phenotype correlation. Significance This study suggested that DLG3 variants were associated with epilepsy with/without NDD, expanding the phenotypic spectrum of DLG3. The observed genotype-phenotype correlation potentially contributes to the understanding of the underlying mechanisms driving phenotypic variation.
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Affiliation(s)
- Yun-Yan He
- Department of Neurology, Women and Children’s Hospital, Qingdao University, Qingdao, China
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China
| | - 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
| | - 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
| | - 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
| | - Jie Xu
- 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
| | - Hong-Liang Jiao
- Department of Neurosurgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Hong-Jun Yan
- Epilepsy Center, Guangdong 999 Brain Hospital, Guangzhou, China
| | - Yao Wang
- Epilepsy Center, Guangdong 999 Brain Hospital, Guangzhou, China
| | - Qiong-Xiang Zhai
- Department of Pediatrics, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Jing-Jing Ji
- 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
| | - Weng-Jun Zhang
- 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 Zhou
- 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
| | - Hua Li
- Epilepsy Center, Guangdong 999 Brain Hospital, Guangzhou, China
| | - Wei-Ping Liao
- 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
| | - Song Lan
- Department of Neurology, Maoming People’s Hospital, Maoming, China
| | - Lin Xu
- Department of Neurology, Women and Children’s Hospital, Qingdao University, Qingdao, China
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7
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Jin L, Li Y, Luo S, Peng Q, Zhai QX, Zhai JX, Gao LD, Guo JJ, Song W, Yi YH, He N, Chen YJ. Recessive APC2 missense variants associated with epilepsies without neurodevelopmental disorders. Seizure 2023; 111:172-177. [PMID: 37657306 DOI: 10.1016/j.seizure.2023.08.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 08/10/2023] [Accepted: 08/17/2023] [Indexed: 09/03/2023] Open
Abstract
OBJECTIVES The APC2 gene, encoding adenomatous polyposis coli protein-2, is involved in cytoskeletal regulation in neurons responding to endogenous extracellular signals and plays an important role in brain development. Previously, the APC2 variants have been reported to be associated with cortical dysplasia and intellectual disability. This study aims to explore the association between APC2 variants and epilepsy. METHODS Whole-exome sequencing (WES) was performed in cases (trios) with epilepsies of unknown causes. The damaging effects of variants were predicted by protein modeling and in silico tools. Previously reported APC2 variants were reviewed to analyze the genotype-phenotype correlations. RESULTS Four pairs of compound heterozygous missense variants were identified in four unrelated patients with epilepsy without brain malformation/intellectual disability. All variants presented no or low allele frequencies in the controls. The missense variants were predicted to be damaging by silico tools, and affect hydrogen bonding with surrounding amino acids or decreased protein stability. Patients with variants that resulted in significant changes in protein stability exhibited more severe and intractable epilepsy, whereas patients with variants that had minor effect on protein stability exhibited relatively mild phenotypes. The previously reported APC2 variants in patients with complex cortical dysplasia with other brain malformations-10 (CDCBM10; MIM: 618677) were all truncating variants; in contrast, the variants identified in epilepsy in this study were all missense variants, suggesting a potential genotype-phenotype correlation. SIGNIFICANCE This study suggests that APC2 is potentially associated with epilepsy without brain malformation/intellectual disability. The genotype-phenotype correlation helps to understand the underlying mechanisms of phenotypic heterogeneity.
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Affiliation(s)
- Liang Jin
- Department of Neurology, the Affiliated Nanhua Hospital, Hengyang Medical School, University of South China, Hengyang, China
| | - Yun Li
- Department of Brain Function and Neuroelectrophysiology, the Affiliated Nanhua Hospital, Hengyang Medical School, University of South China, Hengyang, China
| | - 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
| | - Qian Peng
- Department of Pediatrics, Dongguan Maternal and Child Health Hospital, Southern Medical University Affiliated, Dongguang, China
| | - Qiong-Xiang Zhai
- Department of Pediatrics, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Jin-Xia Zhai
- Department of Neurology, the Affiliated Nanhua Hospital, Hengyang Medical School, University of South China, Hengyang, 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
| | - Jia-Jun Guo
- 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
| | - Wang Song
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China
| | - Yong-Hong Yi
- 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
| | - Na He
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China.
| | - Yong-Jun Chen
- Department of Neurology, the Affiliated Nanhua Hospital, Hengyang Medical School, University of South China, Hengyang, China.
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Powis G, Meuillet EJ, Indarte M, Booher G, Kirkpatrick L. Pleckstrin Homology [PH] domain, structure, mechanism, and contribution to human disease. Biomed Pharmacother 2023; 165:115024. [PMID: 37399719 DOI: 10.1016/j.biopha.2023.115024] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 06/14/2023] [Indexed: 07/05/2023] Open
Abstract
The pleckstrin homology [PH] domain is a structural fold found in more than 250 proteins making it the 11th most common domain in the human proteome. 25% of family members have more than one PH domain and some PH domains are split by one, or several other, protein domains although still folding to give functioning PH domains. We review mechanisms of PH domain activity, the role PH domain mutation plays in human disease including cancer, hyperproliferation, neurodegeneration, inflammation, and infection, and discuss pharmacotherapeutic approaches to regulate PH domain activity for the treatment of human disease. Almost half PH domain family members bind phosphatidylinositols [PIs] that attach the host protein to cell membranes where they interact with other membrane proteins to give signaling complexes or cytoskeleton scaffold platforms. A PH domain in its native state may fold over other protein domains thereby preventing substrate access to a catalytic site or binding with other proteins. The resulting autoinhibition can be released by PI binding to the PH domain, or by protein phosphorylation thus providing fine tuning of the cellular control of PH domain protein activity. For many years the PH domain was thought to be undruggable until high-resolution structures of human PH domains allowed structure-based design of novel inhibitors that selectively bind the PH domain. Allosteric inhibitors of the Akt1 PH domain have already been tested in cancer patients and for proteus syndrome, with several other PH domain inhibitors in preclinical development for treatment of other human diseases.
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Affiliation(s)
- Garth Powis
- PHusis Therapeutics Inc., 6019 Folsom Drive, La Jolla, CA 92037, USA.
| | | | - Martin Indarte
- PHusis Therapeutics Inc., 6019 Folsom Drive, La Jolla, CA 92037, USA
| | - Garrett Booher
- PHusis Therapeutics Inc., 6019 Folsom Drive, La Jolla, CA 92037, USA
| | - Lynn Kirkpatrick
- PHusis Therapeutics Inc., 6019 Folsom Drive, La Jolla, CA 92037, USA
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9
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Yan HJ, He YY, Jin L, Guo Q, Zhou JH, Luo S. Expanding the phenotypic spectrum of KCNK4: From syndromic neurodevelopmental disorder to rolandic epilepsy. Front Mol Neurosci 2023; 15:1081097. [PMID: 36683851 PMCID: PMC9851069 DOI: 10.3389/fnmol.2022.1081097] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 12/02/2022] [Indexed: 01/07/2023] Open
Abstract
The KCNK4 gene, predominantly distributed in neurons, plays an essential role in controlling the resting membrane potential and regulating cellular excitability. Previously, only two variants were identified to be associated with human disease, facial dysmorphism, hypertrichosis, epilepsy, intellectual/developmental delay, and gingival overgrowth (FHEIG) syndrome. In this study, we performed trio-based whole exon sequencing (WES) in a cohort of patients with epilepsy. Two de novo likely pathogenic variants were identified in two unrelated cases with heterogeneous phenotypes, including one with Rolandic epilepsy and one with the FHEIG syndrome. The two variants were predicted to be damaged by the majority of in silico algorithms. These variants showed no allele frequencies in controls and presented statistically higher frequencies in the case cohort than that in controls. The FHEIG syndrome-related variants were all located in the region with vital functions in stabilizing the conductive conformation, while the Rolandic epilepsy-related variant was distributed in the area with less impact on the conductive conformation. This study expanded the genetic and phenotypic spectrum of KCNK4. Phenotypic variations of KCNK4 are potentially associated with the molecular sub-regional effects. Carbamazepine/oxcarbazepine and valproate may be effective antiepileptic drugs for patients with KCNK4 variants.
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Affiliation(s)
- Hong-Jun Yan
- Epilepsy Center, Guangdong Brain Hospital, Guangzhou, China,Hong-Jun Yan,
| | - Yun-yan He
- 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, Women and Children’s Hospital Affiliated to Qingdao University, Qingdao, China
| | - Liang Jin
- 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
| | - Qiang Guo
- Epilepsy Center, Guangdong Brain Hospital, Guangzhou, China
| | - Jing-Hua Zhou
- Epilepsy Center, Guangdong Brain Hospital, Guangzhou, China
| | - Sheng Luo
- Epilepsy Center, Guangdong Brain Hospital, Guangzhou, China,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,*Correspondence: Sheng Luo,
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10
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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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11
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BCOR variants are associated with X-linked recessive partial epilepsy. Epilepsy Res 2022; 187:107036. [DOI: 10.1016/j.eplepsyres.2022.107036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 08/12/2022] [Accepted: 10/17/2022] [Indexed: 11/19/2022]
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12
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Chen Z, Luo S, Liu ZG, Deng YC, He SL, Liu XR, Yi YH, Wang J, Gao LD, Li BM, Wu ZJ, Ye ZL, Liang DH, Bian WJ, Liao WP. CELSR1 variants are associated with partial epilepsy of childhood. Am J Med Genet B Neuropsychiatr Genet 2022; 189:247-256. [PMID: 36453712 DOI: 10.1002/ajmg.b.32916] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 01/25/2022] [Accepted: 07/26/2022] [Indexed: 02/01/2023]
Abstract
CELSR1 gene, encoding cadherin EGF LAG seven-pass G-type receptor 1, is mainly expressed in neural stem cells during the embryonic period. It plays an important role in neurodevelopment. However, the relationship between CELSR1 and disease of the central nervous system has not been defined. In this study, we performed trios-based whole-exome sequencing in a cohort of 356 unrelated cases with partial epilepsy without acquired causes and identified CELSR1 variants in six unrelated cases. The variants included one de novo heterozygous nonsense variant, one de novo heterozygous missense variant, and four compound heterozygous missense variants that had one variant was located in the extracellular region and the other in the cytoplasm. The patients with biallelic variants presented severe epileptic phenotypes, whereas those with heterozygous variants were associated with a mild epileptic phenotype of benign epilepsy with centrotemporal spikes (BECTS). These variants had no or low allele frequency in the gnomAD database. The frequencies of the CELSR1 variants in this cohort were significantly higher than those in the control populations. The evidence from ClinGen Clinical-Validity Framework suggested a strong association between CELSR1 variants and epilepsy. These findings provide evidence that CELSR1 is potentially a candidate pathogenic gene of partial epilepsy of childhood.
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Affiliation(s)
- Zheng Chen
- Institute of Neuroscience, Department of Neurology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province, The Ministry of Education of China, Guangzhou, China.,Department of Pediatrics, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Sheng Luo
- Institute of Neuroscience, Department of Neurology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province, The Ministry of Education of China, Guangzhou, China
| | - Zhi-Gang Liu
- Department of Pediatrics, Affiliated Foshan Maternity and Child Healthcare Hospital, Southern Medical University, Foshan, China
| | - Yan-Chun Deng
- Department of Neurology, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Su-Li He
- Department of Pediatrics, Shantou Chaonan Minsheng Hospital, Shantou, China
| | - Xiao-Rong Liu
- Institute of Neuroscience, Department of Neurology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province, The Ministry of Education of China, Guangzhou, China
| | - Yong-Hong Yi
- Institute of Neuroscience, Department of Neurology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province, The Ministry of Education of China, Guangzhou, China
| | - Jie Wang
- Institute of Neuroscience, Department of Neurology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province, The Ministry of Education of China, Guangzhou, China
| | - Liang-Di Gao
- Institute of Neuroscience, Department of Neurology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province, The Ministry of Education of China, Guangzhou, China
| | - Bing-Mei Li
- Institute of Neuroscience, Department of Neurology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province, The Ministry of Education of China, Guangzhou, China
| | - Zhi-Jun Wu
- Department of Neurology, Second Hospital of Lanzhou University, Lanzhou University, Lanzhou, China
| | - Zi-Long Ye
- Institute of Neuroscience, Department of Neurology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province, The Ministry of Education of China, Guangzhou, China
| | - De-Hai Liang
- Institute of Neuroscience, Department of Neurology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province, The Ministry of Education of China, Guangzhou, China
| | - Wen-Jun Bian
- Institute of Neuroscience, Department of Neurology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province, The Ministry of Education of China, Guangzhou, China
| | - Wei-Ping Liao
- Institute of Neuroscience, Department of Neurology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province, The Ministry of Education of China, Guangzhou, China
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13
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Liu HF, Yuan TY, Yang JW, Li F, Wang F, Fu HM. A novel de novo heterozygous variant of the KCNQ2 gene: Contribution to early‑onset epileptic encephalopathy in a female infant. Mol Med Rep 2022; 26:282. [PMID: 35856407 PMCID: PMC9364154 DOI: 10.3892/mmr.2022.12797] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Accepted: 06/29/2022] [Indexed: 11/16/2022] Open
Abstract
Early-onset epileptic encephalopathy (EOEE) represents one of the most severe epilepsies, characterized by recurrent seizures during early infancy, electroencephalogram (EEG) abnormalities and varying degrees of neurodevelopmental delay. The KCNQ2 gene has been reported to have a major role in EOEE. In the present study, a 3-month-old female infant from the Chinese Lisu minority with EOEE was analyzed. Detailed clinical evaluations and next-generation sequencing were performed to investigate the clinical and genetic characteristics of this patient, respectively. Furthermore, the three-dimensional structure of the mutant protein was predicted by SWISS-Model and the expression of KCNQ2 protein in the patient was assessed by flow cytometry. It was observed that the patient presented with typical clinical features of EOEE, including repeated non-febrile seizures and significant EEG abnormalities. A novel heterozygous missense variant c.431G>C (p.R144P) in KCNQ2 was identified in the patient and the genotyping of KCNQ2 in the patient's parents suggested that this variant was de novo. Subsequently, the breakage of hydrogen bonds between certain amino acids was predicted by structural analysis of the mutant protein. Flow cytometric analysis detected a significant reduction buts not complete loss of native KCNQ2 protein expression in the patient (25.1%). In conclusion, a novel variant in KCNQ2 was confirmed as the genetic cause for EOEE in this patient. The present study expanded the pathogenic mutation spectrum of KCNQ2, enhanced the understanding of the molecular pathogenesis of EOEE and provided novel clues for research on the genotype-phenotype correlation in this disease.
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Affiliation(s)
- Hai-Feng Liu
- Department of Pulmonary and Critical Care Medicine, Kunming Children's Hospital and Yunnan Key Laboratory of Children's Major Disease Research, Kunming, Yunnan 650034, P.R. China
| | - Ting-Yun Yuan
- Department of Pulmonary and Critical Care Medicine, Kunming Children's Hospital and Yunnan Key Laboratory of Children's Major Disease Research, Kunming, Yunnan 650034, P.R. China
| | - Jia-Wu Yang
- Department of Pulmonary and Critical Care Medicine, Kunming Children's Hospital and Yunnan Key Laboratory of Children's Major Disease Research, Kunming, Yunnan 650034, P.R. China
| | - Feng Li
- Department of Pulmonary and Critical Care Medicine, Kunming Children's Hospital and Yunnan Key Laboratory of Children's Major Disease Research, Kunming, Yunnan 650034, P.R. China
| | - Fan Wang
- Department of Pulmonary and Critical Care Medicine, Kunming Children's Hospital and Yunnan Key Laboratory of Children's Major Disease Research, Kunming, Yunnan 650034, P.R. China
| | - Hong-Min Fu
- Department of Pulmonary and Critical Care Medicine, Kunming Children's Hospital and Yunnan Key Laboratory of Children's Major Disease Research, Kunming, Yunnan 650034, P.R. China
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14
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Ma X, Yan W, Xu P, Ma L, Zan Y, Huang L, Wang G, Liu L, Hui W. LncRNA-p21 suppresses cell proliferation and induces apoptosis in gastric cancer by sponging miR-514b-3p and up-regulating ARHGEF9 expression. Biol Chem 2022; 403:945-958. [PMID: 35947460 DOI: 10.1515/hsz-2022-0153] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Accepted: 07/01/2022] [Indexed: 12/24/2022]
Abstract
The long non-coding RNA p21 (lncRNA-p21) was a tumor suppressor gene in most cancer types including gastric cancer (GC). We aimed to identify a specific lncRNA-p21-involved pathway in regulating the proliferation and apoptosis of GC cells. A lower lncRNA-p21 expression in tumors was associated with advanced disease stage and predicted worse survival of GC patients. LncRNA-p21 overexpression in GC cell line somatic gastric cancer (SGC)-7901 and human gastric cancer (HGC)-27 suppressed cell proliferation and enhanced apoptosis, while lncRNA-p21 knockdown caused the opposite effects. Through bioinformatics analysis and luciferase-based reporter assays, we identified miR-514b-3p as a sponge target of lncRNA-p21. Cdc42 guanine nucleotide exchange factor 9 (ARHGEF9), functioned as a tumor suppress factor in GC, was found as the downstream target of miR-514-3p, and their expressions were negatively correlated in GC tumor tissues. In addition, like lncRNA-p21 overexpression alone, miR-514-3p inactivation alone also led to decreased proliferation and increased apoptosis in SGC-7901 and HGC-27 cells, which were markedly attenuated by additional ARHGEF9 knockdown. Xenograft SGC-7901 cells with more lncRNA-p21 or ARHGEF9 expressions or with less miR-514-3p expression exhibited obviously slower in vivo growth than the control SGC-7901 cells in nude mice. Our study reveals a novel lncRNA-p21/miR-514b-3p/ARHGEF9 pathway that can be targeted for GC therapy.
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Affiliation(s)
- Xiaobin Ma
- Department of Oncology, The Second Affiliated Hospital of Medical School of Xi'an Jiaotong University, No. 157 Xiwu Road, Xi'an 710004, Shaanxi, China
| | - Wenyu Yan
- Department of Oncology, The Second Affiliated Hospital of Medical School of Xi'an Jiaotong University, No. 157 Xiwu Road, Xi'an 710004, Shaanxi, China
| | - Peng Xu
- Department of Oncology, The Second Affiliated Hospital of Medical School of Xi'an Jiaotong University, No. 157 Xiwu Road, Xi'an 710004, Shaanxi, China
| | - Li Ma
- Department of Oncology, The Second Affiliated Hospital of Medical School of Xi'an Jiaotong University, No. 157 Xiwu Road, Xi'an 710004, Shaanxi, China
| | - Ying Zan
- Department of Oncology, The Second Affiliated Hospital of Medical School of Xi'an Jiaotong University, No. 157 Xiwu Road, Xi'an 710004, Shaanxi, China
| | - Lanxuan Huang
- Department of Oncology, The Second Affiliated Hospital of Medical School of Xi'an Jiaotong University, No. 157 Xiwu Road, Xi'an 710004, Shaanxi, China
| | - Guanying Wang
- Department of Oncology, The Second Affiliated Hospital of Medical School of Xi'an Jiaotong University, No. 157 Xiwu Road, Xi'an 710004, Shaanxi, China
| | - Lili Liu
- Department of Oncology, The Second Affiliated Hospital of Medical School of Xi'an Jiaotong University, No. 157 Xiwu Road, Xi'an 710004, Shaanxi, China
| | - Wentao Hui
- Department of Oncology, The Second Affiliated Hospital of Medical School of Xi'an Jiaotong University, No. 157 Xiwu Road, Xi'an 710004, Shaanxi, China
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15
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Yang H, Liao H, Gan S, Xiao T, Wu L. ARHGEF9 gene variant leads to developmental and epileptic encephalopathy: Genotypic phenotype analysis and treatment exploration. Mol Genet Genomic Med 2022; 10:e1967. [PMID: 35638461 PMCID: PMC9266599 DOI: 10.1002/mgg3.1967] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 04/20/2022] [Accepted: 05/03/2022] [Indexed: 11/17/2022] Open
Abstract
Background The ARHGEF9 gene variants have phenotypic heterogeneity, the number of reported clinical cases are limited and the genotype–phenotype relationship is still unpredictable. Methods Clinical data of the patients and their family members were gathered in a retrospective study. The exome sequencing that was performed on peripheral blood samples was applied for genetic analysis. We used the ARHGEF9 gene as a key word to search the PubMed database for cases of ARHGEF9 gene variants that have previously been reported and summarized the reported ARHGEF9 gene variant sites, their corresponding clinical phenotypes, and effective treatment. Results We described five patients with developmental and epileptic encephalopathy caused by ARHGEF9 gene variants. Among them, the antiepileptic treatment of valproic acid and levetiracetam was effective in two cases individually. The exome sequencing results showed five children with point mutations in the ARHGEF9 gene: p.R365H, p.M388V, p.D213E, and p.R63H. So far, a total of 40 children with ARHGEF9 gene variants have been reported. Their main clinical phenotypes include developmental delay, epilepsy, epileptic encephalopathy, and autism spectrum disorders. The variants reported in the literature, including 22 de novo variants, nine maternal variants, and one unknown variant. There were 20 variants associated with epileptic phenotypes, of which six variants are effective for valproic acid treatment. Conclusion The genotypes and phenotypes of ARHGEF9 gene variants represent a wide spectrum, and the clinical phenotype of epilepsy is often refractory and the prognosis is poor. The p.R365H, p.M388V, p.D213E, and p.R63H variants have not been reported in the current literature, and our study has expanded the genotype spectrum of ARHGEF9 gene. Our findings indicate that levetiracetam and valproic acid can effectively control seizures in children with epileptic phenotype caused by ARGHEF9 gene variations. These findings will help clinicians improve the level of diagnosis and treatment of the genetic disease.
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Affiliation(s)
- Haiyan Yang
- Department of Neurology, Hunan Children's Hospital, Changsha, P.R. China
| | - Hongmei Liao
- Department of Neurology, Hunan Children's Hospital, Changsha, P.R. China
| | - Siyi Gan
- Department of Neurology, Hunan Children's Hospital, Changsha, P.R. China
| | - Ting Xiao
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, P.R. China
| | - Liwen Wu
- Department of Neurology, Hunan Children's Hospital, Changsha, P.R. China
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16
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Luo S, Liu ZG, Wang J, Luo JX, Ye XG, Li X, Zhai QX, Liu XR, Wang J, Gao LD, Liu FL, Ye ZL, Li H, Gao ZF, Guo QH, Li BM, Yi YH, Liao WP. Recessive LAMA5 Variants Associated With Partial Epilepsy and Spasms in Infancy. Front Mol Neurosci 2022; 15:825390. [PMID: 35663266 PMCID: PMC9162154 DOI: 10.3389/fnmol.2022.825390] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 04/19/2022] [Indexed: 12/23/2022] Open
Abstract
Objective The LAMA5 gene encodes the laminin subunit α5, the most abundant laminin α subunit in the human brain. It forms heterotrimers with the subunit β1/β2 and γ1/γ3 and regulates neurodevelopmental processes. Genes encoding subunits of the laminin heterotrimers containing subunit α5 have been reported to be associated with human diseases. Among LAMAs encoding the laminin α subunit, LAMA1-4 have also been reported to be associated with human disease. In this study, we investigated the association between LAMA5 and epilepsy. Methods Trios-based whole-exome sequencing was performed in a cohort of 118 infants suffering from focal seizures with or without spasms. Protein modeling was used to assess the damaging effects of variations. The LAMAs expression was analyzed with data from the GTEX and VarCards databases. Results Six pairs of compound heterozygous missense variants in LAMA5 were identified in six unrelated patients. All affected individuals suffered from focal seizures with mild developmental delay, and three patients presented also spasms. These variants had no or low allele frequencies in controls and presented statistically higher frequency in the case cohort than in controls. The recessive burden analysis showed that recessive LAMA5 variants identified in this cohort were significantly more than the expected number in the East Asian population. Protein modeling showed that at least one variant in each pair of biallelic variants affected hydrogen bonds with surrounding amino acids. Among the biallelic variants in cases with only focal seizures, two variants of each pair were located in different structural domains or domains/links, whereas in the cases with spasms, the biallelic variants were constituted by two variants in the identical functional domains or both with hydrogen bond changes. Conclusion Recessive LAMA5 variants were potentially associated with infant epilepsy. The establishment of the association between LAMA5 and epilepsy will facilitate the genetic diagnosis and management in patients with infant epilepsy.
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Affiliation(s)
- Sheng Luo
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Zhi-Gang Liu
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
- Department of Pediatrics, Affiliated Foshan Maternity & Child Healthcare Hospital, Southern Medical University, Foshan, China
| | - Juan Wang
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Jun-Xia Luo
- Epilepsy Center, Qilu Children’s Hospital of Shandong University, Jinan, China
| | - Xing-Guang Ye
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
- Department of Pediatrics, Affiliated Foshan Maternity & Child Healthcare Hospital, Southern Medical University, Foshan, China
| | - Xin Li
- Department of Pediatrics, The Second Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Qiong-Xiang Zhai
- Department of Neurology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Xiao-Rong Liu
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Jie Wang
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Liang-Di Gao
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Fu-Li Liu
- Department of Neurology, The First People’s Hospital of Foshan, Foshan, China
| | - Zi-Long Ye
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Huan Li
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Zai-Fen Gao
- Epilepsy Center, Qilu Children’s Hospital of Shandong University, Jinan, China
| | - Qing-Hui Guo
- Department of Pediatrics, The Second Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Bing-Mei Li
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Yong-Hong Yi
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Wei-Ping Liao
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- *Correspondence: Wei-Ping Liao,
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Bian WJ, Li ZJ, Wang J, Luo S, Li BM, Gao LD, He N, Yi YH. SHROOM4 Variants Are Associated With X-Linked Epilepsy With Features of Generalized Seizures or Generalized Discharges. Front Mol Neurosci 2022; 15:862480. [PMID: 35663265 PMCID: PMC9157246 DOI: 10.3389/fnmol.2022.862480] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 04/25/2022] [Indexed: 11/13/2022] Open
Abstract
ObjectiveSHROOM4 gene encodes an actin-binding proteins, which plays an important role in cytoskeletal architecture, synaptogenesis, and maintaining gamma-aminobutyric acid receptors-mediated inhibition. SHROOM4 mutations were reported in patients with the Stocco dos Santos type of X-linked syndromic intellectual developmental disorder (SDSX; OMIM# 300434). In this study, we investigated the association between SHROOM4 and epilepsy.MethodsTrios-based whole-exome sequencing was performed in a cohort of 320 cases with idiopathic generalized epilepsy or idiopathic partial epilepsy. Protein modeling was used to assess the damaging effects of variations.ResultsSix hemizygous missense SHROOM4 variants, including c.13C > A/p. Pro5Thr, c.3236C > T/p.Glu1079Ala, c.3581C > T/p.Ser1194Leu, c.4288C > T/p.Arg1430Cys, c.4303G > A/p.Val1435Met, c.4331C > T/p.Pro1444Leu, were identified in six cases with idiopathic epilepsy without intellectual disability. All patients presented with features of generalized seizures or generalized discharges. These hemizygous variants had no or extremely low allele frequencies in controls and showed statistically higher frequency in the case cohort than controls. All variants were predicted to alter hydrogen bond with surrounding amino acids or decreased protein stability. The SHROOM4 variants reported in patients with SDSX were mostly destructive or duplicative variants; in contrast, the SHROOM4 variants were all missense variants, suggesting a potential genotype-phenotype correlation. The two missense variants associated with SDSX were located in the middle of SHROOM4 protein, whereas variants associated with idiopathic epilepsy were located around the N-terminal PDZ domain and the C-terminal ASD2 domain.SignificanceSHROOM4 was potentially a candidate pathogenic gene of idiopathic epilepsy without intellectual disability. The genotype-phenotype correlation and sub-regional effect helps understanding the mechanism underlying phenotypic variation.
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Tian Y, Zhai QX, Li XJ, Shi Z, Cheng CF, Fan CX, Tang B, Zhang Y, He YY, Li WB, Luo S, Hou C, Chen WX, Liao WP, Wang J. ATP6V0C Is Associated With Febrile Seizures and Epilepsy With Febrile Seizures Plus. Front Mol Neurosci 2022; 15:889534. [PMID: 35600075 PMCID: PMC9120599 DOI: 10.3389/fnmol.2022.889534] [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: 03/04/2022] [Accepted: 04/12/2022] [Indexed: 11/13/2022] Open
Abstract
Purpose To identify novel genetic causes of febrile seizures (FS) and epilepsy with febrile seizures plus (EFS+). Methods We performed whole-exome sequencing in a cohort of 32 families, in which at least two individuals were affected by FS or EFS+. The probands, their parents, and available family members were recruited to ascertain whether the genetic variants were co-segregation. Genes with repetitively identified variants with segregations were selected for further studies to define the gene-disease association. Results We identified two heterozygous ATP6V0C mutations (c.64G > A/p.Ala22Thr and c.361_373del/p.Thr121Profs*7) in two unrelated families with six individuals affected by FS or EFS+. The missense mutation was located in the proteolipid c-ring that cooperated with a-subunit forming the hemichannel for proton transferring. It also affected the hydrogen bonds with surround residues and the protein stability, implying a damaging effect. The frameshift mutation resulted in a loss of function by yielding a premature termination of 28 residues at the C-terminus of the protein. The frequencies of ATP6V0C mutations identified in this cohort were significantly higher than that in the control populations. All the six affected individuals suffered from their first FS at the age of 7-8 months. The two probands later manifested afebrile seizures including myoclonic seizures that responded well to lamotrigine. They all displayed favorable outcomes without intellectual or developmental abnormalities, although afebrile seizures or frequent seizures occurred. Conclusion This study suggests that ATP6V0C is potentially a candidate pathogenic gene of FS and EFS+. Screening for ATP6V0C mutations would help differentiating patients with Dravet syndrome caused by SCN1A mutations, which presented similar clinical manifestation but different responses to antiepileptic treatment.
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Affiliation(s)
- Yang Tian
- Department of Neurology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Qiong-Xiang Zhai
- Department of Pediatrics, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Xiao-Jing Li
- Department of Neurology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Zhen Shi
- Department of Neurology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Chuan-Fang Cheng
- Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province, Ministry of Education of China, Guangzhou, China
| | - Cui-Xia Fan
- Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province, Ministry of Education of China, Guangzhou, China
| | - Bin Tang
- Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province, Ministry of Education of China, Guangzhou, China
| | - Ying Zhang
- The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Yun-Yan He
- Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province, Ministry of Education of China, Guangzhou, China
| | - Wen-Bin Li
- Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province, Ministry of Education of China, Guangzhou, China
| | - Sheng Luo
- Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province, Ministry of Education of China, Guangzhou, China
| | - Chi Hou
- Department of Neurology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Wen-Xiong Chen
- Department of Neurology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Wei-Ping Liao
- Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province, Ministry of Education of China, Guangzhou, China
| | - Jie Wang
- Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province, Ministry of Education of China, Guangzhou, China
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Hines DJ, Contreras A, Garcia B, Barker JS, Boren AJ, Moufawad El Achkar C, Moss SJ, Hines RM. Human ARHGEF9 intellectual disability syndrome is phenocopied by a mutation that disrupts collybistin binding to the GABA A receptor α2 subunit. Mol Psychiatry 2022; 27:1729-1741. [PMID: 35169261 PMCID: PMC9095487 DOI: 10.1038/s41380-022-01468-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 01/12/2022] [Accepted: 01/26/2022] [Indexed: 11/20/2022]
Abstract
Intellectual disability (ID) is a common neurodevelopmental disorder that can arise from genetic mutations ranging from trisomy to single nucleotide polymorphism. Mutations in a growing number of single genes have been identified as causative in ID, including ARHGEF9. Evaluation of 41 ARHGEF9 patient reports shows ubiquitous inclusion of ID, along with other frequently reported symptoms of epilepsy, abnormal baseline EEG activity, behavioral symptoms, and sleep disturbances. ARHGEF9 codes for the Cdc42 Guanine Nucleotide Exchange Factor 9 collybistin (Cb), a known regulator of inhibitory synapse function via direct interaction with the adhesion molecule neuroligin-2 and the α2 subunit of GABAA receptors. We mutate the Cb binding motif within the large intracellular loop of α2 replacing it with the binding motif for gephyrin from the α1 subunit (Gabra2-1). The Gabra2-1 mutation causes a strong downregulation of Cb expression, particularly at cholecystokinin basket cell inhibitory synapses. Gabra2-1 mice have deficits in working and recognition memory, as well as hyperactivity, anxiety, and reduced social preference, recapitulating the frequently reported features of ARHGEF9 patients. Gabra2-1 mice also have spontaneous seizures during postnatal development which can lead to mortality, and baseline abnormalities in low-frequency wavelengths of the EEG. EEG abnormalities are vigilance state-specific and manifest as sleep disturbance including increased time in wake and a loss of free-running rhythmicity in the absence of light as zeitgeber. Gabra2-1 mice phenocopy multiple features of human ARHGEF9 mutation, and reveal α2 subunit-containing GABAA receptors as a druggable target for treatment of this complex ID syndrome.
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Affiliation(s)
- Dustin J Hines
- Department of Psychology, University of Nevada Las Vegas, Las Vegas, NV, USA
| | - April Contreras
- Department of Psychology, University of Nevada Las Vegas, Las Vegas, NV, USA
| | - Betsua Garcia
- Department of Psychology, University of Nevada Las Vegas, Las Vegas, NV, USA
| | - Jeffrey S Barker
- Department of Psychology, University of Nevada Las Vegas, Las Vegas, NV, USA
| | - Austin J Boren
- Department of Psychology, University of Nevada Las Vegas, Las Vegas, NV, USA
| | | | - Stephen J Moss
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, USA
| | - Rochelle M Hines
- Department of Psychology, University of Nevada Las Vegas, Las Vegas, NV, USA.
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Zou D, Qin B, Wang J, Shi Y, Zhou P, Yi Y, Liao J, Lu X. AFF2 Is Associated With X-Linked Partial (Focal) Epilepsy With Antecedent Febrile Seizures. Front Mol Neurosci 2022; 15:795840. [PMID: 35431806 PMCID: PMC9006616 DOI: 10.3389/fnmol.2022.795840] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 02/08/2022] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVE AFF2 mutations were associated with X-linked intellectual developmental disorder-109 and in males with autism spectrum disorder (ASD). The relationship between AFF2 and epilepsy has not been defined. METHOD Trios-based whole-exome sequencing was performed in a cohort of 372 unrelated cases (families) with partial (focal) epilepsy without acquired causes. RESULTS Five hemizygous missense AFF2 mutations were identified in five males with partial epilepsy and antecedent febrile seizures without intellectual disability or other developmental abnormalities. The mutations did not present in the controls of general populations with an aggregate frequency significantly higher than that in the control populations. Previously, intellectual disability-associated AFF2 mutations were genomic rearrangements and CCG repeat expansion mutations mostly, whereas the mutations associated with partial epilepsy were all missense. Missense AFF2 mutations associated with epilepsy fell into the regions from N-terminal to the nuclear localization signal 1 (NLS1), while ASD-associated missense mutations fell in the regions from NLS1 to C-terminal. CONCLUSION AFF2 is potentially a candidate causative gene of X-link partial epilepsy with antecedent febrile seizures. The genotype-phenotype correlation and molecular sub-regional effect of AFF2 help in explaining the mechanisms underlying phenotypic variations.
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Affiliation(s)
- Dongfang Zou
- Epilepsy Center and Department of Neurology, Shenzhen Children’s Hospital, Shenzhen, China
- Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Bing Qin
- Epilepsy Center and Department of Neurosurgery, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Jie Wang
- Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Yiwu Shi
- Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Peng Zhou
- Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Yonghong Yi
- Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Jianxiang Liao
- Epilepsy Center and Department of Neurology, Shenzhen Children’s Hospital, Shenzhen, China
- *Correspondence: Jianxiang Liao,
| | - Xinguo Lu
- Epilepsy Center and Department of Neurology, Shenzhen Children’s Hospital, Shenzhen, China
- Xinguo Lu,
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Li J, Lin SM, Qiao JD, Liu XR, Wang J, Jiang M, Zhang J, Zhong M, Chen XQ, Zhu J, He N, Su T, Shi YW, Yi YH, Liao WP. CELSR3 variants are associated with febrile seizures and epilepsy with antecedent febrile seizures. CNS Neurosci Ther 2021; 28:382-389. [PMID: 34951123 PMCID: PMC8841303 DOI: 10.1111/cns.13781] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 09/27/2021] [Accepted: 11/27/2021] [Indexed: 11/30/2022] Open
Abstract
Aims To identify novel pathogenic gene of febrile seizures (FS)/epilepsy with antecedent FS (EFS+). Methods The trio‐based whole‐exome sequencing was performed in a cohort of 462 cases with FS/EFS+. Silico programs, sequence alignment, and protein modeling were used to predict the damaging of variants. Statistical testing was performed to analyze gene‐based burden of variants. Results Five heterozygous missense variants in CELSR3 were detected in five cases (families) with eight individuals (five females, three males) affected. Two variants were de novo, and three were identified in families with more than one individual affected. All the variants were predicted to be damaging in silico tools. Protein modeling showed that the variants resulted in disappearance of multiple hydrogen bonds and one disulfide bond, which potentially caused functional impairments of protein. The frequency of CELSR3 variants identified in this study was significantly higher than that in controls. All affected individuals were diagnosed with FS/EFS+, including six patients with FS and two patients with EFS+. All cases presented favorable outcomes without neurodevelopmental disorders. Conclusions CELSR3 variants are potentially associated with FS/EFS+.
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Affiliation(s)
- Jia Li
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Si-Mei Lin
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Jing-Da Qiao
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Xiao-Rong Liu
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Jie Wang
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Mi Jiang
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Jing Zhang
- Department of Pediatrics, Xiangya Changde Hospital, Changde, China
| | - Min Zhong
- Department of Neurology, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Xu-Qin Chen
- Department of Neurology, Children's Hospital of Soochow University, Suzhou, China
| | - Jing Zhu
- Department of Pediatrics, The First Hospital of Anhui Medical University, Hefei, China
| | - Na He
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Tao Su
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Yi-Wu Shi
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Yong-Hong Yi
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Wei-Ping Liao
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
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22
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Qiu T, Dai Q, Wang Q. A novel de novo hemizygous ARHGEF9 mutation associated with severe intellectual disability and epilepsy: a case report. J Int Med Res 2021; 49:3000605211058372. [PMID: 34851771 PMCID: PMC8647271 DOI: 10.1177/03000605211058372] [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] [Indexed: 12/05/2022] Open
Abstract
ARHGEF9 encodes collybistin, a brain-specific guanosine diphosphate-guanosine-5′-triphosphate exchange factor that plays an important role in clustering of gephyrin and γ-aminobutyric acid type A receptors in the postsynaptic membrane. Overwhelming evidence suggests that defects in this protein can cause X-linked intellectual disability, which comprises a series of clinical phenotypes, including autism spectrum disorder, behavior disorder, intellectual disability, and febrile seizures. Here, we report a boy with clinical symptoms of severe intellectual disability, epilepsy, and developmental delay and regression. Trio exome sequencing (trio-clinical exome sequencing) identified a novel hemizygous deletion, c.656_c.669delACTTCTTTGAGGCC (p. His219Leu fs*9), in exon 5 of ARHGEF9. This variant was not reported in either the Genome Aggregation Database or our database of 309 patients with neurodevelopmental disorders. Oxcarbazepine and levetiracetam reduced the frequency of the patient’s epileptic seizures to a certain extent, but psychomotor developmental delay and developmental regression became more obvious with age. This case study seeks to report a de novo loss-of-function mutation of ARHGEF9, aiming to emphasize the genetic diagnosis of X-linked intellectual disability and further improve knowledge of the ethnic distribution of ARHGEF9 mutations.
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Affiliation(s)
- Tong Qiu
- Division of Pediatrics, West China Second University Hospital, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu, China
| | - Qian Dai
- Division of Pediatrics, West China Second University Hospital, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu, China
| | - Qiu Wang
- Division of Rehabilitation Medicine, West China Second University Hospital, Sichuan University, Chengdu, China
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Selective Overexpression of Collybistin in Mouse Hippocampal Pyramidal Cells Enhances GABAergic Neurotransmission and Protects against PTZ-Induced Seizures. eNeuro 2021; 8:ENEURO.0561-20.2021. [PMID: 34083383 PMCID: PMC8281261 DOI: 10.1523/eneuro.0561-20.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 04/02/2021] [Accepted: 05/23/2021] [Indexed: 11/21/2022] Open
Abstract
Collybistin (CB) is a rho guanine exchange factor found at GABAergic and glycinergic postsynapses that interacts with the inhibitory scaffold protein, gephyrin, and induces accumulation of gephyrin and GABA type-A receptors (GABAARs) to the postsynapse. We have previously reported that the isoform without the src homology 3 (SH3) domain, CBSH3-, is particularly active in enhancing the GABAergic postsynapse in both cultured hippocampal neurons as well as in cortical pyramidal neurons after chronic in vivo expression in in utero electroporated (IUE) rats. Deficiency of CB in knock-out (KO) mice results in absence of gephyrin and gephyrin-dependent GABAARs at postsynaptic sites in several brain regions, including hippocampus. In the present study, we have generated an adeno-associated virus (AAV) that expresses CBSH3- in a cre-dependent manner. Using male and female VGLUT1-IRES-cre or VGAT-IRES-cre mice, we explore the effect of overexpression of CBSH3- in hippocampal pyramidal cells or hippocampal interneurons. The results show that: (1) the accumulation of gephyrin and GABAARs at inhibitory postsynapses in hippocampal pyramidal neurons or interneurons can be enhanced by CBSH3- overexpression; (2) overexpression of CBSH3- in hippocampal pyramidal cells can enhance the strength of inhibitory neurotransmission; and (3) these enhanced inhibitory synapses provide protection against pentylenetetrazole (PTZ)-induced seizures. The results indicate that this AAV vector carrying CBSH3- can be used for in vivo enhancement of GABAergic synaptic transmission in selected target neurons in the brain.
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Liu XR, Ye TT, Zhang WJ, Guo X, Wang J, Huang SP, Xie LS, Song XW, Deng WW, Li BM, He N, Wu QY, Zhuang MZ, Xu M, Shi YW, Su T, Yi YH, Liao WP. CHD4 variants are associated with childhood idiopathic epilepsy with sinus arrhythmia. CNS Neurosci Ther 2021; 27:1146-1156. [PMID: 34109749 PMCID: PMC8446219 DOI: 10.1111/cns.13692] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 05/20/2021] [Accepted: 05/23/2021] [Indexed: 11/27/2022] Open
Abstract
Aims CHD4 gene, encoding chromodomain helicase DNA‐binding protein 4, is a vital gene for fetal development. In this study, we aimed to explore the association between CHD4 variants and idiopathic epilepsy. Methods Trios‐based whole‐exome sequencing was performed in a cohort of 482 patients with childhood idiopathic epilepsy. The Clinical Validity Framework of ClinGen and an evaluating method from five clinical‐genetic aspects were used to determine the association between CHD4 variants and epilepsy. Results Four novel heterozygous missense mutations in CHD4, including two de novo mutations (c.1597A>G/p.K533E and c.4936G>A/p.E1646K) and two inherited mutations with co‐segregation (c.856C>G/p.P286A and c.4977C>G/p.D1659E), were identified in four unrelated families with eight individuals affected. Seven affected individuals had sinus arrhythmia. From the molecular sub‐regional point of view, the missense mutations located in the central regions from SNF2‐like region to DUF1087 domain were associated with multisystem developmental disorders, while idiopathic epilepsy‐related mutations were outside this region. Strong evidence from ClinGen Clinical Validity Framework and evidences from four of the five clinical‐genetic aspects suggested an association between CHD4 variants and epilepsy. Conclusions CHD4 was potentially a candidate pathogenic gene of childhood idiopathic epilepsy with arrhythmia. The molecular sub‐regional effect of CHD4 mutations helped explaining the mechanisms underlying phenotypic variations.
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Affiliation(s)
- Xiao-Rong Liu
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Ting-Ting Ye
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Wen-Jun Zhang
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Xuan Guo
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Jie Wang
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Shao-Ping Huang
- Department of Pediatrics, The Second Affiliated Hospital of Xi'an Jiao Tong University, Xi'an, China
| | - Long-Shan Xie
- Epilepsy Center of Foshan First Hospital, Foshan, China
| | - Xing-Wang Song
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Wei-Wen Deng
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Bing-Mei Li
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Na He
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Qian-Yi Wu
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Min-Zhi Zhuang
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Meng Xu
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Yi-Wu Shi
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Tao Su
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Yong-Hong Yi
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Wei-Ping Liao
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
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25
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Liaci C, Camera M, Caslini G, Rando S, Contino S, Romano V, Merlo GR. Neuronal Cytoskeleton in Intellectual Disability: From Systems Biology and Modeling to Therapeutic Opportunities. Int J Mol Sci 2021; 22:ijms22116167. [PMID: 34200511 PMCID: PMC8201358 DOI: 10.3390/ijms22116167] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 05/25/2021] [Accepted: 06/04/2021] [Indexed: 02/06/2023] Open
Abstract
Intellectual disability (ID) is a pathological condition characterized by limited intellectual functioning and adaptive behaviors. It affects 1–3% of the worldwide population, and no pharmacological therapies are currently available. More than 1000 genes have been found mutated in ID patients pointing out that, despite the common phenotype, the genetic bases are highly heterogeneous and apparently unrelated. Bibliomic analysis reveals that ID genes converge onto a few biological modules, including cytoskeleton dynamics, whose regulation depends on Rho GTPases transduction. Genetic variants exert their effects at different levels in a hierarchical arrangement, starting from the molecular level and moving toward higher levels of organization, i.e., cell compartment and functions, circuits, cognition, and behavior. Thus, cytoskeleton alterations that have an impact on cell processes such as neuronal migration, neuritogenesis, and synaptic plasticity rebound on the overall establishment of an effective network and consequently on the cognitive phenotype. Systems biology (SB) approaches are more focused on the overall interconnected network rather than on individual genes, thus encouraging the design of therapies that aim to correct common dysregulated biological processes. This review summarizes current knowledge about cytoskeleton control in neurons and its relevance for the ID pathogenesis, exploiting in silico modeling and translating the implications of those findings into biomedical research.
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Affiliation(s)
- Carla Liaci
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126 Torino, Italy; (C.L.); (M.C.); (G.C.); (S.R.)
| | - Mattia Camera
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126 Torino, Italy; (C.L.); (M.C.); (G.C.); (S.R.)
| | - Giovanni Caslini
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126 Torino, Italy; (C.L.); (M.C.); (G.C.); (S.R.)
| | - Simona Rando
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126 Torino, Italy; (C.L.); (M.C.); (G.C.); (S.R.)
| | - Salvatore Contino
- Department of Engineering, University of Palermo, Viale delle Scienze Ed. 8, 90128 Palermo, Italy;
| | - Valentino Romano
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Viale delle Scienze Ed. 16, 90128 Palermo, Italy;
| | - Giorgio R. Merlo
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126 Torino, Italy; (C.L.); (M.C.); (G.C.); (S.R.)
- Correspondence: ; Tel.: +39-0116706449; Fax: +39-0116706432
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26
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Wagner S, Lee C, Rojas L, Specht CG, Rhee J, Brose N, Papadopoulos T. The α3 subunit of GABA A receptors promotes formation of inhibitory synapses in the absence of collybistin. J Biol Chem 2021; 296:100709. [PMID: 33901490 PMCID: PMC8141935 DOI: 10.1016/j.jbc.2021.100709] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 04/14/2021] [Accepted: 04/22/2021] [Indexed: 01/03/2023] Open
Abstract
Signaling at nerve cell synapses is a key determinant of proper brain function, and synaptic defects—or synaptopathies—are at the basis of many neurological and psychiatric disorders. Collybistin (CB), a brain-specific guanine nucleotide exchange factor, is essential for the formation of γ-aminobutyric acidergic (GABAergic) postsynapses in defined regions of the mammalian forebrain, including the hippocampus and basolateral amygdala. This process depends on a direct interaction of CB with the scaffolding protein gephyrin, which leads to the redistribution of gephyrin into submembranous clusters at nascent inhibitory synapses. Strikingly, synaptic clustering of gephyrin and GABAA type A receptors (GABAARs) in several brain regions, including the cerebral cortex and certain thalamic areas, is unperturbed in CB-deficient mice, indicating that the formation of a substantial subset of inhibitory postsynapses must be controlled by gephyrin-interacting proteins other than CB. Previous studies indicated that the α3 subunit of GABAARs (GABAAR-α3) binds directly and with high affinity to gephyrin. Here, we provide evidence (i) that a homooligomeric GABAAR-α3A343W mutant induces the formation of submembranous gephyrin clusters independently of CB in COS-7 cells, (ii) that gephyrin clustering is unaltered in the neuronal subpopulations endogenously expressing the GABAAR-α3 in CB-deficient brains, and (iii) that exogenous expression of GABAAR-α3 partially rescues impaired gephyrin clustering in CB-deficient hippocampal neurons. Our results identify an important role of GABAAR-α3 in promoting gephyrin-mediated and CB-independent formation of inhibitory postsynapses.
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Affiliation(s)
- Sven Wagner
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - ChoongKu Lee
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Lucia Rojas
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Christian G Specht
- Diseases and Hormones of the Nervous System (DHNS), Inserm U1195, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - JeongSeop Rhee
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Nils Brose
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
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27
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Wang J, Qiao JD, Liu XR, Liu DT, Chen YH, Wu Y, Sun Y, Yu J, Ren RN, Mei Z, Liu YX, Shi YW, Jiang M, Lin SM, He N, Li B, Bian WJ, Li BM, Yi YH, Su T, Liu HK, Gu WY, Liao WP. UNC13B variants associated with partial epilepsy with favourable outcome. Brain 2021; 144:3050-3060. [PMID: 33876820 PMCID: PMC8634081 DOI: 10.1093/brain/awab164] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 03/25/2021] [Accepted: 04/03/2021] [Indexed: 11/12/2022] Open
Abstract
The unc-13 homolog B (UNC13B) gene encodes a presynaptic protein, mammalian uncoordinated 13-2 (Munc13-2), that is highly expressed in the brain-predominantly in the cerebral cortex-and plays an essential role in synaptic vesicle priming and fusion, potentially affecting neuronal excitability. However, the functional significance of UNC13B mutation in human disease is not known. In this study we screened for novel genetic variants in a cohort of 446 unrelated cases (families) with partial epilepsy without acquired causes by trio-based whole-exome sequencing. UNC13B variants were identified in 12 individuals affected by partial epilepsy and/or febrile seizures from eight unrelated families. The eight probands all had focal seizures and focal discharges in EEG recordings, including two patients who experienced frequent daily seizures and one who showed abnormalities in the hippocampus by brain MRI; however, all of the patients showed favorable outcome without intellectual or developmental abnormalities. The identified UNC13B variants included one nonsense variant, two variants at or around a splice site, one compound heterozygous missense variant, and four missense variants that cosegregated in the families. The frequency of UNC13B variants identified in the present study was significantly higher than that in a control cohort of Han Chinese and controls of the East Asian and all populations in the Genome Aggregation Database. Computational modeling, including hydrogen bond and docking analyses, suggested that the variants lead to functional impairment. In Drosophila, seizure rate and duration were increased by Unc13b knockdown compared to wild-type flies, but these effects were less pronounced than in sodium voltage-gated channel alpha subunit 1 (Scn1a) knockdown Drosophila. Electrophysiologic recordings showed that excitatory neurons in Unc13b-deficient flies exhibited increased excitability. These results suggest that UNC13B is potentially associated with epilepsy. The frequent daily seizures and hippocampal abnormalities but ultimately favorable outcome under antiepileptic therapy in our patients indicate that partial epilepsy caused by UNC13B variant is a clinically manageable condition.
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Affiliation(s)
- Jie Wang
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Jing-Da Qiao
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Xiao-Rong Liu
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - De-Tian Liu
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Yan-Hui Chen
- Department of Pediatrics, Fujian Medical University Union Hospital, Fujian, China
| | - Yi Wu
- Department of Pediatrics, Fujian Medical University Union Hospital, Fujian, China
| | - Yan Sun
- Department of Pediatrics, People's Hospital of Xinjiang Uygur Autonomous Region, Urumqi, Xinjiang, China
| | - Jing Yu
- Department of Pediatrics, People's Hospital of Xinjiang Uygur Autonomous Region, Urumqi, Xinjiang, China
| | - Rong-Na Ren
- Department of Pediatrics and Neurosurgery, 900 Hospital of the Joint Logistics Team, Fujian, China
| | - Zhen Mei
- Department of Pediatrics and Neurosurgery, 900 Hospital of the Joint Logistics Team, Fujian, China
| | - Yu-Xi Liu
- Department of Neurology, The First Affiliated Hospital of Shanxi Medical University, Shanxi, China
| | - Yi-Wu Shi
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Mi Jiang
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Si-Mei Lin
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Na He
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Bin Li
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Wen-Jun Bian
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Bing-Mei Li
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Yong-Hong Yi
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Tao Su
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | | | - Wei-Yue Gu
- Chigene (Beijing) Translational Medical Research Center Co., Beijing, China
| | - Wei-Ping Liao
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
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28
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Ma MG, Liu XR, Wu Y, Wang J, Li BM, Shi YW, Su T, Li B, Liu DT, Yi YH, Liao WP. RYR2 Mutations Are Associated With Benign Epilepsy of Childhood With Centrotemporal Spikes With or Without Arrhythmia. Front Neurosci 2021; 15:629610. [PMID: 33897349 PMCID: PMC8058200 DOI: 10.3389/fnins.2021.629610] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 02/19/2021] [Indexed: 11/13/2022] Open
Abstract
RYR2 encodes ryanodine receptor 2 protein (RYR-2) that is mainly located on endoplasmic reticulum membrane and regulates intracellular calcium concentration. The RYR-2 protein is ubiquitously distributed and highly expressed in the heart and brain. Previous studies have identified the RYR2 mutations in the etiology of arrhythmogenic right ventricular dysplasia 2 and catecholaminergic polymorphic ventricular tachycardia. However, the relationship between RYR2 gene and epilepsy is not determined. In this study, we screened for novel genetic variants in a group of 292 cases (families) with benign epilepsy of childhood with centrotemporal spikes (BECTS) by trio-based whole-exome sequencing. RYR2 mutations were identified in five cases with BECTS, including one heterozygous frameshift mutation (c.14361dup/p.Arg4790Pro fs∗6), two heterozygous missense mutations (c.2353G > A/p.Asp785Asn and c.8574G > A/p.Met2858Ile), and two pairs of compound heterozygous mutations (c.4652A > G/p.Asn1551Ser and c.11693T > C/p.Ile3898Thr, c.7469T > C/p.Val2490Ala and c.12770G > A/p.Arg4257Gln, respectively). Asp785Asn was a de novo missense mutation. All the missense mutations were suggested to be damaging by at least three web-based prediction tools. These mutations do not present or at low minor allele frequency in gnomAD database and present statistically higher frequency in the cohort of BECTS than in the control populations of gnomAD. Asp785Asn, Asn1551Ser, and Ile3898Thr were predicted to affect hydrogen bonds with surrounding amino acids. Three affected individuals had arrhythmia (sinus arrhythmia and occasional atrial premature). The two probands with compound heterozygous missense mutations presented mild cardiac structural abnormalities. Strong evidence from ClinGen Clinical Validity Framework suggested an association between RYR2 variants and epilepsy. This study suggests that RYR2 gene is potentially a candidate pathogenic gene of BECTS. More attention should be paid to epilepsy patients with RYR2 mutations, which were associated with arrhythmia and sudden unexpected death in previous reports.
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Affiliation(s)
- Mei-Gang Ma
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China.,Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Xiao-Rong Liu
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Yuan Wu
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Jie Wang
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Bing-Mei Li
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Yi-Wu Shi
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Tao Su
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Bin Li
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - De-Tian Liu
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Yong-Hong Yi
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Wei-Ping Liao
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
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29
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Ghesh L, Besnard T, Nizon M, Trochu E, Landeau-Trottier G, Breheret F, Thauvin-Robinet C, Bruel AL, Kuentz P, Coubes C, Cuisset L, Mignot C, Keren B, Bézieau S, Cogné B. Loss-of-function variants in ARHGEF9 are associated with an X-linked intellectual disability dominant disorder. Hum Mutat 2021; 42:498-505. [PMID: 33600053 DOI: 10.1002/humu.24188] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 01/28/2021] [Accepted: 02/14/2021] [Indexed: 01/12/2023]
Abstract
ARHGEF9 defects lead to an X-linked intellectual disability disorder related to inhibitory synaptic dysfunction. This condition is more frequent in males, with a few affected females reported. Up to now, sequence variants and gross deletions have been identified in males, while only chromosomal aberrations have been reported in affected females who showed a skewed pattern of X-chromosome inactivation (XCI), suggesting an X-linked recessive (XLR) disorder. We report three novel loss-of-function (LoF) variants in ARHGEF9: A de novo synonymous variant affecting splicing (NM_015185.2: c.1056G>A, p.(Lys352=)) in one female; a nonsense variant in another female (c.865C>T, p.(Arg289*)), that is, also present as a somatically mosaic variant in her father, and a de novo nonsense variant in a boy (c.899G>A; p.(Trp300*)). Both females showed a random XCI. Thus, we suggest that missense variants are responsible for an XLR disorder affecting males and that LoF variants, mainly occurring de novo, may be responsible for an X-linked dominant disorder affecting males and females.
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Affiliation(s)
- Leïla Ghesh
- Service de Génétique Médicale, Centre Hospitalier Universitaire de Nantes, Nantes, France
| | - Thomas Besnard
- Service de Génétique Médicale, Centre Hospitalier Universitaire de Nantes, Nantes, France
- l'institut du thorax, Université de Nantes, CNRS, INSERM, Nantes, France
| | - Mathilde Nizon
- Service de Génétique Médicale, Centre Hospitalier Universitaire de Nantes, Nantes, France
- l'institut du thorax, Université de Nantes, CNRS, INSERM, Nantes, France
| | - Eva Trochu
- Service de Génétique Médicale, Centre Hospitalier Universitaire de Nantes, Nantes, France
| | | | - Flora Breheret
- Service de Génétique Médicale, Centre Hospitalier Universitaire de Nantes, Nantes, France
| | - Christel Thauvin-Robinet
- FHU TRANSLAD, Centre Hospitalier Universitaire Dijon-Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France
- Génétique des Anomalies du Développement, Inserm UMR 1231, Université de Bourgogne, Dijon, France
- Centre de Génétique et Centre de Référence Déficience Intellectuelle de causes rares, Hôpital d'Enfants, Centre Hospitalier Universitaire Dijon-Bourgogne, Dijon, France
- UF Innovation en diagnostic génomique des maladies rares, CHU Dijon, Dijon, France
| | - Ange-Line Bruel
- FHU TRANSLAD, Centre Hospitalier Universitaire Dijon-Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France
- Génétique des Anomalies du Développement, Inserm UMR 1231, Université de Bourgogne, Dijon, France
- UF Innovation en diagnostic génomique des maladies rares, CHU Dijon, Dijon, France
| | - Paul Kuentz
- FHU TRANSLAD, Centre Hospitalier Universitaire Dijon-Bourgogne et Université de Bourgogne-Franche Comté, Dijon, France
- Génétique des Anomalies du Développement, Inserm UMR 1231, Université de Bourgogne, Dijon, France
| | - Christine Coubes
- Département de Génétique Médicale, Maladies Rares et Médecine Personnalisée, Hôpital Arnaud de Villeneuve, CHU de Montpellier, Montpellier, France
| | - Laurence Cuisset
- Laboratoire de Génétique et Biologie Moléculaires, Département Médico-Universitaire BioPhyGen, Hôpital Cochin, APHP, Université de Paris, Paris, France
| | - Cyril Mignot
- Institut du Cerveau et de la Moelle épinière, ICM, INSERM, U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Paris, France
- Service de Génétique clinique et Médicale, CHU Paris, Hôpital Pitié-Salpêtrière, Paris, France
| | - Boris Keren
- Service de Génétique clinique et Médicale, CHU Paris, Hôpital Pitié-Salpêtrière, Paris, France
| | - Stéphane Bézieau
- Service de Génétique Médicale, Centre Hospitalier Universitaire de Nantes, Nantes, France
- l'institut du thorax, Université de Nantes, CNRS, INSERM, Nantes, France
| | - Benjamin Cogné
- Service de Génétique Médicale, Centre Hospitalier Universitaire de Nantes, Nantes, France
- l'institut du thorax, Université de Nantes, CNRS, INSERM, Nantes, France
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30
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Ye XG, Liu ZG, Wang J, Dai JM, Qiao PX, Gao PM, Liao WP. YWHAG Mutations Cause Childhood Myoclonic Epilepsy and Febrile Seizures: Molecular Sub-regional Effect and Mechanism. Front Genet 2021; 12:632466. [PMID: 33767733 PMCID: PMC7985244 DOI: 10.3389/fgene.2021.632466] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 02/15/2021] [Indexed: 01/27/2023] Open
Abstract
YWHAG, which encodes an adapter protein 14-3-3γ, is highly expressed in the brain and regulates a diverse range of cell signaling pathways. Previously, eight YWHAG mutations have been identified in patients with epileptic encephalopathy (EE). In this study, using trios-based whole exome sequencing, we identified two novel YWHAG mutations in two unrelated families with childhood myoclonic epilepsy and/or febrile seizures (FS). The identified mutations included a heterozygous truncating mutation (c.124C>T/p.Arg42Ter) and a de novo missense mutation (c.373A>G/p.Lys125Glu). The two probands experienced daily myoclonic seizures that were recorded with ictal generalized polyspike-slow waves, but became seizure-free with simple valproate treatment. The other affected individuals presented FS. The truncating mutation was identified in the family with six individuals of mild phenotype, suggesting that YWHAG mutations of haploinsufficiency are relatively less pathogenic. Analysis on all missense mutations showed that nine mutations were located within 14-3-3γ binding groove and another mutation was located at residues critical for dimerization, indicating a molecular sub-regional effect. Mutation Arg132Cys, which was identified recurrently in five patients with EE, would have the strongest influence on binding affinity. 14-3-3γ dimers supports target proteins activity. Thus, a heterozygous missense mutation would lead to majority dimers being mutants; whereas a heterozygous truncating mutation would lead to only decreasing the number of wild-type dimer, being one of the explanations for phenotypical variation. This study suggests that YWHAG is potentially a candidate pathogenic gene of childhood myoclonic epilepsy and FS. The spectrum of epilepsy caused by YWHAG mutations potentially range from mild myoclonic epilepsy and FS to severe EE.
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Affiliation(s)
- Xing-Guang Ye
- Department of Pediatrics, Affiliated Foshan Maternity & Child Healthcare Hospital, Southern Medical University, Foshan, China
| | - Zhi-Gang Liu
- Department of Pediatrics, Affiliated Foshan Maternity & Child Healthcare Hospital, Southern Medical University, Foshan, China.,Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Jie Wang
- Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Jie-Min Dai
- Department of Pediatrics, Affiliated Foshan Maternity & Child Healthcare Hospital, Southern Medical University, Foshan, China
| | - Pei-Xiu Qiao
- Department of Pediatrics, Affiliated Foshan Maternity & Child Healthcare Hospital, Southern Medical University, Foshan, China
| | - Ping-Ming Gao
- Department of Pediatrics, Affiliated Foshan Maternity & Child Healthcare Hospital, Southern Medical University, Foshan, China
| | - Wei-Ping Liao
- Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
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31
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George S, Bear J, Taylor MJ, Kanamalla K, Fekete CD, Chiou TT, Miralles CP, Papadopoulos T, De Blas AL. Collybistin SH3-protein isoforms are expressed in the rat brain promoting gephyrin and GABA-A receptor clustering at GABAergic synapses. J Neurochem 2021; 157:1032-1051. [PMID: 33316079 DOI: 10.1111/jnc.15270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 11/18/2020] [Accepted: 12/08/2020] [Indexed: 01/21/2023]
Abstract
Collybistin (CB) is a guanine nucleotide exchange factor (GEF) selectively localized at GABAergic and glycinergic postsynapses. Analysis of mRNA shows that several isoforms of collybistin are expressed in the brain. Some of the isoforms have a SH3 domain (CBSH3+) and some have no SH3 domain (CBSH3-). The CBSH3+ mRNAs are predominantly expressed over CBSH3-. However, in an immunoblot study of mouse brain homogenates, only CBSH3+ protein isoforms were detected, proposing that CBSH3- protein might not be expressed in the brain. The expression or lack of expression of CBSH3- protein is an important issue because CBSH3- has a strong effect in promoting the postsynaptic clustering of gephyrin and GABA-A receptors (GABAA Rs). Moreover CBSH3- is constitutively active; therefore lower expression of CBSH3- protein might play a relatively stronger functional role than the more abundant but self-inhibited CBSH3+ isoforms, which need to be activated. We are now showing that: (a) CBSH3- protein is expressed in the brain; (b) parvalbumin positive (PV+) interneurons show higher expression of CBSH3- protein than other neurons; (c) CBSH3- is associated with GABAergic synapses in various regions of the brain and (d) knocking down CBSH3- in hippocampal neurons decreases the synaptic clustering of gephyrin and GABAA Rs. The results show that CBSH3- protein is expressed in the brain and that it plays a significant role in the size regulation of the GABAergic postsynapse.
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Affiliation(s)
- Shanu George
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, USA
| | - John Bear
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, USA
| | - Michael J Taylor
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, USA
| | - Karthik Kanamalla
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, USA
| | - Christopher D Fekete
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, USA
| | - Tzu-Ting Chiou
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, USA
| | - Celia P Miralles
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, USA
| | | | - Angel L De Blas
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, USA
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Scala M, Zonneveld-Huijssoon E, Brienza M, Mecarelli O, van der Hout AH, Zambrelli E, Turner K, Zara F, Peron A, Vignoli A, Striano P. De novo ARHGEF9 missense variants associated with neurodevelopmental disorder in females: expanding the genotypic and phenotypic spectrum of ARHGEF9 disease in females. Neurogenetics 2020; 22:87-94. [PMID: 32939676 DOI: 10.1007/s10048-020-00622-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 07/21/2020] [Indexed: 11/24/2022]
Abstract
Individuals harboring pathogenic variants in ARHGEF9, encoding an essential submembrane protein for gamma-aminobutyric acid (GABA)-ergic synapses named collybistin, show intellectual disability (ID), facial dysmorphism, behavioral disorders, and epilepsy. Only few affected females carrying large chromosomal rearrangements involving ARHGEF9 have been reported so far. Through next-generation sequencing (NGS)-based panels, we identified two single nucleotide variants (SNVs) in ARHGEF9 in two females with neurodevelopmental features. Sanger sequencing revealed that these variants were de novo. The X-inactivation pattern in peripheral blood cells was random. We report the first affected females harboring de novo SNVs in ARHGEF9, expanding the genotypic and phenotypic spectrum of ARHGEF9-related neurodevelopmental disorder in females.
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Affiliation(s)
- Marcello Scala
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy. .,Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy.
| | - Evelien Zonneveld-Huijssoon
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Marianna Brienza
- Department of Human Neurosciences, Policlinico Umberto I Hospital, Sapienza University, Rome, Italy
| | - Oriano Mecarelli
- Department of Human Neurosciences, Policlinico Umberto I Hospital, Sapienza University, Rome, Italy
| | - Annemarie H van der Hout
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Elena Zambrelli
- Epilepsy Center - Sleep Medicine Center, San Paolo Hospital, Milan, Italy
| | - Katherine Turner
- Epilepsy Center - Sleep Medicine Center, San Paolo Hospital, Milan, Italy
| | - Federico Zara
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy.,Unit of Medical Genetics, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Angela Peron
- Child Neuropsychiatry Unit - Epilepsy Center, San Paolo Hospital, Milan, Italy.,Department of Health Sciences, Università degli Studi di Milano, Milan, Italy.,Department of Pediatrics, Division of Medical Genetics, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Aglaia Vignoli
- Child Neuropsychiatry Unit - Epilepsy Center, San Paolo Hospital, Milan, Italy.,Department of Health Sciences, Università degli Studi di Milano, Milan, Italy
| | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy.,Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
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Tang B, Li B, Gao LD, He N, Liu XR, Long YS, Zeng Y, Yi YH, Su T, Liao WP. Optimization of in silico tools for predicting genetic variants: individualizing for genes with molecular sub-regional stratification. Brief Bioinform 2019; 21:1776-1786. [PMID: 31686106 DOI: 10.1093/bib/bbz115] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 07/06/2019] [Accepted: 08/09/2019] [Indexed: 12/21/2022] Open
Abstract
Abstract
Genes are unique in functional role and differ in their sensitivities to genetic defects, but with difficulties in pathogenicity prediction. This study attempted to improve the performance of existing in silico algorithms and find a common solution based on individualization strategy. We initiated the individualization with the epilepsy-related SCN1A variants by sub-regional stratification. SCN1A missense variants related to epilepsy were retrieved from mutation databases, and benign missense variants were collected from ExAC database. Predictions were performed by using 10 traditional tools with stepwise optimizations. Model predictive ability was evaluated using the five-fold cross-validations on variants of SCN1A, SCN2A, and KCNQ2. Additional validation was performed in SCN1A variants of damage-confirmed/familial epilepsy. The performance of commonly used predictors was less satisfactory for SCN1A with accuracy less than 80% and varied dramatically by functional domains of Nav1.1. Multistep individualized optimizations, including cutoff resetting, domain-based stratification, and combination of predicting algorithms, significantly increased predictive performance. Similar improvements were obtained for variants in SCN2A and KCNQ2. The predictive performance of the recently developed ensemble tools, such as Mendelian clinically applicable pathogenicity, combined annotation-dependent depletion and Eigen, was also improved dramatically by application of the strategy with molecular sub-regional stratification. The prediction scores of SCN1A variants showed linear correlations with the degree of functional defects and the severity of clinical phenotypes. This study highlights the need of individualized optimization with molecular sub-regional stratification for each gene in practice.
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Affiliation(s)
- Bin Tang
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University
| | - Bin Li
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzo, China
| | - Liang-Di Gao
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University
| | - Na He
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzo, China
| | - Xiao-Rong Liu
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University
| | - Yue-Sheng Long
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University
| | - Yang Zeng
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University
| | - Yong-Hong Yi
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzo, China
| | - Tao Su
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University
| | - Wei-Ping Liao
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzo, China
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Dutta UR, Rao SN, Pidugu VK, V.S. V, Bhattacherjee A, Bhowmik AD, Ramaswamy SK, Singh KG, Dalal A. Breakpoint mapping of a novel de novo translocation t(X;20)(q11.1;p13) by positional cloning and long read sequencing. Genomics 2019; 111:1108-1114. [DOI: 10.1016/j.ygeno.2018.07.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 06/21/2018] [Accepted: 07/06/2018] [Indexed: 01/20/2023]
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35
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Volpatti JR, Al-Maawali A, Smith L, Al-Hashim A, Brill JA, Dowling JJ. The expanding spectrum of neurological disorders of phosphoinositide metabolism. Dis Model Mech 2019; 12:12/8/dmm038174. [PMID: 31413155 PMCID: PMC6737944 DOI: 10.1242/dmm.038174] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Phosphoinositides (PIPs) are a ubiquitous group of seven low-abundance phospholipids that play a crucial role in defining localized membrane properties and that regulate myriad cellular processes, including cytoskeletal remodeling, cell signaling cascades, ion channel activity and membrane traffic. PIP homeostasis is tightly regulated by numerous inositol kinases and phosphatases, which phosphorylate and dephosphorylate distinct PIP species. The importance of these phospholipids, and of the enzymes that regulate them, is increasingly being recognized, with the identification of human neurological disorders that are caused by mutations in PIP-modulating enzymes. Genetic disorders of PIP metabolism include forms of epilepsy, neurodegenerative disease, brain malformation syndromes, peripheral neuropathy and congenital myopathy. In this Review, we provide an overview of PIP function and regulation, delineate the disorders associated with mutations in genes that modulate or utilize PIPs, and discuss what is understood about gene function and disease pathogenesis as established through animal models of these diseases. Summary: This Review highlights the intersection between phosphoinositides and the enzymes that regulate their metabolism, which together are crucial regulators of myriad cellular processes and neurological disorders.
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Affiliation(s)
- Jonathan R Volpatti
- Division of Neurology and Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Almundher Al-Maawali
- Division of Neurology and Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada.,Department of Genetics, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat 123, Oman
| | - Lindsay Smith
- Division of Neurology and Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Aqeela Al-Hashim
- Division of Neurology and Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada.,Department of Neuroscience, King Fahad Medical City, Riyadh 11525, Saudi Arabia
| | - Julie A Brill
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada.,Program in Cell Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - James J Dowling
- Division of Neurology and Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada .,Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
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36
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Contreras A, Hines DJ, Hines RM. Molecular Specialization of GABAergic Synapses on the Soma and Axon in Cortical and Hippocampal Circuit Function and Dysfunction. Front Mol Neurosci 2019; 12:154. [PMID: 31297048 PMCID: PMC6607995 DOI: 10.3389/fnmol.2019.00154] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 05/31/2019] [Indexed: 12/24/2022] Open
Abstract
The diversity of inhibitory interneurons allows for the coordination and modulation of excitatory principal cell firing. Interneurons that release GABA (γ-aminobutyric acid) onto the soma and axon exert powerful control by virtue of proximity to the site of action potential generation at the axon initial segment (AIS). Here, we review and examine the cellular and molecular regulation of soma and axon targeting GABAergic synapses in the cortex and hippocampus. We also describe their role in controlling network activity in normal and pathological states. Recent studies have demonstrated a specific role for postsynaptic dystroglycan in the formation and maintenance of cholecystokinin positive basket cell terminals contacting the soma, and postsynaptic collybistin in parvalbumin positive chandelier cell contacts onto the AIS. Unique presynaptic molecular contributors, LGI2 and FGF13, expressed in parvalbumin positive basket cells and chandelier cells, respectively, have also recently been identified. Mutations in the genes encoding proteins critical for somatic and AIS inhibitory synapses have been associated with human disorders of the nervous system. Dystroglycan dysfunction in some congenital muscular dystrophies is associated with developmental brain malformations, intellectual disability, and rare epilepsy. Collybistin dysfunction has been linked to hyperekplexia, epilepsy, intellectual disability, and developmental disorders. Both LGI2 and FGF13 mutations are implicated in syndromes with epilepsy as a component. Advancing our understanding of the powerful roles of somatic and axonic GABAergic contacts in controlling activity patterns in the cortex and hippocampus will provide insight into the pathogenesis of epilepsy and other nervous system disorders.
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Affiliation(s)
- April Contreras
- Department of Psychology, University of Nevada, Las Vegas, Las Vegas, NV, United States
| | - Dustin J Hines
- Department of Psychology, University of Nevada, Las Vegas, Las Vegas, NV, United States
| | - Rochelle M Hines
- Department of Psychology, University of Nevada, Las Vegas, Las Vegas, NV, United States
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37
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Nashabat M, Al Qahtani XS, Almakdob S, Altwaijri W, Ba-Armah DM, Hundallah K, Al Hashem A, Al Tala S, Maddirevula S, Alkuraya FS, Tabarki B, Alfadhel M. The landscape of early infantile epileptic encephalopathy in a consanguineous population. Seizure 2019; 69:154-172. [PMID: 31054490 DOI: 10.1016/j.seizure.2019.04.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 04/21/2019] [Accepted: 04/24/2019] [Indexed: 11/18/2022] Open
Abstract
PURPOSE Epileptic encephalopathies (EE), are a group of age-related disorders characterized by intractable seizures and electroencephalogram (EEG) abnormalities that may result in cognitive and motor delay. Early infantile epileptic encephalopathies (EIEE) manifest in the first year of life. EIEE are highly heterogeneous genetically but a genetic etiology is only identified in half of the cases, typically in the form of de novo dominant mutations. METHOD This is a descriptive retrospective study of a consecutive series of patients diagnosed with EIEE from the participating hospitals. A chart review was performed for all patients. The diagnosis of epileptic encephalopathy was confirmed by molecular investigations in commercial labs. In silico study was done for all novel mutations. A systematic search was done for all the types of EIEE and their correlated genes in the literature using the Online Mendelian Inheritance In Man and PubMed databases. RESULTS In this case series, we report 72 molecularly characterized EIEE from a highly consanguineous population, and review their clinical course. We identified 50 variants, 26 of which are novel, causing 26 different types of EIEE. Unlike outbred populations, autosomal recessive EIEE accounted for half the cases. The phenotypes ranged from self-limiting and drug-responsive to severe refractory seizures or even death. CONCLUSIONS We reported the largest EIEE case series in the region with confirmed molecular testing and detailed clinical phenotyping. The number autosomal recessive predominance could be explained by the society's high consanguinity. We reviewed all the EIEE registered causative genes in the literature and proposed a functional classification.
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Affiliation(s)
- Marwan Nashabat
- King Abdullah International Medical Research Centre, King Saud bin Abdulaziz University for Health Sciences, Division of Genetics, Department of Pediatrics, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs (NGHA), Riyadh, Saudi Arabia
| | - Xena S Al Qahtani
- Division of Pediatric Neurology, Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Salwa Almakdob
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Waleed Altwaijri
- Division of Pediatric Neurology, Department of Pediatrics, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs (NGHA), Riyadh, Saudi Arabia
| | - Duaa M Ba-Armah
- Division of Pediatric Neurology, Department of Pediatrics, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs (NGHA), Riyadh, Saudi Arabia
| | - Khalid Hundallah
- Division of Pediatric Neurology, Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Amal Al Hashem
- Division of Genetics, Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia; Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Saeed Al Tala
- Division of Genetics, Department of Pediatrics, Armed Forces Hospital, Khamis Mushayt, Saudi Arabia
| | - Sateesh Maddirevula
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Fowzan S Alkuraya
- Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia; Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia; Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Brahim Tabarki
- Division of Pediatric Neurology, Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Majid Alfadhel
- King Abdullah International Medical Research Centre, King Saud bin Abdulaziz University for Health Sciences, Division of Genetics, Department of Pediatrics, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs (NGHA), Riyadh, Saudi Arabia.
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38
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Chiou TT, Long P, Schumann-Gillett A, Kanamarlapudi V, Haas SA, Harvey K, O'Mara ML, De Blas AL, Kalscheuer VM, Harvey RJ. Mutation p.R356Q in the Collybistin Phosphoinositide Binding Site Is Associated With Mild Intellectual Disability. Front Mol Neurosci 2019; 12:60. [PMID: 30914922 PMCID: PMC6422930 DOI: 10.3389/fnmol.2019.00060] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 02/19/2019] [Indexed: 11/13/2022] Open
Abstract
The recruitment of inhibitory GABAA receptors to neuronal synapses requires a complex interplay between receptors, neuroligins, the scaffolding protein gephyrin and the GDP-GTP exchange factor collybistin (CB). Collybistin is regulated by protein-protein interactions at the N-terminal SH3 domain, which can bind neuroligins 2/4 and the GABAAR α2 subunit. Collybistin also harbors a RhoGEF domain which mediates interactions with gephyrin and catalyzes GDP-GTP exchange on Cdc42. Lastly, collybistin has a pleckstrin homology (PH) domain, which binds phosphoinositides, such as phosphatidylinositol 3-phosphate (PI3P/PtdIns3P) and phosphatidylinositol 4-monophosphate (PI4P/PtdIns4P). PI3P located in early/sorting endosomes has recently been shown to regulate the postsynaptic clustering of gephyrin and GABAA receptors and consequently the strength of inhibitory synapses in cultured hippocampal neurons. This process is disrupted by mutations in the collybistin gene (ARHGEF9), which cause X-linked intellectual disability (XLID) by a variety of mechanisms converging on disrupted gephyrin and GABAA receptor clustering at central synapses. Here we report a novel missense mutation (chrX:62875607C>T, p.R356Q) in ARHGEF9 that affects one of the two paired arginine residues in the PH domain that were predicted to be vital for binding phosphoinositides. Functional assays revealed that recombinant collybistin CB3SH3- R356Q was deficient in PI3P binding and was not able to translocate EGFP-gephyrin to submembrane microaggregates in an in vitro clustering assay. Expression of the PI3P-binding mutants CB3SH3- R356Q and CB3SH3- R356N/R357N in cultured hippocampal neurones revealed that the mutant proteins did not accumulate at inhibitory synapses, but instead resulted in a clear decrease in the overall number of synaptic gephyrin clusters compared to controls. Molecular dynamics simulations suggest that the p.R356Q substitution influences PI3P binding by altering the range of structural conformations adopted by collybistin. Taken together, these results suggest that the p.R356Q mutation in ARHGEF9 is the underlying cause of XLID in the probands, disrupting gephyrin clustering at inhibitory GABAergic synapses via loss of collybistin PH domain phosphoinositide binding.
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Affiliation(s)
- Tzu-Ting Chiou
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, United States
| | - Philip Long
- Department of Pharmacology, UCL School of Pharmacy, London, United Kingdom
| | | | | | - Stefan A Haas
- Department of Computational Molecular Biology, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Kirsten Harvey
- Department of Pharmacology, UCL School of Pharmacy, London, United Kingdom
| | - Megan L O'Mara
- Research School of Chemistry, The Australian National University, Canberra, ACT, Australia
| | - Angel L De Blas
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, United States
| | - Vera M Kalscheuer
- Group Development and Disease, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Robert J Harvey
- School of Health and Sport Sciences, University of the Sunshine Coast, Sippy Downs, QLD, Australia.,Sunshine Coast Health Institute, Birtinya, QLD, Australia
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Groeneweg FL, Trattnig C, Kuhse J, Nawrotzki RA, Kirsch J. Gephyrin: a key regulatory protein of inhibitory synapses and beyond. Histochem Cell Biol 2018; 150:489-508. [DOI: 10.1007/s00418-018-1725-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/07/2018] [Indexed: 12/26/2022]
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40
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Ibaraki K, Mizuno M, Aoki H, Niwa A, Iwamoto I, Hara A, Tabata H, Ito H, Nagata KI. Biochemical and Morphological Characterization of a Guanine Nucleotide Exchange Factor ARHGEF9 in Mouse Tissues. Acta Histochem Cytochem 2018; 51:119-128. [PMID: 30083020 PMCID: PMC6066644 DOI: 10.1267/ahc.18009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 05/24/2018] [Indexed: 01/01/2023] Open
Abstract
ARHGEF9, also known as Collybistin, a guanine nucleotide exchange factor for Rho family GTPases, is thought to play an essential role in the mammalian brain. In this study, we prepared a specific polyclonal antibody against ARHGEF9, anti-ARHGEF9, and carried out expression analyses with mouse tissues especially brain. Western blotting analyses demonstrated tissue-dependent expression profiles of ARHGEF9 in the young adult mouse, and strongly suggested a role during brain development. Immunohistochemical analyses revealed developmental stage-dependent expression profiles of ARHGEF9 in cerebral cortex, hippocampus and cerebellum. ARHGEF9 exhibited partial localization at dendritic spines in cultured hippocampal neurons. From the obtained results, anti-ARHGEF9 was found to be a useful tool for biochemical and cell biological analyses of ARHGEF9.
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Affiliation(s)
- Kyoko Ibaraki
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Human Service Center
| | - Makoto Mizuno
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Human Service Center
| | - Hitomi Aoki
- Department of Tissue and Organ Development, Gifu University Graduate School of Medicine
| | - Ayumi Niwa
- Department of Tumor Pathology, Gifu University Graduate School of Medicine
| | - Ikuko Iwamoto
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Human Service Center
| | - Akira Hara
- Department of Tumor Pathology, Gifu University Graduate School of Medicine
| | - Hidenori Tabata
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Human Service Center
| | - Hidenori Ito
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Human Service Center
| | - Koh-ichi Nagata
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Human Service Center
- Department of Neurochemistry, Nagoya University Graduate School of Medicine
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