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Yang Y, Liu Z, Lu Y, Yu X, Zhu R, Cai X, Lin J, Wang Z, Zha D. Rab3a attenuates spinal cord injury by mediating vesicle release. Brain Res Bull 2024; 208:110884. [PMID: 38253132 DOI: 10.1016/j.brainresbull.2024.110884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 01/13/2024] [Accepted: 01/18/2024] [Indexed: 01/24/2024]
Abstract
BACKGROUND Rab3a regulates vesicle secretion and transport. Emerging evidences have shown that extracellular vesicles (EVs) can reach target lesions of injured spinal cords and exert a positive effect on these lesions. However, the molecular mechanism by which Rab3a regulates vesicle secretion to ameliorate spinal cord injury (SCI) is not fully understood. METHODS An SCI rat model was established which was used to examine the pathological changes and Rab3a expression in spinal cord tissue. Rab3a was overexpressed in the model rats to demonstrate its effect on SCI repair. Rab3a was also knocked down in neuronal cells to verify its role in vesicle secretion and neuronal cells. The binding protein of Rab3a was identified by Co-IP and mass spectrometry. RESULTS Rab3a was significantly downregulated in SCI rats and Rab3a overexpression promoted SCI repair. Rab3a knockdown inhibited the secretion of neuronal cell-derived EVs. Compared to the EVs from the equal number of control neuronal cells, EVs from Rab3a-knockdown neuronal cells promoted M1 macrophage polarization, which in turn, promoted neuronal cell apoptosis. Mechanistically, STXBP1 was identified as a binding protein of Rab3a, and their interaction promoted the secretion of neuronal cell-derived EVs. Furthermore, METTL2b was significantly downregulated in SCI rats, and METTL2b knockdown significantly reduced Rab3a protein expression. CONCLUSION These results suggest that Rab3a promotes the secretion of neuronal cell-derived EVs by interacting with its binding protein STXBP1. Neuronal cells-derived EVs inhibited the polarization of M1 macrophages in the spinal cord microenvironment, thereby promoting SCI repair. Our findings provide a theoretical basis for the clinical treatment of SCI.
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Affiliation(s)
- Yuhao Yang
- Department of Orthopaedics, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, China
| | - Ziqiao Liu
- Department of Orthopaedics, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, China
| | - Yang Lu
- Department of Plastic Surgery, The First Affiliated Hospital of Jinan University, Key Laboratory of Regenerative Medicine, Ministry of Education, Guangzhou, Guangdong 510630, China
| | - Xincheng Yu
- Department of Orthopaedics, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, China
| | - Rui Zhu
- Department of Orthopaedics, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, China
| | - Xingda Cai
- Department of Orthopaedics, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, China
| | - Jinghua Lin
- Department of Orthopaedics, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, China
| | - Zemin Wang
- Department of Orthopaedics, Chashan Hospital, Dongguan, Guangdong 523000, China
| | - Dingsheng Zha
- Department of Orthopaedics, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, China; Department of Orthopedics, The Affiliated Shunde Hospital of Jinan University, Foshan, Guangdong 528303, China.
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Guiberson NGL, Black LS, Haller JE, Brukner A, Abramov D, Ahmad S, Xie YX, Sharma M, Burré J. Disease-linked mutations in Munc18-1 deplete synaptic Doc2. Brain 2024:awae019. [PMID: 38242640 DOI: 10.1093/brain/awae019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 11/20/2023] [Accepted: 01/09/2024] [Indexed: 01/21/2024] Open
Abstract
Heterozygous de novo mutations in the neuronal protein Munc18-1/STXBP1 cause syndromic neurological symptoms, including severe epilepsy, intellectual disability, developmental delay, ataxia, and tremor, summarized as STXBP1 encephalopathies. Although haploinsufficiency is the prevailing disease mechanism, it remains unclear how the reduction in Munc18-1 levels causes synaptic dysfunction in disease as well as how haploinsufficiency alone can account for the significant heterogeneity among patients in terms of the presence, onset, and severity of different symptoms. Using biochemical and cell biological readouts on mouse brains, cultured mouse neurons, and heterologous cells, we find that the synaptic Munc18-1 interactors Doc2A and Doc2B are unstable in the absence of Munc18-1 and aggregate in the presence of disease-causing Munc18-1 mutants. In haploinsufficiency-mimicking heterozygous knockout neurons, we find a reduction in Doc2A/B levels that is further aggravated by the presence of the disease-causing Munc18-1 mutation G544D, as well as an impairment in Doc2A/B synaptic targeting in both genotypes. We also demonstrate that overexpression of Doc2A/B partially rescues synaptic dysfunction in heterozygous knockout neurons, but not heterozygous knockout neurons expressing G544D Munc18-1. Our data demonstrate that STXBP1 encephalopathies are not only characterized by the dysfunction of Munc18-1 but also by the dysfunction of the Munc18-1 binding partners Doc2A and Doc2B, and that this dysfunction is exacerbated by the presence of a Munc18-1 missense mutant. These findings may offer a novel explanation for the significant heterogeneity in symptoms observed among STXBP1 encephalopathy patients.
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Affiliation(s)
- Noah Guy Lewis Guiberson
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Luca S Black
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Jillian E Haller
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Aniv Brukner
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Debra Abramov
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Saad Ahmad
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Yan Xin Xie
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Manu Sharma
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Jacqueline Burré
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
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Barker E, Milburn AE, Helassa N, Hammond DE, Sanchez-Soriano N, Morgan A, Barclay JW. Proximity labelling reveals effects of disease-causing mutation on the DNAJC5/cysteine string protein α interactome. Biochem J 2024; 481:BCJ20230319. [PMID: 38193346 PMCID: PMC10903463 DOI: 10.1042/bcj20230319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 01/05/2024] [Accepted: 01/09/2024] [Indexed: 01/10/2024]
Abstract
Cysteine string protein α (CSPα), also known as DNAJC5, is a member of the DnaJ/Hsp40 family of co-chaperones. The name derives from a cysteine-rich domain, palmitoylation of which enables localization to intracellular membranes, notably neuronal synaptic vesicles. Mutations in the DNAJC5 gene that encodes CSPα cause autosomal dominant, adult-onset neuronal ceroid lipofuscinosis (ANCL), a rare neurodegenerative disease. As null mutations in CSP-encoding genes in flies, worms and mice similarly result in neurodegeneration, CSP is evidently an evolutionarily conserved neuroprotective protein. However, the client proteins that CSP chaperones to prevent neurodegeneration remain unclear. Traditional methods for identifying protein-protein interactions such as yeast 2-hybrid and affinity purification approaches are poorly suited to CSP, due to its requirement for membrane anchoring and its tendency to aggregate after cell lysis. Therefore, we employed proximity labelling, which enables identification of interacting proteins in situ in living cells via biotinylation. Neuroendocrine PC12 cell lines stably expressing wild type or L115R ANCL mutant CSP constructs fused to miniTurbo were generated; then the biotinylated proteomes were analysed by liquid chromatographymass spectrometry (LCMS) and validated by western blotting. This confirmed several known CSP-interacting proteins, such as Hsc70 and SNAP-25, but also revealed novel binding proteins, including STXBP1/Munc18-1. Interestingly, some protein interactions (such as Hsc70) were unaffected by the L115R mutation, whereas others (including SNAP-25 and STXBP1/Munc18-1) were inhibited. These results define the CSP interactome in a neuronal model cell line and reveal interactions that are affected by ANCL mutation and hence may contribute to the neurodegeneration seen in patients.
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Affiliation(s)
- Eleanor Barker
- Department of Biochemistry, Cell and Systems Biology, ISMIB, University of Liverpool, Liverpool, U.K
| | - Amy E. Milburn
- Department of Biochemistry, Cell and Systems Biology, ISMIB, University of Liverpool, Liverpool, U.K
| | - Nordine Helassa
- Department of Biochemistry, Cell and Systems Biology, ISMIB, University of Liverpool, Liverpool, U.K
| | - Dean E. Hammond
- Department of Biochemistry, Cell and Systems Biology, ISMIB, University of Liverpool, Liverpool, U.K
| | - Natalia Sanchez-Soriano
- Department of Biochemistry, Cell and Systems Biology, ISMIB, University of Liverpool, Liverpool, U.K
| | - Alan Morgan
- Department of Biochemistry, Cell and Systems Biology, ISMIB, University of Liverpool, Liverpool, U.K
| | - Jeff W. Barclay
- Department of Biochemistry, Cell and Systems Biology, ISMIB, University of Liverpool, Liverpool, U.K
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Weeratunga S, Gormal RS, Liu M, Eldershaw D, Livingstone EK, Malapaka A, Wallis TP, Bademosi AT, Jiang A, Healy MD, Meunier FA, Collins BM. Interrogation and validation of the interactome of neuronal Munc18-interacting Mint proteins with AlphaFold2. J Biol Chem 2024; 300:105541. [PMID: 38072052 PMCID: PMC10820826 DOI: 10.1016/j.jbc.2023.105541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 11/27/2023] [Accepted: 11/29/2023] [Indexed: 01/13/2024] Open
Abstract
Munc18-interacting proteins (Mints) are multidomain adaptors that regulate neuronal membrane trafficking, signaling, and neurotransmission. Mint1 and Mint2 are highly expressed in the brain with overlapping roles in the regulation of synaptic vesicle fusion required for neurotransmitter release by interacting with the essential synaptic protein Munc18-1. Here, we have used AlphaFold2 to identify and then validate the mechanisms that underpin both the specific interactions of neuronal Mint proteins with Munc18-1 as well as their wider interactome. We found that a short acidic α-helical motif within Mint1 and Mint2 is necessary and sufficient for specific binding to Munc18-1 and binds a conserved surface on Munc18-1 domain3b. In Munc18-1/2 double knockout neurosecretory cells, mutation of the Mint-binding site reduces the ability of Munc18-1 to rescue exocytosis, and although Munc18-1 can interact with Mint and Sx1a (Syntaxin1a) proteins simultaneously in vitro, we find that they have mutually reduced affinities, suggesting an allosteric coupling between the proteins. Using AlphaFold2 to then examine the entire cellular network of putative Mint interactors provides a structural model for their assembly with a variety of known and novel regulatory and cargo proteins including ADP-ribosylation factor (ARF3/ARF4) small GTPases and the AP3 clathrin adaptor complex. Validation of Mint1 interaction with a new predicted binder TJAP1 (tight junction-associated protein 1) provides experimental support that AlphaFold2 can correctly predict interactions across such large-scale datasets. Overall, our data provide insights into the diversity of interactions mediated by the Mint family and show that Mints may help facilitate a key trigger point in SNARE (soluble N-ethylmaleimide-sensitive factor attachment receptor) complex assembly and vesicle fusion.
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Affiliation(s)
- Saroja Weeratunga
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Rachel S Gormal
- Clem Jones Centre for Ageing and Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland, Australia
| | - Meihan Liu
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Denaye Eldershaw
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Emma K Livingstone
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Anusha Malapaka
- Clem Jones Centre for Ageing and Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland, Australia
| | - Tristan P Wallis
- Clem Jones Centre for Ageing and Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland, Australia
| | - Adekunle T Bademosi
- Clem Jones Centre for Ageing and Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland, Australia
| | - Anmin Jiang
- Clem Jones Centre for Ageing and Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland, Australia
| | - Michael D Healy
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Frederic A Meunier
- Clem Jones Centre for Ageing and Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland, Australia; School of Biomedical Sciences, The University of Queensland, Queensland, Australia
| | - Brett M Collins
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia.
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Freibauer A, Wohlleben M, Boelman C. STXBP1-Related Disorders: Clinical Presentation, Molecular Function, Treatment, and Future Directions. Genes (Basel) 2023; 14:2179. [PMID: 38137001 PMCID: PMC10742812 DOI: 10.3390/genes14122179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 11/27/2023] [Accepted: 12/01/2023] [Indexed: 12/24/2023] Open
Abstract
In recent years, the affordability and availability of genetic testing have led to its increased use in clinical care. The increased frequency of testing has led to STXBP1 variants being identified as one of the more common variants associated with neurological disorders. In this review, we aim to summarize the common clinical phenotypes associated with STXBP1 pathogenic variants, provide an overview of their known natural history, and discuss current research into the genotype to phenotype correlation. We will also provide an overview of the suspected normal function of the STXBP1-encoded Munc18-1 protein, animal models, and experimental techniques that have been developed to study its function and use this information to try to explain the diverse phenotypes associated with STXBP1-related disorders. Finally, we will explore current therapies for STXBP1 disorders, including an overview of treatment goals for STXBP1-related disorders, a discussion of the current evidence for therapies, and future directions of personalized medications for STXBP1-related disorders.
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Affiliation(s)
- Alexander Freibauer
- Division of Neurology, BC Children’s Hospital, Vancouver, BC V6H 3N1, Canada;
- Faculty of Medicine, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Mikayla Wohlleben
- Faculty of Medicine, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Cyrus Boelman
- Division of Neurology, BC Children’s Hospital, Vancouver, BC V6H 3N1, Canada;
- Faculty of Medicine, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
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6
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Al-Khfaji KMS, Zamani NK, Arefian E. HSV-1 latency-associated transcript miR-H3 and miR-H4 target STXBP1 and GABBR2 genes. J Neurovirol 2023; 29:669-677. [PMID: 37668872 DOI: 10.1007/s13365-023-01174-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 08/21/2023] [Accepted: 08/28/2023] [Indexed: 09/06/2023]
Abstract
During latent infection, the HSV-1 virus generates only a single transcript, LAT, which encodes six miRNAs. The GABAergic pathway signaling system is an essential cell signaling pathway influenced by various therapeutic targets and some brain disorders, such as epilepsy. This study found that miRNAs encoding LAT might target the STXBP1 and GABBR2 genes, which are among the significant genes in the GABAergic pathway. Bioinformatic analysis utilizing TargetScan version 5.2 and the RNA22 tools uncovered miRNAs encoding LAT that can influence STXBP1 and GABBR2 transcripts. To evaluate the targeting effect of candidate microRNAs encoding LAT, namely, miR-H3 and miR-H4, LAT constructs were transfected into HEK 293T cells. The expression levels of microRNAs encoding LAT, as well as STXBP1 and GABBR2, were assayed by real-time PCR. Finally, the targeting potential of STXBP1 and GABBR2 3'UTR by LAT-encoded microRNAs was evaluated by the luciferase assay. In the current study, the bioinformatic tool TargetScan demonstrated that miR-H3 has the potential to target the transcripts of the STXBP1 and GABBR2 genes, whereas miR-H4 solely targeted GABBR2. On the other hand, the bioinformatic tool RNA22 validated the potential targeting of STXBP1 and GABBR2 by miR-H3 and miR-H4. Our findings showed that overexpression of miR-H4, miR-H3, or LAT significantly decreased STXBP1 gene expression by an average of 0.0593-fold, 0.237-fold, and 0.84-fold, respectively. Similarly, overexpression of miR-H3 or miR-H4 decreased GABBR2 expression by an average of 0.055- or 0.687-fold, respectively. Notably, targeting the GABBR2 3'UTR with the LAT transcript had no detectable effect. The evaluation of the targeting potential of STXBP1 and GABBR2 3'UTR by microRNAs encoded by LAT was conducted with a luciferase assay. Our results showed that miR-H3 overexpression reduces Renilla expression in psiCHECK2 plasmids with STXBP1 or GABBR2 3'UTR genes by 0.62- and 0.55-fold, respectively. miR-H4 reduced Renilla gene expression regulated by GABBR2's 3'UTR plasmid but had no effect on the Renilla gene expression regulated by STXBP1's 3'UTR. When the LAT transcript was overexpressed, there was a decrease in Renilla expression by 0.44-fold because of the regulation of STXBP1's 3'UTR. However, there was no significant effect observed through the control of GABBR2's 3'UTR.
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Affiliation(s)
- Karrar Mahmood Shaker Al-Khfaji
- Molecular Virology Lab, Department of Microbiology, School of Biology, College of Sciences, University of Tehran, P.O. Box 14155-6455, Tehran, 1417614411, Iran
| | - Nika Kooshki Zamani
- Department of Biotechnology, College of Sciences, University of Tehran, Tehran, Iran
| | - Ehsan Arefian
- Molecular Virology Lab, Department of Microbiology, School of Biology, College of Sciences, University of Tehran, P.O. Box 14155-6455, Tehran, 1417614411, Iran.
- Paediatric Cell and Gene Therapy Research Center, Gene, Cell & Tissue Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
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Salcedo-Perez-Juana M, Palacios-Ceña D, San-Martín-Gómez A, Aledo-Serrano Á, Florencio LL. Quality of life, socioeconomic and psychological concerns in parents of children with tuberous sclerosis complex, STXBP1 and SYNGAP1 encephalopathies: a mixed method study. Front Pediatr 2023; 11:1285377. [PMID: 38027293 PMCID: PMC10665567 DOI: 10.3389/fped.2023.1285377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 10/27/2023] [Indexed: 12/01/2023] Open
Abstract
Background Developmental and Epileptic Encephalopathies (DEEs) occur in childhood and are associated with severe epileptic seizures and neurological impairment. The aim of this study was to combine quantitative and qualitative methodologies to comprehensively describe factors related to quality of life, impact on the family and psychosocial factors in parents of children with TSC, STXBP1 and SYNGAP1 variants. Methods A convergent parallel mixed design including parents of children with DEE. In the cross-sectional study, 20 parents (10STXBP1, five SYNGAP1, five TSC) were given questionnaires on quality of life, impact on the family and psychological factors. In the descriptive qualitative study, in-depth interviews were conducted with 18 parents (nine STXBP1, five TSC, four SYNGAP1) using a semi-structured questionnaire. A thematic analysis was carried out. The results of the two studies were combined by showing similarities and differences through tables, figures, accounts, and joint displays. Results In terms of quality of life, the integrated results were consistent in highlighting the importance of family interaction, although in the qualitative section the influence of the relationship between the children's siblings, the relationship with health professionals and the difficulties in obtaining public aid were highlighted. In terms of impact, the integrated results show that the illness has a significant impact on the family; the financial burden is highlighted, and the experience of the illness is discussed in depth. Finally, the psychological aspects, symptoms such as anxiety, stress and strain, were consistent. Most of the participants reported sleep disturbance, as identified in the questionnaire, although not mentioned in the interviews. Conclusions The combined results of the mixed method provide an in-depth analysis of the impact of DEEs on parents of children with STXBP1, SYNGAP1 and TSC.
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Affiliation(s)
- María Salcedo-Perez-Juana
- Research Group of Humanities and Qualitative Research in Health Science (Hum&QRinHS), Department of Physical Therapy, Occupational Therapy, Physical Medicine and Rehabilitation, Universidad Rey Juan Carlos, Madrid, Spain
| | - Domingo Palacios-Ceña
- Research Group of Humanities and Qualitative Research in Health Science (Hum&QRinHS), Department of Physical Therapy, Occupational Therapy, Physical Medicine and Rehabilitation, Universidad Rey Juan Carlos, Madrid, Spain
| | - Ana San-Martín-Gómez
- Research Group of Humanities and Qualitative Research in Health Science (Hum&QRinHS), Department of Physical Therapy, Occupational Therapy, Physical Medicine and Rehabilitation, Universidad Rey Juan Carlos, Madrid, Spain
| | - Ángel Aledo-Serrano
- Epilepsyand Neurogenetics Programme, Vithas Madrid La Milagrosa University Hospital, Vithas Hospital Group, Madrid, Spain
| | - Lidiane Lima Florencio
- Research Group of Manual Therapy, Dry Needling and Therapeutic Exercise (GITM-URJC), Department of Physical Therapy, Occupational Therapy, Physical Medicine and Rehabilitation, Universidad Rey Juan Carlos, Madrid, Spain
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Ma Z, Wang L, Huang X, Ji H, Wang H, Yang Y, Ma Y, Chen J. Construction of the metabolism-related models for predicting prognosis and infiltrating immune phenotype in lung squamous cell carcinoma. J Cancer 2023; 14:3539-3549. [PMID: 38021151 PMCID: PMC10647197 DOI: 10.7150/jca.86942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 10/07/2023] [Indexed: 12/01/2023] Open
Abstract
Purpose: Cancers often display disorder metabolism, which closely related to the poor outcome of patients. We aimed to establish prognostic models using metabolism-associated genes, and identify the key factor involved in metabolism in lung squamous cell carcinoma (LUSC). Materials and Methods: R package 'TCGA biolinks' was used to download the mRNA sequencing data of LUSC from TCGA. The clusterProfiler package was performed to analyze biological pathways. The online tool GEPIA2 and cox regression method were applied to identify the two gene lists associated with metabolism and prognosis of LUSC. The lasso modeling was conducted to establish prognostic models. The quantiseq method was used to identify the cellular abundance of expression matrix in TCGA-LUSC dataset. Immunohistochemistry and western blotting were done to evaluate the STXBP1 expression in LUSC samples. Lactate assay and ATP detection were performed to assess metabolic effect, and CCK8 assay was done to test cell proliferation in the LUSC cells with overexpression and suppression of STXBP1. Results: Two lists of survival-metabolism-associated genes (11 and 28 genes) were identified and applied in the prognostic model 1 and model 2 construction from TCGA-LUSC dataset. High-risk LUSC patients associated with poor survival in the training cohort and the test cohort of both model 1 and model 2. Higher ROC values for 10- year survival was shown in model 2 than in model 1. In addition, macrophage M1, macrophage M2, neutrophil, and T regulatory cell were enriched in the high-risk group of model 2. STXBP1 was the only optimized gene in both model 1 and model 2, and related to the poor outcome of LUSC patients. Furthermore, STXBP1 associated with infiltrating immune cells, and increased lactate, ATP levels, and cell proliferation. Conclusion: Our finding provides the metabolism-associated models to predict prognosis of LUSC patients. STXBP1, as the key optimized gene in the model, promotes metabolic progress to increase lactate and ATP levels in LUSC cells.
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Affiliation(s)
- Zeming Ma
- Department of Thoracic Surgery II, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University Cancer Hospital and Institute, Beijing, 100142, People's Republic of China
| | - Liang Wang
- Department of Thoracic Surgery II, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University Cancer Hospital and Institute, Beijing, 100142, People's Republic of China
| | - Xiaoyun Huang
- Department of Computational Oncology, Intelliphecy, Shenzhen, China; Center for Systems Biology, Intelliphecy, Shenzhen, China
| | - Hong Ji
- Department of Gastrointestinal Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Peking University Cancer Hospital and Institute, 100142, People's Republic of China
| | - Haoyang Wang
- Beijing International Bilingual Academy, People's Republic of China
| | - Yue Yang
- Department of Thoracic Surgery II, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University Cancer Hospital and Institute, Beijing, 100142, People's Republic of China
| | - Yuanyuan Ma
- Department of Thoracic Surgery II, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University Cancer Hospital and Institute, Beijing, 100142, People's Republic of China
| | - Jinfeng Chen
- Department of Thoracic Surgery II, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University Cancer Hospital and Institute, Beijing, 100142, People's Republic of China
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Xian J, Thalwitzer KM, McKee J, Sullivan KR, Brimble E, Fitch E, Toib J, Kaufman MC, deCampo D, Cunningham K, Pierce SR, Goss J, Rigby CS, Syrbe S, Boland M, Prosser B, Fitter N, Ruggiero SM, Helbig I. Delineating clinical and developmental outcomes in STXBP1-related disorders. medRxiv 2023:2023.05.10.23289776. [PMID: 37215006 PMCID: PMC10197795 DOI: 10.1101/2023.05.10.23289776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
STXBP1-related disorders are among the most common genetic epilepsies and neurodevelopmental disorders. However, the longitudinal epilepsy course and developmental endpoints have not yet been described in detail, which is a critical prerequisite for clinical trial readiness. Here, we assessed 1,281 cumulative patient-years of seizure and developmental histories in 162 individuals with STXBP1-related disorders and established a natural history framework. STXBP1-related disorders are characterized by a dynamic pattern of seizures in the first year of life and high variability in neurodevelopmental trajectories in early childhood. Epilepsy onset differed across seizure types, with 90% cumulative onset for infantile spasms by 6 months and focal-onset seizures by 27 months of life. Epilepsy histories diverged between variant subgroups in the first 2 years of life, when individuals with protein-truncating variants and deletions in STXBP1 (n=39) were more likely to have infantile spasms between 5 and 6 months followed by seizure remission, while individuals with missense variants (n=30) had an increased risk for focal seizures and ongoing seizures after the first year. Developmental outcomes were mapped using milestone acquisition data in addition to standardized assessments including the Gross Motor Function Measure-66 Item Set and the Grasping and Visual-Motor Integration subsets of the Peabody Developmental Motor Scales. Quantification of endpoints revealed high variability during the first five years of life, with emerging stratification between clinical subgroups, most prominently between individuals with and without infantile spasms. We found that individuals with neonatal seizures or early infantile seizures followed by seizure offset by 12 months of life had more predictable seizure trajectories in early to late childhood than compared to individuals with more severe seizure presentations, including individuals with refractory epilepsy throughout the first year. Characterization of anti-seizure medication response revealed age-dependent response over time, with phenobarbital, levetiracetam, topiramate, and adrenocorticotropic hormone effective in reducing seizures in the first year of life, while clobazam and the ketogenic diet were effective in long-term seizure management. Virtual clinical trials using seizure frequency as the primary outcome resulted in wide range of trial success probabilities across the age span, with the highest probability in early childhood between 1 year and 3.5 years. In summary, we delineated epilepsy and developmental trajectories in STXBP1-related disorders using standardized measures, providing a foundation to interpret future therapeutic strategies and inform rational trial design.
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Affiliation(s)
- Julie Xian
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- The Epilepsy NeuroGenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Department of Biomedical and Health Informatics (DBHi), Children’s Hospital of Philadelphia, Philadelphia, PA 19146, USA
- Epilepsy and Neurodevelopmental Disorders Center (ENDD), Children’s Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Kim Marie Thalwitzer
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- The Epilepsy NeuroGenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Department of Biomedical and Health Informatics (DBHi), Children’s Hospital of Philadelphia, Philadelphia, PA 19146, USA
- Division of Pediatric Epileptology, Centre for Pediatric and Adolescent Medicine, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Jillian McKee
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- The Epilepsy NeuroGenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Department of Biomedical and Health Informatics (DBHi), Children’s Hospital of Philadelphia, Philadelphia, PA 19146, USA
- Epilepsy and Neurodevelopmental Disorders Center (ENDD), Children’s Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Katie Rose Sullivan
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- The Epilepsy NeuroGenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Department of Biomedical and Health Informatics (DBHi), Children’s Hospital of Philadelphia, Philadelphia, PA 19146, USA
- Epilepsy and Neurodevelopmental Disorders Center (ENDD), Children’s Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | | | - Eryn Fitch
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- The Epilepsy NeuroGenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Jonathan Toib
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- The Epilepsy NeuroGenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Michael C. Kaufman
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- The Epilepsy NeuroGenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Department of Biomedical and Health Informatics (DBHi), Children’s Hospital of Philadelphia, Philadelphia, PA 19146, USA
| | - Danielle deCampo
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- The Epilepsy NeuroGenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Epilepsy and Neurodevelopmental Disorders Center (ENDD), Children’s Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Kristin Cunningham
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- The Epilepsy NeuroGenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Epilepsy and Neurodevelopmental Disorders Center (ENDD), Children’s Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Samuel R. Pierce
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- The Epilepsy NeuroGenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Epilepsy and Neurodevelopmental Disorders Center (ENDD), Children’s Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | | | | | - Steffen Syrbe
- Division of Pediatric Epileptology, Centre for Pediatric and Adolescent Medicine, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Michael Boland
- Epilepsy and Neurodevelopmental Disorders Center (ENDD), Children’s Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
- Institute for Genomic Medicine, Columbia University, New York, NY 10032, USA
| | - Ben Prosser
- Epilepsy and Neurodevelopmental Disorders Center (ENDD), Children’s Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | | | - Sarah M. Ruggiero
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- The Epilepsy NeuroGenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Epilepsy and Neurodevelopmental Disorders Center (ENDD), Children’s Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Ingo Helbig
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- The Epilepsy NeuroGenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Department of Biomedical and Health Informatics (DBHi), Children’s Hospital of Philadelphia, Philadelphia, PA 19146, USA
- Epilepsy and Neurodevelopmental Disorders Center (ENDD), Children’s Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
- Department of Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
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10
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McLeod F, Dimtsi A, Marshall AC, Lewis-Smith D, Thomas R, Clowry GJ, Trevelyan AJ. Altered synaptic connectivity in an in vitro human model of STXBP1 encephalopathy. Brain 2023; 146:850-857. [PMID: 36315647 PMCID: PMC9976961 DOI: 10.1093/brain/awac396] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 08/05/2022] [Accepted: 10/01/2022] [Indexed: 01/14/2023] Open
Abstract
Early infantile developmental and epileptic encephalopathies are devastating conditions, generally of genetic origin, but the pathological mechanisms often remain obscure. A major obstacle in this field of research is the difficulty of studying cortical brain development in humans, at the relevant time period in utero. To address this, we established an in vitro assay to study the impact of gene variants on the developing human brain by using living organotypic cultures of the human subplate and neighbouring cortical regions, prepared from ethically sourced, 14-17 post-conception week brain tissue (www.hdbr.org). We were able to maintain cultures for several months, during which time the gross anatomical structures of the cortical plate, subplate and marginal zone persisted, while neurons continued to develop morphologically and form new synaptic networks. This preparation thus permits the study of genetic manipulations and their downstream effects on an intact developing human cortical network. We focused on STXBP1 haploinsufficiency, which is among the most common genetic causes of developmental and epileptic encephalopathy. This was induced using shRNA interference, leading to impaired synaptic function and a reduced density of glutamatergic synapses. We thereby provide a critical proof-of-principle for how to study the impact of any gene of interest on the development of the human cortex.
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Affiliation(s)
- Faye McLeod
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Anna Dimtsi
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Amy C Marshall
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - David Lewis-Smith
- Newcastle University Translational and Clinical Research Institute, Newcastle upon Tyne NE2 4HH, UK
- Department of Clinical Neurosciences, Royal Victoria Infirmary, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE1 4LP, UK
| | - Rhys Thomas
- Newcastle University Translational and Clinical Research Institute, Newcastle upon Tyne NE2 4HH, UK
- Department of Clinical Neurosciences, Royal Victoria Infirmary, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE1 4LP, UK
| | - Gavin J Clowry
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Andrew J Trevelyan
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
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11
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Aristidou C, Theodosiou A, Alexandrou A, Papaevripidou I, Evangelidou P, Kosmaidou-Aravidou Z, Behjati F, Christophidou-Anastasiadou V, Tanteles GA, Sismani C. Exploring the Genetic Causality of Discordant Phenotypes in Familial Apparently Balanced Translocation Cases Using Whole Exome Sequencing. Genes (Basel) 2022; 14. [PMID: 36672823 DOI: 10.3390/genes14010082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 12/23/2022] [Accepted: 12/24/2022] [Indexed: 12/29/2022] Open
Abstract
Familial apparently balanced translocations (ABTs) are usually not associated with a phenotype; however, rarely, ABTs segregate with discordant phenotypes in family members carrying identical rearrangements. The current study was a follow-up investigation of four familial ABTs, where whole exome sequencing (WES) was implemented as a diagnostic tool to identify the underlying genetic aetiology of the patients' phenotypes. Data were analysed using an in-house bioinformatics pipeline alongside VarSome Clinical. WES findings were validated with Sanger sequencing, while the impact of splicing and missense variants was assessed by reverse-transcription PCR and in silico tools, respectively. Novel candidate variants were identified in three families. In family 1, it was shown that the de novo pathogenic STXBP1 variant (NM_003165.6:c.1110+2T>G) affected splicing and segregated with the patient's phenotype. In family 2, a likely pathogenic TUBA1A variant (NM_006009.4:c.875C>T, NP_006000.2:p.(Thr292Ile)) could explain the patient's symptoms. In family 3, an SCN1A variant of uncertain significance (NM_006920.6:c.5060A>G, NP_008851.3:p.(Glu1687Gly)) required additional evidence to sufficiently support causality. This first report of WES application in familial ABT carriers with discordant phenotypes supported our previous findings describing such rearrangements as coincidental. Thus, WES can be recommended as a complementary test to find the monogenic cause of aberrant phenotypes in familial ABT carriers.
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12
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Moog M, Baraban SC. Clemizole and Trazodone are Effective Antiseizure Treatments in a Zebrafish Model of STXBP1 Disorder. Epilepsia Open 2022; 7:504-511. [PMID: 35451230 PMCID: PMC9436285 DOI: 10.1002/epi4.12604] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 04/19/2022] [Indexed: 11/07/2022] Open
Abstract
CRISPR-Cas9-generated zebrafish carrying a 12 base-pair deletion in stxbpb1b, a paralog sharing 79% amino acid sequence identity with human, exhibit spontaneous electrographic seizures during larval stages of development. Zebrafish stxbp1b mutants provide an efficient preclinical platform to test antiseizure therapeutics. The present study was designed to test antiseizure medications approved for clinical use and two recently identified repurposed drugs with antiseizure activity. Larval homozygous stxbp1b zebrafish (4 days post-fertilization) were agarose-embedded and monitored for electrographic seizure activity using a local field recording electrode placed in midbrain. Frequency of ictal-like events was evaluated at baseline and following 45 min of continuous drug exposure (1 mM, bath application). Analysis was performed on coded files by an experimenter blinded to drug treatment and genotype. Phenytoin, valproate, ethosuximide, levetiracetam, and diazepam had no effect on ictal-like event frequency in stxbp1b mutant zebrafish. Clemizole and trazodone decreased ictal-like event frequency in stxbp1b mutant zebrafish by 80% and 83%, respectively. These results suggest that repurposed drugs with serotonin receptor binding affinities could be effective antiseizure treatments. Clemizole and trazodone were previously identified in a larval zebrafish model for Dravet syndrome. Based primarily on these preclinical zebrafish studies, compassionate-use and double-blind clinical trials with both drugs have progressed. The present study extends this approach to a preclinical zebrafish model representing STXBP1-related disorders, and suggests that future clinical studies may be warranted.
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Affiliation(s)
- Maia Moog
- Department of Neurological Surgery & Weill Institute for NeuroscienceUniversity of CaliforniaSan FranciscoCaliforniaUSA
| | - Scott C. Baraban
- Department of Neurological Surgery & Weill Institute for NeuroscienceUniversity of CaliforniaSan FranciscoCaliforniaUSA
- Helen Wills Neuroscience InstituteUniversity of CaliforniaBerkeleyCaliforniaUSA
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13
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Yang P, Broadbent R, Prasad C, Levin S, Goobie S, Knoll JH, Prasad AN. De novo STXBP1 Mutations in Two Patients With Developmental Delay With or Without Epileptic Seizures. Front Neurol 2022; 12:804078. [PMID: 35002943 PMCID: PMC8739808 DOI: 10.3389/fneur.2021.804078] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 11/29/2021] [Indexed: 12/03/2022] Open
Abstract
Objectives: Mutations in the STXBP1 gene have been associated with epileptic encephalopathy. Previous studies from in vitro neuroblastoma 2A cells showed that haploinsufficiency of STXBP1 is the mechanism for epileptic encephalopathy. In this ex vivo study, STXPB1 DNA mutations and RNA expression were assessed from two patients to help understand the impact of STXBP1 mutations on the disease etiology and mechanism. Methods: Microarray analysis and DNA sequencing were performed on two children with development delay, one with and one without infantile spasms. Different pathogenic mutations of STXBP1 were identified in the patients and RNA expression of STXPB1 was then performed by RT-Q-PCR on RNA extracted from blood samples of each patient. Results: Pathogenic deletion [of exons 13–20 and 3′ downstream of STXBP1] and nonsense mutation [c.1663G>T (p.Glu555X) in exon 18 of STXBP1] were detected from the two patients, respectively. RNA analysis showed that 1) the deletion mediated RNA decay, and that 2) no RNA decay was identified for the nonsense mutation at codon 555 which predicts a truncated STXBP1 protein. Significance: Our RNA expression analyses from the patient blood samples are the first ex vivo studies to support that both haploinsufficiency and truncation of STXBP1 protein (either dominant negative or haploinsufficiency) are causative mechanisms for epileptic encephalopathies, intellectual disability and developmental delay. The RNA assay also suggests that escape from nonsense-mediated RNA decay is possible when the nonsense mutation resides <50 nucleotides upstream of the last coding exon-exon junction even in the presence of additional non-coding exons that are 3′ downstream of the last coding exon.
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Affiliation(s)
- Ping Yang
- Department of Pathology and Laboratory Medicine, Western University, London, ON, Canada.,London Health Sciences Centre, London, ON, Canada
| | - Robert Broadbent
- Department of Pathology and Laboratory Medicine, Western University, London, ON, Canada.,London Health Sciences Centre, London, ON, Canada
| | - Chitra Prasad
- Department of Paediatrics, London Health Sciences Centre, Western University, London, ON, Canada
| | - Simon Levin
- Department of Paediatrics, London Health Sciences Centre, Western University, London, ON, Canada
| | - Sharan Goobie
- Maritime Medical Genetic Service, Department of Paediatrics, Izaak Walton Killam Health Centre, Halifax, NS, Canada
| | - Joan H Knoll
- Department of Pathology and Laboratory Medicine, Western University, London, ON, Canada.,London Health Sciences Centre, London, ON, Canada
| | - Asuri N Prasad
- Department of Paediatrics, London Health Sciences Centre, Western University, London, ON, Canada
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14
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Wang QH, Cao JJ, Wang YY, Zhang MN, Liu LY, Wang J, Lu Q, He W, Shen YW, Chen HM, Luo XM, Chen Q, Zou LP. Efficacy of levetiracetam in STXBP1 encephalopathy with different phenotypic and genetic spectra. Seizure 2021; 95:64-74. [PMID: 35007884 DOI: 10.1016/j.seizure.2021.12.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 12/08/2021] [Accepted: 12/15/2021] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE Syntaxin binding protein 1 (STXBP1) plays an important role in the release of synaptic vesicles. STXBP1-related encephalopathy is a brain dysfunction caused by STXBP1 variation. Levetiracetam (LEV) exerts antiepileptic effects by binding to synaptic vesicle protein 2A (SV2A). This study aimed to analyze the prognosis of LEV treatment of STXBP1 encephalopathy (STXBP1-E) and the correlation among genotype, phenotype, and LEV efficacy. METHODS Patients with pathogenic STXBP1 variants were collected from multiple centers, and their clinical history, video electroencephalogram (vEEG) characteristics, imaging examination data, and anti-seizure medication (ASM) history were systematically analyzed. The ASMs related to the prognosis were explored. RESULTS Forty patients with STXBP1-E were enrolled in this study. The detailed ASM usage of 37 patients was recorded without intervening in ASM selection. At the endpoint of six months treatment, the results of Fisher's exact test showed that in all ASMs, LEV affected the prognosis of patients with STXBP1-E. LEV was effective in improving the partial remission rate but did not achieve seizure freedom. However, LEV monotherapy could achieve seizure freedom in patients with other early-onset epileptic and encephalopathy. For refractory West syndrome (WS) or Ohtahara syndrome (OS), LEV combined with other ASMs could improve the seizure remission rate. CONCLUSION LEV increased the seizure reduction rate and improved the vEEG characteristics in patients with STXBP1-E, but not seizure freedom. LEV combined with other ASMs could increase the seizure reduction rate, especially for refractory WS or OS. Thus, LEV could be considered after identifying the pathogenicity of STXBP1 variants.
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15
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Suo G, Cao X, Zheng Y, Li H, Zhang Q, Tang J, Wu Y. A de novo nonsense mutation of STXBP1 causes early-onset epileptic encephalopathy. Epilepsy Behav 2021; 123:108245. [PMID: 34390894 DOI: 10.1016/j.yebeh.2021.108245] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 07/26/2021] [Accepted: 07/26/2021] [Indexed: 01/16/2023]
Abstract
Mutations in syntaxin-binding protein 1, STXBP1 (also known as MUNC18-1), are linked to multiple neurodevelopmental disorders, including severe early-onset epileptic encephalopathies (EOEEs). A de novo nonsense mutation of STXBP1 (c. 863G > A, p. W288X) was found in a patient diagnosed with EOEE at the age of 17 days. The electroencephalogram (EEG) showed sharp waves and spikes, while brain magnetic resonance imaging was normal. We generated a zebrafish EOEE model by overexpressing mutant STXBP1(W288X) and studied the behavioral changes further to understand the mechanism of W288X mutation in epileptogenesis. In addition, effective antiepileptic drugs were screened in the zebrafish model. Zebrafish STXBP1 homologs were highly conserved and prominently expressed in the larval zebrafish brain. The Tg(hSTXBP1W288X) zebrafish larvae exhibited hyperactivity compared with the wild-type (WT) controls. The expression of STXBP1 decreased during the development course from 1 to 5 days post fertilization. Spontaneous seizures and increased c-fos expression were observed in the mutant zebrafish larvae. The susceptibility of Tg(hSTXBP1W288X) zebrafish to pentylenetetrazol challenge also dramatically increased. Levetiracetam, clonazepam, and topiramate showed antiepileptic effects in the Tg(hSTXBP1W288X) larvae to different extents. Our findings in the newly generated mutant line of zebrafish suggested that zebrafish recapitulated clinical phenotypes associated with human STXBP1 mutation, which provided an appropriate in vivo model for epilepsy research.
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Affiliation(s)
- Guihai Suo
- Department of Pediatrics, Affiliated Hospital of Nantong University, Nantong, China; Department of Neurology, Children's Hospital of Soochow University, Suzhou, China
| | - Xing Cao
- Department of Pediatrics, Affiliated Hospital of Nantong University, Nantong, China
| | - Yuqin Zheng
- Department of Pediatrics, Affiliated Hospital of Nantong University, Nantong, China
| | - Haiying Li
- Department of Pediatrics, Affiliated Hospital of Nantong University, Nantong, China
| | - Qi Zhang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Jihong Tang
- Department of Neurology, Children's Hospital of Soochow University, Suzhou, China
| | - Youjia Wu
- Department of Pediatrics, Affiliated Hospital of Nantong University, Nantong, China
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16
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Liu L, Liu F, Wang Q, Xie H, Li Z, Lu Q, Wang Y, Zhang M, Zhang Y, Picker J, Cui X, Zou L, Chen X. Confirming the contribution and genetic spectrum of de novo mutation in infantile spasms: Evidence from a Chinese cohort. Mol Genet Genomic Med 2021; 9:e1689. [PMID: 33951346 PMCID: PMC8222834 DOI: 10.1002/mgg3.1689] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 03/24/2021] [Accepted: 03/30/2021] [Indexed: 01/21/2023] Open
Abstract
Objective We determined the yield, genetic spectrum, and actual origin of de novo mutations (DNMs) for infantile spasms (ISs) in a Chinese cohort. The efficacy of levetiracetam (LEV) for STXBP1‐related ISs was explored also. Methods Targeted sequencing of 153 epilepsy‐related candidate genes was applied to 289 Chinese patients with undiagnosed ISs. Trio‐based amplicon deep sequencing was used for all DNMs to distinguish somatic/mosaic mutations from germline ones. Results Total of 26 DNMs were identified from 289 recruited Chinese patients with undiagnosed ISs. Among them, 24 DNMs were interpreted as pathogenic mutations based on American College of Medical Genetics and Genomics guidelines, contributing to 8.3% (24/289) of diagnosis yield in the Chinese IS cohort. CDKL5 and STXBP1 are the top genes with recurrent DNMs, accounting for 3.1% (9/289) of yield. Further deep resequencing for the trio members showed that 22.7% (5/22) of DNMs are actually somatic in the proband or a parent. These somatic carriers presented milder seizure attacks than those with true germline DNMs. After treatment with LEV for half a year, three patients with DNM in STXBP1 showed improved clinical symptoms, including seizure‐free and normal electroencephalogram, except for a patient with a second DNM in DIAPH3. Significance Our study confirmed the contribution and genetic spectrum of DNMs in Chinese IS patients. Somatic mutation account for a quarter of DNMs in IS cases. Treatment with LEV improved the prognosis of STXBP1‐related ISs.
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Affiliation(s)
- Liying Liu
- Department of Pediatrics, The First Medical Center of Chinese, PLA General Hospital, Beijing, China
| | - Fang Liu
- Graduate School of Peking, Union Medical College, Beijing, China.,Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Qiuhong Wang
- Department of Pediatrics, The First Medical Center of Chinese, PLA General Hospital, Beijing, China
| | - Hua Xie
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Zhengchang Li
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Qian Lu
- Department of Pediatrics, The First Medical Center of Chinese, PLA General Hospital, Beijing, China.,Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing, China
| | - Yangyang Wang
- Department of Pediatrics, The First Medical Center of Chinese, PLA General Hospital, Beijing, China
| | - Mengna Zhang
- Department of Pediatrics, The First Medical Center of Chinese, PLA General Hospital, Beijing, China
| | - Yu Zhang
- Department of Lab Center, Capital Institute of Pediatrics, Beijing, China
| | - Jonathan Picker
- Division of Genetics & Genomics (Department of Medicine) and Department of Child & Adolescent Psychiatry, Boston Children's Hospital, Boston, MA, USA
| | - Xiaodai Cui
- Department of Lab Center, Capital Institute of Pediatrics, Beijing, China
| | - Liping Zou
- Department of Pediatrics, The First Medical Center of Chinese, PLA General Hospital, Beijing, China.,Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing, China
| | - Xiaoli Chen
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China.,Beijing Municipal Key Laboratory of Child Development and Nutriomics, Capital Institute of Pediatrics, Beijing, China
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17
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Abramov D, Guiberson NGL, Burré J. STXBP1 encephalopathies: Clinical spectrum, disease mechanisms, and therapeutic strategies. J Neurochem 2021; 157:165-178. [PMID: 32643187 PMCID: PMC7812771 DOI: 10.1111/jnc.15120] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 06/24/2020] [Accepted: 06/30/2020] [Indexed: 12/13/2022]
Abstract
Mutations in Munc18-1/STXBP1 (syntaxin-binding protein 1) are linked to various severe early epileptic encephalopathies and neurodevelopmental disorders. Heterozygous mutations in the STXBP1 gene include missense, nonsense, frameshift, and splice site mutations, as well as intragenic deletions and duplications and whole-gene deletions. No genotype-phenotype correlation has been identified so far, and patients are treated by anti-epileptic drugs because of the lack of a specific disease-modifying therapy. The molecular disease mechanisms underlying STXBP1-linked disorders are yet to be fully understood, but both haploinsufficiency and dominant-negative mechanisms have been proposed. This review focuses on the current understanding of the phenotypic spectrum of STXBP1-linked disorders, as well as discusses disease mechanisms in the context of the numerous pathways in which STXBP1 functions in the brain. We additionally evaluate the available animal models to study these disorders and highlight potential therapeutic approaches for treating these devastating diseases.
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Affiliation(s)
- Debra Abramov
- Appel Institute for Alzheimer's Disease Research, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Noah Guy Lewis Guiberson
- Appel Institute for Alzheimer's Disease Research, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Jacqueline Burré
- Appel Institute for Alzheimer's Disease Research, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
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18
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Chirinskaite AV, Siniukova VA, Velizhanina ME, Sopova JV, Belashova TA, Zadorsky SP. STXBP1 forms amyloid-like aggregates in rat brain and demonstrates amyloid properties in bacterial expression system. Prion 2021; 15:29-36. [PMID: 33590815 PMCID: PMC7894455 DOI: 10.1080/19336896.2021.1883980] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Amyloids are the fibrillar protein aggregates with cross-β structure. Traditionally amyloids were associated with pathology, however, nowadays more data is emerging about functional amyloids playing essential roles in cellular processes. We conducted screening for functional amyloids in rat brain. One of the identified proteins was STXBP1 taking part in vesicular transport and neurotransmitter secretion. Using SDD-AGE and protein fractionation we found out that STXBP1 forms small detergent-insoluble aggregates in rat brain. With immunoprecipitation analysis and C-DAG system, we showed that STXBP1 forms amyloid-like fibrils. Thus, STXBP1 demonstrates amyloid properties in rat brain and in bacterial expression system.
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Affiliation(s)
- A V Chirinskaite
- Department of Genetics and Biotechnology, St. Petersburg State University , St. Petersburg, Russian Federation.,Institute of Translational Biomedicine, St. Petersburg State University , St. Petersburg, Russian Federation
| | - V A Siniukova
- Vavilov Institute of General Genetics, St. Petersburg Branch, Russian Academy of Sciences , St. Petersburg, Russian Federation
| | - M E Velizhanina
- Department of Genetics and Biotechnology, St. Petersburg State University , St. Petersburg, Russian Federation.,Laboratory of Signal Regulation, All-Russia Research Institute for Agricultural Microbiology , Pushkin, St. Petersburg, Russian Federation
| | - J V Sopova
- Institute of Translational Biomedicine, St. Petersburg State University , St. Petersburg, Russian Federation.,Vavilov Institute of General Genetics, St. Petersburg Branch, Russian Academy of Sciences , St. Petersburg, Russian Federation.,Laboratory of Amyloid Biology, St. Petersburg State University , St. Petersburg, Russian Federation
| | - T A Belashova
- Vavilov Institute of General Genetics, St. Petersburg Branch, Russian Academy of Sciences , St. Petersburg, Russian Federation.,Laboratory of Amyloid Biology, St. Petersburg State University , St. Petersburg, Russian Federation
| | - S P Zadorsky
- Department of Genetics and Biotechnology, St. Petersburg State University , St. Petersburg, Russian Federation.,Vavilov Institute of General Genetics, St. Petersburg Branch, Russian Academy of Sciences , St. Petersburg, Russian Federation
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19
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Zhang K, Wang T, Liu X, Yuan Q, Xiao T, Yuan X, Zhang Y, Yuan L, Wang Y. CASK, APBA1, and STXBP1 collaborate during insulin secretion. Mol Cell Endocrinol 2021; 520:111076. [PMID: 33159991 DOI: 10.1016/j.mce.2020.111076] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 11/01/2020] [Accepted: 11/03/2020] [Indexed: 01/09/2023]
Abstract
Calcium/calmodulin-dependent serine protein kinase (CASK) knockdown reduces insulin vesicle docking to cell membranes. Here, we explored CASK interactions with other proteins during insulin secretion. Using co-immunoprecipitation, liquid chromatography-mass spectrometry and bioinformatic analysis, we identified that CASK, Adapter protein X11 alpha (APBA1), and Syntaxin binding protein 1 (STXBP1) formed tripartite complex during insulin secretion. CASK enhanced APBA1-STXBP1 interaction and mediated their traffic from cytoplasm to plasma membrane during insulin release. High fatty acid stimulation decreased insulin secretion along with CASK, APBA1, and STXBP1 expression; Cask overexpression enhanced CASK/APBA1/STXBP1 tripartite complex function, and may thereby rescue lipotoxicity-induced insulin-release defects. Collectively, our results illustrated the function of CASK in insulin granules exocytosis, which broadens the underlying mechanism of insulin secretion and highlights the clinical potential of CASK as a drug target of type 2 Diabetes Mellitus (T2DM).
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Affiliation(s)
- Kai Zhang
- Department of Endocrinology, Zhongda Hospital, Institute of Diabetes, Medical School, Southeast University, Nanjing, 210009, China
| | - Tianyuan Wang
- Department of Endocrinology, Zhongda Hospital, Institute of Diabetes, Medical School, Southeast University, Nanjing, 210009, China
| | - Xingjing Liu
- Department of Endocrinology, Zhongda Hospital, Institute of Diabetes, Medical School, Southeast University, Nanjing, 210009, China
| | - Qingzhao Yuan
- Department of Endocrinology, Zhongda Hospital, Institute of Diabetes, Medical School, Southeast University, Nanjing, 210009, China
| | - Tin Xiao
- Department of Endocrinology, Zhongda Hospital, Institute of Diabetes, Medical School, Southeast University, Nanjing, 210009, China
| | - Xiangjiang Yuan
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, 210009, China
| | - Yijian Zhang
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, 210009, China
| | - Li Yuan
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, 210009, China
| | - Yao Wang
- Department of Endocrinology, Zhongda Hospital, Institute of Diabetes, Medical School, Southeast University, Nanjing, 210009, China.
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20
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Abramov D, Guiberson NGL, Daab A, Na Y, Petsko GA, Sharma M, Burré J. Targeted stabilization of Munc18-1 function via pharmacological chaperones. EMBO Mol Med 2021; 13:e12354. [PMID: 33332765 PMCID: PMC7799358 DOI: 10.15252/emmm.202012354] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 11/01/2020] [Accepted: 11/11/2020] [Indexed: 11/16/2022] Open
Abstract
Heterozygous de novo mutations in the neuronal protein Munc18-1 cause syndromic neurological symptoms, including severe epilepsy, intellectual disability, developmental delay, ataxia, and tremor. No disease-modifying therapy exists to treat these disorders, and while chemical chaperones have been shown to alleviate neuronal dysfunction caused by missense mutations in Munc18-1, their required high concentrations and potential toxicity necessitate a Munc18-1-targeted therapy. Munc18-1 is essential for neurotransmitter release, and mutations in Munc18-1 have been shown to cause neuronal dysfunction via aggregation and co-aggregation of the wild-type protein, reducing functional Munc18-1 levels well below hemizygous levels. Here, we identify two pharmacological chaperones via structure-based drug design, that bind to wild-type and mutant Munc18-1, and revert Munc18-1 aggregation and neuronal dysfunction in vitro and in vivo, providing the first targeted treatment strategy for these severe pediatric encephalopathies.
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Affiliation(s)
- Debra Abramov
- Appel Institute for Alzheimer’s Disease ResearchBrain and Mind Research InstituteWeill Cornell MedicineNew YorkNYUSA
| | - Noah Guy Lewis Guiberson
- Appel Institute for Alzheimer’s Disease ResearchBrain and Mind Research InstituteWeill Cornell MedicineNew YorkNYUSA
| | - Andrew Daab
- Appel Institute for Alzheimer’s Disease ResearchBrain and Mind Research InstituteWeill Cornell MedicineNew YorkNYUSA
- Present address:
University of BathBathUK
| | - Yoonmi Na
- Appel Institute for Alzheimer’s Disease ResearchBrain and Mind Research InstituteWeill Cornell MedicineNew YorkNYUSA
| | - Gregory A Petsko
- Appel Institute for Alzheimer’s Disease ResearchBrain and Mind Research InstituteWeill Cornell MedicineNew YorkNYUSA
- Present address:
Ann Romney Center for Neurologic DiseasesDepartment of NeurologyBrigham and Women’s Hospital and Harvard Medical SchoolBostonMA, USA
| | - Manu Sharma
- Appel Institute for Alzheimer’s Disease ResearchBrain and Mind Research InstituteWeill Cornell MedicineNew YorkNYUSA
| | - Jacqueline Burré
- Appel Institute for Alzheimer’s Disease ResearchBrain and Mind Research InstituteWeill Cornell MedicineNew YorkNYUSA
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21
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Değerliyurt A, Kesen GG, Ceylaner S. Ataxia, tremor, intellectual disability: a case of STXBP1 encephalopathy with a new mutation. Turk J Pediatr 2020; 61:757-759. [PMID: 32105008 DOI: 10.24953/turkjped.2019.05.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Değerliyurt A, Gezgen Kesen G, Ceylaner S. Ataxia, tremor, intellectual disability: a case of STXBP1 encephalopathy with a new mutation. Turk J Pediatr 2019; 61: 757-759. STXBP1 gene mutations are among the most common mutations in earlyonset epileptic encephalopathies. The clinical spectrum of STXBP1 mutations is not limited to epileptic phenotypes and also includes atypical Rett syndrome and non-syndromic sporadic severe intellectual disability. Tremor, dystonia, choreiform movements, stereotypical head movements and ataxia may also be seen. However, the phenotypical spectrum is not as well-known as the other common SCN1A or CDKL5 gene mutations, making the clinical diagnosis difficult and usually requiring gene panel studies or whole exome sequencing for the diagnosis. We present a 17-year-old male patient whose seizures started at the age of 12 years. The patient could only make limited eye contact, would continuously scream, and also had severe intellectual disability, marked ataxic walking and a very significant coarse tremor. The patient was clinically thought to have STXBP1 encephalopathy due to the presence of severe intellectual disability together with tremor, and ataxia. STXBP1 gene analysis revealed a new c.9_13delCATTG (pIle4Profs*12) (p.I4Pfs*12) (heterozygous) frameshift mutation. In conclusion, STXBP1 encephalopathy should be considered if severe intellectual disability is accompanied by severe tremor and ataxia in a patient with epileptic and developmental encephalopathy. A normal head circumference supports the diagnosis in such patients.
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Affiliation(s)
- Aydan Değerliyurt
- Departments of Pediatric Neurology, Ankara Children's Hematology and Oncology Training and Research Hospital, Ankara
| | - Gamze Gezgen Kesen
- Departments of Pediatrics, Ankara Children's Hematology and Oncology Training and Research Hospital, Ankara
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22
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Lammertse HCA, van Berkel AA, Iacomino M, Toonen RF, Striano P, Gambardella A, Verhage M, Zara F. Homozygous STXBP1 variant causes encephalopathy and gain-of-function in synaptic transmission. Brain 2020; 143:441-451. [PMID: 31855252 PMCID: PMC7009479 DOI: 10.1093/brain/awz391] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 10/09/2019] [Accepted: 10/29/2019] [Indexed: 11/14/2022] Open
Abstract
Heterozygous mutations in the STXBP1 gene encoding the presynaptic protein MUNC18-1 cause STXBP1 encephalopathy, characterized by developmental delay, intellectual disability and epilepsy. Impaired mutant protein stability leading to reduced synaptic transmission is considered the main underlying pathogenetic mechanism. Here, we report the first two cases carrying a homozygous STXBP1 mutation, where their heterozygous siblings and mother are asymptomatic. Both cases were diagnosed with Lennox-Gastaut syndrome. In Munc18-1 null mouse neurons, protein stability of the disease variant (L446F) is less dramatically affected than previously observed for heterozygous disease mutants. Neurons expressing Munc18L446F showed minor changes in morphology and synapse density. However, patch clamp recordings demonstrated that L446F causes a 2-fold increase in evoked synaptic transmission. Conversely, paired pulse plasticity was reduced and recovery after stimulus trains also. Spontaneous release frequency and amplitude, the readily releasable vesicle pool and the kinetics of short-term plasticity were all normal. Hence, the homozygous L446F mutation causes a gain-of-function phenotype regarding release probability and synaptic transmission while having less impact on protein levels than previously reported (heterozygous) mutations. These data show that STXBP1 mutations produce divergent cellular effects, resulting in different clinical features, while sharing the overarching encephalopathic phenotype (developmental delay, intellectual disability and epilepsy).
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Affiliation(s)
- Hanna C A Lammertse
- Department of Clinical Genetics, Center for Neurogenomics and Cognitive Research (CNCR), University Medical Center Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.,Department of Functional Genomics, Center for Neurogenomics and Cognitive Research (CNCR), VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
| | - Annemiek A van Berkel
- Department of Clinical Genetics, Center for Neurogenomics and Cognitive Research (CNCR), University Medical Center Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.,Department of Functional Genomics, Center for Neurogenomics and Cognitive Research (CNCR), VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
| | - Michele Iacomino
- Laboratory of Neurogenetics and Neuroscience, IRCCS Istituto G. Gaslini, Via Gerolamo Gaslini 5, 16147 Genova, Italy
| | - Ruud F Toonen
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research (CNCR), VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
| | - Pasquale Striano
- IRCCS Istituto "G. Gaslini", Genova, Italy.,Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genova, Genova, Italy
| | | | - Matthijs Verhage
- Department of Clinical Genetics, Center for Neurogenomics and Cognitive Research (CNCR), University Medical Center Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.,Department of Functional Genomics, Center for Neurogenomics and Cognitive Research (CNCR), VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
| | - Federico Zara
- Laboratory of Neurogenetics and Neuroscience, IRCCS Istituto G. Gaslini, Via Gerolamo Gaslini 5, 16147 Genova, Italy
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23
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Wang Z, Sun X, Gao L, Guo X, Feng C, Lian W, Deng K, Xing B. Comprehensive identification of a two-genesignature as a novel potential prognostic model for patients with medulloblastoma. Am J Transl Res 2020; 12:1600-1613. [PMID: 32509164 PMCID: PMC7270006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 05/08/2020] [Indexed: 06/11/2023]
Abstract
Medulloblastoma is one of the most common malignant pediatric brain tumors and has a poor prognosis and high mortality. We investigated the prognostic significance of specific gene signatures and established a novel prognostic model for medulloblastoma patients. Ninety-seven differentially expressed genes between 69 medulloblastoma samples and 4 normal cerebellum samples were identified using the GSE68956 dataset. Univariate and multivariate Cox regression analyses revealed optimal prognosis-related genes, of which PFKP and STXBP1 exhibited significant prognostic values. A risk score model was then established to assess the prognostic value of the gene signature. Kaplan-Meier survival analysis demonstrated that patients with a high risk score had significantly poorer overall survival (OS, log-rank P = 0.003308). The concordance index (C-index) of the two-gene prognostic model for OS prediction was 0.752 (95% CI, 0.740-0.764). The area under the receiver operating characteristic curve (AUC) values for predicting 3-year and 5-year survival were 0.726 and 0.730, respectively. The risk score model was further validated in the ICGC cohort and PUMCH cohort using quantitative real-time polymerase chain reaction (qRT-PCR). Cox regression analyses were performed to assess the two-gene risk score model, metastasis stage, and chemotherapy as independent prognostic factors for medulloblastoma. The C-index of the comprehensive prognostic model composed of the two-gene signature integrated with clinicopathological features for predicting OS was 0.823 (95% CI, 0.739-0.907). The AUCs of the comprehensive prognostic model for predicting 3-year and 5-year survival were 0.774 and 0.759, respectively. Thus, the two-gene risk score model is a promising prognostic biomarker for medulloblastoma.
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Affiliation(s)
- Zihao Wang
- Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical CollegeDongcheng District, Beijing, P. R. China
| | - Xuesong Sun
- Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and TherapyGuangzhou, P. R. China
- Department of Nasopharyngeal Carcinoma, Sun Yat-Sen University Cancer CenterGuangzhou, P. R. China
| | - Lu Gao
- Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical CollegeDongcheng District, Beijing, P. R. China
| | - Xiaopeng Guo
- Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical CollegeDongcheng District, Beijing, P. R. China
| | - Chenzhe Feng
- Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical CollegeDongcheng District, Beijing, P. R. China
| | - Wei Lian
- Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical CollegeDongcheng District, Beijing, P. R. China
| | - Kan Deng
- Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical CollegeDongcheng District, Beijing, P. R. China
| | - Bing Xing
- Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical CollegeDongcheng District, Beijing, P. R. China
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24
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Abstract
Researchers from the University of Antwerp, Belgium, and numerous international collaborators report a comprehensive overview of the phenotypic and genetic spectrum of Syntaxin-binding protein 1 (STXBP1) encephalopathy.
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Affiliation(s)
- Brittani Wild
- Departments of Pediatrics and Neurology, Tulane University School of Medicine, New Orleans, LA
| | - Stephen Nelson
- Departments of Pediatrics and Neurology, Tulane University School of Medicine, New Orleans, LA
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25
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O'Brien S, Ng-Cordell E, Astle DE, Scerif G, Baker K. STXBP1-associated neurodevelopmental disorder: a comparative study of behavioural characteristics. J Neurodev Disord 2019; 11:17. [PMID: 31387522 PMCID: PMC6683428 DOI: 10.1186/s11689-019-9278-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 07/22/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND De novo loss of function mutations in STXBP1 are a relatively common cause of epilepsy and intellectual disability (ID). However, little is known about the types and severities of behavioural features associated with this genetic diagnosis. METHODS To address this, we collected systematic phenotyping data encompassing neurological, developmental, and behavioural characteristics. Participants were 14 individuals with STXBP1-associated neurodevelopmental disorder, ascertained from clinical genetics and neurology services UK-wide. Data was collected via standardised questionnaires administered to parents at home, supplemented by researcher observations. To isolate discriminating phenotypes, the STXBP1 group was compared to 33 individuals with pathogenic mutations in other ID-associated genes (ID group). To account for the potential impact of global cognitive impairment, a secondary comparison was made to an ability-matched subset of the ID group (low-ability ID group). RESULTS The STXBP1 group demonstrated impairments across all assessed domains. In comparison to the ID group, the STXBP1 group had more severe global adaptive impairments, fine motor difficulties, and hyperactivity. In comparison to the low-ability ID group, severity of receptive language and social impairments discriminated the STXBP1 group. A striking feature of the STXBP1 group, with reference to both comparison groups, was preservation of social motivation. CONCLUSIONS De novo mutations in STXBP1 are associated with complex and variable neurodevelopmental impairments. Consistent features, which discriminate this disorder from other monogenic causes of ID, are severe language impairment and difficulties managing social interactions, despite strong social motivation. Future work could explore the physiological mechanisms linking motor, speech, and social development in this disorder. Understanding the developmental emergence of behavioural characteristics can help to focus clinical assessment and management after genetic diagnosis, with the long-term aim of improving outcomes for patients and families.
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Affiliation(s)
- Sinéad O'Brien
- MRC Cognition and Brain Sciences Unit, University of Cambridge, 15 Chaucer Road, Cambridge, CB2 7EF, UK
| | - Elise Ng-Cordell
- MRC Cognition and Brain Sciences Unit, University of Cambridge, 15 Chaucer Road, Cambridge, CB2 7EF, UK.,Department of Experimental Psychology, University of Oxford, Anna Watts Building, Radcliffe Observatory Quarter, Woodstock Road, Oxford, OX2 6GG, UK
| | | | - Duncan E Astle
- MRC Cognition and Brain Sciences Unit, University of Cambridge, 15 Chaucer Road, Cambridge, CB2 7EF, UK
| | - Gaia Scerif
- Department of Experimental Psychology, University of Oxford, Anna Watts Building, Radcliffe Observatory Quarter, Woodstock Road, Oxford, OX2 6GG, UK
| | - Kate Baker
- MRC Cognition and Brain Sciences Unit, University of Cambridge, 15 Chaucer Road, Cambridge, CB2 7EF, UK. .,Department of Medical Genetics, University of Cambridge, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, UK.
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26
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Cogliati F, Giorgini V, Masciadri M, Bonati MT, Marchi M, Cracco I, Gentilini D, Peron A, Savini MN, Spaccini L, Scelsa B, Maitz S, Veneselli E, Prato G, Pintaudi M, Moroni I, Vignoli A, Larizza L, Russo S. Pathogenic Variants in STXBP1 and in Genes for GABAa Receptor Subunities Cause Atypical Rett/Rett-like Phenotypes. Int J Mol Sci 2019; 20:E3621. [PMID: 31344879 DOI: 10.3390/ijms20153621] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 07/16/2019] [Accepted: 07/19/2019] [Indexed: 12/19/2022] Open
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder, affecting 1 in 10,000 girls. Intellectual disability, loss of speech and hand skills with stereotypies, seizures and ataxia are recurrent features. Stringent diagnostic criteria distinguish classical Rett, caused by a MECP2 pathogenic variant in 95% of cases, from atypical girls, 40-73% carrying MECP2 variants, and rarely CDKL5 and FOXG1 alterations. A large fraction of atypical and RTT-like patients remain without genetic cause. Next Generation Sequencing (NGS) targeted to multigene panels/Whole Exome Sequencing (WES) in 137 girls suspected for RTT led to the identification of a de novo variant in STXBP1 gene in four atypical RTT and two RTT-like girls. De novo pathogenic variants-one in GABRB2 and, for first time, one in GABRG2-were disclosed in classic and atypical RTT patients. Interestingly, the GABRG2 variant occurred at low rate percentage in blood and buccal swabs, reinforcing the relevance of mosaicism in neurological disorders. We confirm the role of STXBP1 in atypical RTT/RTT-like patients if early psychomotor delay and epilepsy before 2 years of age are observed, indicating its inclusion in the RTT diagnostic panel. Lastly, we report pathogenic variants in Gamma-aminobutyric acid-A (GABAa) receptors as a cause of atypical/classic RTT phenotype, in accordance with the deregulation of GABAergic pathway observed in MECP2 defective in vitro and in vivo models.
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27
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Murillo E. [Characteristics of people with the STXBP1 syndrome in Spain: Implications for diagnosis]. An Pediatr (Barc) 2019; 92:71-78. [PMID: 31151759 DOI: 10.1016/j.anpedi.2019.04.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 04/23/2019] [Accepted: 04/24/2019] [Indexed: 11/28/2022] Open
Abstract
INTRODUCTION STXBP1 syndrome is a genetic disorder that affects one of the regulatory mechanisms of neurotransmitter release by the synaptic vesicles and has serious implications for neurodevelopment. Symptoms usually appear in the first days or months of life, and very often include epilepsy, psychomotor delay, and intellectual disability. Although it was initially regarded as an early epileptic encephalopathy, the increase in the number of cases diagnosed, as well as the advances in research have been expanding the phenotype and characterising this disease as a disorder of neurodevelopment. Furthermore, on being linked to epileptic problems, this genetic mutation could be associated with many cases of intellectual disability and movement disorders of unknown cause. OBJECTIVES To describe the characteristics of the patients identified in Spain with STXBP1 syndrome, and the implications for the diagnosis of these characteristics. PATIENTS AND METHODS The details are presented on 17 individuals, aged between 2 years and 17 years, diagnosed in Spain with STXBP1 syndrome. CONCLUSIONS There is a clear under-diagnosis of STXBP1 syndrome in Spain. Besides the inherent diversity of the disorder, with the increase in the number diagnoses the variability of the phenotype is even wider. The description of the alarm signs is necessary in order to identify those individuals with less prototypical manifestations of the disorder.
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Affiliation(s)
- Eva Murillo
- Departamento de Psicología Básica, Universidad Autónoma de Madrid, Madrid, España.
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28
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Rezazadeh A, Uddin M, Snead OC, Lira V, Silberberg A, Weiss S, Donner EJ, Zak M, Bradbury L, Scherer SW, Fasano A, Andrade DM. STXBP1 encephalopathy is associated with awake bruxism. Epilepsy Behav 2019; 92:121-124. [PMID: 30654231 DOI: 10.1016/j.yebeh.2018.12.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 12/15/2018] [Accepted: 12/21/2018] [Indexed: 12/20/2022]
Abstract
Heterozygous mutations in syntaxin-binding protein 1 (STXBP1) gene are associated with early infantile epileptic encephalopathy 4 (EIEE4). This condition is characterized by epilepsy, developmental delay (DD), and various movement disorders. Herein, we will report 5 unrelated patients with different de novo mutations in STXBP1. In addition, we conducted an online survey through Facebook to identify the incidence of bruxism (BRX) in these patients. Four out of 5 patients (80%) presented with awake BRX (A-BRX). Bruxism was also reported in 81.4% (57/70) of the patients with STXBP1 encephalopathy through the online questionnaire. No consistent correlation was identified between the type of mutation and development of movement disorders or BRX. This is the first study to demonstrate A-BRX in patients with STXBP1 mutation. Given the role of STXBP1 in exocytosis of neurotransmitters and other manifestations of dopamine dysregulation in patients with STXBP1-EIEE4, we suggest that in patients with STXBP1 encephalopathy, A-BRX might be the result of the involvement of dopaminergic circuits.
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Affiliation(s)
- Arezoo Rezazadeh
- Krembil Neurosciences Epilepsy Genetics Program, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada.
| | - Mohammed Uddin
- The Centre for Applied Genomics, Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada.
| | - O Carter Snead
- Division of Neurology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
| | - Victor Lira
- Krembil Neurosciences Epilepsy Genetics Program, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada
| | | | - Shelly Weiss
- Division of Neurology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
| | - Elizabeth J Donner
- Division of Neurology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
| | - Maria Zak
- Division of Neurology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
| | - Laura Bradbury
- Division of Neurology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
| | - Stephen W Scherer
- The Centre for Applied Genomics, Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada; Department of Molecular Genetics and McLaughlin Centre, University of Toronto, Toronto, Ontario, Canada.
| | - Alfonso Fasano
- Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, Toronto, Ontario, Canada; Division of Neurology, Department of Medicine, Toronto Western Hospital, Krembil Neuroscience Centre, University of Toronto, Toronto, Ontario, Canada.
| | - Danielle M Andrade
- Krembil Neurosciences Epilepsy Genetics Program, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada; Division of Neurology, Department of Medicine, Toronto Western Hospital, Krembil Neuroscience Centre, University of Toronto, Toronto, Ontario, Canada.
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Shao LR, Habela CW, Stafstrom CE. Pediatric Epilepsy Mechanisms: Expanding the Paradigm of Excitation/Inhibition Imbalance. Children (Basel) 2019; 6:children6020023. [PMID: 30764523 PMCID: PMC6406372 DOI: 10.3390/children6020023] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 01/31/2019] [Accepted: 01/31/2019] [Indexed: 02/07/2023]
Abstract
Mechanisms underlying seizures and epilepsy have traditionally been considered to involve abnormalities of ion channels or synaptic function. Those considerations gave rise to the excitation/inhibition (E/I) imbalance theory, whereby increased excitation, decreased inhibition, or both favor a hyperexcitable state and an increased propensity for seizure generation and epileptogenesis. Several recent findings warrant reconsideration and expansion of the E/I hypothesis: novel genetic mutations have been identified that do not overtly affect E/I balance; neurotransmitters may exert paradoxical effects, especially during development; anti-seizure medications do not necessarily work by decreasing excitation or increasing inhibition; and metabolic factors participate in the regulation of neuronal and network excitability. These novel conceptual and experimental advances mandate expansion of the E/I paradigm, with the expectation that new and exciting therapies will emerge from this broadened understanding of how seizures and epilepsy arise and progress.
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Affiliation(s)
- Li-Rong Shao
- Division of Pediatric Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
| | - Christa W Habela
- Division of Pediatric Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
| | - Carl E Stafstrom
- Division of Pediatric Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
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30
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Abstract
Although the majority of seizures in neonates are related to acute brain injury, a substantial minority are the first symptom of a neonatal-onset epilepsy often linked to a pathogenic genetic variant. Historically, studies on neonatal seizures including treatment response and long-term consequences have lumped all etiologies together. However, etiology has been consistently shown to be the most important determinant of outcome. In the past few years, an increasing number of monogenic disorders have been described and might explain up to a third of neonatal-onset epilepsy syndromes previously included under the umbrella of Ohtahara syndrome and early myoclonic encephalopathy. In this chapter, we define the concept of genetic epilepsy and review the classification. Then, we review the most relevant monogenic neonatal-onset epilepsies, detail their underlying pathophysiologic mechanisms, and present their electroclinical phenotypes. We highlight that, in some cases, such as neonates with KCNQ2 or KCNT1 gene mutations, the early recognition of the electroclinical phenotype can lead to targeted diagnostic testing and precision medicine treatment, enabling the possibility of improved outcome.
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31
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Chen X, Jin J, Wang Q, Xue H, Zhang N, Du Y, Zhang T, Zhang B, Wu J, Liu Z. A de novo pathogenic CSNK1E mutation identified by exome sequencing in family trios with epileptic encephalopathy. Hum Mutat 2018; 40:281-287. [PMID: 30488659 DOI: 10.1002/humu.23690] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Revised: 11/07/2018] [Accepted: 11/24/2018] [Indexed: 12/29/2022]
Abstract
Recent whole-exome sequencing (WES) studies have demonstrated the contribution of de novo mutations (DNMs) to epileptic encephalopathies (EEs). Here, we performed WES on four trios with West syndrome and identified three loss-of-function DNMs in both CSNK1E (c.885+1G>A) and STXBP1 (splicing, c.1111-2A>G; nonsense, p.(Y519X)). The splicing mutation in CSNK1E creates insertion of 116 new amino acids at position 246 followed by a premature stop codon. Both CSNK1E and STXBP1 showed a closer coexpression relationship with epilepsy candidate genes beyond that expected by chance. In addition, genes coexpressed with CSNK1E were enriched in early prenatal stages across multiple brain regions. We also found that 60 CSNK1E-interacting genes share an association with multiple neuropsychiatric disorders, and these genes formed a significant interconnected interaction network with roles in the midbrain development. Our study supported the potential role of CSNK1E variants in EE susceptibility and expanded the phenotypic spectrum associated with CSNK1E variation.
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Affiliation(s)
- Xiaomin Chen
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China.,Center of Scientific Research, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Jing Jin
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China
| | - Qiongdan Wang
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China.,Department of Laboratory Medicine, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Huangqi Xue
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China
| | - Na Zhang
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China
| | - Yaoqiang Du
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China.,Research Center of Blood Transfusion Medicine, Education Ministry Key Laboratory of Laboratory Medicine, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China
| | - Tao Zhang
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China
| | - Bing Zhang
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China
| | - Jinyu Wu
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China
| | - Zhenwei Liu
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China
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32
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Salunkhe VA, Ofori JK, Gandasi NR, Salö SA, Hansson S, Andersson ME, Wendt A, Barg S, Esguerra JLS, Eliasson L. MiR-335 overexpression impairs insulin secretion through defective priming of insulin vesicles. Physiol Rep 2018; 5:5/21/e13493. [PMID: 29122960 PMCID: PMC5688784 DOI: 10.14814/phy2.13493] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 10/11/2017] [Accepted: 10/13/2017] [Indexed: 01/01/2023] Open
Abstract
MicroRNAs contribute to the maintenance of optimal cellular functions by fine‐tuning protein expression levels. In the pancreatic β‐cells, imbalances in the exocytotic machinery components lead to impaired insulin secretion and type 2 diabetes (T2D). We hypothesize that dysregulated miRNA expression exacerbates β‐cell dysfunction, and have earlier shown that islets from the diabetic GK‐rat model have increased expression of miRNAs, including miR‐335‐5p (miR‐335). Here, we aim to determine the specific role of miR‐335 during development of T2D, and the influence of this miRNA on glucose‐stimulated insulin secretion and Ca2+‐dependent exocytosis. We found that the expression of miR‐335 negatively correlated with secretion index in human islets of individuals with prediabetes. Overexpression of miR‐335 in human EndoC‐βH1 and in rat INS‐1 832/13 cells (OE335) resulted in decreased glucose‐stimulated insulin secretion, and OE335 cells showed concomitant reduction in three exocytotic proteins: SNAP25, Syntaxin‐binding protein 1 (STXBP1), and synaptotagmin 11 (SYT11). Single‐cell capacitance measurements, complemented with TIRF microscopy of the granule marker NPY‐mEGFP demonstrated a significant reduction in exocytosis in OE335 cells. The reduction was not associated with defective docking or decreased Ca2+ current. More likely, it is a direct consequence of impaired priming of already docked granules. Earlier reports have proposed reduced granular priming as the cause of reduced first‐phase insulin secretion during prediabetes. Here, we show a specific role of miR‐335 in regulating insulin secretion during this transition period. Moreover, we can conclude that miR‐335 has the capacity to modulate insulin secretion and Ca2+‐dependent exocytosis through effects on granular priming.
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Affiliation(s)
- Vishal A Salunkhe
- Department of Clinical Sciences Malmö, Islet Cell Exocytosis Lund University Diabetes Centre Lund University, Malmö, Sweden
| | - Jones K Ofori
- Department of Clinical Sciences Malmö, Islet Cell Exocytosis Lund University Diabetes Centre Lund University, Malmö, Sweden
| | - Nikhil R Gandasi
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Sofia A Salö
- Department of Clinical Sciences Malmö, Islet Cell Exocytosis Lund University Diabetes Centre Lund University, Malmö, Sweden
| | - Sofia Hansson
- Department of Clinical Sciences Malmö, Islet Cell Exocytosis Lund University Diabetes Centre Lund University, Malmö, Sweden
| | - Markus E Andersson
- Department of Clinical Sciences Malmö, Islet Cell Exocytosis Lund University Diabetes Centre Lund University, Malmö, Sweden
| | - Anna Wendt
- Department of Clinical Sciences Malmö, Islet Cell Exocytosis Lund University Diabetes Centre Lund University, Malmö, Sweden
| | - Sebastian Barg
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Jonathan L S Esguerra
- Department of Clinical Sciences Malmö, Islet Cell Exocytosis Lund University Diabetes Centre Lund University, Malmö, Sweden
| | - Lena Eliasson
- Department of Clinical Sciences Malmö, Islet Cell Exocytosis Lund University Diabetes Centre Lund University, Malmö, Sweden
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33
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Álvarez Bravo G, Yusta Izquierdo A. The adult motor phenotype of Dravet syndrome is associated with mutation of the STXBP1 gene and responds well to cannabidiol treatment. Seizure 2018; 60:68-70. [PMID: 29929108 DOI: 10.1016/j.seizure.2018.06.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 06/10/2018] [Accepted: 06/12/2018] [Indexed: 11/20/2022] Open
Abstract
Dravet syndrome is a terrible disease generally caused by mutations of the SCN1A gene. Recently others genes such as STXBP1 have been involved in the pathogenesis of the disease. The STXBP1 mutation in patients with Dravet Syndrome may additionally causes several parkinsonian features usually attributed to carriers of the SCN1A mutation. Management continues to be difficult that is why Cannabidiol emerged as valid option for treatment of this condition.
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34
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Abstract
The use of human pluripotent stem cells to model human diseases has become a new standard in biomedical sciences. To this end, patient-derived somatic cells are studied in vitro to mimic human pathological conditions. Here, we describe an alternative experimental strategy, the ‘conditional KO approach’, which allows engineering disease-relevant mutations in pluripotent stem cells from healthy donors. In combination with the Cre/Lox technology, this strategy enables us to study the molecular causes of human diseases independent of the genetic background or of genetic alterations induced by clonal selection. As a proof-of-principle, we generated pluripotent stem cells with conditional loss-of-function mutations in the human STXBP1 gene that encodes Munc18-1. Using neurons derived from these cells, we show that heterozygous disruption of STXBP1 produces a specific and selective impairment in synaptic transmission that may account for the severe neurological disease caused by such mutations in human patients.
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Affiliation(s)
- Christopher Patzke
- Department of Molecular and Cellular Physiology, Stanford University , Stanford, CA, USA
| | - Thomas C Südhof
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA; Howard Hughes Medical Institute, Stanford University School of Medicine; Stanford, CA, USA
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35
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Guacci A, Chetta M, Rizzo F, Marchese G, De Filippo MR, Giurato G, Nassa G, Ravo M, Tarallo R, Rocco T, Operto FF, Weisz A, Coppola G. Phenytoin neurotoxicity in a child carrying new STXBP1 and CYP2C9 gene mutations. Seizure 2015; 34:26-8. [PMID: 26658169 DOI: 10.1016/j.seizure.2015.11.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Revised: 11/11/2015] [Accepted: 11/14/2015] [Indexed: 11/20/2022] Open
Affiliation(s)
- Anna Guacci
- Laboratory of Molecular Medicine and Genomics, Department of Medicine and Surgery, University of Salerno, via S. Allende 1, 84081 Baronissi, SA, Italy
| | - Massimiliano Chetta
- Laboratory of Molecular Medicine and Genomics, Department of Medicine and Surgery, University of Salerno, via S. Allende 1, 84081 Baronissi, SA, Italy
| | - Francesca Rizzo
- Laboratory of Molecular Medicine and Genomics, Department of Medicine and Surgery, University of Salerno, via S. Allende 1, 84081 Baronissi, SA, Italy
| | - Giovanna Marchese
- Laboratory of Molecular Medicine and Genomics, Department of Medicine and Surgery, University of Salerno, via S. Allende 1, 84081 Baronissi, SA, Italy; Genomix4Life Srl, Department of Medicine and Surgery, University of Salerno, 84081 Baronissi, SA, Italy
| | | | - Giorgio Giurato
- Laboratory of Molecular Medicine and Genomics, Department of Medicine and Surgery, University of Salerno, via S. Allende 1, 84081 Baronissi, SA, Italy
| | - Giovanni Nassa
- Laboratory of Molecular Medicine and Genomics, Department of Medicine and Surgery, University of Salerno, via S. Allende 1, 84081 Baronissi, SA, Italy
| | - Maria Ravo
- Laboratory of Molecular Medicine and Genomics, Department of Medicine and Surgery, University of Salerno, via S. Allende 1, 84081 Baronissi, SA, Italy
| | - Roberta Tarallo
- Laboratory of Molecular Medicine and Genomics, Department of Medicine and Surgery, University of Salerno, via S. Allende 1, 84081 Baronissi, SA, Italy
| | - Teresa Rocco
- Laboratory of Molecular Medicine and Genomics, Department of Medicine and Surgery, University of Salerno, via S. Allende 1, 84081 Baronissi, SA, Italy
| | - Francesca Felicia Operto
- Child and Adolescent Neuropsychiatry, Department of Medicine and Surgery and "SS. Giovanni di Dio e Ruggi d'Aragona-Schola Medica Salernitana" Hospital of the University of Salerno, 84131 Salerno, Italy
| | - Alessandro Weisz
- Laboratory of Molecular Medicine and Genomics, Department of Medicine and Surgery, University of Salerno, via S. Allende 1, 84081 Baronissi, SA, Italy; Molecular Pathology and Medical Genomics, "SS. Giovanni di Dio e Ruggi d'Aragona-Schola Medica Salernitana" Hospital of the University of Salerno, 84131 Salerno, Italy.
| | - Giangennaro Coppola
- Child and Adolescent Neuropsychiatry, Department of Medicine and Surgery and "SS. Giovanni di Dio e Ruggi d'Aragona-Schola Medica Salernitana" Hospital of the University of Salerno, 84131 Salerno, Italy.
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36
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Peng Y, Lee J, Rowland K, Wen Y, Hua H, Carlson N, Lavania S, Parrish JZ, Kim MD. Regulation of dendrite growth and maintenance by exocytosis. J Cell Sci 2015; 128:4279-92. [PMID: 26483382 DOI: 10.1242/jcs.174771] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 10/08/2015] [Indexed: 01/07/2023] Open
Abstract
Dendrites lengthen by several orders of magnitude during neuronal development, but how membrane is allocated in dendrites to facilitate this growth remains unclear. Here, we report that Ras opposite (Rop), the Drosophila ortholog of the key exocytosis regulator Munc18-1 (also known as STXBP1), is an essential factor mediating dendrite growth. Neurons with depleted Rop function exhibit reduced terminal dendrite outgrowth followed by primary dendrite degeneration, suggestive of differential requirements for exocytosis in the growth and maintenance of different dendritic compartments. Rop promotes dendrite growth together with the exocyst, an octameric protein complex involved in tethering vesicles to the plasma membrane, with Rop-exocyst complexes and exocytosis predominating in primary dendrites over terminal dendrites. By contrast, membrane-associated proteins readily diffuse from primary dendrites into terminals, but not in the reverse direction, suggesting that diffusion, rather than targeted exocytosis, supplies membranous material for terminal dendritic growth, revealing key differences in the distribution of materials to these expanding dendritic compartments.
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Affiliation(s)
- Yun Peng
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Jiae Lee
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Kimberly Rowland
- Department of Molecular and Cellular Pharmacology, University of Miami, Miller School of Medicine, Miami, FL 33136, USA
| | - Yuhui Wen
- Department of Molecular and Cellular Pharmacology, University of Miami, Miller School of Medicine, Miami, FL 33136, USA
| | - Hope Hua
- Department of Molecular and Cellular Pharmacology, University of Miami, Miller School of Medicine, Miami, FL 33136, USA
| | - Nicole Carlson
- Department of Molecular and Cellular Pharmacology, University of Miami, Miller School of Medicine, Miami, FL 33136, USA
| | - Shweta Lavania
- Department of Molecular and Cellular Pharmacology, University of Miami, Miller School of Medicine, Miami, FL 33136, USA
| | - Jay Z Parrish
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Michael D Kim
- Department of Molecular and Cellular Pharmacology, University of Miami, Miller School of Medicine, Miami, FL 33136, USA
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Ehret JK, Engels H, Cremer K, Becker J, Zimmermann JP, Wohlleber E, Grasshoff U, Rossier E, Bonin M, Mangold E, Bevot A, Schön S, Heilmann-Heimbach S, Dennert N, Mathieu-Dramard M, Lacaze E, Plessis G, de Broca A, Jedraszak G, Röthlisberger B, Miny P, Filges I, Dufke A, Andrieux J, Lee JA, Zink AM. Microdeletions in 9q33.3-q34.11 in five patients with intellectual disability, microcephaly, and seizures of incomplete penetrance: is STXBP1 not the only causative gene? Mol Cytogenet 2015; 8:72. [PMID: 26421060 DOI: 10.1186/s13039-015-0178-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 09/22/2015] [Indexed: 11/18/2022] Open
Abstract
Background Most microdeletions involving chromosome sub-bands 9q33.3-9q34.11 to this point have been detected by analyses focused on STXBP1, a gene known to cause early infantile epileptic encephalopathy 4 and other seizure phenotypes. Loss-of-function mutations of STXBP1 have also been identified in some patients with intellectual disability without epilepsy. Consequently, STXBP1 is widely assumed to be the gene causing both seizures and intellectual disability in patients with 9q33.3-q34.11 microdeletions. Results We report five patients with overlapping microdeletions of chromosome 9q33.3-q34.11, four of them previously unreported. Their common clinical features include intellectual disability, psychomotor developmental delay with delayed or absent speech, muscular hypotonia, and strabismus. Microcephaly and short stature are each present in four of the patients. Two of the patients had seizures. De novo deletions range from 1.23 to 4.13 Mb, whereas the smallest deletion of 432 kb in patient 3 was inherited from her mother who is reported to have mild intellectual disability. The smallest region of overlap (SRO) of these deletions in 9q33.3 does not encompass STXBP1, but includes two genes that have not been previously associated with disease, RALGPS1 and GARNL3. Sequencing of the two SRO genes RALGPS1 and GARNL3 in at least 156 unrelated patients with mild to severe idiopathic intellectual disability detected no causative mutations. Gene expression analyses in our patients demonstrated significantly reduced expression levels of GARNL3, RALGPS1 and STXBP1 only in patients with deletions of the corresponding genes. Thus, reduced expression of STXBP1 was ruled out as a cause for seizures in our patient whose deletion did not encompass STXBP1. Conclusions We suggest that microdeletions of this region on chromosome 9q cause a clinical spectrum including intellectual disability, developmental delay especially concerning speech, microcephaly, short stature, mild dysmorphisms, strabismus, and seizures of incomplete penetrance, and may constitute a new contiguous gene deletion syndrome which cannot completely be explained by deletion of STXBP1. Electronic supplementary material The online version of this article (doi:10.1186/s13039-015-0178-8) contains supplementary material, which is available to authorized users.
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38
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Olson HE, Tambunan D, LaCoursiere C, Goldenberg M, Pinsky R, Martin E, Ho E, Khwaja O, Kaufmann WE, Poduri A. Mutations in epilepsy and intellectual disability genes in patients with features of Rett syndrome. Am J Med Genet A 2015; 167A:2017-25. [PMID: 25914188 DOI: 10.1002/ajmg.a.37132] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 04/12/2015] [Indexed: 11/09/2022]
Abstract
Rett syndrome and neurodevelopmental disorders with features overlapping this syndrome frequently remain unexplained in patients without clinically identified MECP2 mutations. We recruited a cohort of 11 patients with features of Rett syndrome and negative initial clinical testing for mutations in MECP2. We analyzed their phenotypes to determine whether patients met formal criteria for Rett syndrome, reviewed repeat clinical genetic testing, and performed exome sequencing of the probands. Using 2010 diagnostic criteria, three patients had classical Rett syndrome, including two for whom repeat MECP2 gene testing had identified mutations. In a patient with neonatal onset epilepsy with atypical Rett syndrome, we identified a frameshift deletion in STXBP1. Among seven patients with features of Rett syndrome not fulfilling formal diagnostic criteria, four had suspected pathogenic mutations, one each in MECP2, FOXG1, SCN8A, and IQSEC2. MECP2 mutations are highly correlated with classical Rett syndrome. Genes associated with atypical Rett syndrome, epilepsy, or intellectual disability should be considered in patients with features overlapping with Rett syndrome and negative MECP2 testing. While most of the identified mutations were apparently de novo, the SCN8A variant was inherited from an unaffected parent mosaic for the mutation, which is important to note for counseling regarding recurrence risks.
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Affiliation(s)
- Heather E Olson
- Epilepsy Genetics Program, Division of Epilepsy & Clinical Neurophysiology, Boston Children's Hospital, Boston, Massachusetts.,Harvard Medical School, Boston, Massachusetts.,Neurogenetics Program, Boston Children's Hospital, Boston, Massachusetts.,Department of Neurology, Boston Children's Hospital, Boston, Massachusetts
| | - Dimira Tambunan
- Epilepsy Genetics Program, Division of Epilepsy & Clinical Neurophysiology, Boston Children's Hospital, Boston, Massachusetts
| | - Christopher LaCoursiere
- Epilepsy Genetics Program, Division of Epilepsy & Clinical Neurophysiology, Boston Children's Hospital, Boston, Massachusetts
| | - Marti Goldenberg
- Department of Neurology, Boston Children's Hospital, Boston, Massachusetts
| | - Rebecca Pinsky
- Epilepsy Genetics Program, Division of Epilepsy & Clinical Neurophysiology, Boston Children's Hospital, Boston, Massachusetts
| | - Emilie Martin
- Epilepsy Genetics Program, Division of Epilepsy & Clinical Neurophysiology, Boston Children's Hospital, Boston, Massachusetts
| | - Eugenia Ho
- Department of Neurology, Boston Children's Hospital, Boston, Massachusetts.,Rett Syndrome Program, Boston Children's Hospital, Boston, Massachusetts
| | - Omar Khwaja
- Neurogenetics Program, Boston Children's Hospital, Boston, Massachusetts.,Department of Neurology, Boston Children's Hospital, Boston, Massachusetts.,Rett Syndrome Program, Boston Children's Hospital, Boston, Massachusetts
| | - Walter E Kaufmann
- Harvard Medical School, Boston, Massachusetts.,Neurogenetics Program, Boston Children's Hospital, Boston, Massachusetts.,Department of Neurology, Boston Children's Hospital, Boston, Massachusetts.,Rett Syndrome Program, Boston Children's Hospital, Boston, Massachusetts
| | - Annapurna Poduri
- Epilepsy Genetics Program, Division of Epilepsy & Clinical Neurophysiology, Boston Children's Hospital, Boston, Massachusetts.,Harvard Medical School, Boston, Massachusetts.,Neurogenetics Program, Boston Children's Hospital, Boston, Massachusetts.,Department of Neurology, Boston Children's Hospital, Boston, Massachusetts.,F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts
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39
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Abstract
The authors describe 2 patients with early infantile epileptic encephalopathy caused by 2 novel mutations involving the STXBP1 gene. The authors suggest that in spite of the rarity of STXBP1 mutations, molecular analysis of STXBP1 gene should be performed in patients with early infantile epileptic encephalopathy, after exclusion of ARX mutations in male patients and CDKL5 mutations in female patients. The potential mechanisms explaining the variable clinical phenotypes caused by STXBP1 mutations are discussed and the designation of early-onset epileptic encephalopathies, including an updated genetic classification, is proposed to encompass the epileptic encephalopathies beginning in the first 6 months of life.
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Affiliation(s)
- Mafalda Sampaio
- Pediatric Neurology Department, Hospital Pediátrico Integrado, Centro Hospitalar São João, Porto, Portugal
| | - Ruben Rocha
- Pediatric Neurology Department, Hospital Pediátrico Integrado, Centro Hospitalar São João, Porto, Portugal
| | - Saskia Biskup
- Center for Genomics and Transcriptomics (CeGaT), Tubingen, Germany
| | - Miguel Leão
- Pediatric Neurology Department, Hospital Pediátrico Integrado, Centro Hospitalar São João, Porto, Portugal Genetics Department, Faculdade de Medicina da Universidade do Porto, Portugal
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40
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Nicita F, Ulgiati F, Bernardini L, Garone G, Papetti L, Novelli A, Spalice A. Early myoclonic encephalopathy in 9q33-q34 deletion encompassing STXBP1 and SPTAN1. Ann Hum Genet 2015; 79:209-17. [PMID: 25779878 DOI: 10.1111/ahg.12106] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 01/07/2015] [Indexed: 02/01/2023]
Abstract
Deletions in the 9q33-q34 region have been reported in patients with early onset epileptic encephalopathy, but a consistent phenotype has yet to emerge. We report on the diagnosis of a de novo 9q33-q34.12 microdeletion of 4 Mb in a 15-month-old girl presenting with severe psychomotor delay, facial dysmorphisms, thin corpus callosum and early myoclonic encephalopathy. This deletion encompasses 101 RefSeq genes, including the four autosomal dominant genes STXBP1, SPTAN1, ENG and TOR1A. We discuss genetic, clinical and epileptic features comparing our patient with those previously reported in the literature.
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Affiliation(s)
- Francesco Nicita
- Child Neurology Division, Department of Pediatrics, Sapienza University, Rome, Italy
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41
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Ortega-Moreno L, Giráldez BG, Verdú A, García-Campos O, Sánchez-Martín G, Serratosa JM, Guerrero-López R. Novel mutation in STXBP1 gene in a patient with non-lesional Ohtahara syndrome. Neurologia 2015; 31:523-7. [PMID: 25631041 DOI: 10.1016/j.nrl.2014.10.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 10/27/2014] [Indexed: 10/24/2022] Open
Abstract
INTRODUCTION Ohtahara syndrome (OS, OMIM#308350, ORPHA1934) is an early-onset epileptic encephalopathy (EOEE) characterised by spasms, intractable seizures, suppression-burst pattern on the electroencephalogram, and severe psychomotor retardation. Mutations in STXBP1 -a gene that codes for syntaxin binding protein 1 and is involved in synaptic vesicle exocytosis- has been identified in most patients with OS. PATIENT AND RESULTS We report the case of a 19-month-old child with OS who displays a previously unreported mutation in STXBP1 (c.1249+2T>C, G417AfsX7). This mutation is located in a donor splice site and eliminates exon 14, resulting in a truncated protein. CONCLUSION This previously unreported STXBP1 mutation in a subject with Ohtahara syndrome and non-lesional magnetic resonance imaging (MRI) broadens the mutational spectrum associated with this devastating epileptic syndrome.
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Affiliation(s)
- L Ortega-Moreno
- Laboratorio de Neurología y Unidad de Epilepsia, Servicio de Neurología, IIS-Fundación Jiménez Díaz, UAM, Madrid, España; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, España
| | - B G Giráldez
- Laboratorio de Neurología y Unidad de Epilepsia, Servicio de Neurología, IIS-Fundación Jiménez Díaz, UAM, Madrid, España; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, España
| | - A Verdú
- Unidad de Neuropediatría, Hospital Virgen de la Salud, Toledo, España
| | - O García-Campos
- Unidad de Neuropediatría, Hospital Virgen de la Salud, Toledo, España
| | - G Sánchez-Martín
- Laboratorio de Neurología y Unidad de Epilepsia, Servicio de Neurología, IIS-Fundación Jiménez Díaz, UAM, Madrid, España; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, España
| | - J M Serratosa
- Laboratorio de Neurología y Unidad de Epilepsia, Servicio de Neurología, IIS-Fundación Jiménez Díaz, UAM, Madrid, España; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, España.
| | - R Guerrero-López
- Laboratorio de Neurología y Unidad de Epilepsia, Servicio de Neurología, IIS-Fundación Jiménez Díaz, UAM, Madrid, España; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, España
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Boutry-Kryza N, Labalme A, Ville D, de Bellescize J, Touraine R, Prieur F, Dimassi S, Poulat AL, Till M, Rossi M, Bourel-Ponchel E, Delignières A, Le Moing AG, Rivier C, des Portes V, Edery P, Calender A, Sanlaville D, Lesca G. Molecular characterization of a cohort of 73 patients with infantile spasms syndrome. Eur J Med Genet 2014; 58:51-8. [PMID: 25497044 DOI: 10.1016/j.ejmg.2014.11.007] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 11/30/2014] [Indexed: 01/10/2023]
Abstract
Infantile Spasms syndrome (ISs) is a characterized by epileptic spasms occurring in clusters with an onset in the first year of life. West syndrome represents a subset of ISs that associates spasms in clusters, a hypsarrhythmia EEG pattern and a developmental arrest or regression. Aetiology of ISs is widely heterogeneous including many genetic causes. Many patients, however, remain without etiological diagnosis, which is critical for prognostic purpose and genetic counselling. In the present study, we performed genetic screening of 73 patients with different types of ISs by array-CGH and molecular analysis of 5 genes: CDKL5, STXBP1, KCNQ2, and GRIN2A, whose mutations cause different types of epileptic encephalopathies, including ISs, as well as MAGI2, which was suggested to be related to a subset of ISs. In total, we found a disease-causing mutation or CNV (Copy Number Variation) in 15% of the patients. These included 6 point mutations found in CDKL5 (n = 3) and STXBP1 (n = 3), 3 microdeletions (10 Mb in 2q24.3, 3.2 Mb in 5q14.3 including the region upstream to MEF2C, and 256 kb in 9q34 disrupting EHMT1), and 2 microduplications (671 kb in 2q24.3 encompassing SCN2A, and 11.93 Mb in Xq28). In addition, we discuss 3 CNVs as potential risk factors, including one 16p12.1 deletion, one intronic deletion of the NEDD4 gene, and one intronic deletion of CALN1 gene. The present findings highlight the efficacy of combined cytogenetic and targeted mutation screening to improve the diagnostic yield in patient with ISs.
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Affiliation(s)
- Nadia Boutry-Kryza
- Department of Molecular Genetics, Lyon University Hospital, Lyon, France; CRNL, CNRS UMR 5292, INSERM U1028, Lyon, France
| | - Audrey Labalme
- Department of Genetics, Lyon University Hospital, Lyon, France
| | - Dorothee Ville
- Reference Center for Tuberous Sclerosis and Rare Epileptic Syndromes, Lyon University Hospital, Lyon, France
| | - Julitta de Bellescize
- Epilepsy, Sleep and Pediatric Neurophysiology Department, Lyon University Hospital, Lyon, France
| | - Renaud Touraine
- Department of Genetics, Hospital Nord, Saint-Etienne University Hospital, France
| | - Fabienne Prieur
- Department of Genetics, Hospital Nord, Saint-Etienne University Hospital, France
| | - Sarra Dimassi
- CRNL, CNRS UMR 5292, INSERM U1028, Lyon, France; Department of Genetics, Lyon University Hospital, Lyon, France; Claude Bernard Lyon I University, Lyon, France
| | - Anne-Lise Poulat
- Reference Center for Tuberous Sclerosis and Rare Epileptic Syndromes, Lyon University Hospital, Lyon, France
| | - Marianne Till
- Department of Genetics, Lyon University Hospital, Lyon, France
| | - Massimiliano Rossi
- CRNL, CNRS UMR 5292, INSERM U1028, Lyon, France; Department of Genetics, Lyon University Hospital, Lyon, France
| | - Emilie Bourel-Ponchel
- Pediatric Functional Exploration of the Nervous System Service, Hospital Nord, Amiens University Hospital, Amiens, France
| | - Aline Delignières
- Department of Neurology, Hospital Nord, Amiens University Hospital, Amiens, France
| | - Anne-Gaelle Le Moing
- Department of Neurology, Hospital Nord, Amiens University Hospital, Amiens, France
| | - Clotilde Rivier
- Department of Pediatrics, Hospital Nord-Ouest, Villefranche sur Saone, France
| | - Vincent des Portes
- Reference Center for Tuberous Sclerosis and Rare Epileptic Syndromes, Lyon University Hospital, Lyon, France; Claude Bernard Lyon I University, Lyon, France; CNRS UMR 5403, Institut des Sciences Cognitives, L2C2, Bron, France
| | - Patrick Edery
- CRNL, CNRS UMR 5292, INSERM U1028, Lyon, France; Department of Genetics, Lyon University Hospital, Lyon, France; Claude Bernard Lyon I University, Lyon, France
| | - Alain Calender
- Department of Molecular Genetics, Lyon University Hospital, Lyon, France; Claude Bernard Lyon I University, Lyon, France; INSERM U1052, Lyon, France
| | - Damien Sanlaville
- CRNL, CNRS UMR 5292, INSERM U1028, Lyon, France; Department of Genetics, Lyon University Hospital, Lyon, France; Claude Bernard Lyon I University, Lyon, France
| | - Gaetan Lesca
- CRNL, CNRS UMR 5292, INSERM U1028, Lyon, France; Department of Genetics, Lyon University Hospital, Lyon, France; Claude Bernard Lyon I University, Lyon, France.
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Matsumoto H, Zaha K, Nakamura Y, Hayashi S, Inazawa J, Nonoyama S. Chromosome 9q33q34 microdeletion with early infantile epileptic encephalopathy, severe dystonia, abnormal eye movements, and nephroureteral malformations. Pediatr Neurol 2014; 51:170-5. [PMID: 24938147 DOI: 10.1016/j.pediatrneurol.2014.03.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Revised: 03/10/2014] [Accepted: 03/15/2014] [Indexed: 01/01/2023]
Abstract
BACKGROUND Microdeletion of chromosome 9q33q34 is an emerging disease disorder associated with early infantile epileptic encephalopathy, intellectual disability, and a variety of movement disorders. PATIENT We describe a male infant with early infantile epileptic encephalopathy with suppression-burst (Ohtahara syndrome) who carried a de novo 2.0-Mb microdeletion in chromosome 9q33q34, including STXBP1. The previously reported examples of 9q33q34 microdeletion including STXBP1 are reviewed. RESULTS The patient developed infantile spasms at 4 months of age, and these were refractory to multiple antiepileptic drugs. He also developed severe dystonia during infancy, rotatory nystagmus, and nephroureteral malformations. Immunoglobulin and clobazam administered at 11 months were effective for the spasms, but profound psychomotor retardation remained. A comparative genomic hybridization array analysis and the fluorescence in situ hybridization analysis revealed a de novo 2.0-Mb microdeletion in chromosome 9q33q34, which encompasses STXBP1, ENG, SPTAN1, and 52 other genes. A total of 14 patients (13 from the literature) with a 9q33q24 microdeletion including STXBP1 were reviewed, five of them displayed early infantile epileptic encephalopathy with suppression-burst, and six of them had early-onset epilepsy but not early infantile epileptic encephalopathy. Dystonia has been previously described in 9q33q34 deletions involving TOR1A but not STXBP1. Neither abnormal eye movements nor nephroureteral malformations has been previously described. CONCLUSIONS This patient adds unique clinical presentations of neurological and nephroureteral abnormalities to the features of 9q33q34 microdeletion.
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Affiliation(s)
- Hiroshi Matsumoto
- Department of Pediatrics, National Defense Medical College, Tokorozawa, Japan.
| | - Kiyotaka Zaha
- Department of Pediatrics, National Defense Medical College, Tokorozawa, Japan
| | - Yasuko Nakamura
- Department of Pediatrics, National Defense Medical College, Tokorozawa, Japan
| | - Shin Hayashi
- Department of Molecular Cytogenetics, Medical Research Institute and School of Biomedical Science, Tokyo Medical and Dental University, Tokyo, Japan
| | - Johji Inazawa
- Department of Molecular Cytogenetics, Medical Research Institute and School of Biomedical Science, Tokyo Medical and Dental University, Tokyo, Japan
| | - Shigeaki Nonoyama
- Department of Pediatrics, National Defense Medical College, Tokorozawa, Japan
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Hussain S. Developing a PPI inhibitor-based therapy for STXBP1 haploinsufficiency-associated epileptic disorders. Front Mol Neurosci 2014; 7:6. [PMID: 24550774 PMCID: PMC3912442 DOI: 10.3389/fnmol.2014.00006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 01/18/2014] [Indexed: 11/13/2022] Open
Affiliation(s)
- Shobbir Hussain
- Wellcome Trust - Medical Research Council Cambridge Stem Cell Institute, University of Cambridge Cambridge, UK ; Department of Physiology, Development and Neuroscience, University of Cambridge Cambridge, UK
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Barcia G, Chemaly N, Gobin S, Milh M, Van Bogaert P, Barnerias C, Kaminska A, Dulac O, Desguerre I, Cormier V, Boddaert N, Nabbout R. Early epileptic encephalopathies associated with STXBP1 mutations: Could we better delineate the phenotype? Eur J Med Genet 2013; 57:15-20. [PMID: 24189369 DOI: 10.1016/j.ejmg.2013.10.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Accepted: 10/22/2013] [Indexed: 01/24/2023]
Abstract
STXBP1 (MUNC18.1), encoding syntaxin binding protein 1, is a gene causing epileptic encephalopathy. Mutations in STXBP1 have first been reported in early onset epileptic encephalopathy with suppression-bursts, then in infantile spasms and, more recently, in patients with non syndromic mental retardation without epilepsy. We analyzed clinical evolution and brain magnetic resonance imaging in 7 patients (6 females, 1 male) with early onset epileptic encephalopathies associated with STXBP1 mutations. We documented a peculiar brain MRI aspect characterized by frontal hypoplasia and a thin and dysmorphic corpus callosum. The course of the epilepsy was relatively benign. These clinical and neuroradiological features could orient the clinician in selecting patients' candidate to genetic testing for STXBP1 gene.
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Affiliation(s)
- Giulia Barcia
- Department of Neuropediatrics, Centre de Reference des Epilepsies Rares, Hopital Necker Enfants Malades, Paris Descartes University, Paris, France; Inserm U663, University Paris Descartes, PRES Sorbonne Paris Cité, Paris F-75005; CEA, Neurospin, 91190 Gif/Yvette, France
| | - Nicole Chemaly
- Department of Neuropediatrics, Centre de Reference des Epilepsies Rares, Hopital Necker Enfants Malades, Paris Descartes University, Paris, France; Inserm U663, University Paris Descartes, PRES Sorbonne Paris Cité, Paris F-75005; CEA, Neurospin, 91190 Gif/Yvette, France
| | - Stephanie Gobin
- Department of Genetics, Inserm U781, Hopital Necker Enfants Malades, Paris Descartes University, Paris, France
| | - Mathieu Milh
- APHM, CINAPSE, Pediatric Neurology Department, Timone Children Hospital, Marseille, France
| | | | - Christine Barnerias
- Department of Neuropediatrics, Centre de Reference des Epilepsies Rares, Hopital Necker Enfants Malades, Paris Descartes University, Paris, France
| | - Anna Kaminska
- Department of Neuropediatrics, Centre de Reference des Epilepsies Rares, Hopital Necker Enfants Malades, Paris Descartes University, Paris, France; Inserm U663, University Paris Descartes, PRES Sorbonne Paris Cité, Paris F-75005; CEA, Neurospin, 91190 Gif/Yvette, France
| | - Olivier Dulac
- Department of Neuropediatrics, Centre de Reference des Epilepsies Rares, Hopital Necker Enfants Malades, Paris Descartes University, Paris, France; Inserm U663, University Paris Descartes, PRES Sorbonne Paris Cité, Paris F-75005; CEA, Neurospin, 91190 Gif/Yvette, France
| | - Isabelle Desguerre
- Department of Neuropediatrics, Centre de Reference des Epilepsies Rares, Hopital Necker Enfants Malades, Paris Descartes University, Paris, France
| | - Valerie Cormier
- Department of Genetics, Inserm U781, Hopital Necker Enfants Malades, Paris Descartes University, Paris, France
| | - Nathalie Boddaert
- Department of Pediatric Radiology, Hopital Necker Enfants Malades, APHP, Paris, Descartes University, Paris, France
| | - Rima Nabbout
- Department of Neuropediatrics, Centre de Reference des Epilepsies Rares, Hopital Necker Enfants Malades, Paris Descartes University, Paris, France.
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Barcia G, Barnerias C, Rio M, Siquier-Pernet K, Desguerre I, Colleaux L, Munnich A, Rotig A, Nabbout R. A novel mutation in STXBP1 causing epileptic encephalopathy (late onset infantile spasms) with partial respiratory chain complex IV deficiency. Eur J Med Genet 2013; 56:683-5. [PMID: 24095819 DOI: 10.1016/j.ejmg.2013.09.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Accepted: 09/24/2013] [Indexed: 01/15/2023]
Abstract
STXBP1 (MUNC18.1), encoding syntaxin binding protein 1, has been reported in Ohtahara syndrome, a rare epileptic encephalopathy with suppression burst pattern on EEG, in patients with infantile spasms and in a few patients with nonsyndromic mental retardation without epilepsy. We report a patient who presented late onset infantile spasms. Epilepsy was controlled but the patient developed severe mental delay. A first diagnosis of mitochondrial disease was based on clinical presentation and on a partial deficit of respiratory chain complex IV, but molecular screening for mitochondrial genes was negative. The sequencing of STXBP1 gene found a de novo nonsense mutation (c.585C>G/p.Tyr195X). This observation widens the clinical spectrum linked to STXBP1 mutations with the description of a patient with late onset infantile spasms. It raises the question of the value of epilepsy genes screening in patients with uncertain, partial or unconfirmed mitochondrial dysfunction.
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Mastrangelo M, Peron A, Spaccini L, Novara F, Scelsa B, Introvini P, Raviglione F, Faiola S, Zuffardi O. Neonatal suppression-burst without epileptic seizures: expanding the electroclinical phenotype of STXBP1-related, early-onset encephalopathy. Epileptic Disord 2013; 15:55-61. [PMID: 23531706 DOI: 10.1684/epd.2013.0558] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Early-onset epileptic encephalopathies (EOEEs) are characterised by epileptic seizures beginning in the first months of life, abnormal background EEG activity, and are associated with severe developmental delay and poor prognosis. Mutations and deletions in the STXBP1 gene are associated with Ohtahara syndrome, also known as "early infantile epileptic encephalopathy". We report an infant affected by EOEE with a 9q34.11 deletion that encompassed the genes STXBP1 and SPTAN1. The infant presented with neonatal encephalopathy without epileptic seizures and an EEG pattern varying from highly discontinuous to suppression-burst. This was followed by West syndrome at 2 months with atypical hypsarrhythmia and spasms, easily controlled by therapy. Our findings suggest that molecular analysis of STXBP1 should be considered for newborns affected by neonatal encephalopathy associated with a peculiar EEG pattern, even in the absence of neonatal epileptic seizures.
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