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Gu C, Wei X, Yan D, Cai Y, Li D, Shu J, Cai C. DEPDC5 plays a vital role in epilepsy: Genotypic and phenotypic features in cohort and literature. Epileptic Disord 2024; 26:341-349. [PMID: 38752894 DOI: 10.1002/epd2.20223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 03/18/2024] [Accepted: 03/24/2024] [Indexed: 06/12/2024]
Abstract
OBJECTIVE DEPDC5 emerges to play a vital role in focal epilepsy. However, genotype-phenotype correlation in DEPDC5-related focal epilepsies is challenging and controversial. In this study, we aim to investigate the genotypic and phenotypic features in DEPDC5-affected patients. METHODS Genetic testing combined with criteria published by the American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG/AMP), was used to identify pathogenic/likely pathogenic variants in DEPDC5 among the cohort of 479 patients with focal epilepsy. Besides, the literature review was performed to explore the genotype-phenotype correlation and the penetrance in DEPDC5-related focal epilepsies. RESULTS Eight unrelated probands were revealed to carry different pathogenic/likely pathogenic variants in DEPDC5 and the total prevalence of DEPDC5-related focal epilepsy was 1.67% in the cohort. Sixty-five variants from 28 studies were included in our review. Combined with the cases reported, null variants accounted for a larger proportion than missense variants and were related to unfavorable prognosis (drug resistance or even sudden unexpected death in epilepsy; χ2 = 5.429, p = .020). And, the prognosis of probands with developmental delay/intellectual disability or focal cortical dysplasia was worse than that of probands with simple epilepsy (χ2 = -, p = .006). Besides, the overall penetrance of variants in DEPDC5 was 68.96% (231/335). SIGNIFICANCE The study expands the variant spectrum of DEPDC5 and proves that the DEPDC5 variant plays a significant role in focal epilepsy. Due to the characteristics of phenotypic heterogeneity and incomplete penetrance, genetic testing is necessary despite no specific family history. And we propose to adopt the ACMG/AMP criteria refined by ClinGen Sequence Variant Interpretation Working Group, for consistency in usage and transparency in classification rationale. Moreover, we reveal an important message to clinicians that the prognosis of DEPDC5-affected patients is related to the variant type and complications.
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Affiliation(s)
- Chunyu Gu
- Tianjin Pediatric Research Institute, Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, China
| | - Xinping Wei
- The Medical Department of Neurology, Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, China
| | - Dandan Yan
- Tianjin Pediatric Research Institute, Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, China
| | - Yingzi Cai
- Tianjin Pediatric Research Institute, Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, China
| | - Dong Li
- The Medical Department of Neurology, Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, China
| | - Jianbo Shu
- Tianjin Pediatric Research Institute, Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, China
| | - Chunquan Cai
- Tianjin Pediatric Research Institute, Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, China
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Kovačević M, Milićević O, Branković M, Janković M, Novaković I, Sokić D, Ristić A, Shamsani J, Vojvodić N. Novel variants in established epilepsy genes in focal epilepsy. Seizure 2023; 110:146-152. [PMID: 37390664 DOI: 10.1016/j.seizure.2023.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 05/30/2023] [Accepted: 06/06/2023] [Indexed: 07/02/2023] Open
Abstract
INTRODUCTION Next generation sequencing (NGS) has greatly expanded our understanding of genetic contributors in multiple epilepsy syndromes, including focal epilepsy. Describing the genetic architecture of common syndromes promises to facilitate the diagnostic process as well as aid in the identification of patients who stand to benefit from genetic testing, but most studies to date have been limited to examining children or adults with intellectual disability. Our aim was to determine the yield of targeted sequencing of 5 established epilepsy genes (DEPDC5, LGI1, SCN1A, GRIN2A, and PCHD19) in an extensively phenotyped cohort of focal epilepsy patients with normal intellectual function or mild intellectual disability, as well as describe novel variants and determine the characteristics of variant carriers. PATIENTS AND METHODS Targeted panel sequencing was performed on 96 patients with a strong clinical suspicion of genetic focal epilepsy. Patients had previously gone through a comprehensive diagnostic epilepsy evaluation in The Neurology Clinic, University Clinical Center of Serbia. Variants of interest (VOI) were classified using the American College of Medical Genetics and the Association for Molecular Pathology criteria. RESULTS Six VOI in eight (8/96, 8.3%) patients were found in our cohort. Four likely pathogenic VOI were determined in six (6/96, 6.2%) patients, two DEPDC5 variants in two patients, one SCN1A variant in two patients and one PCDH19 variant in two patients. One variant of unknown significance (VUS) was found in GRIN2A in one (1/96, 1.0%) patient. Only one VOI in GRIN2A was classified as likely benign. No VOI were detected in LGI1. CONCLUSION Sequencing of only five known epilepsy genes yielded a diagnostic result in 6.2% of our cohort and revealed multiple novel variants. Further research is necessary for a better understanding of the genetic basis in common epilepsy syndromes in patients with normal intellectual function or mild intellectual disability.
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Affiliation(s)
- Maša Kovačević
- Neurology Clinic, University Clinical Center of Serbia, Belgrade, Serbia; Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
| | | | | | - Milena Janković
- Neurology Clinic, University Clinical Center of Serbia, Belgrade, Serbia
| | - Ivana Novaković
- Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Dragoslav Sokić
- Neurology Clinic, University Clinical Center of Serbia, Belgrade, Serbia; Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Aleksandar Ristić
- Neurology Clinic, University Clinical Center of Serbia, Belgrade, Serbia; Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | | | - Nikola Vojvodić
- Neurology Clinic, University Clinical Center of Serbia, Belgrade, Serbia; Faculty of Medicine, University of Belgrade, Belgrade, Serbia
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Khoshkhoo S, Wang Y, Chahine Y, Erson-Omay EZ, Robert SM, Kiziltug E, Damisah EC, Nelson-Williams C, Zhu G, Kong W, Huang AY, Stronge E, Phillips HW, Chhouk BH, Bizzotto S, Chen MH, Adikari TN, Ye Z, Witkowski T, Lai D, Lee N, Lokan J, Scheffer IE, Berkovic SF, Haider S, Hildebrand MS, Yang E, Gunel M, Lifton RP, Richardson RM, Blümcke I, Alexandrescu S, Huttner A, Heinzen EL, Zhu J, Poduri A, DeLanerolle N, Spencer DD, Lee EA, Walsh CA, Kahle KT. Contribution of Somatic Ras/Raf/Mitogen-Activated Protein Kinase Variants in the Hippocampus in Drug-Resistant Mesial Temporal Lobe Epilepsy. JAMA Neurol 2023; 80:578-587. [PMID: 37126322 PMCID: PMC10152377 DOI: 10.1001/jamaneurol.2023.0473] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 12/31/2022] [Indexed: 05/02/2023]
Abstract
Importance Mesial temporal lobe epilepsy (MTLE) is the most common focal epilepsy subtype and is often refractory to antiseizure medications. While most patients with MTLE do not have pathogenic germline genetic variants, the contribution of postzygotic (ie, somatic) variants in the brain is unknown. Objective To test the association between pathogenic somatic variants in the hippocampus and MTLE. Design, Setting, and Participants This case-control genetic association study analyzed the DNA derived from hippocampal tissue of neurosurgically treated patients with MTLE and age-matched and sex-matched neurotypical controls. Participants treated at level 4 epilepsy centers were enrolled from 1988 through 2019, and clinical data were collected retrospectively. Whole-exome and gene-panel sequencing (each genomic region sequenced more than 500 times on average) were used to identify candidate pathogenic somatic variants. A subset of novel variants was functionally evaluated using cellular and molecular assays. Patients with nonlesional and lesional (mesial temporal sclerosis, focal cortical dysplasia, and low-grade epilepsy-associated tumors) drug-resistant MTLE who underwent anterior medial temporal lobectomy were eligible. All patients with available frozen tissue and appropriate consents were included. Control brain tissue was obtained from neurotypical donors at brain banks. Data were analyzed from June 2020 to August 2022. Exposures Drug-resistant MTLE. Main Outcomes and Measures Presence and abundance of pathogenic somatic variants in the hippocampus vs the unaffected temporal neocortex. Results Of 105 included patients with MTLE, 53 (50.5%) were female, and the median (IQR) age was 32 (26-44) years; of 30 neurotypical controls, 11 (36.7%) were female, and the median (IQR) age was 37 (18-53) years. Eleven pathogenic somatic variants enriched in the hippocampus relative to the unaffected temporal neocortex (median [IQR] variant allele frequency, 1.92 [1.5-2.7] vs 0.3 [0-0.9]; P = .01) were detected in patients with MTLE but not in controls. Ten of these variants were in PTPN11, SOS1, KRAS, BRAF, and NF1, all predicted to constitutively activate Ras/Raf/mitogen-activated protein kinase (MAPK) signaling. Immunohistochemical studies of variant-positive hippocampal tissue demonstrated increased Erk1/2 phosphorylation, indicative of Ras/Raf/MAPK activation, predominantly in glial cells. Molecular assays showed abnormal liquid-liquid phase separation for the PTPN11 variants as a possible dominant gain-of-function mechanism. Conclusions and Relevance Hippocampal somatic variants, particularly those activating Ras/Raf/MAPK signaling, may contribute to the pathogenesis of sporadic, drug-resistant MTLE. These findings may provide a novel genetic mechanism and highlight new therapeutic targets for this common indication for epilepsy surgery.
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Affiliation(s)
- Sattar Khoshkhoo
- Department of Neurology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, Massachusetts
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts
| | - Yilan Wang
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, Massachusetts
- Program in Biological and Biomedical Sciences, Harvard Medical School, Boston, Massachusetts
| | - Yasmine Chahine
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, Massachusetts
| | - E. Zeynep Erson-Omay
- Department of Neurosurgery, Yale University School of Medicine, New Haven, Connecticut
| | - Stephanie M. Robert
- Department of Neurosurgery, Yale University School of Medicine, New Haven, Connecticut
| | - Emre Kiziltug
- Department of Neurosurgery, Yale University School of Medicine, New Haven, Connecticut
| | - Eyiyemisi C. Damisah
- Department of Neurosurgery, Yale University School of Medicine, New Haven, Connecticut
| | | | - Guangya Zhu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, China
| | - Wenna Kong
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, China
| | - August Yue Huang
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, Massachusetts
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts
| | - Edward Stronge
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
| | - H. Westley Phillips
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, Massachusetts
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts
- Department of Neurosurgery, David Geffen School of Medicine, University of California, Los Angeles
| | - Brian H. Chhouk
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, Massachusetts
| | - Sara Bizzotto
- Sorbonne University, Paris Brain Institute (ICM), National Institute of Health and Medical Research (INSERM), National Center for Scientific Research (CNRS), Paris, France
| | - Ming Hui Chen
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, Massachusetts
| | - Thiuni N. Adikari
- Department of Medicine (Austin Health), University of Melbourne, Heidelberg, Australia
| | - Zimeng Ye
- Department of Medicine (Austin Health), University of Melbourne, Heidelberg, Australia
| | - Tom Witkowski
- Department of Medicine (Austin Health), University of Melbourne, Heidelberg, Australia
| | - Dulcie Lai
- Division of Pharmacotherapy and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill
| | - Nadine Lee
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, Massachusetts
| | - Julie Lokan
- Department of Anatomical Pathology, Austin Health, Heidelberg, Australia
| | - Ingrid E. Scheffer
- Department of Medicine (Austin Health), University of Melbourne, Heidelberg, Australia
- Murdoch Children’s Research Institute, Parkville, Australia
- Florey Institute of Neuroscience and Mental Health, Heidelberg, Australia
- Department of Pediatrics, University of Melbourne, Royal Children’s Hospital, Parkville, Australia
- Bladin-Berkovic Comprehensive Epilepsy Program, Department of Neurology, Austin Health, Heidelberg, Australia
| | - Samuel F. Berkovic
- Department of Medicine (Austin Health), University of Melbourne, Heidelberg, Australia
- Bladin-Berkovic Comprehensive Epilepsy Program, Department of Neurology, Austin Health, Heidelberg, Australia
| | - Shozeb Haider
- Department of Pharmaceutical and Biological Chemistry, University College London School of Pharmacy, London, United Kingdom
| | - Michael S. Hildebrand
- Department of Medicine (Austin Health), University of Melbourne, Heidelberg, Australia
- Murdoch Children’s Research Institute, Parkville, Australia
| | - Edward Yang
- Department of Radiology, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Murat Gunel
- Department of Neurosurgery, Yale University School of Medicine, New Haven, Connecticut
| | - Richard P. Lifton
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut
- Laboratory of Human Genetics and Genomics, The Rockefeller University, New York, New York
| | | | - Ingmar Blümcke
- Department of Neuropathology, University Hospitals Erlangen, Erlangen, Germany
- Epilepsy Center, Cleveland Clinic, Cleveland, Ohio
| | - Sanda Alexandrescu
- Department of Pathology, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Anita Huttner
- Department of Pathology, Yale University School of Medicine, New Haven, Connecticut
| | - Erin L. Heinzen
- Division of Pharmacotherapy and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill
- Department of Genetics, School of Medicine, University of North Carolina at Chapel Hill
| | - Jidong Zhu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, China
| | - Annapurna Poduri
- Epilepsy Genetics Program, Division of Epilepsy and Neurophysiology, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Nihal DeLanerolle
- Department of Neurosurgery, Yale University School of Medicine, New Haven, Connecticut
| | - Dennis D. Spencer
- Department of Neurosurgery, Yale University School of Medicine, New Haven, Connecticut
| | - Eunjung Alice Lee
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, Massachusetts
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts
| | - Christopher A. Walsh
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, Massachusetts
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts
- Department of Neurology and Pediatrics, Harvard Medical School, Boston, Massachusetts
- Allen Discovery Center for Human Brain Evolution, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts
- Howard Hughes Medical Institute, Boston, Massachusetts
| | - Kristopher T. Kahle
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, Massachusetts
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts
- Laboratory of Human Genetics and Genomics, The Rockefeller University, New York, New York
- Department of Neurosurgery, Boston Children’s Hospital, Boston, Massachusetts
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Krey I, Platzer K, Lemke JR. Monogenetic epilepsies and how to approach them in 2022. MED GENET-BERLIN 2022; 34:201-205. [PMID: 38835882 PMCID: PMC11006248 DOI: 10.1515/medgen-2022-2143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Affiliation(s)
- Ilona Krey
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
| | - Konrad Platzer
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
| | - Johannes R Lemke
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
- Center for Rare Diseases, University of Leipzig Medical Center, Leipzig, Germany
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Sheidley BR, Malinowski J, Bergner AL, Bier L, Gloss DS, Mu W, Mulhern MM, Partack EJ, Poduri A. Genetic testing for the epilepsies: A systematic review. Epilepsia 2021; 63:375-387. [PMID: 34893972 DOI: 10.1111/epi.17141] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 11/22/2021] [Accepted: 11/23/2021] [Indexed: 12/29/2022]
Abstract
OBJECTIVE Numerous genetic testing options for individuals with epilepsy have emerged over the past decade without clear guidelines regarding optimal testing strategies. We performed a systematic evidence review (SER) and conducted meta-analyses of the diagnostic yield of genetic tests commonly utilized for patients with epilepsy. We also assessed nonyield outcomes (NYOs) such as changes in treatment and/or management, prognostic information, recurrence risk determination, and genetic counseling. METHODS We performed an SER, in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses), using PubMed, Embase, CINAHL, and Cochrane Central through December of 2020. We included studies that utilized genome sequencing (GS), exome sequencing (ES), multigene panel (MGP), and/or genome-wide comparative genomic hybridization/chromosomal microarray (CGH/CMA) in cohorts (n ≥ 10) ascertained for epilepsy. Quality assessment was undertaken using ROBINS-I (Risk of Bias in Non-Randomized Studies of Interventions). We estimated diagnostic yields and 95% confidence intervals with random effects meta-analyses and narratively synthesized NYOs. RESULTS From 5985 nonduplicated articles published through 2020, 154 met inclusion criteria and were included in meta-analyses of diagnostic yield; 43 of those were included in the NYO synthesis. The overall diagnostic yield across all test modalities was 17%, with the highest yield for GS (48%), followed by ES (24%), MGP (19%), and CGH/CMA (9%). The only phenotypic factors that were significantly associated with increased yield were (1) the presence of developmental and epileptic encephalopathy and/or (2) the presence of neurodevelopmental comorbidities. Studies reporting NYOs addressed clinical and personal utility of testing. SIGNIFICANCE This comprehensive SER, focused specifically on the literature regarding patients with epilepsy, provides a comparative assessment of the yield of clinically available tests, which will help shape clinician decision-making and policy regarding insurance coverage for genetic testing. We highlight the need for prospective assessment of the clinical and personal utility of genetic testing for patients with epilepsy and for standardization in reporting patient characteristics.
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Affiliation(s)
- Beth R Sheidley
- Epilepsy Genetics Program, Division of Epilepsy and Neurophysiology, Department of Neurology, Boston Children's Hospital, Boston, Massachusetts, USA
| | | | - Amanda L Bergner
- Department of Genetics and Development, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Louise Bier
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, New York, USA
| | - David S Gloss
- Department of Neurology, Charleston Area Medical Center, Charleston, West Virginia, USA
| | - Weiyi Mu
- Department of Genetic Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Maureen M Mulhern
- Department of Pathology, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA.,Department of Neurology, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Emily J Partack
- Genomics Services, Quest Diagnostics, Marlborough, Massachusetts, USA
| | - Annapurna Poduri
- Epilepsy Genetics Program, Division of Epilepsy and Neurophysiology, Department of Neurology, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Neurology, Harvard Medical School, Boston, Massachusetts, USA
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Massimino CR, Portale L, Sapuppo A, Pizzo F, Sciuto L, Romano C, Salafia S, Falsaperla R. PRRT2 Related Epilepsies: A Gene Review. JOURNAL OF PEDIATRIC NEUROLOGY 2021. [DOI: 10.1055/s-0041-1728683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Abstract
PRRT2 encodes for proline-rich transmembrane protein 2 involved in synaptic vesicle fusion and presynaptic neurotransmitter release. Mutations in human PRRT2 have been related to paroxysmal kinesigenic dyskinesia (PKD), infantile convulsions with choreoathetosis, benign familial infantile epilepsies, and hemiplegic migraine. PRRT2 mutations cause neuronal hyperexcitability, which could be related to basal ganglia or cortical circuits dysfunction, leading to paroxysmal disorders. PRRT2 is expressed in the cerebral cortex, basal ganglia, and cerebellum. Approximately, 90% of pathogenic variants are inherited and 10% are de novo. Paroxysmal attacks in PKD are characterized by dystonia, choreoathetosis, and ballismus. In the benign familial infantile epilepsy (BFIE), seizures are usually focal with or without generalization, usually begin between 3 and 12 months of age and remit by 2 years of age. In 30% of cases of PRRT2-associated PKD, there is an association with BFIE, and this entity is referred to as PKD with infantile convulsions (PKD/IC). PRRT2 mutations are the cause of benign family childhood epilepsy and PKD/IC. On the other hand, PRRT2 mutations do not seem to correlate with other types of epilepsy. The increasing incidence of hemiplegic migraine in families with PRRT2-associated PKD or PKD/IC suggests a common disease pathway, and it is possible to assert that BFIE, paroxysmal kinesigenic dyskinesia, and PKD with IC belong to a continuous disease spectrum of PRRT2-associated diseases.
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Affiliation(s)
- Carmela Rita Massimino
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Laura Portale
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Annamaria Sapuppo
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Francesco Pizzo
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Laura Sciuto
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Catia Romano
- Italian Blind Union, Catania section, Catania, Italy
| | | | - Raffaele Falsaperla
- Unit of Pediatrics and Pediatric Emergency, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
- Unit of Neonatal Intensive Care and Neonatology, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
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7
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Salomone G, Comella M, Portale A, Pecora G, Costanza G, Lo Bianco M, Sciuto S, Praticò ER, Falsaperla R. The Spectrum of DEPDC5-Related Epilepsy. JOURNAL OF PEDIATRIC NEUROLOGY 2021. [DOI: 10.1055/s-0041-1727139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
AbstractDisheveled EGL-10 and pleckstrin domain-containing protein 5 (DEPDC5) is a key member of the GAP activity toward rags complex 1 complex, which inhibits the mammalian target of rapamycin complex 1 (mTORC1) pathway. DEPDC5 loss-of-function mutations lead to an aberrant activation of the mTOR signaling. At neuronal level, the increased mTOR cascade causes the generation of epileptogenic dysplastic neuronal circuits and it is often associated with malformation of cortical development. The DEPDC5 phenotypic spectrum ranges from sporadic early-onset epilepsies with poor neurodevelopmental outcomes to familial focal epilepsies and sudden unexpected death in epilepsy; a high rate of inter- and intrafamilial variability has been reported. To date, clear genotype–phenotype correlations have not been proven. More studies are required to elucidate the significance of likely pathogenic/variants of uncertain significance. The pursuit of a molecular targeted antiepileptic therapy is a future challenge.
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Affiliation(s)
- Giulia Salomone
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Mattia Comella
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Anna Portale
- Unit of Pediatrics, Avola Hospital, Siracusa, Italy
| | - Giulia Pecora
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Giuseppe Costanza
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Manuela Lo Bianco
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Sarah Sciuto
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | | | - Raffaele Falsaperla
- Unit of Pediatrics and Pediatric Emergency, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
- Units of Neonatal Intensive Care and Neonatology, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
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Abstract
Because of next-generation sequencing and the discovery of many new causative genes, genetic testing in epilepsy patients has become widespread. Pathologic variants resulting in epilepsy cause a variety of changes that can be broadly classified into syndromic disorders (i.e., chromosomal abnormalities), metabolic disorders, brain malformations, and abnormal cellular signaling. Here, we review the available genetic testing, reasons to pursue genetic testing, common genetic causes of epilepsy, the data behind what patients are found to have genetic epilepsies based on current testing, and discussing these results with patients. We propose an algorithm for testing patients with epilepsy to maximize yield and limit costs based on their phenotype (including electroencephalography and magnetic resonance imaging findings), age of seizure onset, and presence of other neurologic comorbidities. Being able to discern which type of genetic testing to order, using that information to give targeted and cost-effective patient care, and interpreting results accurately will be a crucial skill for the modern neurologist.
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Affiliation(s)
- David M Ritter
- Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Katherine Holland
- Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio
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Tsai MH, Cheng HY, Nian FS, Liu C, Chao NH, Chiang KL, Chen SF, Tsai JW. Impairment in dynein-mediated nuclear translocation by BICD2 C-terminal truncation leads to neuronal migration defect and human brain malformation. Acta Neuropathol Commun 2020; 8:106. [PMID: 32665036 PMCID: PMC7362644 DOI: 10.1186/s40478-020-00971-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 06/19/2020] [Indexed: 02/06/2023] Open
Abstract
During brain development, the nucleus of migrating neurons follows the centrosome and translocates into the leading process. Defects in these migratory events, which affect neuronal migration, cause lissencephaly and other neurodevelopmental disorders. However, the mechanism of nuclear translocation remains elusive. Using whole exome sequencing (WES), we identified a novel nonsense BICD2 variant p.(Lys775Ter) (K775X) from a lissencephaly patient. Interestingly, most BICD2 missense variants have been associated with human spinal muscular atrophy (SMA) without obvious brain malformations. By in utero electroporation, we showed that BicD2 knockdown in mouse embryos inhibited neuronal migration. Surprisingly, we observed severe blockage of neuronal migration in cells overexpressing K775X but not in those expressing wild-type BicD2 or SMA-associated missense variants. The centrosome of the mutant was, on average, positioned farther away from the nucleus, indicating a failure in nuclear translocation without affecting the centrosome movement. Furthermore, BicD2 localized at the nuclear envelope (NE) through its interaction with NE protein Nesprin-2. K775X variant disrupted this interaction and further interrupted the NE recruitment of BicD2 and dynein. Remarkably, fusion of BicD2-K775X with NE-localizing domain KASH resumed neuronal migration. Our results underscore impaired nuclear translocation during neuronal migration as an important pathomechanism of lissencephaly.
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The role of targeted gene panel in pediatric drug-resistant epilepsy. Epilepsy Behav 2020; 106:107003. [PMID: 32169601 DOI: 10.1016/j.yebeh.2020.107003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 02/21/2020] [Accepted: 02/23/2020] [Indexed: 11/23/2022]
Abstract
About 10-30% of pediatric patients with epilepsy have drug-resistant epilepsy. Genetic panels may be useful in identifying etiology and guiding treatment in pediatric patients with drug-resistant epilepsy. In our tertiary center, we used two epilepsy panels, an initial 24-genes panel followed by a more comprehensive 122-genes panel to screen for genetic cause over recent 2 years. A total of 96 patients with drug-resistant epilepsy were evaluated using the 24-genes panel, which revealed 10 (10.4%) of the patients with pathogenic variants. Another 22 patients without causative genetic variants using first-gene panel were evaluated using the 122-genes panel. Out of the 22 patients, 4 had pathogenic variants, and 6 had variants of unknown significance. The total yield rate for the second panel was 18.2% (4/22). In conclusion, although whole exome sequencing has entered clinical practice, epilepsy gene panels may still play some roles because of lower cost and faster time, especially in those with fever-associated epilepsy.
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Customized multigene panels in epilepsy: the best things come in small packages. Neurogenetics 2019; 21:1-18. [PMID: 31834528 DOI: 10.1007/s10048-019-00598-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 11/12/2019] [Indexed: 12/13/2022]
Abstract
Over the past 10 years, the increasingly important role played by next-generation sequencing panels in the genetic diagnosis of epilepsy has led to a growing list of gene variants and a plethora of new scientific data. To date, however, there is still no consensus on what constitutes the "ideal panel design," or on the most rational criteria for selecting the best candidates for gene-panel analysis, even though both might optimize the cost-benefit ratio and the diagnostic efficiency of customized gene panels. Even though more and more laboratories are adopting whole-exome sequencing as a first-tier diagnostic approach, interpreting, "in silico," a set of epilepsy-related genes remains difficult. In the light of these considerations, we performed a systematic review of the targeted gene panels for epilepsy already reported in the available scientific literature, with a view to identifying the best criteria for selecting patients for gene-panel analysis, and the best way to design an "ideal," gold-standard panel that includes all genes with an established role in epilepsy pathogenesis, as well as those that might help to guide decisions regarding specific medical interventions and treatments. Our analyses suggest that the usefulness and diagnostic power of customized gene panels for epilepsy may be greatest when these panels are confined to rationally selected, relatively small, pools of genes, and applied in more carefully selected epilepsy patients (those with complex forms of epilepsy). A panel containing 64 genes, which includes the 45 genes harboring a significant number of pathogenic variants identified in previous literature, the 32 clinically actionable genes, and the 21 ILAE (International League Against Epilepsy) recommended genes, may represent an "ideal" core set likely able to provide the highest diagnostic efficiency and cost-effectiveness and facilitate gene prioritization when testing patients with whole-exome/whole-genome sequencing.
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12
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Abstract
Zusammenfassung
Je nach Anfallssemiologie und EEG-Befund werden Epilepsien klinisch zumeist in fokale bzw. generalisierte Formen unterteilt. Tritt bei einem Kind infolge einer Epilepsie zusätzlich eine Entwicklungsstörung auf, kann dies oft auf eine epileptische Enzephalopathie zurückgeführt werden. Das Mutationsspektrum genetischer Epilepsien ist ausgesprochen heterogen und kann am besten mithilfe der Hochdurchsatzsequenzierung erfasst werden. Insbesondere bei den Enzephalopathien besteht eine hohe Aufklärungsrate. Mittlerweile gibt es für diverse genetisch bedingte Epilepsieerkrankungen individualisierte Therapien, die auf den jeweiligen molekularen Pathomechanismus abzielen, und die Zahl solcher personalisierter Therapieoptionen steigt stetig.
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Affiliation(s)
- Johannes R. Lemke
- 1 grid.411339.d 0000 0000 8517 9062 Institut für Humangenetik Universitätsklinikum Leipzig Ph.-Rosenthal-Str. 55 04103 Leipzig Deutschland
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Clinical and molecular genetic features of cerebrotendinous xanthomatosis in Taiwan: Report of a novel CYP27A1 mutation and literature review. J Clin Lipidol 2019; 13:954-959.e1. [PMID: 31706903 DOI: 10.1016/j.jacl.2019.10.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 09/26/2019] [Accepted: 10/01/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND Cerebrotendinous xanthomatosis (CTX) is an autosomal recessive lipid storage disorder associated with mutations in the CYP27A1 gene, and the genetic features of CTX in Taiwanese have not been examined before. OBJECTIVES We report a new CTX family with a novel mutation in the CYP27A1 gene and analyze the clinical and molecular genetic features of CTX in Taiwan. METHODS The clinical and molecular genetic features of the two siblings from the new CTX family and the other 7 reported Taiwanese CTX patients were included for analysis. The clinical features of the enrolled CTX patients were recorded using the indicators that make up the suspicion index (SI). RESULTS The age at CTX diagnosis of the two siblings in the new CTX family were in late 30s, and predominantly psychiatric features. Both siblings had compound heterozygous splicing mutations in the CYP27A1 gene, including one mutation in exon 2 (c.435G>T, cryptic splice site) and one mutation in intron 7 (c.1264A>G, canonical splice site). None of the CTX patients in Taiwan were diagnosed during childhood or adolescence, and the most common clinical features of the 9 Taiwanese CTX patients were tendinous xanthomas, followed by ataxia and/or spastic paraparesis, dentate nuclei signal alternation at magnetic resonance imaging, intellectual disability and/or psychiatric disturbance, and polyneuropathy. Mutations in the CYP27A1 gene in the Taiwanese population were most commonly observed in exon 2, followed by exon 8 and intron 7. Except for one CTX patient who had an SI score of 100, the SI scores ranged from 300 to 400 before the study of the CYP27A1 gene and diagnosis. CONCLUSIONS We reported two Taiwanese CTX siblings who had compound heterozygous mutations in CYP27A1. Exons 2 and 8 and intron 7 are the hotspots for Taiwanese CTX mutations. The diagnosis of CTX in Taiwan is usually delayed and is probably under-recognized based on statistical estimations. Early identification and genetic diagnosis may be helpful to CTX patients because early treatment can reduce the accumulation of cholestanol and slow disease progression.
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Tsai M, Nian F, Hsu M, Liu W, Liu Y, Liu C, Lin P, Hwang D, Chuang Y, Tsai J. PRRT
2
missense mutations cluster near C‐terminus and frequently lead to protein mislocalization. Epilepsia 2019; 60:807-817. [DOI: 10.1111/epi.14725] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 03/19/2019] [Indexed: 01/06/2023]
Affiliation(s)
- Meng‐Han Tsai
- Department of NeurologyCollege of MedicineKaohsiung Chang Gung Memorial HospitalChang Gung University Kaohsiung Taiwan
| | - Fang‐Shin Nian
- Institute of Brain ScienceSchool of MedicineNational Yang‐Ming University Taipei Taiwan
- Program in Molecular MedicineNational Yang‐Ming University and Academia Sinica Taipei Taiwan
| | - Mei‐Hsin Hsu
- Department of PediatricsKaohsiung Chang Gung Memorial Hospital Kaohsiung Taiwan
| | - Wei‐Szu Liu
- Department of Life SciencesNational Yang‐Ming University Taipei Taiwan
| | - Yo‐Tsen Liu
- Institute of Brain ScienceSchool of MedicineNational Yang‐Ming University Taipei Taiwan
- Department of NeurologyNeurological InstituteTaipei Veterans General Hospital Taipei Taiwan
- Department of MedicineSchool of MedicineNational Yang‐Ming University Taipei Taiwan
- Brain Research CenterNational Yang‐Ming University Taipei Taiwan
| | - Chen Liu
- Institute of Brain ScienceSchool of MedicineNational Yang‐Ming University Taipei Taiwan
| | - Po‐Hsi Lin
- Department of MedicineSchool of MedicineNational Yang‐Ming University Taipei Taiwan
| | - Daw‐Yang Hwang
- Division of NephrologyKaohsiung Medical University HospitalKaohsiung Medical University Kaohsiung Taiwan
| | - Yao‐Chung Chuang
- Department of NeurologyCollege of MedicineKaohsiung Chang Gung Memorial HospitalChang Gung University Kaohsiung Taiwan
| | - Jin‐Wu Tsai
- Institute of Brain ScienceSchool of MedicineNational Yang‐Ming University Taipei Taiwan
- Brain Research CenterNational Yang‐Ming University Taipei Taiwan
- Biophotonics and Molecular Imaging Research CenterNational Yang‐Ming University Taipei Taiwan
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15
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Møller RS, Hammer TB, Rubboli G, Lemke JR, Johannesen KM. From next-generation sequencing to targeted treatment of non-acquired epilepsies. Expert Rev Mol Diagn 2019; 19:217-228. [DOI: 10.1080/14737159.2019.1573144] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Rikke S. Møller
- Department of Epilepsy Genetics and Precision Medicine, The Danish Epilepsy Centre, Dianalund, Denmark
- Institute for Regional Health Services, University of Southern Denmark, Odense, Denmark
| | - Trine B. Hammer
- Department of Epilepsy Genetics and Precision Medicine, The Danish Epilepsy Centre, Dianalund, Denmark
| | - Guido Rubboli
- Department of Epilepsy Genetics and Precision Medicine, The Danish Epilepsy Centre, Dianalund, Denmark
- Institute of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Johannes R. Lemke
- Institute of Human Genetics, University of Leipzig Hospitals and Clinics, Leipzig, Germany
| | - Katrine M. Johannesen
- Department of Epilepsy Genetics and Precision Medicine, The Danish Epilepsy Centre, Dianalund, Denmark
- Institute for Regional Health Services, University of Southern Denmark, Odense, Denmark
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