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Yoganathan S, Whitney R, Thomas M, Danda S, Chettali AM, Prasad AN, Farhan SMK, AlSowat D, Abukhaled M, Aldhalaan H, Gowda VK, Kinhal UV, Bylappa AY, Konanki R, Lingappa L, Parchuri BM, Appendino JP, Scantlebury MH, Cunningham J, Hadjinicolaou A, El Achkar CM, Kamate M, Menon RN, Jose M, Riordan G, Kannan L, Jain V, Manokaran RK, Chau V, Donner EJ, Costain G, Minassian BA, Jain P. KCTD7-related progressive myoclonic epilepsy: Report of 42 cases and review of literature. Epilepsia 2024; 65:709-724. [PMID: 38231304 DOI: 10.1111/epi.17880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 01/02/2024] [Accepted: 01/03/2024] [Indexed: 01/18/2024]
Abstract
OBJECTIVE KCTD7-related progressive myoclonic epilepsy (PME) is a rare autosomal-recessive disorder. This study aimed to describe the clinical details and genetic variants in a large international cohort. METHODS Families with molecularly confirmed diagnoses of KCTD7-related PME were identified through international collaboration. Furthermore, a systematic review was done to identify previously reported cases. Salient demographic, epilepsy, treatment, genetic testing, electroencephalographic (EEG), and imaging-related variables were collected and summarized. RESULTS Forty-two patients (36 families) were included. The median age at first seizure was 14 months (interquartile range = 11.75-22.5). Myoclonic seizures were frequently the first seizure type noted (n = 18, 43.9%). EEG and brain magnetic resonance imaging findings were variable. Many patients exhibited delayed development with subsequent progressive regression (n = 16, 38.1%). Twenty-one cases with genetic testing available (55%) had previously reported variants in KCTD7, and 17 cases (45%) had novel variants in KCTD7 gene. Six patients died in the cohort (age range = 1.5-21 years). The systematic review identified 23 eligible studies and further identified 59 previously reported cases of KCTD7-related disorders from the literature. The phenotype for the majority of the reported cases was consistent with a PME (n = 52, 88%). Other reported phenotypes in the literature included opsoclonus myoclonus ataxia syndrome (n = 2), myoclonus dystonia (n = 2), and neuronal ceroid lipofuscinosis (n = 3). Eight published cases died over time (14%, age range = 3-18 years). SIGNIFICANCE This study cohort and systematic review consolidated the phenotypic spectrum and natural history of KCTD7-related disorders. Early onset drug-resistant epilepsy, relentless neuroregression, and severe neurological sequalae were common. Better understanding of the natural history may help future clinical trials.
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Affiliation(s)
- Sangeetha Yoganathan
- Department of Neurological Sciences, Christian Medical College, Vellore, Tamil Nadu, India
| | - Robyn Whitney
- Comprehensive Pediatric Epilepsy Program, Division of Neurology, Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
| | - Maya Thomas
- Department of Neurological Sciences, Christian Medical College, Vellore, Tamil Nadu, India
| | - Sumita Danda
- Department of Medical Genetics, Christian Medical College, Vellore, Tamil Nadu, India
| | | | - Asuri N Prasad
- Division of Pediatric Neurology and Clinical Neurosciences, Department of Pediatrics, Children's Hospital, London Health Sciences Centre, London, Ontario, Canada
| | - Sali M K Farhan
- Department of Neurology and Neurosurgery, and Department of Human Genetics, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Daad AlSowat
- Division of Pediatric Neurology, Neurosciences Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Musaad Abukhaled
- Division of Pediatric Neurology, Neurosciences Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Hesham Aldhalaan
- Division of Pediatric Neurology, Neurosciences Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Vykuntaraju K Gowda
- Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Bangalore, Karnataka, India
| | - Uddhava V Kinhal
- Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Bangalore, Karnataka, India
| | - Arun Y Bylappa
- Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Bangalore, Karnataka, India
| | - Ramesh Konanki
- Department of Pediatric Neurology, Rainbow Children's Hospital, Hyderabad, Telangana, India
| | - Lokesh Lingappa
- Department of Pediatric Neurology, Rainbow Children's Hospital, Hyderabad, Telangana, India
| | | | - Juan P Appendino
- Pediatric Neurology Service, Department of Pediatrics, Cumming School of Medicine, University of Calgary, Alberta Children's Hospital, Calgary, Alberta, Canada
| | - Morris H Scantlebury
- Departments of Pediatrics and Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Jessie Cunningham
- Hospital Library and Archives, Learning Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Aristides Hadjinicolaou
- Division of Neurology, Department of Pediatrics, CHU (Centre Hospitalier Universitaire) Sainte-Justine, Université de Montréal, Montreal, Quebec, Canada
| | - Christelle Moufawad El Achkar
- Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Mahesh Kamate
- Department of Pediatric Neurology, Jawaharlal Nehru Medical College, KLE (Karnataka Lingayat Education) Academy of Higher Education and Research, KLE's Dr Prabhakar Kore (PK) Hospital, Belagavi, Karnataka, India
| | - Ramshekhar N Menon
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences & Technology, Thiruvananthapuram, Kerala, India
| | - Manna Jose
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences & Technology, Thiruvananthapuram, Kerala, India
| | - Gillian Riordan
- Department of Paediatric Neurology, Red Cross War Memorial Children's Hospital, University of Cape Town, Cape Town, South Africa
| | | | - Vivek Jain
- Department of Pediatric Neurology, Neoclinic Children's Hospital, Jaipur, Rajasthan, India
| | - Ranjith Kumar Manokaran
- Division of Pediatric neurology, Department of Neurology, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India
| | - Vann Chau
- Division of Neurology, Department of Pediatrics, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Elizabeth J Donner
- Epilepsy Program, Division of Neurology, Department of Pediatrics, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Gregory Costain
- Division of Clinical and Metabolic Genetics, Hospital for Sick Children, and Program in Genetics & Genome Biology, SickKids Research Institute, Toronto, Ontario, Canada
| | - Berge A Minassian
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Puneet Jain
- Epilepsy Program, Division of Neurology, Department of Pediatrics, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
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2
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Liang JH, Alevy J, Akhanov V, Seo R, Massey CA, Jiang D, Zhou J, Sillitoe RV, Noebels JL, Samuel MA. Kctd7 deficiency induces myoclonic seizures associated with Purkinje cell death and microvascular defects. Dis Model Mech 2022; 15:dmm049642. [PMID: 35972048 PMCID: PMC9509889 DOI: 10.1242/dmm.049642] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 07/29/2022] [Indexed: 01/27/2023] Open
Abstract
Mutations in the potassium channel tetramerization domain-containing 7 (KCTD7) gene are associated with a severe neurodegenerative phenotype characterized by childhood onset of progressive and intractable myoclonic seizures accompanied by developmental regression. KCTD7-driven disease is part of a large family of progressive myoclonic epilepsy syndromes displaying a broad spectrum of clinical severity. Animal models of KCTD7-related disease are lacking, and little is known regarding how KCTD7 protein defects lead to epilepsy and cognitive dysfunction. We characterized Kctd7 expression patterns in the mouse brain during development and show that it is selectively enriched in specific regions as the brain matures. We further demonstrate that Kctd7-deficient mice develop seizures and locomotor defects with features similar to those observed in human KCTD7-associated diseases. We also show that Kctd7 is required for Purkinje cell survival in the cerebellum and that selective degeneration of these neurons is accompanied by defects in cerebellar microvascular organization and patterning. Taken together, these results define a new model for KCTD7-associated epilepsy and identify Kctd7 as a modulator of neuron survival and excitability linked to microvascular alterations in vulnerable regions.
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Affiliation(s)
- Justine H. Liang
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jonathan Alevy
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
| | - Viktor Akhanov
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ryan Seo
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Developmental Neurogenetics Laboratory, Department of Neurology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Human and Molecular Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Cory A. Massey
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Developmental Neurogenetics Laboratory, Department of Neurology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Human and Molecular Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Danye Jiang
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
| | - Joy Zhou
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, Houston, TX 77030, USA
| | - Roy V. Sillitoe
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, Houston, TX 77030, USA
| | - Jeffrey L. Noebels
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Developmental Neurogenetics Laboratory, Department of Neurology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Human and Molecular Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Melanie A. Samuel
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
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3
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Binaafar S, Garshasbi M, Tavasoli AR, Badv RS, Hosseiny SMM, Samanta D, Rabbani B, Mahdieh N. Nonsyndromic Early-Onset Epileptic Encephalopathies: Two Novel KCTD7 Pathogenic Variants and a Literature Review. Dev Neurosci 2021; 43:348-357. [PMID: 34469883 DOI: 10.1159/000519318] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 08/30/2021] [Indexed: 11/19/2022] Open
Abstract
Early-onset epileptic encephalopathies (EOEE) affect cognitive, sensory, and motor development. Genetic variations are among the identifiable primary causes of these syndromes. However, some patients have been reported to be affected by EOEE without any other clinical symptoms and signs. We study the genotype and phenotype of patients with nonsyndromic early-onset epileptic encephalopathy (NSEOEE) and report 2 novel patients from Iran. A comprehensive search was conducted in PubMed, John Willy, Springer, Elsevier, and Google Scholar databases to collect related information of all the previously reported cases with KCTD7 mutations. Fifty-four patients (from 40 families) were investigated. Using trio-whole-exome sequencing (trio-WES) and Sanger sequencing, the possible genetic causes of the disorder were checked. The probable impacts of the identified variants on the KCTD7 protein structure and function were predicted. This study provided a detailed overview of all published KCTD7 mutations and 2 de novo ones. We identified 2 novel homozygous variants of uncertain significance, c.458 G > A p. Arg153His and c.529C > T (p.Arg177Cys), in KCTD7 (NM_153033.4) (Chr7(GRCh37)). There is a significant wide distribution of the KCTD7 gene causing NSEOEE among different populations. In conclusion, KCTD7 mutations demonstrate a diverse geographical distribution alongside a wide range of ethnicities. This highlights the importance of careful consideration in the WES data analysis. Mutations of this gene may be a common cause of NSEOEE. Also, this study imprints targeted therapeutic opportunities for potassium channelepsies such as KCTD7-related NSEOEE.
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Affiliation(s)
- Sima Binaafar
- Growth and Development Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Masoud Garshasbi
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Ali Reza Tavasoli
- Myelin Disorders Clinic, Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Reza Shervin Badv
- Children's Hospital Center, Pediatric Center of Excellence, Tehran University of Medical Center, Tehran, Iran
| | - Seyyed Mohammad Mahdi Hosseiny
- Myelin Disorders Clinic, Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Debopam Samanta
- Child Neurology Section, Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Bahareh Rabbani
- Growth and Development Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Nejat Mahdieh
- Growth and Development Research Center, Tehran University of Medical Sciences, Tehran, Iran.,Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
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4
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Burke EA, Sturgeon M, Zastrow DB, Fernandez L, Prybol C, Marwaha S, Frothingham EP, Ward PA, Eng CM, Fresard L, Montgomery SB, Enns GM, Fisher PG, Wolfe LA, Harding B, Carrington B, Bishop K, Sood R, Huang Y, Elkahloun A, Toro C, Bassuk AG, Wheeler MT, Markello TC, Gahl WA, Malicdan MCV. Compound heterozygous KCTD7 variants in progressive myoclonus epilepsy. J Neurogenet 2021; 35:74-83. [PMID: 33970744 DOI: 10.1080/01677063.2021.1892095] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
KCTD7 is a member of the potassium channel tetramerization domain-containing protein family and has been associated with progressive myoclonic epilepsy (PME), characterized by myoclonus, epilepsy, and neurological deterioration. Here we report four affected individuals from two unrelated families in which we identified KCTD7 compound heterozygous single nucleotide variants through exome sequencing. RNAseq was used to detect a non-annotated splicing junction created by a synonymous variant in the second family. Whole-cell patch-clamp analysis of neuroblastoma cells overexpressing the patients' variant alleles demonstrated aberrant potassium regulation. While all four patients experienced many of the common clinical features of PME, they also showed variable phenotypes not previously reported, including dysautonomia, brain pathology findings including a significantly reduced thalamus, and the lack of myoclonic seizures. To gain further insight into the pathogenesis of the disorder, zinc finger nucleases were used to generate kctd7 knockout zebrafish. Kctd7 homozygous mutants showed global dysregulation of gene expression and increased transcription of c-fos, which has previously been correlated with seizure activity in animal models. Together these findings expand the known phenotypic spectrum of KCTD7-associated PME, report a new animal model for future studies, and contribute valuable insights into the disease.
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Affiliation(s)
- Elizabeth A Burke
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH and National Human Genome Research Institute, NIH, Bethesda, MD, USA
| | - Morgan Sturgeon
- Department of Pediatrics, University of Iowa, Iowa City, IA, USA
| | - Diane B Zastrow
- Center for Undiagnosed Diseases, Stanford University School of Medicine, Stanford, CA, USA
| | - Liliana Fernandez
- Center for Undiagnosed Diseases, Stanford University School of Medicine, Stanford, CA, USA
| | - Cameron Prybol
- Center for Undiagnosed Diseases, Stanford University School of Medicine, Stanford, CA, USA
| | - Shruti Marwaha
- Center for Undiagnosed Diseases, Stanford University School of Medicine, Stanford, CA, USA
| | | | - Patricia A Ward
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Christine M Eng
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Laure Fresard
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
| | - Stephen B Montgomery
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA.,Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Gregory M Enns
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA
| | - Paul G Fisher
- Center for Undiagnosed Diseases, Stanford University School of Medicine, Stanford, CA, USA.,Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA.,Department of Neurology, Stanford University School of Medicine, Stanford, CA, USA
| | - Lynne A Wolfe
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH and National Human Genome Research Institute, NIH, Bethesda, MD, USA
| | - Brian Harding
- Departments of Pathology and Lab Medicine (Neuropathology), Children's Hospital of Philadelphia and the Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Blake Carrington
- Zebrafish Core, Translational and Functional Genomics Branch, National Human Genome Research Institute, NIH, Bethesda, MD, USA
| | - Kevin Bishop
- Zebrafish Core, Translational and Functional Genomics Branch, National Human Genome Research Institute, NIH, Bethesda, MD, USA
| | - Raman Sood
- Zebrafish Core, Translational and Functional Genomics Branch, National Human Genome Research Institute, NIH, Bethesda, MD, USA
| | - Yan Huang
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH and National Human Genome Research Institute, NIH, Bethesda, MD, USA
| | - Abdel Elkahloun
- Microarray Core, Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, NIH, Bethesda, MD, USA
| | - Camilo Toro
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH and National Human Genome Research Institute, NIH, Bethesda, MD, USA
| | | | - Matthew T Wheeler
- Center for Undiagnosed Diseases, Stanford University School of Medicine, Stanford, CA, USA
| | - Thomas C Markello
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH and National Human Genome Research Institute, NIH, Bethesda, MD, USA
| | - William A Gahl
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH and National Human Genome Research Institute, NIH, Bethesda, MD, USA.,Medical Genetics Branch, National Human Genome Research Institute, NIH, Bethesda, MD, USA
| | - May Christine V Malicdan
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH and National Human Genome Research Institute, NIH, Bethesda, MD, USA
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5
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Dudipala SC, M P, Chennadi AK. A Novel Mutation in KCDT7 Gene in an Indian Girl With Progressive Myoclonus Epilepsy. Cureus 2021; 13:e13447. [PMID: 33767931 PMCID: PMC7982382 DOI: 10.7759/cureus.13447] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The progressive myoclonus epilepsy (PME) is a rare group of clinically and genetically heterogeneous disorders characterized by myoclonus, drug refractory epilepsy, and neurological deterioration. Here, we report a three-year-old female patient with neuroregression after a period of normal development and uncontrollable myoclonic seizures, which fulfill the criteria of PME. Next-generation sequencing revealed a novel homozygous mutation of variant c.173G>C in exon 2 of the KCDT7 (potassium channel tetramerization domain containing protein 7) gene that was compatible with the diagnosis of progressive myoclonic epilepsy 3 (PME3) with or without intracellular inclusions. This is a rare report of KCTD7 mutations causing PME in the Indian population. Our findings supported the important role of KCTD7 in PME and broadened the mutation spectrum.
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Affiliation(s)
- Sai Chandar Dudipala
- Pediatric Neurology, Star Women & Children Hospital, Karimnagar, IND.,Pediatrics, Prathima Institute of Medical Sciences, Karimnagar, IND
| | - Prashanthi M
- Pediatrics, Prathima Institute of Medical Sciences, Karimnagar, IND
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6
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Dai L, Ding C, Fang F. Two Chinese siblings with two novel KCTD7 mutations have dystonia or seizures and epileptic discharge on electroencephalograms. Seizure 2019; 70:27-29. [DOI: 10.1016/j.seizure.2019.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 06/06/2019] [Accepted: 06/07/2019] [Indexed: 10/26/2022] Open
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