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Whitney R, Go C, Abushama A, Jain P. CNKSR2-Related Developmental and Epileptic Encephalopathy with Spike-Wave Activation in Sleep: A Report of Two Additional Cases and Review of the Literature. Neurol India 2024; 72:129-137. [PMID: 38443014 DOI: 10.4103/ni.ni_1191_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 06/14/2022] [Indexed: 03/07/2024]
Abstract
CNKSR2 variants have been associated with X linked intellectual disability and epilepsy including developmental and epileptic encephalopathy with spike wave activation in sleep (D/EE SWAS) in males. We aimed to describe a sibling pair with a novel pathogenic variant in CNKSR2 with D/EE SWAS and review published cases of D/EE SWAS. A retrospective chart review and a comprehensive review of the literature were conducted. Two brothers with a novel pathogenic variant in the CNKSR2 gene (c. 114delG, p.Ile39SerfsX14) were identified. The epilepsy phenotype was similar to previous cases and was characterized by early onset seizures, nocturnal seizures (focal motor with/without impaired awareness), global developmental delay and language impairment, frontal central temporal predominant epileptiform discharges with a spike wave index >95%, and treatment resistance. However, phenotypic variability was observed and the younger brother had milder neuro developmental impairment, and the diagnosis of D/EE SWAS was made by surveillance electro encephalogram (EEG). Literature search yielded 23 cases, and their clinical/neuro physiological features are discussed. To conclude, CNKSR2 related D/EE SWAS may be early onset and occur before the age of 5 years in some. Early surveillance EEG may aid in diagnosis. Phenotypic variability was observed in our cases as well as sibling pairs in the literature, which may impact genetic counseling.
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Affiliation(s)
- Robyn Whitney
- Department of Paediatrics, Division of Neurology, McMaster University, Hamilton, ON, Canada
| | - Cristina Go
- Department of Paediatrics, Division of Neurology, Hospital for Sick Children (HSC), University of Toronto, Toronto, ON, Canada
| | - Ahmed Abushama
- Department of Paediatrics, Division of Neurology, Hospital for Sick Children (HSC), University of Toronto, Toronto, ON, Canada
| | - Puneet Jain
- Department of Paediatrics, Division of Neurology, Hospital for Sick Children (HSC), University of Toronto, Toronto, ON, Canada
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2
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Goh Y, Tay SH, Yeo LLL, Rathakrishnan R. Bridging the Gap: Tailoring an Approach to Treatment in Febrile Infection-Related Epilepsy Syndrome. Neurology 2023; 100:1151-1155. [PMID: 36797068 PMCID: PMC10264048 DOI: 10.1212/wnl.0000000000207068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Accepted: 01/03/2023] [Indexed: 02/18/2023] Open
Abstract
Cytokine profiling before immunotherapy is increasingly prevalent in febrile infection-related epilepsy syndrome (FIRES). In this case, an 18-year-old man presented with first-onset seizure after a nonspecific febrile illness. He developed super-refractory status epilepticus requiring multiple antiseizure medications and general anesthetic infusions. He was treated with pulsed methylprednisolone and plasma exchange and started on ketogenic diet. Contrast-enhanced MRI brain revealed postictal changes. EEG findings showed multifocal ictal runs and generalized periodic epileptiform discharges. CSF analysis, autoantibody testing, and malignancy screening were unremarkable. Genetic testing revealed variants of uncertain significance in the CNKSR2 and OPN1LW genes. Initial serum and CSF cytokine analyses performed on days 6 and 21 revealed that interleukin (IL)-6, IL-1RA, monocyte chemoattractant protein-1, macrophage inflammatory protein 1β, and interferon γ were elevated predominantly in the CNS, a profile consistent with cytokine release syndrome. Tofacitinib was initially trialed on day 30 of admission. There was no clinical improvement, and IL-6 continued to rise. Tocilizumab was given on day 51 with significant clinical and electrographic response. Anakinra was subsequently trialed from days 99 to 103 because clinical ictal activity re-emerged on weaning anesthetics but stopped because of poor response. Serial cytokine profiles showed improvement after 7 doses of tocilizumab. There was corresponding improved seizure control. This case illustrates how personalized immunomonitoring may be helpful in cases of FIRES, where proinflammatory cytokines are postulated to act in epileptogenesis. There is an emerging role for cytokine profiling and close collaboration with immunologists for the treatment of FIRES. The use of tocilizumab may be considered in patients with FIRES with upregulated IL-6.
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Affiliation(s)
- Yihui Goh
- From the Divisions of Neurology (Y.G., L.L.L.Y., R.R.) and Rheumatology (S.H.T.), Department of Medicine, National University Hospital and Department of Medicine (Y.G., S.H.T., L.L.L.Y., R.R.), Yong Loo Lin School of Medicine, National University of Singapore
| | - Sen Hee Tay
- From the Divisions of Neurology (Y.G., L.L.L.Y., R.R.) and Rheumatology (S.H.T.), Department of Medicine, National University Hospital and Department of Medicine (Y.G., S.H.T., L.L.L.Y., R.R.), Yong Loo Lin School of Medicine, National University of Singapore
| | - Leonard Leong Litt Yeo
- From the Divisions of Neurology (Y.G., L.L.L.Y., R.R.) and Rheumatology (S.H.T.), Department of Medicine, National University Hospital and Department of Medicine (Y.G., S.H.T., L.L.L.Y., R.R.), Yong Loo Lin School of Medicine, National University of Singapore
| | - Rahul Rathakrishnan
- From the Divisions of Neurology (Y.G., L.L.L.Y., R.R.) and Rheumatology (S.H.T.), Department of Medicine, National University Hospital and Department of Medicine (Y.G., S.H.T., L.L.L.Y., R.R.), Yong Loo Lin School of Medicine, National University of Singapore.
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3
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Maruo T, Mizutani K, Miyata M, Kuriu T, Sakakibara S, Takahashi H, Kida D, Maesaka K, Sugaya T, Sakane A, Sasaki T, Takai Y, Mandai K. s-Afadin binds to MAGUIN/Cnksr2 and regulates the localization of the AMPA receptor and glutamatergic synaptic response in hippocampal neurons. J Biol Chem 2023; 299:103040. [PMID: 36803960 PMCID: PMC10040811 DOI: 10.1016/j.jbc.2023.103040] [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: 03/22/2022] [Revised: 02/02/2023] [Accepted: 02/03/2023] [Indexed: 02/19/2023] Open
Abstract
A hippocampal mossy fiber synapse implicated in learning and memory is a complex structure in which a presynaptic bouton attaches to the dendritic trunk by puncta adherentia junctions (PAJs) and wraps multiply branched spines. The postsynaptic densities (PSDs) are localized at the heads of each of these spines and faces to the presynaptic active zones. We previously showed that the scaffolding protein afadin regulates the formation of the PAJs, PSDs, and active zones in the mossy fiber synapse. Afadin has two splice variants: l-afadin and s-afadin. l-Afadin, but not s-afadin, regulates the formation of the PAJs but the roles of s-afadin in synaptogenesis remain unknown. We found here that s-afadin more preferentially bound to MAGUIN (a product of the Cnksr2 gene) than l-afadin in vivo and in vitro. MAGUIN/CNKSR2 is one of the causative genes for nonsyndromic X-linked intellectual disability accompanied by epilepsy and aphasia. Genetic ablation of MAGUIN impaired PSD-95 localization and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic (AMPA) receptor surface accumulation in cultured hippocampal neurons. Our electrophysiological analysis revealed that the postsynaptic response to glutamate, but not its release from the presynapse, was impaired in the MAGUIN-deficient cultured hippocampal neurons. Furthermore, disruption of MAGUIN did not increase the seizure susceptibility to flurothyl, a GABAA receptor antagonist. These results indicate that s-afadin binds to MAGUIN and regulates the PSD-95-dependent cell surface localization of the AMPA receptor and glutamatergic synaptic responses in the hippocampal neurons and that MAGUIN is not involved in the induction of epileptic seizure by flurothyl in our mouse model.
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Affiliation(s)
- Tomohiko Maruo
- Department of Molecular and Cellular Neurobiology, Kitasato University Graduate School of Medical Sciences, Sagamihara, Kanagawa, Japan; Department of Biochemistry, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan; Division of Pathogenetic Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan; Department of Biochemistry, Tokushima University Graduate School of Medical Sciences, Tokushima, Japan
| | - Kiyohito Mizutani
- Division of Pathogenetic Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
| | - Muneaki Miyata
- Division of Pathogenetic Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
| | - Toshihiko Kuriu
- Research and Development Center, Osaka Medical and Pharmaceutical University, Takatsuki, Osaka, Japan
| | - Shotaro Sakakibara
- Division of Pathogenetic Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan; Department of Biochemistry, Tokushima University Graduate School of Medical Sciences, Tokushima, Japan
| | - Hatena Takahashi
- Department of Molecular and Cellular Neurobiology, Kitasato University Graduate School of Medical Sciences, Sagamihara, Kanagawa, Japan
| | - Daichi Kida
- Department of Molecular and Cellular Neurobiology, Kitasato University Graduate School of Medical Sciences, Sagamihara, Kanagawa, Japan
| | - Kouki Maesaka
- Department of Molecular and Cellular Neurobiology, Kitasato University Graduate School of Medical Sciences, Sagamihara, Kanagawa, Japan
| | - Tsukiko Sugaya
- Department of Biochemistry, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Ayuko Sakane
- Department of Biochemistry, Tokushima University Graduate School of Medical Sciences, Tokushima, Japan; Department of Interdisciplinary Researches for Medicine and Photonics, Institute of Post-LED Photonics, Tokushima University, Tokushima, Japan
| | - Takuya Sasaki
- Department of Biochemistry, Tokushima University Graduate School of Medical Sciences, Tokushima, Japan
| | - Yoshimi Takai
- Division of Pathogenetic Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan.
| | - Kenji Mandai
- Department of Molecular and Cellular Neurobiology, Kitasato University Graduate School of Medical Sciences, Sagamihara, Kanagawa, Japan; Department of Biochemistry, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan.
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Udaykumar N, Zaidi MAA, Rai A, Sen J. CNKSR2, a downstream mediator of retinoic acid signaling, modulates the Ras/Raf/MEK pathway to regulate patterning and invagination of the chick forebrain roof plate. Development 2023; 150:286897. [PMID: 36734326 DOI: 10.1242/dev.200857] [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: 04/13/2022] [Accepted: 01/03/2023] [Indexed: 02/04/2023]
Abstract
During embryonic development, the forebrain roof plate undergoes invagination, leading to separation of the cerebral hemispheres. Any defects in this process, in humans, lead to middle interhemispheric holoprosencephaly (MIH-HPE). In this study, we have identified a previously unreported downstream mediator of retinoic acid (RA) signaling, CNKSR2, which is expressed in the forebrain roof plate in the chick embryo. Knockdown of CNKSR2 affects invagination, cell proliferation and patterning of the roof plate, similar to the phenotypes observed upon inhibition of RA signaling. We further demonstrate that CNKSR2 functions by modulating the Ras/Raf/MEK signaling. This appears to be crucial for patterning of the forebrain roof plate and its subsequent invagination, leading to the formation of the cerebral hemispheres. Thus, a set of novel molecular players have been identified that regulate the morphogenesis of the avian forebrain.
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Affiliation(s)
- Niveda Udaykumar
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur 208016 Uttar Pradesh, India
| | - Mohd Ali Abbas Zaidi
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur 208016 Uttar Pradesh, India
| | - Aishwarya Rai
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur 208016 Uttar Pradesh, India
| | - Jonaki Sen
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur 208016 Uttar Pradesh, India
- Mehta Family Center for Engineering in Medicine (MFCEM), Indian Institute of Technology Kanpur, Kanpur 208016, Uttar Pradesh, India
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Schwartz CE, Louie RJ, Toutain A, Skinner C, Friez MJ, Stevenson RE. X-Linked intellectual disability update 2022. Am J Med Genet A 2023; 191:144-159. [PMID: 36300573 DOI: 10.1002/ajmg.a.63008] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 07/28/2022] [Accepted: 09/29/2022] [Indexed: 12/14/2022]
Abstract
Genes that are involved in the transcription process, mitochondrial function, glycoprotein metabolism, and ubiquitination dominate the list of 21 new genes associated with X-linked intellectual disability since the last update in 2017. The new genes were identified by sequencing of candidate genes (2), the entire X-chromosome (2), the whole exome (15), or the whole genome (2). With these additions, 42 (21%) of the 199 named XLID syndromes and 27 (25%) of the 108 numbered nonsyndromic XLID families remain to be resolved at the molecular level. Although the pace of discovery of new XLID genes has slowed during the past 5 years, the density of genes on the X chromosome that cause intellectual disability still appears to be twice the density of intellectual disability genes on the autosomes.
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Affiliation(s)
| | | | - Annick Toutain
- Department of Medical Genetics, Centre Hospitalier Universitaire, Tours, France
| | - Cindy Skinner
- Greenwood Genetic Center, Greenwood, South Carolina, USA
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6
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Functions of CNKSR2 and Its Association with Neurodevelopmental Disorders. Cells 2022; 11:cells11020303. [PMID: 35053419 PMCID: PMC8774548 DOI: 10.3390/cells11020303] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 01/05/2022] [Accepted: 01/13/2022] [Indexed: 02/04/2023] Open
Abstract
The Connector Enhancer of Kinase Suppressor of Ras-2 (CNKSR2), also known as CNK2 or MAGUIN, is a scaffolding molecule that contains functional protein binding domains: Sterile Alpha Motif (SAM) domain, Conserved Region in CNK (CRIC) domain, PSD-95/Dlg-A/ZO-1 (PDZ) domain, Pleckstrin Homology (PH) domain, and C-terminal PDZ binding motif. CNKSR2 interacts with different molecules, including RAF1, ARHGAP39, and CYTH2, and regulates the Mitogen-Activated Protein Kinase (MAPK) cascade and small GTPase signaling. CNKSR2 has been reported to control the development of dendrite and dendritic spines in primary neurons. CNKSR2 is encoded by the CNKSR2 gene located in the X chromosome. CNKSR2 is now considered as a causative gene of the Houge type of X-linked syndromic mental retardation (MRXHG), an X-linked Intellectual Disability (XLID) that exhibits delayed development, intellectual disability, early-onset seizures, language delay, attention deficit, and hyperactivity. In this review, we summarized molecular features, neuronal function, and neurodevelopmental disorder-related variations of CNKSR2.
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7
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Ito H, Morishita R, Noda M, Ishiguro T, Nishikawa M, Nagata KI. The synaptic scaffolding protein CNKSR2 interacts with CYTH2 to mediate hippocampal granule cell development. J Biol Chem 2021; 297:101427. [PMID: 34800437 DOI: 10.1016/j.jbc.2021.101427] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 11/02/2021] [Accepted: 11/15/2021] [Indexed: 11/25/2022] Open
Abstract
CNKSR2 is a synaptic scaffolding molecule that is encoded by the CNKSR2 gene located on the X chromosome. Heterozygous mutations to CNKSR2 in humans are associated with intellectual disability and epileptic seizures, yet the cellular and molecular roles for CNKSR2 in nervous system development and disease remain poorly characterized. Here, we identify a molecular complex comprising CNKSR2 and the guanine nucleotide exchange factor (GEF) for ARF small GTPases, CYTH2, that is necessary for the proper development of granule neurons in the mouse hippocampus. Notably, we show that CYTH2 binding prevents proteasomal degradation of CNKSR2. Furthermore, to explore the functional significance of coexpression of CNKSR2 and CYTH2 in the soma of granule cells within the hippocampal dentate gyrus, we transduced mouse granule cell precursors in vivo with small hairpin RNAs (shRNAs) to silence CNKSR2 or CYTH2 expression. We found that such manipulations resulted in the abnormal localization of transduced cells at the boundary between the granule cell layer and the hilus. In both cases, CNKSR2-knockdown and CYTH2-knockdown cells exhibited characteristics of immature granule cells, consistent with their putative roles in neuron differentiation. Taken together, our results demonstrate that CNKSR2 and its molecular interaction partner CYTH2 are necessary for the proper development of dentate granule cells within the hippocampus through a mechanism that involves the stabilization of a complex comprising these proteins.
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Affiliation(s)
- Hidenori Ito
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, Aichi, Japan.
| | - Rika Morishita
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, Aichi, Japan
| | - Mariko Noda
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, Aichi, Japan
| | - Tomoki Ishiguro
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, Aichi, Japan
| | - Masashi Nishikawa
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, Aichi, Japan
| | - Koh-Ichi Nagata
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, Aichi, Japan; Department of Neurochemistry, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya, Japan.
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Higa LA, Wardley J, Wardley C, Singh S, Foster T, Shen JJ. CNKSR2-related neurodevelopmental and epilepsy disorder: a cohort of 13 new families and literature review indicating a predominance of loss of function pathogenic variants. BMC Med Genomics 2021; 14:186. [PMID: 34266427 PMCID: PMC8281706 DOI: 10.1186/s12920-021-01033-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 07/01/2021] [Indexed: 11/25/2022] Open
Abstract
Background Pathogenic variants in connector enhancer of kinase suppressor of Ras-2 (CNKSR2) located on the X chromosome (Xp22.12) lead to a disorder characterized by developmental delay and a characteristic seizure phenotype. To date, 20 affected males representing 13 different pathogenic variants have been published. Case presentation We identified an 8-year-old male with seizures, abnormal electroencephalogram (EEG) with epileptiform abnormalities in the right hemisphere, and developmental delay with notable loss of speech following seizure onset. Additional concerns include multiple nighttime awakenings, hyperactivity, and autism spectrum disorder. Genetic testing identified a de novo pathogenic nonsense variant in CNKSR2. Through an active family support group, an additional 12 males are described, each harboring a different CNKSR2 variant. The clinical presentation and natural history consistently show early developmental delay, sleep disturbances, and seizure onset in childhood that is initially intractable but later becomes better controlled. Virtually all of the pathogenic variants are predicted to be loss of function, including genomic deletions, nonsense variants, splice site mutations, and small insertions or deletions. Conclusions This expanded knowledge, combined with functional studies and work with animal models currently underway, will enable a better understanding and improved ability to care for individuals with CNKSR2-related neurodevelopmental and epilepsy disorder. Supplementary Information The online version contains supplementary material available at 10.1186/s12920-021-01033-7.
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Affiliation(s)
- Leigh Ann Higa
- Department of Pediatrics, Community Regional Medical Center, Fresno, CA, USA.,Division of Genomic Medicine, Department of Pediatrics, MIND Institute, University of California, Davis, 2825 50th Street, Sacramento, CA, 95817, USA
| | | | | | - Susan Singh
- CNKSR2 Family Support Group, Sanger, CA, USA
| | - Timothy Foster
- Division of Pediatric Neurology, Department of Pediatrics, UCSF Fresno, Fresno, CA, USA
| | - Joseph J Shen
- Division of Genetics, Department of Pediatrics, UCSF Fresno, Fresno, CA, USA. .,Division of Genomic Medicine, Department of Pediatrics, MIND Institute, University of California, Davis, 2825 50th Street, Sacramento, CA, 95817, USA.
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Kang Q, Yang L, Liao H, Wu L, Chen B, Yang S, Kuang X, Yang H, Liao C. CNKSR2 gene mutation leads to Houge type of X-linked syndromic mental retardation: A case report and review of literature. Medicine (Baltimore) 2021; 100:e26093. [PMID: 34114993 PMCID: PMC8202604 DOI: 10.1097/md.0000000000026093] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 05/06/2021] [Indexed: 01/04/2023] Open
Abstract
RATIONALE Mutations of connector enhancer of kinase suppressor of Ras-2 (CNKSR2) gene were identified as the cause of Houge type of X-linked syndromic mental retardation. The mutations of CNKSR2 gene are rare, we reporta patient carrying a novel nonsense mutation of CNKSR2,c.625C > T(p.Gln209∗) and review the clinical features and mutations of CNKSR2 gene for this rare condition considering previous literature. PATIENT CONCERNS We report a case of a 7-year and 5-month-old Chinese patient with clinical symptoms of intellectual disability, language defect, epilepsy and hyperactivity. Genetic study revealed a novel nonsense variant of CNKSR2, which has not been reported yet. DIAGNOSIS According to clinical manifestations, genetic pattern and ACMG classification of mutation site as Class 1-cause disease, the patient was diagnosed as Houge type of X-linked syndromic mental retardation caused by CNKSR2 gene mutation. INTERVENTIONS The patient was administrated with a gradual titration of valproic acid (VPA). OUTCOMES On administration of valproic acid, he had no further seizures. LESSONS This is the first time to report a nonsense variant in CNKSR2, c.625C > T(p.Gln209∗), this finding could expand the spectrum of CNKSR2 mutations and might also support the further study of Houge type of X-linked syndromic mental retardation.
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10
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Zhang Y, Yu T, Li N, Wang J, Wang J, Ge Y, Yao R. Psychomotor development and attention problems caused by a splicing variant of CNKSR2. BMC Med Genomics 2020; 13:182. [PMID: 33298018 PMCID: PMC7727132 DOI: 10.1186/s12920-020-00844-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 12/01/2020] [Indexed: 11/26/2022] Open
Abstract
Background Mutations in CNKSR2 have been described in patients with neurodevelopmental disorders characterized by childhood epilepsy, language deficits, and attention problems. The encoded protein plays an important role in synaptic function. Case presentation Whole-exome sequencing was applied to detect pathogenic variants in a patient with clinical symptoms of psychomotor development, attention deficit, poor logical thinking ability, and an introverted personality, but without epilepsy or any significant electroencephalogram changes. Genetic study revealed a splicing mutation (c.1904 + 1G > A) and RT-PCR revealed aberrant splicing of exon 16, leading to a reading-frame shift and a truncated protein in the PH domain.
Conclusions This is the first report of a splicing variant of CNKSR2, and the unique clinical features of this pedigree will help extend our understanding of the genetic and phenotypic spectra of CNKSR2-related disorders.
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Affiliation(s)
- Yi Zhang
- Department of Medical Genetics and Molecular Diagnostic Laboratory, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, People's Republic of China
| | - Tingting Yu
- Department of Medical Genetics and Molecular Diagnostic Laboratory, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, People's Republic of China
| | - Niu Li
- Department of Medical Genetics and Molecular Diagnostic Laboratory, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, People's Republic of China
| | - Jiwen Wang
- Department of Neurology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, People's Republic of China
| | - Jian Wang
- Department of Medical Genetics and Molecular Diagnostic Laboratory, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, People's Republic of China
| | - Yihua Ge
- Department of Orthopedics Pediatric, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, People's Republic of China.
| | - Ruen Yao
- Department of Medical Genetics and Molecular Diagnostic Laboratory, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, People's Republic of China.
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11
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Daoqi M, Guohong C, Yuan W, Zhixiao Y, Kaili X, Shiyue M. Exons deletion of CNKSR2 gene identified in X-linked syndromic intellectual disability. BMC MEDICAL GENETICS 2020; 21:69. [PMID: 32245427 PMCID: PMC7119275 DOI: 10.1186/s12881-020-01004-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 03/18/2020] [Indexed: 02/07/2023]
Abstract
Background The Houge type of X-linked syndromic mental retardation is an X-linked intellectual disability (XLID) recently recorded in the Online Mendelian Inheritance in Man (OMIM) and only 8 cases have been reported in literature thus far. Case presentation We present two brothers with intractable seizures and syndromic intellectual disability with symptoms consisting of delayed development, intellectual disability, and speech and language delay. The mother was a symptomatic carrier with milder clinical phenotype. Whole exome sequencing identified a small fragment deletion spanning four exons, about 9.5 kilobases (kb) in length in the CNKSR2 gene in the patients. The mutation co-segregation revealed that exon deletions occurred de novo in the proband’s mother. Conclusion Although large deletions have been reported, no small deletions have yet been identified. In this case report, we identified a small deletion in the CNKSR2 gene. This study enhances our knowledge of the CNKSR2 gene mutation spectrum and provides further information about the phenotypic characteristics of X-linked syndromic intellectual disability.
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Affiliation(s)
- Mei Daoqi
- Department of of Eastern Neurology, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou Children's Hospital, Zhengzhou, China
| | - Chen Guohong
- Department of of Eastern Neurology, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou Children's Hospital, Zhengzhou, China
| | - Wang Yuan
- Department of of Eastern Neurology, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou Children's Hospital, Zhengzhou, China
| | - Yang Zhixiao
- Department of of Eastern Neurology, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou Children's Hospital, Zhengzhou, China
| | - Xu Kaili
- Department of of Eastern Neurology, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou Children's Hospital, Zhengzhou, China
| | - Mei Shiyue
- Department of Intensive Care Unit, Henan Provincial Key Laboratory of Children's Genetics and Metabolic Diseases, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou Children's Hospital, Zhengzhou, China.
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Disease-associated synaptic scaffold protein CNK2 modulates PSD size and influences localisation of the regulatory kinase TNIK. Sci Rep 2020; 10:5709. [PMID: 32235845 PMCID: PMC7109135 DOI: 10.1038/s41598-020-62207-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 03/05/2020] [Indexed: 01/13/2023] Open
Abstract
Scaffold proteins are responsible for structural organisation within cells; they form complexes with other proteins to facilitate signalling pathways and catalytic reactions. The scaffold protein connector enhancer of kinase suppressor of Ras 2 (CNK2) is predominantly expressed in neural tissues and was recently implicated in X-linked intellectual disability (ID). We have investigated the role of CNK2 in neurons in order to contribute to our understanding of how CNK2 alterations might cause developmental defects, and we have elucidated a functional role for CNK2 in the molecular processes that govern morphology of the postsynaptic density (PSD). We have also identified novel CNK2 interaction partners and explored their functional interdependency with CNK2. We focussed on the novel interaction partner TRAF2- and NCK-interacting kinase TNIK, which is also associated with ID. Both CNK2 and TNIK are expressed in neuronal dendrites and concentrated in dendritic spines, and staining with synaptic markers indicates a clear postsynaptic localisation. Importantly, our data highlight that CNK2 plays a role in directing TNIK subcellular localisation, and in neurons, CNK2 participates in ensuring that this multifunctional kinase is present in the correct place at desirable levels. In summary, our data indicate that CNK2 expression is critical for modulating PSD morphology; moreover, our study highlights that CNK2 functions as a scaffold with the potential to direct the localisation of regulatory proteins within the cell. Importantly, we describe a novel link between CNK2 and the regulatory kinase TNIK, and provide evidence supporting the idea that alterations in CNK2 localisation and expression have the potential to influence the behaviour of TNIK and other important regulatory molecules in neurons.
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Bonardi CM, Mignot C, Serratosa JM, Giraldez BG, Moretti R, Rudolf G, Reale C, Gellert PM, Johannesen KM, Lesca G, Tassinari CA, Gardella E, Møller RS, Rubboli G. Expanding the clinical and EEG spectrum of CNKSR2-related encephalopathy with status epilepticus during slow sleep (ESES). Clin Neurophysiol 2020; 131:1030-1039. [PMID: 32197126 DOI: 10.1016/j.clinph.2020.01.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 01/11/2020] [Accepted: 01/13/2020] [Indexed: 12/12/2022]
Abstract
OBJECTIVE To investigate the clinical and EEG features of Encephalopathy with Status Epilepticus during slow Sleep (ESES) related to CNKSR2 pathogenic variants. METHODS Detailed clinical history, repeated wakefulness/overnight sleep EEGs, brain MRI were collected in five patients, including one female, with CNKSR2-related ESES. RESULTS Neurodevelopment in infancy was normal in two patients, delayed in three. Epilepsy onset (age range: 2-6 years) was associated with appearance or aggravation of cognitive impairment, language regression and/or behavioral disorders. Worsening of epilepsy and of cognitive/behavioral disturbances paralleled by enhancement of non-rapid eye movement (NREM) sleep-related, frontally predominant, EEG epileptic discharges [spike-wave-index (SWI): range 60-96%] was consistent with ESES. In three patients, episodes of absence status epilepticus or aggravation of atypical absences occurred, in this latter case associated with striking increment of awake SWI. Speech/oro-motor dyspraxia was diagnosed in four patients. In two patients, long-term follow-up showed epilepsy remission and persistence of mild/moderate cognitive disorders and behavioral disturbances into adulthood. CONCLUSIONS Novel findings of our study are occurrence also in females, normal neurodevelopment before epilepsy onset, epilepsy aggravation associated with enhanced awake SWI, mild/moderate evolution in adulthood and language disorder due to speech/oro-motor dyspraxia. SIGNIFICANCE Our findings expand the phenotypic spectrum of CNKSR2-related ESES.
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Affiliation(s)
- Claudia M Bonardi
- Danish Epilepsy Centre, Dianalund, Denmark; Department of Woman's and Child's Health, University Hospital of Padua, Italy.
| | - Cyril Mignot
- APHP, Groupe Hospitalier Pitié Salpêtrière, Unité Fonctionnelle de Génétique Médicale, Paris, France; Centre de Référence Déficiences Intellectuelles de Causes Rares, Paris, France; INSERM U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013 Paris, France.
| | - Jose M Serratosa
- Neurology Laboratory and Epilepsy Unit, Department of Neurology, IIS-Fundación Jiménez Díaz, UAM, Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain.
| | - Beatriz G Giraldez
- Neurology Laboratory and Epilepsy Unit, Department of Neurology, IIS-Fundación Jiménez Díaz, UAM, Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain.
| | | | - Gabrielle Rudolf
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS U7104, INSERM U1258 Illkirch 67400, France; Department of Neurology, Strasbourg University Hospital, Université de Strasbourg Strasbourg, France.
| | - Chiara Reale
- Danish Epilepsy Centre, Dianalund, Denmark; Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy.
| | | | | | - Gaetan Lesca
- Hospices Civils de Lyon, Service de Génétique, CHU de Lyon, Lyon, France.
| | | | - Elena Gardella
- Danish Epilepsy Centre, Dianalund, Denmark; Institute for Regional Health Services, University of Southern Denmark, Odense, Denmark.
| | - Rikke S Møller
- Danish Epilepsy Centre, Dianalund, Denmark; Institute for Regional Health Services, University of Southern Denmark, Odense, Denmark.
| | - Guido Rubboli
- Danish Epilepsy Centre, Dianalund, Denmark; University of Copenhagen, Copenhagen, Denmark.
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Polla DL, Saunders HR, de Vries BBA, van Bokhoven H, de Brouwer APM. A de novo variant in the X-linked gene CNKSR2 is associated with seizures and mild intellectual disability in a female patient. Mol Genet Genomic Med 2019; 7:e00861. [PMID: 31414730 PMCID: PMC6785448 DOI: 10.1002/mgg3.861] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 06/03/2019] [Accepted: 07/05/2019] [Indexed: 01/18/2023] Open
Abstract
Background Eight different deletions and point variants of the X‐chromosomal gene CNKSR2 have been reported in families with males presenting intellectual disability (ID) and epilepsy. Obligate carrier females with a frameshift variant in the N‐terminal protein coding part of CNKSR2 or with a deletion of the complete gene are not affected. Only for one C‐terminal nonsense variant, two carrier females were mildly affected by seizures without or with mild motor and language delay. Methods Exome sequencing was performed in one female child of a Dutch family, presenting seizures, mild ID, facial dysmorphisms, and abnormalities of the extremities. Potential causative variants were validated by Sanger sequencing. X‐chromosome‐inactivation (XCI) analysis was performed by methylation‐sensitive PCR and fragment‐length analysis of the androgen‐receptor CAG repeat polymorphism. Results We identified a de novo variant, c.2304G>A (p.(Trp768*)), in the C‐terminal protein coding part of the X‐chromosomal gene CNKSR2 in a female patient with seizures and mild ID. Sanger sequencing confirmed the presence of this nonsense variant. XCI analysis showed a mild skewing of X inactivation (20:80) in the blood of our patient. Our variant is the second C‐terminal–affecting CNKSR2 variant described in neurologically affected females. Conclusion Our results indicate that CNKSR2 nonsense variants in the C‐terminal coding part can result in ID with seizures in female variant carriers.
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Affiliation(s)
- Daniel L Polla
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands.,CAPES Foundation, Ministry of Education of Brazil, Brasília, Brazil
| | - Harriet R Saunders
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Bert B A de Vries
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Hans van Bokhoven
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Arjan P M de Brouwer
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
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Pavlidis E, Møller RS, Nikanorova M, Kölmel MS, Stendevad P, Beniczky S, Tassinari CA, Rubboli G, Gardella E. Idiopathic encephalopathy related to status epilepticus during slow sleep (ESES) as a "pure" model of epileptic encephalopathy. An electroclinical, genetic, and follow-up study. Epilepsy Behav 2019; 97:244-252. [PMID: 31254844 DOI: 10.1016/j.yebeh.2019.05.030] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 05/20/2019] [Accepted: 05/21/2019] [Indexed: 01/06/2023]
Abstract
OBJECTIVE The objective of the study was to investigate electroclinical and neuropsychological features, genetic background, and evolution of children with idiopathic encephalopathy with status epilepticus during slow sleep (ESES), including Landau-Kleffner syndrome (LKS). MATERIAL AND METHODS All children diagnosed with idiopathic ESES at the Danish Epilepsy Centre between March 2003 and December 2014 were retrospectively reviewed. Repeated 24-hour electroencephalography (24-h EEG) recordings, neuropsychological assessments, and clinical-neurological evaluation were performed throughout the follow-up in all patients. In 13 children, genetic investigations were performed. RESULTS We collected 24 children (14 males and 10 females). Mean age at ESES diagnosis was 6 years, and mean ESES duration was 2 years and 7 months. Twenty-one children had epileptic seizures. Three children had LKS. Topography of sleep-related EEG epileptic abnormalities was diffuse in 3 subjects, hemispheric in 6, multifocal in 9, and focal in 6. During the active phase of ESES, all children presented with a heterogeneous combination of behavioral and cognitive disturbances. In 14 children, a parallel between severity of the clinical picture and spike-wave index (SWI) was observed. We could not find a strict correlation between the type and severity of neurobehavioral impairment and the side/topography of sleep-related EEG discharges during the active phase of ESES. At the last follow-up, 21 children were in remission from ESES. Complete recovery from neurobehavioral disorders was observed in 5 children. Genetic assessment, performed in 13 children, showed GRIN2A variant in two (15.4%). SIGNIFICANCE Our patients with idiopathic ESES showed a heterogeneous pattern of epileptic seizures, neurobehavioral disorders, and sleep EEG features. Only one-fourth of children completely recovered from the neuropsychological disturbances after ESES remission. Lack of correlation between severity/type of cognitive derangement and SWI and/or topography of sleep EEG epileptic abnormalities may suggest the contribution of additional factors (including impaired sleep homeostasis due to epileptic activity) in the neurobehavioral derangement that characterize ESES.
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Affiliation(s)
- Elena Pavlidis
- Danish Epilepsy Centre - Filadelfia, Dianalund, Denmark; Child Neuropsychiatry Unit, Department of Neuroscience, University of Parma, Parma, Italy; Child Neuropsychiatry Service of Carpi, Mental Health Department, AUSL Modena, Carpi, Italy.
| | - Rikke S Møller
- Danish Epilepsy Centre - Filadelfia, Dianalund, Denmark; Department of Regional Health Research, University of Southern Denmark, Odense, Denmark
| | - Marina Nikanorova
- Danish Epilepsy Centre - Filadelfia, Dianalund, Denmark; Department of Regional Health Research, University of Southern Denmark, Odense, Denmark
| | | | - Pia Stendevad
- Danish Epilepsy Centre - Filadelfia, Dianalund, Denmark
| | - Sandor Beniczky
- Danish Epilepsy Centre - Filadelfia, Dianalund, Denmark; Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | | | - Guido Rubboli
- Danish Epilepsy Centre - Filadelfia, Dianalund, Denmark; Institute of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark.
| | - Elena Gardella
- Danish Epilepsy Centre - Filadelfia, Dianalund, Denmark; Department of Regional Health Research, University of Southern Denmark, Odense, Denmark
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Wang J, Wen Y, Zhang Q, Yu S, Chen Y, Wu X, Zhang Y, Bao X. Gene mutational analysis in a cohort of Chinese children with unexplained epilepsy: Identification of a new KCND3 phenotype and novel genes causing Dravet syndrome. Seizure 2019; 66:26-30. [PMID: 30776697 DOI: 10.1016/j.seizure.2019.01.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 01/24/2019] [Accepted: 01/26/2019] [Indexed: 01/10/2023] Open
Abstract
PURPOSE This study aimed to investigate the genetic etiology of epilepsy in a cohort of Chinese children. METHODS Targeted next-generation sequencing (NGS) was performed for 120 patients with unexplained epilepsy, including 71 patients with early-onset epileptic encephalopathies, and 16 patients with Dravet syndrome (including three patients with a Dravet-like phenotype) but without SCN1A pathogenic variants. RESULTS Pathogenic variants of 14 genes were discovered in 22 patients (18%). A de novo KCND3 pathogenic variant (c.1174G > A, p.Val392Ile) was identified in a boy with refractory epilepsy, psychomotor regression, attention deficit, and visual decline. Pathogenic variants in other coding genes were excluded via whole exome sequencing. This KCND3 variant was previously confirmed to be pathogenic by Giudicessi, et al. However, the clinical profile was different: sudden death at 20 years old without any medical history of neurological disorders, nor with any diseases typically caused by KCND3 pathogenic variants such as Brugada syndrome, spinocerebellar ataxia type 19/22 or ataxia accompanied by epilepsy. This indicates that we have identified a new KCND3 phenotype. In addition, we also uncovered a GRIN1 pathogenic variant and a novel HCN1 pathogenic variant in the Dravet cohort. CONCLUSION Our study highlights the significant utility of NGS panels in the genetic diagnosis of pediatric epilepsy. Our findings indicate that KCND3 pathogenic variants may be responsible for a wider phenotypic spectrum than previously thought, by including childhood epileptic encephalopathy. Furthermore, this study provides evidence that GRIN1 and HCN1 are candidate genes for Dravet and Dravet-like phenotypes.
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Affiliation(s)
- Jiaping Wang
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China
| | - Yongxin Wen
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China
| | - Qingping Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China
| | - Shujie Yu
- Department of Neurology, Harbin Children's Hospital, Harbin 150010, Heilongjiang Province, China
| | - Yan Chen
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China
| | - Xiru Wu
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China
| | - YueHua Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China
| | - Xinhua Bao
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China.
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17
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Sun Y, Liu YD, Xu ZF, Kong QX, Wang YL. CNKSR2 mutation causes the X-linked epilepsy-aphasia syndrome: A case report and review of literature. World J Clin Cases 2018; 6:570-576. [PMID: 30397616 PMCID: PMC6212609 DOI: 10.12998/wjcc.v6.i12.570] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Revised: 08/21/2018] [Accepted: 08/28/2018] [Indexed: 02/05/2023] Open
Abstract
The mutation in CNKSR2 leads to a broad spectrum of phenotypic variability and manifests as an X-linked intellectual disability. However, we reported that the male patient in this study not only had intellectual disability but also epileptic seizures. In addition, there were progressive language impairment, attention deficit hyperactivity disorder and autism. Electroencephalograms showed continuous spike-and-wave during sleep. Genetic testing revealed a de novo mutation of the CNKSR2 gene (c.2185C>T, p.Arg729Ter) in the child that was not detected in the parents. Therefore, the child was diagnosed with X-linked epilepsy aphasia syndrome. Deletion of the CNKSR2 gene has been rarely reported in epilepsy aphasia syndrome, but no de novo mutation has been found in this gene. This report not only adds to the spectrum of epilepsy aphasia syndrome but also helps clinicians in diagnosis and genetic counseling.
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Affiliation(s)
- Ying Sun
- Cheeloo College of Medicine, Shandong University, Jinan 250012, Shandong Province, China
| | - Yi-Dan Liu
- Cheeloo College of Medicine, Shandong University, Jinan 250012, Shandong Province, China
| | - Zhi-Feng Xu
- First Hospital of Handan, Handan 056002, Hebei Province, China
| | - Qing-Xia Kong
- Department of Neurology, Affiliated Hospital of Jining Medical University, Jining 272000, Shandong Province, China
| | - Yan-Ling Wang
- Department of Neurology, Affiliated Hospital of Jining Medical University, Jining 272000, Shandong Province, China
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18
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Kessi M, Peng J, Yang L, Xiong J, Duan H, Pang N, Yin F. Genetic etiologies of the electrical status epilepticus during slow wave sleep: systematic review. BMC Genet 2018; 19:40. [PMID: 29976148 PMCID: PMC6034250 DOI: 10.1186/s12863-018-0628-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 06/19/2018] [Indexed: 12/25/2022] Open
Abstract
Background Electrical status epilepticus during slow-wave sleep (ESESS) which is also known as continuous spike-wave of slow sleep (CSWSS) is type of electroencephalographic (EEG) pattern which is seen in ESESS/CSWSS/epilepsy aphasia spectrum. This EEG pattern can occur alone or with other syndromes. Its etiology is not clear, however, brain malformations, immune disorders, and genetic etiologies are suspected to contribute. We aimed to perform a systematic review of all genetic etiologies which have been reported to associate with ESESS/CSWSS/epilepsy-aphasia spectrum. We further aimed to identify the common underlying pathway which can explain it. To our knowledge, there is no available systematic review of genetic etiologies of ESESS/CSWSS/epilepsy-aphasia spectrum. MEDLINE, EMBASE, PubMed and Cochrane review database were searched, using terms specific to electrical status epilepticus during sleep or continuous spike–wave discharges during slow sleep or epilepsy-aphasia spectrum and of studies of genetic etiologies. These included monogenic mutations and copy number variations (CNVs). For each suspected dosage-sensitive gene, further studies were performed through OMIM and PubMed database. Results Twenty-six studies out of the 136 identified studies satisfied our inclusion criteria. I51 cases were identified among those 26 studies. 16 studies reported 11 monogenic mutations: SCN2A (N = 6), NHE6/SLC9A6 (N = 1), DRPLA/ ATN1 (N = 1), Neuroserpin/SRPX2 (N = 1), OPA3 (N = 1), KCNQ2 (N = 2), KCNA2 (N = 5), GRIN2A (N = 34), CNKSR2 (N = 2), SLC6A1 (N = 2) and KCNB1 (N = 5). 10 studies reported 89 CNVs including 9 recurrent ones: Xp22.12 deletion encompassing CNKSR2 (N = 6), 16p13 deletion encompassing GRIN2A (N = 4), 15q11.2–13.1 duplication (N = 15), 3q29 duplication (N = 11), 11p13 duplication (N = 2), 10q21.3 deletion (N = 2), 3q25 deletion (N = 2), 8p23.3 deletion (N = 2) and 9p24.2 (N = 2). 68 of the reported genetic etiologies including monogenic mutations and CNVs were detected in patients with ESESS/CSWSS/epilepsy aphasia spectrum solely. The most common underlying pathway was channelopathy (N = 56). Conclusions Our review suggests that genetic etiologies have a role to play in the occurrence of ESESS/CSWSS/epilepsy-aphasia spectrum. The common underlying pathway is channelopathy. Therefore we propose more genetic studies to be done for more discoveries which can pave a way for proper drug identification. We also suggest development of common cut-off value for spike-wave index to ensure common language among clinicians and researchers. Electronic supplementary material The online version of this article (10.1186/s12863-018-0628-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Miriam Kessi
- Department of Pediatrics, Xiangya Hospital, Central South University, 87 Xiang Ya Road, Changsha, 410008, Hunan Province, China. .,Kilimanjaro Christian Medical University College, 2240, Moshi, Tanzania.
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, 87 Xiang Ya Road, Changsha, 410008, Hunan Province, China
| | - Lifen Yang
- Department of Pediatrics, Xiangya Hospital, Central South University, 87 Xiang Ya Road, Changsha, 410008, Hunan Province, China
| | - Juan Xiong
- Department of Pediatrics, Xiangya Hospital, Central South University, 87 Xiang Ya Road, Changsha, 410008, Hunan Province, China
| | - Haolin Duan
- Department of Pediatrics, Xiangya Hospital, Central South University, 87 Xiang Ya Road, Changsha, 410008, Hunan Province, China
| | - Nan Pang
- Department of Pediatrics, Xiangya Hospital, Central South University, 87 Xiang Ya Road, Changsha, 410008, Hunan Province, China
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital, Central South University, 87 Xiang Ya Road, Changsha, 410008, Hunan Province, China.
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Lesca G. Aspetti genetici delle epilessie. Neurologia 2018. [DOI: 10.1016/s1634-7072(18)41286-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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20
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Lamers IJC, Reijnders MRF, Venselaar H, Kraus A, Jansen S, de Vries BBA, Houge G, Gradek GA, Seo J, Choi M, Chae JH, van der Burgt I, Pfundt R, Letteboer SJF, van Beersum SEC, Dusseljee S, Brunner HG, Doherty D, Kleefstra T, Roepman R. Recurrent De Novo Mutations Disturbing the GTP/GDP Binding Pocket of RAB11B Cause Intellectual Disability and a Distinctive Brain Phenotype. Am J Hum Genet 2017; 101:824-832. [PMID: 29106825 DOI: 10.1016/j.ajhg.2017.09.015] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 09/19/2017] [Indexed: 12/20/2022] Open
Abstract
The Rab GTPase family comprises ∼70 GTP-binding proteins, functioning in vesicle formation, transport and fusion. They are activated by a conformational change induced by GTP-binding, allowing interactions with downstream effectors. Here, we report five individuals with two recurrent de novo missense mutations in RAB11B; c.64G>A; p.Val22Met in three individuals and c.202G>A; p.Ala68Thr in two individuals. An overlapping neurodevelopmental phenotype, including severe intellectual disability with absent speech, epilepsy, and hypotonia was observed in all affected individuals. Additionally, visual problems, musculoskeletal abnormalities, and microcephaly were present in the majority of cases. Re-evaluation of brain MRI images of four individuals showed a shared distinct brain phenotype, consisting of abnormal white matter (severely decreased volume and abnormal signal), thin corpus callosum, cerebellar vermis hypoplasia, optic nerve hypoplasia and mild ventriculomegaly. To compare the effects of both variants with known inactive GDP- and active GTP-bound RAB11B mutants, we modeled the variants on the three-dimensional protein structure and performed subcellular localization studies. We predicted that both variants alter the GTP/GDP binding pocket and show that they both have localization patterns similar to inactive RAB11B. Evaluation of their influence on the affinity of RAB11B to a series of binary interactors, both effectors and guanine nucleotide exchange factors (GEFs), showed induction of RAB11B binding to the GEF SH3BP5, again similar to inactive RAB11B. In conclusion, we report two recurrent dominant mutations in RAB11B leading to a neurodevelopmental syndrome, likely caused by altered GDP/GTP binding that inactivate the protein and induce GEF binding and protein mislocalization.
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Affiliation(s)
- Ideke J C Lamers
- Department of Human Genetics, and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, 6500 HB, the Netherlands
| | - Margot R F Reijnders
- Department of Human Genetics, and Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Center, Nijmegen, 6500 HB, the Netherlands.
| | - Hanka Venselaar
- Centre for Molecular and Biomolecular Informatics, Radboud University Medical Center, Nijmegen, 6500 HB, the Netherlands
| | - Alison Kraus
- Yorkshire Regional Genetics Service, Chapel Allerton Hospital, Leeds, LS7 4SA, UK
| | - Sandra Jansen
- Department of Human Genetics, and Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Center, Nijmegen, 6500 HB, the Netherlands
| | - Bert B A de Vries
- Department of Human Genetics, and Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Center, Nijmegen, 6500 HB, the Netherlands
| | - Gunnar Houge
- Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, N-5021, Norway
| | - Gyri Aasland Gradek
- Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, N-5021, Norway
| | - Jieun Seo
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea
| | - Murim Choi
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea
| | - Jong-Hee Chae
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea
| | - Ineke van der Burgt
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, 6500 HB, the Netherlands
| | - Rolph Pfundt
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, 6500 HB, the Netherlands
| | - Stef J F Letteboer
- Department of Human Genetics, and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, 6500 HB, the Netherlands
| | - Sylvia E C van Beersum
- Department of Human Genetics, and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, 6500 HB, the Netherlands
| | - Simone Dusseljee
- Department of Human Genetics, and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, 6500 HB, the Netherlands
| | - Han G Brunner
- Department of Human Genetics, and Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Center, Nijmegen, 6500 HB, the Netherlands; Department of Clinical Genetics and School for Oncology & Developmental Biology (GROW), Maastricht University Medical Center, Maastricht, 6229 ER, the Netherlands
| | - Dan Doherty
- Department of Pediatrics, University of Washington and Seattle Children's Research Institute, Seattle, WA 98195, USA
| | - Tjitske Kleefstra
- Department of Human Genetics, and Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Center, Nijmegen, 6500 HB, the Netherlands
| | - Ronald Roepman
- Department of Human Genetics, and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, 6500 HB, the Netherlands.
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