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Liu X, Qin H, Liu Y, Ma J, Li Y, He Y, Zhu H, Mao L. The biological functions and pathological mechanisms of CASK in various diseases. Heliyon 2024; 10:e28863. [PMID: 38638974 PMCID: PMC11024568 DOI: 10.1016/j.heliyon.2024.e28863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 03/21/2024] [Accepted: 03/26/2024] [Indexed: 04/20/2024] Open
Abstract
Background As a scaffold protein, calcium/calmodulin-dependent serine protein kinase (CASK) has been extensively studied in a variety of tissues throughout the body. The Cask gene is ubiquitous in several tissues, such as the neurons, islets, heart, kidneys and sperm, and is mostly localised in the cytoplasm adjacent to the basement membrane. CASK binds to a variety of proteins through its domains to exerting its biological activity. Scope of review Here, we discuss the role of CASK in multiple tissues throughout the body. The role of different CASK domains in regulating neuronal development, neurotransmitter release and synaptic vesicle secretion was emphasised; the regulatory mechanism of CASK on the function of pancreatic islet β cells was analysed; the role of CASK in cardiac physiology, kidney and sperm development was discussed; and the role of CASK in different tumours was compared. Finally, we clarify the importance of the Cask gene in the body, and how deletion or mutation of the Cask gene can have adverse consequences. Major conclusions CASK is a conserved gene with similar roles in various tissues. The function of the Cask gene in the nervous system is mainly involved in the development of the nervous system and the release of neurotransmitters. In the endocrine system, an involvement of CASK has been reported in the process of insulin vesicle transport. CASK is also involved in cardiomyocyte ion channel regulation, kidney and sperm development, and tumour proliferation. CASK is an indispensable gene for the whole body, and CASK mutations can cause foetal malformations or death at birth. In this review, we summarise the biological functions and pathological mechanisms of CASK in various systems, thereby providing a basis for further in-depth studies of CASK functions.
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Affiliation(s)
- Xingjing Liu
- Department of Endocrinology, The Affiliated Huaian No.1 People’s Hospital of Nanjing Medical University, Huaian, Jiangsu Province, China
| | - Haonan Qin
- Department of Orthopedics, The Affiliated Huaian No.1 People’s Hospital of Nanjing Medical University, Huaian, Jiangsu Province, China
| | - Yuanyuan Liu
- Department of Endocrinology, The Affiliated Huaian No.1 People’s Hospital of Nanjing Medical University, Huaian, Jiangsu Province, China
| | - Jingjing Ma
- Department of Endocrinology, The Affiliated Huaian No.1 People’s Hospital of Nanjing Medical University, Huaian, Jiangsu Province, China
| | - Yiming Li
- Department of Endocrinology, The Affiliated Huaian No.1 People’s Hospital of Nanjing Medical University, Huaian, Jiangsu Province, China
| | - Yu He
- Department of Endocrinology, The Affiliated Huaian No.1 People’s Hospital of Nanjing Medical University, Huaian, Jiangsu Province, China
| | - Huimin Zhu
- Department of Electrophysiology, The Affiliated Huaian No.1 People’s Hospital of Nanjing Medical University, Huaian, Jiangsu Province, China
| | - Li Mao
- Department of Endocrinology, The Affiliated Huaian No.1 People’s Hospital of Nanjing Medical University, Huaian, Jiangsu Province, China
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2
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Patel PA, LaConte LEW, Liang C, Cecere T, Rajan D, Srivastava S, Mukherjee K. Genetic evidence for splicing-dependent structural and functional plasticity in CASK protein. J Med Genet 2024:jmg-2023-109747. [PMID: 38670634 DOI: 10.1136/jmg-2023-109747] [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: 11/10/2023] [Accepted: 04/14/2024] [Indexed: 04/28/2024]
Abstract
BACKGROUND Pontocerebellar hypoplasia (PCH) may present with supratentorial phenotypes and is often accompanied by microcephaly. Damaging mutations in the X-linked gene CASK produce self-limiting microcephaly with PCH in females but are often lethal in males. CASK deficiency leads to early degeneration of cerebellar granule cells but its role in other regions of the brain remains uncertain. METHOD We generated a conditional Cask knockout mice and deleted Cask ubiquitously after birth at different times. We examined the clinical features in several subjects with damaging mutations clustered in the central part of the CASK protein. We have performed phylogenetic analysis and RT-PCR to assess the splicing pattern within the same protein region and performed in silico structural analysis to examine the effect of splicing on the CASK's structure. RESULT We demonstrate that deletion of murine Cask after adulthood does not affect survival but leads to cerebellar degeneration and ataxia over time. Intriguingly, damaging hemizygous CASK mutations in boys who display microcephaly and cerebral dysfunction but without PCH are known. These mutations are present in two vertebrate-specific CASK exons. These exons are subject to alternative splicing both in forebrain and hindbrain. Inclusion of these exons differentially affects the molecular structure and hence possibly the function/s of the CASK C-terminus. CONCLUSION Loss of CASK function disproportionately affects the cerebellum. Clinical data, however, suggest that CASK may have additional vertebrate-specific function/s that play a role in the mammalian forebrain. Thus, CASK has an ancient function shared between invertebrates and vertebrates as well as novel vertebrate-specific function/s.
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Affiliation(s)
- Paras A Patel
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA
| | - Leslie E W LaConte
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA
- Basic Science Education, Virginia Tech Carilion School of Medicine, Roanoke, VA, USA
| | - Chen Liang
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA
| | - Thomas Cecere
- Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia, USA
| | - Deepa Rajan
- University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Sarika Srivastava
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA
- Department of Genetics, The University of Alabama at Birmingham Heersink School of Medicine, Birmingham, Alabama, USA
| | - Konark Mukherjee
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA
- Department of Genetics, The University of Alabama at Birmingham Heersink School of Medicine, Birmingham, Alabama, USA
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3
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Mori T, Zhou M, Tabuchi K. Diverse Clinical Phenotypes of CASK-Related Disorders and Multiple Functional Domains of CASK Protein. Genes (Basel) 2023; 14:1656. [PMID: 37628707 PMCID: PMC10454856 DOI: 10.3390/genes14081656] [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: 08/07/2023] [Revised: 08/17/2023] [Accepted: 08/17/2023] [Indexed: 08/27/2023] Open
Abstract
CASK-related disorders are a form of rare X-linked neurological diseases and most of the patients are females. They are characterized by several symptoms, including microcephaly with pontine and cerebellar hypoplasia (MICPCH), epilepsy, congenital nystagmus, and neurodevelopmental disorders. Whole-genome sequencing has identified various mutations, including nonsense and missense mutations, from patients with CASK-related disorders, revealing correlations between specific mutations and clinical phenotypes. Notably, missense mutations associated with epilepsy and intellectual disability were found throughout the whole region of the CASK protein, while missense mutations related to microcephaly and MICPCH were restricted in certain domains. To investigate the pathophysiology of CASK-related disorders, research groups have employed diverse methods, including the generation of CASK knockout mice and the supplementation of CASK to rescue the phenotypes. These approaches have yielded valuable insights into the identification of functional domains of the CASK protein associated with a specific phenotype. Additionally, recent advancements in the AI-based prediction of protein structure, such as AlphaFold2, and the application of genome-editing techniques to generate CASK mutant mice carrying missense mutations from patients with CASK-related disorders, allow us to understand the pathophysiology of CASK-related disorders in more depth and to develop novel therapeutic methods for the fundamental treatment of CASK-related disorders.
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Affiliation(s)
- Takuma Mori
- Department of Neuroinnovation, Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Matsumoto 390-8621, Japan;
- Department of Molecular and Cellular Physiology, Shinshu University School of Medicine, Matsumoto 390-8621, Japan;
| | - Mengyun Zhou
- Department of Molecular and Cellular Physiology, Shinshu University School of Medicine, Matsumoto 390-8621, Japan;
| | - Katsuhiko Tabuchi
- Department of Neuroinnovation, Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Matsumoto 390-8621, Japan;
- Department of Molecular and Cellular Physiology, Shinshu University School of Medicine, Matsumoto 390-8621, Japan;
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Shimada T, Yamagata K. Spine morphogenesis and synapse formation in tubular sclerosis complex models. Front Mol Neurosci 2022; 15:1019343. [PMID: 36606143 PMCID: PMC9807618 DOI: 10.3389/fnmol.2022.1019343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 12/05/2022] [Indexed: 12/24/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is caused by mutations in the Tsc1 or Tsc2 genes, whose products form a complex and inactivate the small G-protein Rheb1. The activation of Rheb1 may cause refractory epilepsy, intellectual disability, and autism, which are the major neuropsychiatric manifestations of TSC. Abnormalities in dendritic spines and altered synaptic structure are hallmarks of epilepsy, intellectual disability, and autism. In addition, spine dysmorphology and aberrant synapse formation are observed in TSC animal models. Therefore, it is important to investigate the molecular mechanism underlying the regulation of spine morphology and synapse formation in neurons to identify therapeutic targets for TSC. In this review, we focus on the representative proteins regulated by Rheb1 activity, mTORC1 and syntenin, which are pivotal downstream factors of Rheb1 in the alteration of spine formation and synapse function in TSC neurons.
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Affiliation(s)
- Tadayuki Shimada
- Child Brain Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan,*Correspondence: Tadayuki Shimada,
| | - Kanato Yamagata
- Child Brain Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan,Department of Psychiatry, Takada Nishishiro Hospital, Niigata, Japan,Kanato Yamagata,
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Dubbs H, Ortiz-Gonzalez X, Marsh ED. Pathogenic variants in CASK: Expanding the genotype-phenotype correlations. Am J Med Genet A 2022; 188:2617-2626. [PMID: 35670295 DOI: 10.1002/ajmg.a.62863] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 05/04/2022] [Accepted: 05/16/2022] [Indexed: 01/24/2023]
Abstract
Pathogenic variants in CASK, an X-linked gene that plays a role in brain development and synaptic function, are the cause of both microcephaly with pontine and cerebellar hypoplasia (MICPCH), and X-linked intellectual disability (XLID) with or without nystagmus. MICPCH is caused by loss of function variants in CASK, typically affects females, and is associated with moderate-to-severe intellectual disability (ID). Additional findings, present in about one-third of individuals, include feeding difficulties, ophthalmologic issues, hypertonicity, epilepsy, and sensorineural hearing loss. Only a few affected males with MICPCH phenotype have been reported and most have had profound developmental disability and intractable epilepsy. The XLID phenotype is typically caused by missense variants and most often manifests in males; carrier females are mildly affected or unaffected. Nystagmus is often present. In total, over 175 patients have been reported in the literature. We now report an additional 11 patients with pathogenic variants in CASK that expand these phenotypes and reported genotype-phenotype correlations.
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Affiliation(s)
- Holly Dubbs
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Xilma Ortiz-Gonzalez
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.,Departments of Neurology and Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Eric D Marsh
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.,Departments of Neurology and Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Zhang R, Jia P, Yao Y, Zhu F. Case Report: Identification of a novel CASK missense variant in a Chinese family with MICPCH. Front Genet 2022; 13:933785. [PMID: 36092876 PMCID: PMC9452731 DOI: 10.3389/fgene.2022.933785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Accepted: 07/25/2022] [Indexed: 11/13/2022] Open
Abstract
Mental retardation and microcephaly with pontine and cerebellar hypoplasia (MICPCH) is a rare genetic disorder that results in varying levels of pontocerebellar hypoplasia, microcephaly, and severe intellectual disabilities. Prior genetic analyses have identified the CASK gene as a driver of MICPCH. Herein, we analyzed a Chinese family with MICPCH. The index patient was an 8-year-old male. He and his 3-year-old brother suffered from microcephaly, pontocerebellar hypoplasia, serious mental retardation, ataxia, gait disorder, and inability to speak. Through a combination of whole-exome sequencing and subsequent Sanger sequencing, a novel X-linked missense mutation, c.1882G>C (p.D628H) in the CASK gene, was identified in two siblings, as well as their mother and grandmother, who exhibited mild mental retardation. Other family members with negative genetic testing were normal. In silico analyses indicated that this missense mutation was predicted to reduce CASK protein stability, disrupt the SRC homology 3 (SH3) domain, and abolish its function. In summary, we identified a novel missense variate in CASK associated with MICPCH. Our work facilitates the diagnosis of the disease in this family and broadens the gene variant spectrum of the CASK in MICPCH patients.
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Affiliation(s)
- Runfeng Zhang
- College of Life Sciences, Hubei Normal University, Huangshi, China
| | - Peng Jia
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yanyi Yao
- Medical Genetic Center, Maternal and Child Health Hospital of Hubei Province, Wuhan, China
- *Correspondence: Feng Zhu, ; Yanyi Yao,
| | - Feng Zhu
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Clinic Center of Human Gene Research, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- *Correspondence: Feng Zhu, ; Yanyi Yao,
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Wu S, Jiang C, Li J, Zhang G, Shen Y, Wang J. A novel missense variant in the CASK gene causes intellectual developmental disorder and microcephaly with pontine and cerebellar hypoplasia. BMC Med Genomics 2022; 15:127. [PMID: 35668446 PMCID: PMC9169347 DOI: 10.1186/s12920-022-01275-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 05/23/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Variants in the CASK gene result in a wide range of observed phenotypes in humans, such as FG Syndrome 4 and intellectual disabilities. Intellectual developmental disorder with microcephaly and pontine and cerebellar hypoplasia (MICPCH) is an X-linked disorder that affects females and is characterized by severely impaired intellectual development and variable degrees of pontocerebellar hypoplasia. Variants in CASK are the main genetic cause of MICPCH. Variants in CASK can explain most patients with MICPCH, but there are still some patients whose disease aetiology cannot be explained. CASE PRESENTATION An 11-month-old female diagnosed with MICPCH exhibited general developmental delays, microcephaly, and cerebellar hypoplasia. Whole-exome sequencing (WES) was used to find a novel heterozygous missense variant (NM_003688.3: c.638T>G) of CASK in this patient. Strikingly, this variant reduced the expression of CASK at the protein level but not at the mRNA level. By using protein structure prediction analysis, this study found that the amino acid change caused by the variant resulted in further changes in the stability of the protein structure, and these changes caused the downregulation of protein expression and loss of protein function. CONCLUSION In this study, we first reported a novel heterozygous pathogenic variant and a causative mechanism of MICPCH. The amino acid change cause by this variant led to changes in the protein structure and a decrease in its stability, which caused a loss of protein function. This study could be helpful to the genetic diagnosis of this disease.
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Affiliation(s)
- Sixian Wu
- Joint Laboratory of Reproductive Medicine, Gynaecology and Paediatric Diseases and Birth Defects of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, 610041, People's Republic of China.,West China School of Pharmacy, Sichuan University, Chengdu, 610041, People's Republic of China
| | - Chuan Jiang
- Joint Laboratory of Reproductive Medicine, Gynaecology and Paediatric Diseases and Birth Defects of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, 610041, People's Republic of China
| | - Jiaman Li
- West China School of Pharmacy, Sichuan University, Chengdu, 610041, People's Republic of China
| | - Guohui Zhang
- Joint Laboratory of Reproductive Medicine, Gynaecology and Paediatric Diseases and Birth Defects of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, 610041, People's Republic of China
| | - Ying Shen
- Joint Laboratory of Reproductive Medicine, Gynaecology and Paediatric Diseases and Birth Defects of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, 610041, People's Republic of China.
| | - Jing Wang
- Department of Obstetrics and Gynaecology, West China Second University Hospital of Sichuan University and Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, 610041, People's Republic of China.
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Zhang Y, Nie Y, Mu Y, Zheng J, Xu X, Zhang F, Shu J, Liu Y. A de novo variant in CASK gene causing intellectual disability and brain hypoplasia: a case report and literature review. Ital J Pediatr 2022; 48:73. [PMID: 35550617 PMCID: PMC9097383 DOI: 10.1186/s13052-022-01248-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 03/17/2022] [Indexed: 12/02/2022] Open
Abstract
Background The pathogenic variation of CASK gene can cause CASK related mental disorders. The main clinical manifestations are microcephaly with pontine and cerebellar hypoplasia, X-linked mental disorders with or without nystagmus and FG syndrome. The main pathogenic mechanism is the loss of function of related protein caused by variant. We reported a Chinese male newborn with a de novo variant in CASK gene. Case presentation We present an 18-day-old baby with growth retardation and brain hypoplasia. Whole-exome sequencing was performed, which detected a hemizygous missense variant c.764G > A of CASK gene. The variant changed the 255th amino acid from Arg to His. Software based bioinformatics analyses were conducted to infer its functional effect. Conclusions In this paper, a de novo variant of CASK gene was reported. Moreover, a detailed description of all the cases described in the literature is reported. CASK variants cause a variety of clinical phenotypes. Its diagnosis is difficult due to the lack of typical clinical symptoms. Genetic testing should be performed as early as possible if this disease is suspected. This case provides an important reference for the diagnosis and treatment of future cases.
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Affiliation(s)
- Ying Zhang
- Department of Neonatology, Tianjin Children's Hospital (Tianjin University Children's Hospital), No. 238 Longyan Road, Beichen District, Tianjin, 300134, China.,Graduate College of Tianjin Medical University, Tianjin, China
| | - Yanyan Nie
- Department of Neonatology, Tianjin Children's Hospital (Tianjin University Children's Hospital), No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
| | - Yu Mu
- Department of Neonatology, Tianjin Children's Hospital (Tianjin University Children's Hospital), No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
| | - Jie Zheng
- Graduate College of Tianjin Medical University, Tianjin, China
| | - Xiaowei Xu
- Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin, China.,Tianjin Pediatric Research Institute, Tianjin Children's Hospital (Tianjin University Children's Hospital), No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
| | - Fang Zhang
- Department of Neonatology, Tianjin Children's Hospital (Tianjin University Children's Hospital), No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
| | - Jianbo Shu
- Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin, China. .,Tianjin Pediatric Research Institute, Tianjin Children's Hospital (Tianjin University Children's Hospital), No. 238 Longyan Road, Beichen District, Tianjin, 300134, China.
| | - Yang Liu
- Department of Neonatology, Tianjin Children's Hospital (Tianjin University Children's Hospital), No. 238 Longyan Road, Beichen District, Tianjin, 300134, China.
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The Non-Linear Path from Gene Dysfunction to Genetic Disease: Lessons from the MICPCH Mouse Model. Cells 2022; 11:cells11071131. [PMID: 35406695 PMCID: PMC8997851 DOI: 10.3390/cells11071131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 03/09/2022] [Accepted: 03/24/2022] [Indexed: 11/17/2022] Open
Abstract
Most human disease manifests as a result of tissue pathology, due to an underlying disease process (pathogenesis), rather than the acute loss of specific molecular function(s). Successful therapeutic strategies thus may either target the correction of a specific molecular function or halt the disease process. For the vast majority of brain diseases, clear etiologic and pathogenic mechanisms are still elusive, impeding the discovery or design of effective disease-modifying drugs. The development of valid animal models and their proper characterization is thus critical for uncovering the molecular basis of the underlying pathobiological processes of brain disorders. MICPCH (microcephaly and pontocerebellar hypoplasia) is a monogenic condition that results from variants of an X-linked gene, CASK (calcium/calmodulin-dependent serine protein kinase). CASK variants are associated with a wide range of clinical presentations, from lethality and epileptic encephalopathies to intellectual disabilities, microcephaly, and autistic traits. We have examined CASK loss-of-function mutations in model organisms to simultaneously understand the pathogenesis of MICPCH and the molecular function/s of CASK. Our studies point to a highly complex relationship between the potential molecular function/s of CASK and the phenotypes observed in model organisms and humans. Here we discuss the implications of our observations from the pathogenesis of MICPCH as a cautionary narrative against oversimplifying molecular interpretations of data obtained from genetically modified animal models of human diseases.
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Catino G, Genovese S, Di Tommaso S, Orlando V, Petti MT, De Bernardi ML, Dallapiccola B, Novelli A, Ulgheri L, Piscopo C, Alesi V. Reciprocal Xp11.4p11.3 microdeletion/microduplication spanning USP9X, DDX3X, and CASK genes in two patients with syndromic intellectual disability. Am J Med Genet A 2022; 188:1836-1847. [PMID: 35238482 DOI: 10.1002/ajmg.a.62694] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 02/02/2022] [Accepted: 02/05/2022] [Indexed: 12/13/2022]
Abstract
Only a few patients with deletions or duplications at Xp11.4, bridging USP9X, DDX3X, and CASK genes, have been described so far. Here, we report on a female harboring a de novo Xp11.4p11.3 deletion and a male with an overlapping duplication inherited from an unaffected mother, presenting with syndromic intellectual disability. We discuss the role of USP9X, DDX3X, and CASK genes in human development and describe the effects of Xp11.4 deletion and duplications in female and male patients, respectively.
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Affiliation(s)
- Giorgia Catino
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, Rome, Italy
| | - Silvia Genovese
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, Rome, Italy
| | - Silvia Di Tommaso
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, Rome, Italy
| | - Valeria Orlando
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, Rome, Italy
| | - Maria Teresa Petti
- Department of Molecular Medicine and Medical Biotechnology, University Federico II, Naples, Italy
| | | | - Bruno Dallapiccola
- Genetics and Rare Disease Research Division, Bambino Gesu Children Hospital, IRCCS, Rome, Italy
| | - Antonio Novelli
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, Rome, Italy
| | - Lucia Ulgheri
- Department of Biomedical Sciences, Clinical Genetics Service, Azienda Ospedaliero-Universitaria, Sassari, Italy
| | - Carmelo Piscopo
- Department of Molecular Medicine and Medical Biotechnology, University Federico II, Naples, Italy
| | - Viola Alesi
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, Rome, Italy
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Patel PA, Hegert JV, Cristian I, Kerr A, LaConte LEW, Fox MA, Srivastava S, Mukherjee K. Complete loss of the X-linked gene CASK causes severe cerebellar degeneration. J Med Genet 2022; 59:1044-1057. [PMID: 35149592 DOI: 10.1136/jmedgenet-2021-108115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 01/13/2022] [Indexed: 01/19/2023]
Abstract
BACKGROUND Heterozygous loss of X-linked genes like CASK and MeCP2 (Rett syndrome) causes developmental delay in girls, while in boys, loss of the only allele of these genes leads to epileptic encephalopathy. The mechanism for these disorders remains unknown. CASK-linked cerebellar hypoplasia is presumed to result from defects in Tbr1-reelin-mediated neuronal migration. METHOD Here we report clinical and histopathological analyses of a deceased 2-month-old boy with a CASK-null mutation. We next generated a mouse line where CASK is completely deleted (hemizygous and homozygous) from postmigratory neurons in the cerebellum. RESULT The CASK-null human brain was smaller in size but exhibited normal lamination without defective neuronal differentiation, migration or axonal guidance. The hypoplastic cerebellum instead displayed astrogliosis and microgliosis, which are markers for neuronal loss. We therefore hypothesise that CASK loss-induced cerebellar hypoplasia is the result of early neurodegeneration. Data from the murine model confirmed that in CASK loss, a small cerebellum results from postdevelopmental degeneration of cerebellar granule neurons. Furthermore, at least in the cerebellum, functional loss from CASK deletion is secondary to degeneration of granule cells and not due to an acute molecular functional loss of CASK. Intriguingly, female mice with heterozygous deletion of CASK in the cerebellum do not display neurodegeneration. CONCLUSION We suggest that X-linked neurodevelopmental disorders like CASK mutation and Rett syndrome are pathologically neurodegenerative; random X-chromosome inactivation in heterozygous mutant girls, however, results in 50% of cells expressing the functional gene, resulting in a non-progressive pathology, whereas complete loss of the only allele in boys leads to unconstrained degeneration and encephalopathy.
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Affiliation(s)
- Paras A Patel
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA
| | - Julia V Hegert
- Department of Pathology, Orlando Health, Orlando, Florida, USA
| | | | - Alicia Kerr
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA
| | | | - Michael A Fox
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA.,School of Neuroscience, Blacksburg, Virginia, USA
| | - Sarika Srivastava
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA.,Department of Internal Medicine, Virginia Tech Carilion School of Medicine, Roanoke, Virginia, USA
| | - Konark Mukherjee
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA .,Department of Psychiatry, Virginia Tech Carilion School of Medicine, Roanoke, Virginia, USA
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12
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Cross-platform validation of neurotransmitter release impairments in schizophrenia patient-derived NRXN1-mutant neurons. Proc Natl Acad Sci U S A 2021; 118:2025598118. [PMID: 34035170 DOI: 10.1073/pnas.2025598118] [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] [Indexed: 11/18/2022] Open
Abstract
Heterozygous NRXN1 deletions constitute the most prevalent currently known single-gene mutation associated with schizophrenia, and additionally predispose to multiple other neurodevelopmental disorders. Engineered heterozygous NRXN1 deletions impaired neurotransmitter release in human neurons, suggesting a synaptic pathophysiological mechanism. Utilizing this observation for drug discovery, however, requires confidence in its robustness and validity. Here, we describe a multicenter effort to test the generality of this pivotal observation, using independent analyses at two laboratories of patient-derived and newly engineered human neurons with heterozygous NRXN1 deletions. Using neurons transdifferentiated from induced pluripotent stem cells that were derived from schizophrenia patients carrying heterozygous NRXN1 deletions, we observed the same synaptic impairment as in engineered NRXN1-deficient neurons. This impairment manifested as a large decrease in spontaneous synaptic events, in evoked synaptic responses, and in synaptic paired-pulse depression. Nrxn1-deficient mouse neurons generated from embryonic stem cells by the same method as human neurons did not exhibit impaired neurotransmitter release, suggesting a human-specific phenotype. Human NRXN1 deletions produced a reproducible increase in the levels of CASK, an intracellular NRXN1-binding protein, and were associated with characteristic gene-expression changes. Thus, heterozygous NRXN1 deletions robustly impair synaptic function in human neurons regardless of genetic background, enabling future drug discovery efforts.
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13
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Morrison-Levy N, Borlot F, Jain P, Whitney R. Early-Onset Developmental and Epileptic Encephalopathies of Infancy: An Overview of the Genetic Basis and Clinical Features. Pediatr Neurol 2021; 116:85-94. [PMID: 33515866 DOI: 10.1016/j.pediatrneurol.2020.12.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 11/30/2020] [Accepted: 12/04/2020] [Indexed: 12/19/2022]
Abstract
Our current knowledge of genetically determined forms of epilepsy has shortened the diagnostic pathway usually experienced by the families of infants diagnosed with early-onset developmental and epileptic encephalopathies. Genetic causes can be found in up to 80% of infants presenting with early-onset developmental and epileptic encephalopathies, often in the context of an uneventful perinatal history and with no clear underlying brain abnormalities. Although current disease-specific therapies remain limited and patient outcomes are often guarded, a genetic diagnosis may lead to early therapeutic intervention using new and/or repurposed therapies. In this review, an overview of epilepsy genetics, the indications for genetic testing in infants, the advantages and limitations of each test, and the challenges and ethical implications of genetic testing are discussed. In addition, the following causative genes associated with early-onset developmental and epileptic encephalopathies are discussed in detail: KCNT1, KCNQ2, KCNA2, SCN2A, SCN8A, STXBP1, CDKL5, PIGA, SPTAN1, and GNAO1. The epilepsy phenotypes, comorbidities, electroencephalgraphic findings, neuroimaging findings, and potential targeted therapies for each gene are reviewed.
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Affiliation(s)
| | - Felippe Borlot
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Puneet Jain
- Division of Neurology, Department of Paediatrics, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Robyn Whitney
- Division of Neurology, Department of Paediatrics, McMaster University, Hamilton, Ontario, Canada.
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14
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CASK related disorder: Epilepsy and developmental outcome. Eur J Paediatr Neurol 2021; 31:61-69. [PMID: 33640666 DOI: 10.1016/j.ejpn.2021.02.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 02/09/2021] [Accepted: 02/15/2021] [Indexed: 11/24/2022]
Abstract
OBJECTIVE CASK pathogenic variants are associated with variable features, as intellectual disability, optic atrophy, brainstem/cerebellar hypoplasia, and epileptic encephalopathy. Few studies describe the electroclinical features of epilepsy in patients with CASK pathogenic variants and their relationship with developmental delay. METHODS this national multicentre cohort included genetically confirmed patients with different CASK pathogenic variants. Our findings were compared with cohorts reported in the literature. RESULTS we collected 34 patients (29 females) showing from moderate (4 patients) to severe (22) and profound (8) developmental delay; all showed pontine and cerebellar hypoplasia, all except three with microcephaly. Seventeen out of 34 patients (50%) suffered from epileptic seizures, including spasms (11 patients, 32.3%), generalized (5) or focal seizures (1). In 8/17 individuals (47.1%), epilepsy started at or beyond the age of 24 months. Seven (3 males) out of the 11 children with spasms showed EEG features and a course supporting the diagnosis of a developmental and epileptic encephalopathy (DEE). Drug resistance was frequent in our cohort (52.9% of patients with epilepsy). EEG abnormalities included poorly organized background activity with diffuse or multifocal epileptiform abnormalities and sleep-activation, with possible appearance over the follow-up period. Developmental delay degree was not statistically different among patients with or without seizures but feeding difficulties were more frequent in patients with epilepsy. CONCLUSIONS epilepsy is a frequent comorbidity with a high incidence of spasms and drug resistance. Overall developmental disability does not seem to be more severe in the group of patients with epilepsy nor to be linked to specific epilepsy/EEG characteristics. A childhood onset of epilepsy is frequent, with possible worsening over time, so that serial and systematic monitoring is mandatory.
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15
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Shelby ES, Lupu OT, Axente M, Leanca MC, Badina M, Padure L, Mirea A, Pelttari LM. New VOUS in CASK Gene Correlating with the MICPCH Phenotype. MAEDICA 2021; 16:135-139. [PMID: 34221169 DOI: 10.26574/maedica.2020.16.1.135] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We present the case of a three-year-old girl with normal family history who was admitted to our hospital for medical recovery. The patient had microcephaly, pontocerebellar hypoplasia, slight facial dysmorphism, axial hypotonia, epileptic seizures, absent walking skills and severe speech delay. Genetic testing identified a heterozygous intronic variant in the CASK gene, namely CASK c.278 + 5G>A, which has never been reported in the medical literature or in other databases (gnomAD, ClinVar, HGMD). In mammals as well as more distant species, the G nucleotide is fully conserved at this position, suggesting it may not tolerate variation. In silico tools predict the substitution to be deleterious. Pathogenic mutations of these gene are responsible of mental retardation and microcephaly with pontine and cerebellar hypoplasia (MICPCH) syndrome, which overlaps completely with our patient's phenotype.
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Affiliation(s)
- Elena Silvia Shelby
- "Dr. Nicolae Robanescu" National Clinical Center for Children's Neurorecovery, Bucharest, Romania
| | - Onda Tabita Lupu
- "Carol Davila'' University of Medicine and Pharmacy, Bucharest, Romania
| | - Mihaela Axente
- "Dr. Nicolae Robanescu" National Clinical Center for Children's Neurorecovery, Bucharest, Romania
| | - Madalina Cristina Leanca
- "Dr. Nicolae Robanescu" National Clinical Center for Children's Neurorecovery, Bucharest, Romania
| | - Mihaela Badina
- "Dr. Nicolae Robanescu" National Clinical Center for Children's Neurorecovery, Bucharest, Romania
| | - Liliana Padure
- "Dr. Nicolae Robanescu" National Clinical Center for Children's Neurorecovery, Bucharest, Romania
| | - Andrada Mirea
- "Dr. Nicolae Robanescu" National Clinical Center for Children's Neurorecovery, Bucharest, Romania
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16
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Zhao J, Hou M, Wang H, Liu Q, Sun D, Wei W. Microcephaly, disproportionate pontine, and cerebellar hypoplasia syndrome: Two novel mutations in the CASK gene were discovered in Chinese females. Int J Dev Neurosci 2021; 81:277-284. [PMID: 33629417 DOI: 10.1002/jdn.10100] [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: 11/01/2020] [Revised: 01/08/2021] [Accepted: 02/21/2021] [Indexed: 11/10/2022] Open
Abstract
Microcephaly, disproportionate pontine and cerebellar hypoplasia (MICPCH) syndrome is a rare and genetic disorder, which is mainly caused by mutations in the CASK gene. We described four variations in the CASK gene in Chinese female patients with MICPCH, who presented with microcephaly, developmental delay, and motor disorder. The CASK mutations were identified using NGS (the next-generation sequencing), copy number variation sequencing. Two novel variations in the CASK gene were revealed including a frameshift mutation c.1000_1001insG (p.Asp334GlyfsTer32) and a nonsense mutation c.2110A > T (p.Lys704Ter). Two other aberrations were c.316C > T (p.Arg106Ter) and Xp11.4-p11.3 (41,700,001-44,660,000) × 1 loss. We provided clinical manifestations and neuroimaging findings of the four patients. The genetic variation spectrum of MICPCH caused by CASK was updated. Furthermore, we expounded on the molecular mechanism of the disease and noticed that it was not possible to relate the magnitude of the genetic alteration to a particular phenotype.
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Affiliation(s)
- Jianhui Zhao
- Department of Neurology & Rehabilitation, Qingdao Women and Children's Hospital, Qingdao, P.R. China
| | - Mei Hou
- Department of Neurology & Rehabilitation, Qingdao Women and Children's Hospital, Qingdao, P.R. China
| | - Haiqiao Wang
- Department of Traditional Chinese Medicine, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, P.R. China
| | - Qiuyan Liu
- Department of Neurology & Rehabilitation, Qingdao Women and Children's Hospital, Qingdao, P.R. China
| | - Dianrong Sun
- Department of Neurology & Rehabilitation, Qingdao Women and Children's Hospital, Qingdao, P.R. China
| | - Wei Wei
- Kangso Medical Inspection Co, Ltd., Beijing, P.R. China
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17
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Mukherjee K, Patel PA, Rajan DS, LaConte LEW, Srivastava S. Survival of a male patient harboring CASK Arg27Ter mutation to adolescence. Mol Genet Genomic Med 2020; 8:e1426. [PMID: 32696595 PMCID: PMC7549553 DOI: 10.1002/mgg3.1426] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 06/01/2020] [Accepted: 07/02/2020] [Indexed: 02/06/2023] Open
Abstract
Background CASK is an X‐linked gene in mammals and its deletion in males is incompatible with life. CASK heterozygous mutations in female patients associate with intellectual disability, microcephaly, pontocerebellar hypoplasia, and optic nerve hypoplasia, whereas CASK hemizygous mutations in males manifest as early infantile epileptic encephalopathy with a grim prognosis. Here, we report a rare case of survival of a male patient harboring a CASK null mutation to adolescent age. Methods Trio whole exome sequencing analysis was performed from blood genomic DNA. Magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), and electroencephalogram (EEG) analyses were performed to determine anomalies in brain development, metabolite concentrations, and electrical activity, respectively. Results Trio‐WES analysis identified a de novo c.79C>T (p.Arginine27Ter) mutation in CASK causing a premature translation termination at the very N‐terminus of the protein. The 17‐years, and 11‐month‐old male patient displayed profound intellectual disability, microcephaly, dysmorphism, ponto‐cerebellar hypoplasia, and intractable epilepsy. His systemic symptoms included overall reduced somatic growth, dysautonomia, ventilator and G tube dependence, and severe osteopenia. Brain MRI revealed a severe cerebellar and brain stem hypoplasia with progressive cerebral atrophy. EEG spectral analysis revealed a global functional defect with generalized background slowing and delta waves dominating even in the awake state. Conclusion This case study is the first to report survival of a male patient carrying a CASK loss‐of‐function mutation to adolescence and highlights that improved palliative care could extend survival. Moreover, the genomic position encoding Arg27 in CASK may possess an increased susceptibility to mutations.
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Affiliation(s)
- Konark Mukherjee
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, USA
| | - Paras A Patel
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, USA
| | - Deepa S Rajan
- Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh, Pittsburgh, PA, USA
| | - Leslie E W LaConte
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, USA
| | - Sarika Srivastava
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, USA.,Department of Internal Medicine, Virginia Tech Carilion School of Medicine, Roanoke, VA, USA
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18
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Suzuki T, Suzuki T, Raveau M, Miyake N, Sudo G, Tsurusaki Y, Watanabe T, Sugaya Y, Tatsukawa T, Mazaki E, Shimohata A, Kushima I, Aleksic B, Shiino T, Toyota T, Iwayama Y, Nakaoka K, Ohmori I, Sasaki A, Watanabe K, Hirose S, Kaneko S, Inoue Y, Yoshikawa T, Ozaki N, Kano M, Shimoji T, Matsumoto N, Yamakawa K. A recurrent PJA1 variant in trigonocephaly and neurodevelopmental disorders. Ann Clin Transl Neurol 2020; 7:1117-1131. [PMID: 32530565 PMCID: PMC7359110 DOI: 10.1002/acn3.51093] [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: 04/25/2020] [Accepted: 05/10/2020] [Indexed: 12/30/2022] Open
Abstract
OBJECTIVE Neurodevelopmental disorders (NDDs) often associate with epilepsy or craniofacial malformations. Recent large-scale DNA analyses identified hundreds of candidate genes for NDDs, but a large portion of the cases still remain unexplained. We aimed to identify novel candidate genes for NDDs. METHODS We performed exome sequencing of 95 patients with NDDs including 51 with trigonocephaly and subsequent targeted sequencing of additional 463 NDD patients, functional analyses of variant in vitro, and evaluations of autism spectrum disorder (ASD)-like phenotypes and seizure-related phenotypes in vivo. RESULTS We identified de novo truncation variants in nine novel genes; CYP1A1, C14orf119, FLI1, CYB5R4, SEL1L2, RAB11FIP2, ZMYND8, ZNF143, and MSX2. MSX2 variants have been described in patients with cranial malformations, and our present patient with the MSX2 de novo truncation variant showed cranial meningocele and partial epilepsy. MSX2 protein is known to be ubiquitinated by an E3 ubiquitin ligase PJA1, and interestingly we found a PJA1 hemizygous p.Arg376Cys variant recurrently in seven Japanese NDD patients; five with trigonocephaly and one with partial epilepsy, and the variant was absent in 886 Japanese control individuals. Pja1 knock-in mice carrying p.Arg365Cys, which is equivalent to p.Arg376Cys in human, showed a significant decrease in PJA1 protein amount, suggesting a loss-of-function effect of the variant. Pja1 knockout mice displayed moderate deficits in isolation-induced ultrasonic vocalizations and increased seizure susceptibility to pentylenetetrazole. INTERPRETATION These findings propose novel candidate genes including PJA1 and MSX2 for NDDs associated with craniofacial abnormalities and/or epilepsy.
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Affiliation(s)
- Toshimitsu Suzuki
- Department of Neurodevelopmental Disorder Genetics, Institute of Brain Science, Nagoya City University Graduate School of Medical Science, Nagoya, Aichi, 467-8601, Japan.,Laboratory for Neurogenetics, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan
| | - Toshifumi Suzuki
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, 236-0004, Japan.,Department of Obstetrics and Gynecology, Juntendo University Faculty of Medicine, Tokyo, 113-8421, Japan
| | - Matthieu Raveau
- Laboratory for Neurogenetics, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan
| | - Noriko Miyake
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, 236-0004, Japan
| | - Genki Sudo
- Laboratory for Neurogenetics, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan
| | - Yoshinori Tsurusaki
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, 236-0004, Japan.,Faculty of Nutritional Science, Sagami Women's University, Sagamihara, Kanagawa, 252-0383, Japan
| | - Takaki Watanabe
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Yuki Sugaya
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Tetsuya Tatsukawa
- Laboratory for Neurogenetics, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan
| | - Emi Mazaki
- Laboratory for Neurogenetics, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan
| | - Atsushi Shimohata
- Laboratory for Neurogenetics, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan
| | - Itaru Kushima
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Aichi, 466-8550, Japan.,Medical Genomics Center, Nagoya University Hospital, Nagoya, Aichi, 466-8560, Japan
| | - Branko Aleksic
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Aichi, 466-8550, Japan
| | - Tomoko Shiino
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Aichi, 466-8550, Japan
| | - Tomoko Toyota
- Laboratory for Molecular Psychiatry, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan
| | - Yoshimi Iwayama
- Laboratory for Molecular Psychiatry, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan
| | - Kentaro Nakaoka
- National Epilepsy Center, NHO Shizuoka Institute of Epilepsy and Neurological Disorders, Aoi-ku, Shizuoka, 420-8688, Japan
| | - Iori Ohmori
- Department of Special Needs Education, Okayama University Graduate School of Education, Okayama, 700-8530, Japan
| | - Aya Sasaki
- Department of Pathology and Laboratory Medicine, Tokyo Dental College Ichikawa General Hospital, Ichikawa, Chiba, 272-8513, Japan
| | - Ken Watanabe
- Section of Bone Function, Department of Bone and Joint Diseases, National Center for Geriatrics and Gerontology (NCGG), Obu, Aichi, 474-8511, Japan
| | - Shinichi Hirose
- Department of Pediatrics, School of Medicine and Research Institute for the Molecular Pathomechanisms of Epilepsy, Fukuoka University, Fukuoka, Fukuoka, 814-0180, Japan
| | - Sunao Kaneko
- Department of Neuropsychiatry, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, 036-8562, Japan.,North Tohoku Epilepsy Center, Minato Hospital, Hachinohe, 031-0813, Japan
| | - Yushi Inoue
- National Epilepsy Center, NHO Shizuoka Institute of Epilepsy and Neurological Disorders, Aoi-ku, Shizuoka, 420-8688, Japan
| | - Takeo Yoshikawa
- Laboratory for Molecular Psychiatry, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan
| | - Norio Ozaki
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Aichi, 466-8550, Japan
| | - Masanobu Kano
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Takeyoshi Shimoji
- Department of Neurosurgery, Okinawa Pref. Nanbu Medical Center and Children's Medical Center, Arakawa Haebaru, Okinawa, 901-1193, Japan
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, 236-0004, Japan
| | - Kazuhiro Yamakawa
- Department of Neurodevelopmental Disorder Genetics, Institute of Brain Science, Nagoya City University Graduate School of Medical Science, Nagoya, Aichi, 467-8601, Japan.,Laboratory for Neurogenetics, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan
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19
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Patel PA, Liang C, Arora A, Vijayan S, Ahuja S, Wagley PK, Settlage R, LaConte LEW, Goodkin HP, Lazar I, Srivastava S, Mukherjee K. Haploinsufficiency of X-linked intellectual disability gene CASK induces post-transcriptional changes in synaptic and cellular metabolic pathways. Exp Neurol 2020; 329:113319. [PMID: 32305418 DOI: 10.1016/j.expneurol.2020.113319] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 04/04/2020] [Accepted: 04/15/2020] [Indexed: 12/17/2022]
Abstract
Heterozygous mutations in the X-linked gene CASK are associated with intellectual disability, microcephaly, pontocerebellar hypoplasia, optic nerve hypoplasia and partially penetrant seizures in girls. The Cask+/- heterozygous knockout female mouse phenocopies the human disorder and exhibits postnatal microencephaly, cerebellar hypoplasia and optic nerve hypoplasia. It is not known if Cask+/- mice also display seizures, nor is known the molecular mechanism by which CASK haploinsufficiency produces the numerous documented phenotypes. 24-h video electroencephalography demonstrates that despite sporadic seizure activity, the overall electrographic patterns remain unaltered in Cask+/- mice. Additionally, seizure threshold to the commonly used kindling agent, pentylenetetrazol, remains unaltered in Cask+/- mice, indicating that even in mice the seizure phenotype is only partially penetrant and may have an indirect mechanism. RNA sequencing experiments on Cask+/- mouse brain uncovers a very limited number of changes, with most differences arising in the transcripts of extracellular matrix proteins and the transcripts of a group of nuclear proteins. In contrast to limited changes at the transcript level, quantitative whole-brain proteomics using iTRAQ quantitative mass-spectrometry reveals major changes in synaptic, metabolic/mitochondrial, cytoskeletal, and protein metabolic pathways. Unbiased protein-protein interaction mapping using affinity chromatography demonstrates that CASK may form complexes with proteins belonging to the same functional groups in which altered protein levels are observed. We discuss the mechanism of the observed changes in the context of known molecular function/s of CASK. Overall, our data indicate that the phenotypic spectrum of female Cask+/- mice includes sporadic seizures and thus closely parallels that of CASK haploinsufficient girls; the Cask+/- mouse is thus a face-validated model for CASK-related pathologies. We therefore surmise that CASK haploinsufficiency is likely to affect brain structure and function due to dysregulation of several cellular pathways including synaptic signaling and cellular metabolism.
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Affiliation(s)
- P A Patel
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, United States; Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA, United States
| | - C Liang
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, United States
| | - A Arora
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, United States
| | - S Vijayan
- School of Neuroscience, Virginia Tech, Blacksburg, VA, United States
| | - S Ahuja
- Biological Sciences, Virginia Tech, Blacksburg, VA, United States
| | - P K Wagley
- Neurology, University of Virginia, Charlottesville, VA, USA
| | - R Settlage
- Advanced Research Computing, Virginia Tech, Blacksburg, VA, United States
| | - L E W LaConte
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, United States
| | - H P Goodkin
- Neurology, University of Virginia, Charlottesville, VA, USA
| | - I Lazar
- Biological Sciences, Virginia Tech, Blacksburg, VA, United States
| | - S Srivastava
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, United States
| | - K Mukherjee
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, United States; Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, United States; Department of Psychiatry and Behavioral Medicine, Virginia Tech Carilion School of Medicine, Roanoke, VA, United States.
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20
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Lee S, Kim SH, Kim B, Lee ST, Choi JR, Kim HD, Lee JS, Kang HC. Genetic diagnosis and clinical characteristics by etiological classification in early-onset epileptic encephalopathy with burst suppression pattern. Epilepsy Res 2020; 163:106323. [PMID: 32247221 DOI: 10.1016/j.eplepsyres.2020.106323] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 03/01/2020] [Accepted: 03/20/2020] [Indexed: 01/17/2023]
Abstract
BACKGROUND Early-onset epileptic encephalopathies with burst suppression (EOEE-BS) are a group of neonatal epileptic syndromes characterized by intractable epilepsy and severe psychomotor delay with structural and metabolic factors accounting for major etiologies. However, recent advances in gene sequencing have identified that genetic factors might also play a significant role in the development of EOEE-BS. Herein, we used various genetic tests to identify pathogenic genetic variants in EOEE-BS irrespective of structural malformations and analyzed the clinical features associated with each different etiology. METHODS A total of 48 patients with EOEE-BS were included. Except for patients with severe hypoxic damage, patients with structural malformations were included in our patient cohort. Clinical features of the patients were reviewed, and etiological diagnoses were made based on several genetic tests, metabolic studies, and radiological findings. RESULT A genetic diagnosis was made in 31 (64.6 %) patients, with the most commonly diagnosed gene being STXBP1 (n = 13, 27.1 %), followed by KCNQ2 (n = 5, 10.4 %), SCN2A (n = 5, 10.4 %), DEPDC5 (n = 3, 6.3 %), CASK (n = 1, 2.1 %), CDKL5 (n = 1, 2.1 %), GNAO1 (n = 1, 2.1 %), SLC6A8 (n = 1, 2.1 %), and LIS1 deletion (n = 1, 2.1 %). Other than the classification of epilepsy syndrome, no clinical features were associated with the genetically diagnosed group. Among eight patients with structural malformations, genetic diagnosis was achieved in five (62.5 %), and those patients had pathogenic mutations in DEPDC5 and CASK or LIS1 deletion, indicating the significance of gene sequencing irrespective of structural abnormalities. Treatment responses to a variety of medications and the ketogenic diet differed by etiology, and surgical resection proved to be effective in patients with cortical dysplasia. CONCLUSION Genetic etiologies are an important factor in EOEE-BS irrespective of structural malformations and the treatment options may differ by etiology.
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Affiliation(s)
- Sangbo Lee
- Division of Pediatric Neurology, Epilepsy Research Institute, Severance Children's Hospital, Department of Pediatrics, Yonsei University College of Medicine, Yonsei-ro 50-1, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Se Hee Kim
- Division of Pediatric Neurology, Epilepsy Research Institute, Severance Children's Hospital, Department of Pediatrics, Yonsei University College of Medicine, Yonsei-ro 50-1, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Borahm Kim
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Yonsei-ro 50-1, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Seung-Tae Lee
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Yonsei-ro 50-1, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Jong Rak Choi
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Yonsei-ro 50-1, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Heung Dong Kim
- Division of Pediatric Neurology, Epilepsy Research Institute, Severance Children's Hospital, Department of Pediatrics, Yonsei University College of Medicine, Yonsei-ro 50-1, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Joon Soo Lee
- Division of Pediatric Neurology, Epilepsy Research Institute, Severance Children's Hospital, Department of Pediatrics, Yonsei University College of Medicine, Yonsei-ro 50-1, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Hoon-Chul Kang
- Division of Pediatric Neurology, Epilepsy Research Institute, Severance Children's Hospital, Department of Pediatrics, Yonsei University College of Medicine, Yonsei-ro 50-1, Seodaemun-gu, Seoul, 03722, Republic of Korea.
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21
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Abstract
Developmental and epileptic encephalopathies (DEEs) can be primarily attributed to genetic causes. The genetic landscape of DEEs has been largely shaped by the rise of high-throughput sequencing, which led to the discovery of new DEE-associated genes and helped identify de novo pathogenic variants. We discuss briefly the contribution of de novo variants to DEE and also focus on alternative inheritance models that contribute to DEE. First, autosomal recessive inheritance in outbred populations may have a larger contribution than previously appreciated, accounting for up to 13% of DEEs. A small subset of genes that typically harbor de novo variants have been associated with recessive inheritance, and often these individuals have more severe clinical presentations. Additionally, pathogenic variants in X-linked genes have been identified in both affected males and females, possibly due to a lack of X-chromosome inactivation skewing. Collectively, exome sequencing has resulted in a molecular diagnosis for many individuals with DEE, but this still leaves many cases unsolved. Multiple factors contribute to the missing etiology, including nonexonic variants, mosaicism, epigenetics, and oligogenic inheritance. Here, we focus on the first 2 factors. We discuss the promises and challenges of genome sequencing, which allows for a more comprehensive analysis of the genome, including interpretation of structural and noncoding variants and also yields a high number of de novo variants for interpretation. We also consider the contribution of genetic mosaicism, both what it means for a molecular diagnosis in mosaic individuals and the important implications for genetic counseling.
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Affiliation(s)
- Hannah C Happ
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Gemma L Carvill
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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22
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Kerr A, Patel PA, LaConte LEW, Liang C, Chen CK, Shah V, Fox MA, Mukherjee K. Non-Cell Autonomous Roles for CASK in Optic Nerve Hypoplasia. Invest Ophthalmol Vis Sci 2019; 60:3584-3594. [PMID: 31425583 PMCID: PMC6701874 DOI: 10.1167/iovs.19-27197] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Purpose Heterozygous mutations in the essential X-linked gene CASK associate with optic nerve hypoplasia (ONH) and other retinal disorders in girls. CASK+/− heterozygous knockout mice with mosaic CASK expression exhibit ONH with a loss of retinal ganglion cells (RGCs) but no changes in retinal morphology. It remains unclear if CASK deficiency selectively affects RGCs or also affects other retinal cells. Furthermore, it is not known if CASK expression in RGCs is critical for optic nerve (ON) development and maintenance. Methods The visual behavior of CASK+/− mice was assessed and electroretinography (ERG) was performed. Using a mouse line with a floxed CASK gene that expresses approximately 40% CASK globally in all cells (hypomorph) under hemizygous and homozygous conditions, we investigated effects of CASK reduction on the retina and ON. CASK then was completely deleted from RGCs to examine its cell-autonomous role. Finally, for the first time to our knowledge, we describe a hemizygous CASK missense mutation in a boy with ONH. Results CASK+/− heterozygous mutant mice display reduced visual contrast sensitivity, but ERG is indistinguishable from wildtype. CASK hypomorph mice exhibit ONH, but deletion of CASK from RGCs in this background does not exacerbate the condition. The boy with ONH harbors a missense mutation (p.Pro673Leu) that destabilizes CASK and weakens the crucial CASK–neurexin interaction. Conclusions Our results demonstrate that mosaic or global reduction in CASK expression and/or function disproportionately affects RGCs. CASK expression in RGCs does not appear critical for cell survival, indicating a noncell autonomous role for CASK in the development of ON.
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Affiliation(s)
- Alicia Kerr
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, United States.,Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, Virginia, United States
| | - Paras A Patel
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, United States.,Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, Virginia, United States
| | - Leslie E W LaConte
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, United States.,Department of Basic Science Education, Virginia Tech Carilion School of Medicine, Roanoke, Virginia, United States
| | - Chen Liang
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, United States
| | - Ching-Kang Chen
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States
| | - Veeral Shah
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States.,Texas Children's Hospital, Houston, Texas, United States
| | - Michael A Fox
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, United States.,Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, United States.,Department of Pediatrics, Virginia Tech Carilion School of Medicine, Roanoke, Virginia, United States
| | - Konark Mukherjee
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, United States.,Department of Psychiatry and Behavioral Medicine, Virginia Tech Carilion School of Medicine, Roanoke, Virginia, United States
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23
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Syntenin: PDZ Protein Regulating Signaling Pathways and Cellular Functions. Int J Mol Sci 2019; 20:ijms20174171. [PMID: 31454940 PMCID: PMC6747541 DOI: 10.3390/ijms20174171] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 08/22/2019] [Accepted: 08/22/2019] [Indexed: 12/29/2022] Open
Abstract
Syntenin is an adaptor-like molecule that has two adjacent tandem postsynaptic density protein 95/Discs large protein/Zonula occludens 1 (PDZ) domains. The PDZ domains of syntenin recognize multiple peptide motifs with low to moderate affinity. Many reports have indicated interactions between syntenin and a plethora of proteins. Through interactions with various proteins, syntenin regulates the architecture of the cell membrane. As a result, increases in syntenin levels induce the metastasis of tumor cells, protrusion along the neurite in neuronal cells, and exosome biogenesis in various cell types. Here, we review the updated data that support various roles for syntenin in the regulation of neuronal synapses, tumor cell invasion, and exosome control.
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24
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Mori T, Kasem EA, Suzuki-Kouyama E, Cao X, Li X, Kurihara T, Uemura T, Yanagawa T, Tabuchi K. Deficiency of calcium/calmodulin-dependent serine protein kinase disrupts the excitatory-inhibitory balance of synapses by down-regulating GluN2B. Mol Psychiatry 2019; 24:1079-1092. [PMID: 30610199 PMCID: PMC6756202 DOI: 10.1038/s41380-018-0338-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 11/27/2018] [Accepted: 12/10/2018] [Indexed: 11/24/2022]
Abstract
Calcium/calmodulin-dependent serine protein kinase (CASK) is a membrane-associated guanylate kinase (MAGUK) protein that is associated with neurodevelopmental disorders. CASK is thought to have both pre- and postsynaptic functions, but the mechanism and consequences of its functions in the brain have yet to be elucidated, because homozygous CASK-knockout (CASK-KO) mice die before brain maturation. Taking advantage of the X-chromosome inactivation (XCI) mechanism, here we examined the synaptic functions of CASK-KO neurons in acute brain slices of heterozygous CASK-KO female mice. We also analyzed CASK-knockdown (KD) neurons in acute brain slices generated by in utero electroporation. Both CASK-KO and CASK-KD neurons showed a disruption of the excitatory and inhibitory (E/I) balance. We further found that the expression level of the N-methyl-D-aspartate receptor subunit GluN2B was decreased in CASK-KD neurons and that overexpressing GluN2B rescued the disrupted E/I balance in CASK-KD neurons. These results suggest that the down-regulation of GluN2B may be involved in the mechanism of the disruption of synaptic E/I balance in CASK-deficient neurons.
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Affiliation(s)
- Takuma Mori
- 0000 0001 1507 4692grid.263518.bDepartment of Molecular and Cellular Physiology, Institute of Medicine, Academic Assembly, Shinshu University, Nagano, 390-8621 Japan
| | - Enas A. Kasem
- 0000 0001 1507 4692grid.263518.bDepartment of Molecular and Cellular Physiology, Institute of Medicine, Academic Assembly, Shinshu University, Nagano, 390-8621 Japan ,0000 0004 0578 3577grid.411978.2Department of Zoology, Faculty of Science, Kafr Elsheikh University, Kafr Elsheihk, 33511 Egypt
| | - Emi Suzuki-Kouyama
- 0000 0001 1507 4692grid.263518.bDepartment of Molecular and Cellular Physiology, Institute of Medicine, Academic Assembly, Shinshu University, Nagano, 390-8621 Japan
| | - Xueshan Cao
- 0000 0001 1507 4692grid.263518.bDepartment of Molecular and Cellular Physiology, Institute of Medicine, Academic Assembly, Shinshu University, Nagano, 390-8621 Japan
| | - Xue Li
- 0000 0001 1507 4692grid.263518.bDepartment of Molecular and Cellular Physiology, Institute of Medicine, Academic Assembly, Shinshu University, Nagano, 390-8621 Japan
| | - Taiga Kurihara
- 0000 0001 1507 4692grid.263518.bDepartment of Molecular and Cellular Physiology, Institute of Medicine, Academic Assembly, Shinshu University, Nagano, 390-8621 Japan
| | - Takeshi Uemura
- 0000 0001 1507 4692grid.263518.bDepartment of Molecular and Cellular Physiology, Institute of Medicine, Academic Assembly, Shinshu University, Nagano, 390-8621 Japan ,0000 0001 1507 4692grid.263518.bInstitute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Nagano, 390-8621 Japan ,0000 0004 1754 9200grid.419082.6CREST, JST, Saitama, 332-0012 Japan
| | - Toru Yanagawa
- 0000 0001 2369 4728grid.20515.33Department of Oral and Maxillofacial Surgery, Faculty of Medicine, University of Tsukuba, Ibaraki, 305-8575 Japan
| | - Katsuhiko Tabuchi
- Department of Molecular and Cellular Physiology, Institute of Medicine, Academic Assembly, Shinshu University, Nagano, 390-8621, Japan. .,Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Nagano, 390-8621, Japan. .,PRESTO, JST, Saitama, 332-0012, Japan.
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25
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LaConte LEW, Chavan V, DeLuca S, Rubin K, Malc J, Berry S, Gail Summers C, Mukherjee K. An N-terminal heterozygous missense CASK mutation is associated with microcephaly and bilateral retinal dystrophy plus optic nerve atrophy. Am J Med Genet A 2018; 179:94-103. [PMID: 30549415 DOI: 10.1002/ajmg.a.60687] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 09/26/2018] [Accepted: 10/17/2018] [Indexed: 11/08/2022]
Abstract
Heterozygous loss-of-function mutations in the X-linked gene CASK are associated with mental retardation and microcephaly with pontine and cerebellar hypoplasia (MICPCH) and ophthalmological disorders including optic nerve atrophy (ONA) and optic nerve hypoplasia (ONH). Recently, we have demonstrated that CASK(+/-) mice display ONH with 100% penetrance but exhibit no change in retinal lamination or structure. It is not clear if CASK loss-of-function predominantly affects retinal ganglion cells, or if other retinal cells like photoreceptors are also involved. Here, we report a heterozygous missense mutation in the N-terminal calcium/calmodulin-dependent kinase (CaMK) domain of the CASK protein in which a highly conserved leucine is mutated to the cyclic amino acid proline. In silico analysis suggests that the mutation may produce destabilizing structural changes. Experimentally, we observe pronounced misfolding and insolubility of the CASKL209P protein. Interestingly, the remaining soluble mutant protein fails to interact with Mint1, which specifically binds to CASK's CaMK domain, suggesting a mechanism for the phenotypes observed with the CASKL209P mutation. In addition to microcephaly, cerebellar hypoplasia and delayed development, the subject with the L209P mutation also presented with bilateral retinal dystrophy and ONA. Electroretinography indicated that rod photoreceptors are the most prominently affected cells. Our data suggest that the CASK interactions mediated by the CaMK domain may play a crucial role in retinal function, and thus, in addition to ONH, individuals with mutations in the CASK gene may exhibit other retinal disorders, depending on the nature of mutation.
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Affiliation(s)
| | - Vrushali Chavan
- Virginia Tech Carilion Research Institute, Roanoke, Virginia
| | | | - Karol Rubin
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, Minnesota
| | - Jessica Malc
- Virginia Tech Carilion Research Institute, Roanoke, Virginia
| | - Susan Berry
- Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota.,Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, Minnesota
| | - C Gail Summers
- Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota.,Department of Ophthalmology & Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota
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26
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Bindu PS, Nagappa M, Chiplunkar S, Govindaraj P, Mathuranath PS, Sinha S, Taly AB. Clinical Reasoning: West syndrome, pontocerebellar hypoplasia, and hypomyelination in a 6-month-old boy. Neurology 2018; 91:e1652-e1656. [PMID: 30348860 DOI: 10.1212/wnl.0000000000006381] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Parayil Sankaran Bindu
- From the Department of Neurology (P.S.B., M.N., P.G., P.S.M., S.S., A.B.T.) and Neuromuscular Lab-Neurobiology Research Center (P.S.B., M.N., S.C., P.G., A.B.T.), National Institute of Mental Health and Neurosciences, Bangalore, India.
| | - Madhu Nagappa
- From the Department of Neurology (P.S.B., M.N., P.G., P.S.M., S.S., A.B.T.) and Neuromuscular Lab-Neurobiology Research Center (P.S.B., M.N., S.C., P.G., A.B.T.), National Institute of Mental Health and Neurosciences, Bangalore, India
| | - Shwetha Chiplunkar
- From the Department of Neurology (P.S.B., M.N., P.G., P.S.M., S.S., A.B.T.) and Neuromuscular Lab-Neurobiology Research Center (P.S.B., M.N., S.C., P.G., A.B.T.), National Institute of Mental Health and Neurosciences, Bangalore, India
| | - Periyasamy Govindaraj
- From the Department of Neurology (P.S.B., M.N., P.G., P.S.M., S.S., A.B.T.) and Neuromuscular Lab-Neurobiology Research Center (P.S.B., M.N., S.C., P.G., A.B.T.), National Institute of Mental Health and Neurosciences, Bangalore, India
| | - Pavagada S Mathuranath
- From the Department of Neurology (P.S.B., M.N., P.G., P.S.M., S.S., A.B.T.) and Neuromuscular Lab-Neurobiology Research Center (P.S.B., M.N., S.C., P.G., A.B.T.), National Institute of Mental Health and Neurosciences, Bangalore, India
| | - Sanjib Sinha
- From the Department of Neurology (P.S.B., M.N., P.G., P.S.M., S.S., A.B.T.) and Neuromuscular Lab-Neurobiology Research Center (P.S.B., M.N., S.C., P.G., A.B.T.), National Institute of Mental Health and Neurosciences, Bangalore, India
| | - Arun B Taly
- From the Department of Neurology (P.S.B., M.N., P.G., P.S.M., S.S., A.B.T.) and Neuromuscular Lab-Neurobiology Research Center (P.S.B., M.N., S.C., P.G., A.B.T.), National Institute of Mental Health and Neurosciences, Bangalore, India
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27
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Bozarth X, Foss K, Mefford HC. A de novo in-frame deletion of CASK
gene causes early onset infantile spasms and supratentorial cerebral malformation in a female patient. Am J Med Genet A 2018; 176:2425-2429. [DOI: 10.1002/ajmg.a.40429] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 06/06/2018] [Accepted: 06/10/2018] [Indexed: 11/06/2022]
Affiliation(s)
- Xiuhua Bozarth
- Department of Neurology; Seattle Children's Hospital, University of Washington; Seattle Washington
| | - Kimberly Foss
- Department of Genetics; Seattle Children's Hospital; Seattle Washington
| | - Heather C. Mefford
- Division of Genetic Medicine, Department of Pediatrics; University of Washington; Seattle Washington
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28
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Cristofoli F, Devriendt K, Davis EE, Van Esch H, Vermeesch JR. Novel CASK mutations in cases with syndromic microcephaly. Hum Mutat 2018; 39:993-1001. [PMID: 29691940 PMCID: PMC5995665 DOI: 10.1002/humu.23536] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 04/13/2018] [Accepted: 04/17/2018] [Indexed: 11/05/2022]
Abstract
Mutations in CASK cause a wide spectrum of phenotypes in humans ranging from mild X-linked intellectual disability to a severe microcephaly (MC) and pontocerebellar hypoplasia syndrome. Nevertheless, predicting pathogenicity and phenotypic consequences of novel CASK mutations through the exclusive consideration of genetic information and population-based data remains a challenge. Using whole exome sequencing, we identified four novel CASK mutations in individuals with syndromic MC. To understand the functional consequences of the different point mutations on the development of MC and cerebellar defects, we established a transient loss-of-function zebrafish model, and demonstrate recapitulation of relevant neuroanatomical phenotypes. Furthermore, we utilized in vivo complementation studies to demonstrate that the three point mutations confer a loss-of-function effect. This work endorses zebrafish as a tractable model to rapidly assess the effect of novel CASK variants on brain development.
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Affiliation(s)
- Francesca Cristofoli
- Laboratory for Cytogenetics and Genome Research, Center for Human Genetics, KU Leuven, Leuven, Belgium
| | - Koen Devriendt
- Center for Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Erica E Davis
- Center for Human Disease Modeling, Duke University Medical Center, Durham, North Carolina
| | - Hilde Van Esch
- Center for Human Genetics, University Hospitals Leuven, Leuven, Belgium
- Laboratory for the Genetics of Cognition, Center for Human Genetics, KU Leuven, Leuven, Belgium
| | - Joris R Vermeesch
- Laboratory for Cytogenetics and Genome Research, Center for Human Genetics, KU Leuven, Leuven, Belgium
- Center for Human Genetics, University Hospitals Leuven, Leuven, Belgium
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29
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Abstract
Neonatal epilepsy genetics is a rapidly expanding field with recent technological advances in genomics leading to an expanding list of genetic disorders associated with neonatal-onset epilepsy. The genetic causes of neonatal epilepsy can be grouped into the following categories: (i) malformations of cortical development, (ii) genetic-metabolic, (iii) genetic-vascular, (iv) genetic-syndromic, and (v) genetic-cellular. Clinically, epilepsy in the neonate shows phenotypic overlap with pathogenic variants in unrelated genes causing similar clinical presentation (locus heterogeneity) and variants in the same gene leading to a wide clinical spectrum ranging from benign familial neonatal seizures to more severe epileptic encephalopathies (variable expressivity). We suggest a diagnostic approach to obtaining a genetic diagnosis with emphasis on clinical features such as electro-clinical phenotype and magnetic resonance imaging findings. Rapid identification of genetic disorders with targeted treatments should be a clinical priority. Achieving a genetic diagnosis can be challenging in a rapidly changing genetic landscape, but is increasingly possible.
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30
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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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31
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Lei T, Feng JL, Xie YJ, Xie HN, Zheng J, Lin MF. Chromosomal aneuploidies and copy number variations in posterior fossa abnormalities diagnosed by prenatal ultrasonography. Prenat Diagn 2017; 37:1160-1168. [PMID: 28940600 DOI: 10.1002/pd.5159] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 09/07/2017] [Accepted: 09/13/2017] [Indexed: 01/04/2023]
Abstract
OBJECTIVE To explore the genetic aetiology of fetal posterior fossa abnormalities (PFAs). METHODS This study involved cases of PFAs that were identified by prenatal ultrasonographic screening and confirmed postnatally between January 2012 and January 2016. Conventional cytogenetic analyses and chromosomal microarray analysis were performed, and chromosomal aneuploidies and copy number variations (CNVs) were identified. RESULTS Among 74 cases included in this study, 8 were of Blake's pouch cyst; 7, Dandy-Walker malformation; 11, vermian hypoplasia; 32, enlarged cisterna magna; and 16, cerebellar hypoplasia. The rates of nonbenign chromosomal aberrations (including chromosomal aneuploidies, pathogenic CNVs, and variants of unknown significance) were 2/8 (25.0%), 2/7 (28.5%), 8/11 (72.7%), 7/32 (21.9%), and 6/16 (37.5%), respectively. Cases were also classified as isolated PFAs (30/74), PFAs with other central nervous system (CNS) abnormalities (13/74), or PFAs with extra-CNS structural abnormalities (31/74). No fetuses with isolated PFAs or PFAs accompanied by other CNS abnormalities exhibited chromosomal aneuploidies or pathogenic CNVs. The rate of pathogenic chromosomal aberrations in the remaining fetuses was 17/31 (22.9%). CONCLUSION The combined use of chromosomal microarray analysis and karyotype analysis might assist the prenatal diagnosis and management of PFAs, with extra-CNS structural abnormalities being detected by ultrasonography.
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Affiliation(s)
- Ting Lei
- Department of Ultrasonic Medicine, Fetal Medical Centre, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Jie-Ling Feng
- Department of Ultrasonic Medicine, Fetal Medical Centre, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Ying-Jun Xie
- Key Laboratory for Major Obstetric Diseases of Guangdong Province, Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutes, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Hong-Ning Xie
- Department of Ultrasonic Medicine, Fetal Medical Centre, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Ju Zheng
- Department of Ultrasonic Medicine, Fetal Medical Centre, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Mei-Fang Lin
- Department of Ultrasonic Medicine, Fetal Medical Centre, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
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32
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Seto T, Hamazaki T, Nishigaki S, Kudo S, Shintaku H, Ondo Y, Shimojima K, Yamamoto T. A novel CASK mutation identified in siblings exhibiting developmental disorders with/without microcephaly. Intractable Rare Dis Res 2017; 6:177-182. [PMID: 28944139 PMCID: PMC5608927 DOI: 10.5582/irdr.2017.01031] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The calcium/calmodulin-dependent serine protein kinase gene (CASK) mutations are associated with various neurological disorders; a syndrome of intellectual disability (ID) and microcephaly with pontine and cerebellar hypoplasia (MICPCH), FG syndrome, X-linked ID with/without nystagmus, epileptic encephalopathy, and autistic spectrum disorder (ASD). Next generation sequencing was performed to elucidate genetic causes in siblings exhibiting developmental disorders, and a novel CASK mutation, c.1424G>T (p.Ser475Ile), was detected in a male patient with ID, ASD, and microcephaly. Radiological examination of his brain showed no structural abnormality. The identified mutation was shared with the healthy mother and a younger sister exhibiting ASD. Although the mother showed a skewed X-chromosome inactivation (XCI) pattern, the sister showed a paradoxical XCI pattern. This would explain why this sister possessed a normal intellectual level, but showed the same ASD symptoms as the affected brother. A novel CASK mutation was identified in two siblings with ID and/or ASD, suggesting a relationship between the CASK mutation and ASD. Recently performed large molecular cohorts for patients with developmental disorders suggest that CASK is one of the genes related to developmental disorders. For better understanding of genotype-phenotype correlation in ASD cases with CASK mutations, more information should be accumulated.
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Affiliation(s)
- Toshiyuki Seto
- Department of Pediatrics, Osaka City University, Osaka, Japan
| | | | | | - Satoshi Kudo
- Department of Pediatrics, Osaka City University, Osaka, Japan
| | - Haruo Shintaku
- Department of Pediatrics, Osaka City University, Osaka, Japan
| | - Yumiko Ondo
- Institute of Medical Genetics, Tokyo Women's Medical University, Tokyo, Japan
| | - Keiko Shimojima
- Institute of Medical Genetics, Tokyo Women's Medical University, Tokyo, Japan
| | - Toshiyuki Yamamoto
- Institute of Medical Genetics, Tokyo Women's Medical University, Tokyo, Japan
- Address correspondence to: Dr. Toshiyuki Yamamoto, Institute of Medical Genetics, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ward, Tokyo 162-8666, Japan. E-mail:
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33
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Leto K, Arancillo M, Becker EBE, Buffo A, Chiang C, Ding B, Dobyns WB, Dusart I, Haldipur P, Hatten ME, Hoshino M, Joyner AL, Kano M, Kilpatrick DL, Koibuchi N, Marino S, Martinez S, Millen KJ, Millner TO, Miyata T, Parmigiani E, Schilling K, Sekerková G, Sillitoe RV, Sotelo C, Uesaka N, Wefers A, Wingate RJT, Hawkes R. Consensus Paper: Cerebellar Development. CEREBELLUM (LONDON, ENGLAND) 2016; 15:789-828. [PMID: 26439486 PMCID: PMC4846577 DOI: 10.1007/s12311-015-0724-2] [Citation(s) in RCA: 240] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The development of the mammalian cerebellum is orchestrated by both cell-autonomous programs and inductive environmental influences. Here, we describe the main processes of cerebellar ontogenesis, highlighting the neurogenic strategies used by developing progenitors, the genetic programs involved in cell fate specification, the progressive changes of structural organization, and some of the better-known abnormalities associated with developmental disorders of the cerebellum.
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Affiliation(s)
- Ketty Leto
- Department of Neuroscience Rita Levi Montalcini, University of Turin, via Cherasco 15, 10026, Turin, Italy.
- Neuroscience Institute Cavalieri-Ottolenghi, University of Turin, Regione Gonzole 10, 10043, Orbassano, Torino, Italy.
| | - Marife Arancillo
- Departments of Pathology & Immunology and Neuroscience, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA
| | - Esther B E Becker
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK
| | - Annalisa Buffo
- Department of Neuroscience Rita Levi Montalcini, University of Turin, via Cherasco 15, 10026, Turin, Italy
- Neuroscience Institute Cavalieri-Ottolenghi, University of Turin, Regione Gonzole 10, 10043, Orbassano, Torino, Italy
| | - Chin Chiang
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, 4114 MRB III, Nashville, TN, 37232, USA
| | - Baojin Ding
- Department of Microbiology and Physiological Systems and Program in Neuroscience, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA, 01605-2324, USA
| | - William B Dobyns
- Seattle Children's Research Institute, Center for Integrative Brain Research, Seattle, WA, USA
- Department of Pediatrics, Genetics Division, University of Washington, Seattle, WA, USA
| | - Isabelle Dusart
- Sorbonne Universités, Université Pierre et Marie Curie Univ Paris 06, Institut de Biologie Paris Seine, France, 75005, Paris, France
- Centre National de la Recherche Scientifique, CNRS, UMR8246, INSERM U1130, Neuroscience Paris Seine, France, 75005, Paris, France
| | - Parthiv Haldipur
- Seattle Children's Research Institute, Center for Integrative Brain Research, Seattle, WA, USA
| | - Mary E Hatten
- Laboratory of Developmental Neurobiology, The Rockefeller University, New York, NY, 10065, USA
| | - Mikio Hoshino
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Alexandra L Joyner
- Developmental Biology Program, Sloan Kettering Institute, New York, NY, 10065, USA
| | - Masanobu Kano
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Daniel L Kilpatrick
- Department of Microbiology and Physiological Systems and Program in Neuroscience, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA, 01605-2324, USA
| | - Noriyuki Koibuchi
- Department of Integrative Physiology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma, 371-8511, Japan
| | - Silvia Marino
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Salvador Martinez
- Department Human Anatomy, IMIB-Arrixaca, University of Murcia, Murcia, Spain
| | - Kathleen J Millen
- Seattle Children's Research Institute, Center for Integrative Brain Research, Seattle, WA, USA
| | - Thomas O Millner
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Takaki Miyata
- Department of Anatomy and Cell Biology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Elena Parmigiani
- Department of Neuroscience Rita Levi Montalcini, University of Turin, via Cherasco 15, 10026, Turin, Italy
- Neuroscience Institute Cavalieri-Ottolenghi, University of Turin, Regione Gonzole 10, 10043, Orbassano, Torino, Italy
| | - Karl Schilling
- Anatomie und Zellbiologie, Anatomisches Institut, Rheinische Friedrich-Wilhelms-Universität, Bonn, Germany
| | - Gabriella Sekerková
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Roy V Sillitoe
- Departments of Pathology & Immunology and Neuroscience, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX, 77030, USA
| | - Constantino Sotelo
- Institut de la Vision, UPMC Université de Paris 06, Paris, 75012, France
| | - Naofumi Uesaka
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Annika Wefers
- Center for Neuropathology, Ludwig-Maximilians-University, Munich, Germany
| | - Richard J T Wingate
- MRC Centre for Developmental Neurobiology, King's College London, London, UK
| | - Richard Hawkes
- Department of Cell Biology & Anatomy and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, T2N 4NI, AB, Canada
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Jiang X, Lachance M, Rossignol E. Involvement of cortical fast-spiking parvalbumin-positive basket cells in epilepsy. PROGRESS IN BRAIN RESEARCH 2016; 226:81-126. [PMID: 27323940 DOI: 10.1016/bs.pbr.2016.04.012] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
GABAergic interneurons of the parvalbumin-positive fast-spiking basket cells subtype (PV INs) are important regulators of cortical network excitability and of gamma oscillations, involved in signal processing and cognition. Impaired development or function of PV INs has been associated with epilepsy in various animal models of epilepsy, as well as in some genetic forms of epilepsy in humans. In this review, we provide an overview of some of the experimental data linking PV INs dysfunction with epilepsy, focusing on disorders of the specification, migration, maturation, synaptic function, or connectivity of PV INs. Furthermore, we reflect on the potential therapeutic use of cell-type specific stimulation of PV INs within active networks and on the transplantation of PV INs precursors in the treatment of epilepsy and its comorbidities.
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Affiliation(s)
- X Jiang
- Université de Montréal, Montréal, QC, Canada; CHU Ste-Justine Research Center, Montréal, QC, Canada
| | - M Lachance
- CHU Ste-Justine Research Center, Montréal, QC, Canada
| | - E Rossignol
- Université de Montréal, Montréal, QC, Canada; CHU Ste-Justine Research Center, Montréal, QC, Canada.
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X-linked intellectual disability gene CASK regulates postnatal brain growth in a non-cell autonomous manner. Acta Neuropathol Commun 2016; 4:30. [PMID: 27036546 PMCID: PMC4818453 DOI: 10.1186/s40478-016-0295-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 03/07/2016] [Indexed: 01/07/2023] Open
Abstract
The phenotypic spectrum among girls with heterozygous mutations in the X-linked intellectual disability (XLID) gene CASK (calcium/calmodulin-dependent serine protein kinase) includes postnatal microcephaly, ponto-cerebellar hypoplasia, seizures, optic nerve hypoplasia, growth retardation and hypotonia. Although CASK knockout mice were previously reported to exhibit perinatal lethality and a 3-fold increased apoptotic rate in the brain, CASK deletion was not found to affect neuronal physiology and their electrical properties. The pathogenesis of CASK associated disorders and the potential function of CASK therefore remains unknown. Here, using Cre-LoxP mediated gene excision experiments; we demonstrate that deleting CASK specifically from mouse cerebellar neurons does not alter the cerebellar architecture or function. We demonstrate that the neuron-specific deletion of CASK in mice does not cause perinatal lethality but induces severe recurrent epileptic seizures and growth retardation before the onset of adulthood. Furthermore, we demonstrate that although neuron-specific haploinsufficiency of CASK is inconsequential, the CASK mutation associated human phenotypes are replicated with high fidelity in CASK heterozygous knockout female mice (CASK(+/-)). These data suggest that CASK-related phenotypes are not purely neuronal in origin. Surprisingly, the observed microcephaly in CASK(+/-) animals is not associated with a specific loss of CASK null brain cells indicating that CASK regulates postnatal brain growth in a non-cell autonomous manner. Using biochemical assay, we also demonstrate that CASK can interact with metabolic proteins. CASK knockdown in human cell lines cause reduced cellular respiration and CASK(+/-) mice display abnormalities in muscle and brain oxidative metabolism, suggesting a novel function of CASK in metabolism. Our data implies that some phenotypic components of CASK heterozygous deletion mutation associated disorders represent systemic manifestation of metabolic stress and therefore amenable to therapeutic intervention.
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Abstract
While genetic causes of epilepsy have been hypothesized from the time of Hippocrates, the advent of new genetic technologies has played a tremendous role in elucidating a growing number of specific genetic causes for the epilepsies. This progress has contributed vastly to our recognition of the epilepsies as a diverse group of disorders, the genetic mechanisms of which are heterogeneous. Genotype-phenotype correlation, however, is not always clear. Nonetheless, the developments in genetic diagnosis raise the promise of a future of personalized medicine. Multiple genetic tests are now available, but there is no one test for all possible genetic mutations, and the balance between cost and benefit must be weighed. A genetic diagnosis, however, can provide valuable information regarding comorbidities, prognosis, and even treatment, as well as allow for genetic counseling. In this review, we will discuss the genetic mechanisms of the epilepsies as well as the specifics of particular genetic epilepsy syndromes. We will include an overview of the available genetic testing methods, the application of clinical knowledge into the selection of genetic testing, genotype-phenotype correlations of epileptic disorders, and therapeutic advances as well as a discussion of the importance of genetic counseling.
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Affiliation(s)
- Christelle M El Achkar
- Division of Epilepsy, Department of Neurology, Boston Children's Hospital, and Harvard Medical School, Fegan 9, 300 Longwood Ave, Boston, MA, 02115, USA,
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McTague A, Howell KB, Cross JH, Kurian MA, Scheffer IE. The genetic landscape of the epileptic encephalopathies of infancy and childhood. Lancet Neurol 2016; 15:304-16. [DOI: 10.1016/s1474-4422(15)00250-1] [Citation(s) in RCA: 296] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 09/16/2015] [Accepted: 09/17/2015] [Indexed: 10/22/2022]
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Hardies K, Weckhuysen S, De Jonghe P, Suls A. Lessons learned from gene identification studies in Mendelian epilepsy disorders. Eur J Hum Genet 2015; 24:961-7. [PMID: 26603999 DOI: 10.1038/ejhg.2015.251] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 10/05/2015] [Accepted: 10/29/2015] [Indexed: 01/23/2023] Open
Abstract
Next-generation sequencing (NGS) technologies are now routinely used for gene identification in Mendelian disorders. Setting up cost-efficient NGS projects and managing the large amount of variants remains, however, a challenging job. Here we provide insights in the decision-making processes before and after the use of NGS in gene identification studies. Genetic factors are thought to have a role in ~70% of all epilepsies, and a variety of inheritance patterns have been described for seizure-associated gene defects. We therefore chose epilepsy as disease model and selected 35 NGS studies that focused on patients with a Mendelian epilepsy disorder. The strategies used for gene identification and their respective outcomes were reviewed. High-throughput NGS strategies have led to the identification of several new epilepsy-causing genes, enlarging our knowledge on both known and novel pathomechanisms. NGS findings have furthermore extended the awareness of phenotypical and genetic heterogeneity. By discussing recent studies we illustrate: (I) the power of NGS for gene identification in Mendelian disorders, (II) the accelerating pace in which this field evolves, and (III) the considerations that have to be made when performing NGS studies. Nonetheless, the enormous rise in gene discovery over the last decade, many patients and families included in gene identification studies still remain without a molecular diagnosis; hence, further genetic research is warranted. On the basis of successful NGS studies in epilepsy, we discuss general approaches to guide human geneticists and clinicians in setting up cost-efficient gene identification NGS studies.
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Affiliation(s)
- Katia Hardies
- VIB-Department of Molecular Genetics, Neurogenetics Group, University of Antwerp, Antwerp, Belgium.,Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Sarah Weckhuysen
- VIB-Department of Molecular Genetics, Neurogenetics Group, University of Antwerp, Antwerp, Belgium.,Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Peter De Jonghe
- VIB-Department of Molecular Genetics, Neurogenetics Group, University of Antwerp, Antwerp, Belgium.,Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium.,Division of Neurology, Antwerp University Hospital, Antwerp, Belgium
| | - Arvid Suls
- VIB-Department of Molecular Genetics, Neurogenetics Group, University of Antwerp, Antwerp, Belgium.,Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
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Gonsales MC, Montenegro MA, Soler CV, Coan AC, Guerreiro MM, Lopes-Cendes I. Recent developments in the genetics of childhood epileptic encephalopathies: impact in clinical practice. ARQUIVOS DE NEURO-PSIQUIATRIA 2015; 73:946-58. [PMID: 26517219 DOI: 10.1590/0004-282x20150122] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 07/20/2015] [Indexed: 01/03/2023]
Abstract
Recent advances in molecular genetics led to the discovery of several genes for childhood epileptic encephalopathies (CEEs). As the knowledge about the genes associated with this group of disorders develops, it becomes evident that CEEs present a number of specific genetic characteristics, which will influence the use of molecular testing for clinical purposes. Among these, there are the presence of marked genetic heterogeneity and the high frequency of de novo mutations. Therefore, the main objectives of this review paper are to present and discuss current knowledge regarding i) new genetic findings in CEEs, ii) phenotype-genotype correlations in different forms of CEEs; and, most importantly, iii) the impact of these new findings in clinical practice. Accompanying this text we have included a comprehensive table, containing the list of genes currently known to be involved in the etiology of CEEs.
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Affiliation(s)
- Marina C Gonsales
- Instituto Brasileiro de Neurociências e Neurotecnologia, Faculdade de Ciências Médicas, Universidade de Campinas, Campinas, SP, Brazil
| | - Maria Augusta Montenegro
- Instituto Brasileiro de Neurociências e Neurotecnologia, Faculdade de Ciências Médicas, Universidade de Campinas, Campinas, SP, Brazil
| | - Camila V Soler
- Instituto Brasileiro de Neurociências e Neurotecnologia, Faculdade de Ciências Médicas, Universidade de Campinas, Campinas, SP, Brazil
| | - Ana Carolina Coan
- Instituto Brasileiro de Neurociências e Neurotecnologia, Faculdade de Ciências Médicas, Universidade de Campinas, Campinas, SP, Brazil
| | - Marilisa M Guerreiro
- Instituto Brasileiro de Neurociências e Neurotecnologia, Faculdade de Ciências Médicas, Universidade de Campinas, Campinas, SP, Brazil
| | - Iscia Lopes-Cendes
- Instituto Brasileiro de Neurociências e Neurotecnologia, Faculdade de Ciências Médicas, Universidade de Campinas, Campinas, SP, Brazil
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Nakajiri T, Kobayashi K, Okamoto N, Oka M, Miya F, Kosaki K, Yoshinaga H. Late-onset epileptic spasms in a female patient with a CASK mutation. Brain Dev 2015; 37:919-23. [PMID: 25765806 DOI: 10.1016/j.braindev.2015.02.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2014] [Revised: 02/06/2015] [Accepted: 02/16/2015] [Indexed: 10/23/2022]
Abstract
We report a female patient with late-onset epileptic spasms (ESs) of a rare form, distinct from those seen in typical West syndrome, in association with a heterozygous frameshift CASK mutation (c.1896dupC (p.C633fs(∗)2)). She has a phenotype of microcephaly with pontine and cerebellar hypoplasia (MICPCH), and has had intractable ESs in clusters since 3 years 8 months of age with multifocal, particularly bifrontal, epileptic discharges in electroencephalogram. The available literature on patients with both ESs and CASK mutations has been reviewed, revealing that four of the five female children, including the present girl, had late-onset ESs, in contrast to the four males, who tended toward early-onset ESs.
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Affiliation(s)
- Tomoshi Nakajiri
- Department of Child Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences and Okayama University Hospital, Okayama, Japan; Department of Pediatrics, Kakogawa West City Hospital, Kakogawa, Japan
| | - Katsuhiro Kobayashi
- Department of Child Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences and Okayama University Hospital, Okayama, Japan.
| | - Nobuhiko Okamoto
- Department of Medical Genetics, Osaka Medical Center and Research Institute for Maternal and Child Health, Osaka, Japan
| | - Makio Oka
- Department of Child Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences and Okayama University Hospital, Okayama, Japan
| | - Fuyuki Miya
- Laboratory for Medical Science Mathematics, Center for Integrative Medical Sciences, RIKEN, Yokohama, Japan
| | - Kenjiro Kosaki
- Center for Medical Genetics, Keio University School of Medicine, Tokyo, Japan
| | - Harumi Yoshinaga
- Department of Child Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences and Okayama University Hospital, Okayama, Japan
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Lee BH, Smith T, Paciorkowski AR. Autism spectrum disorder and epilepsy: Disorders with a shared biology. Epilepsy Behav 2015; 47:191-201. [PMID: 25900226 PMCID: PMC4475437 DOI: 10.1016/j.yebeh.2015.03.017] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 03/06/2015] [Accepted: 03/13/2015] [Indexed: 12/17/2022]
Abstract
There is an increasing recognition of clinical overlap in patients presenting with epilepsy and autism spectrum disorder (ASD), and a great deal of new information regarding the genetic causes of both disorders is available. Several biological pathways appear to be involved in both disease processes, including gene transcription regulation, cellular growth, synaptic channel function, and maintenance of synaptic structure. We review several genetic disorders where ASD and epilepsy frequently co-occur, and we discuss the screening tools available for practicing neurologists and epileptologists to help determine which patients should be referred for formal ASD diagnostic evaluation. Finally, we make recommendations regarding the workflow of genetic diagnostic testing available for children with both ASD and epilepsy. This article is part of a Special Issue entitled "Autism and Epilepsy".
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Affiliation(s)
- Bo Hoon Lee
- Department of Pediatrics, University of Rochester Medical Center, Rochester, NY, USA
| | - Tristram Smith
- Division of Neurodevelopmental and Behavioral Pediatrics, Department of Pediatrics, University of Rochester Medical Center, Rochester, NY, USA
| | - Alex R Paciorkowski
- Department of Pediatrics, University of Rochester Medical Center, Rochester, NY, USA; Department of Neurology, University of Rochester Medical Center, Rochester, NY, USA; Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, NY, USA; Center for Neural Development and Disease, University of Rochester Medical Center, Rochester, NY, USA.
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42
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Lesca G, Depienne C. Epilepsy genetics: the ongoing revolution. Rev Neurol (Paris) 2015; 171:539-57. [PMID: 26003806 DOI: 10.1016/j.neurol.2015.01.569] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 12/24/2014] [Accepted: 01/20/2015] [Indexed: 01/04/2023]
Abstract
Epilepsies have long remained refractory to gene identification due to several obstacles, including a highly variable inter- and intrafamilial expressivity of the phenotypes, a high frequency of phenocopies, and a huge genetic heterogeneity. Recent technological breakthroughs, such as array comparative genomic hybridization and next generation sequencing, have been leading, in the past few years, to the identification of an increasing number of genomic regions and genes in which mutations or copy-number variations cause various epileptic disorders, revealing an enormous diversity of pathophysiological mechanisms. The field that has undergone the most striking revolution is that of epileptic encephalopathies, for which most of causing genes have been discovered since the year 2012. Some examples are the continuous spike-and-waves during slow-wave sleep and Landau-Kleffner syndromes for which the recent discovery of the role of GRIN2A mutations has finally confirmed the genetic bases. These new technologies begin to be used for diagnostic applications, and the main challenge now resides in the interpretation of the huge mass of variants detected by these methods. The identification of causative mutations in epilepsies provides definitive confirmation of the clinical diagnosis, allows accurate genetic counselling, and sometimes permits the development of new appropriate and specific antiepileptic therapies. Future challenges include the identification of the genetic or environmental factors that modify the epileptic phenotypes caused by mutations in a given gene and the understanding of the role of somatic mutations in sporadic epilepsies.
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Affiliation(s)
- G Lesca
- Service de génétique, groupement hospitalier Est, hospices civils de Lyon, 59, boulevard Pinel, 69677 Bron, France; Université Claude-Bernard Lyon 1, 43, boulevard du 11-Novembre-1918, 69100 Villeurbanne, France; CRNL, CNRS UMR 5292, Inserm U1028, bâtiment IMBL, 11, avenue Jean-Capelle, 69621 Villeurbanne cedex, France.
| | - C Depienne
- Département de génétique et cytogénétique, hôpital Pitié-Salpêtrière, AP-HP, 47-83, boulevard de l'Hôpital, 75651 Paris cedex 13, France; Sorbonne universités, UPMC université Paris 06, 4, place Jussieu, 75005 Paris, France; ICM, CNRS UMR 7225, Inserm U1127, 47, boulevard de l'Hôpital, 75651 Paris cedex 13, France
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Rheb activation disrupts spine synapse formation through accumulation of syntenin in tuberous sclerosis complex. Nat Commun 2015; 6:6842. [PMID: 25880340 DOI: 10.1038/ncomms7842] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 03/03/2015] [Indexed: 01/14/2023] Open
Abstract
Rheb is a small GTP-binding protein and its GTPase activity is activated by the complex of Tsc1 and Tsc2 whose mutations cause tuberous sclerosis complex (TSC). We previously reported that cultured TSC neurons showed impaired spine synapse morphogenesis in an mTORC1-independent manner. Here we show that the PDZ protein syntenin preferentially binds to the GDP-bound form of Rheb. The levels of syntenin are significantly higher in TSC neurons than in wild-type neurons because the Rheb-GDP-syntenin complex is prone to proteasomal degradation. Accumulated syntenin in TSC neurons disrupts spine synapse formation through inhibition of the association between syndecan-2 and calcium/calmodulin-dependent serine protein kinase. Instead, syntenin enhances excitatory shaft synapse formation on dendrites by interacting with ephrinB3. Downregulation of syntenin in TSC neurons restores both spine and shaft synapse densities. These findings suggest that Rheb-syntenin signalling may be a novel therapeutic target for abnormalities in spine and shaft synapses in TSC neurons.
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Moog U, Bierhals T, Brand K, Bautsch J, Biskup S, Brune T, Denecke J, de Die-Smulders CE, Evers C, Hempel M, Henneke M, Yntema H, Menten B, Pietz J, Pfundt R, Schmidtke J, Steinemann D, Stumpel CT, Van Maldergem L, Kutsche K. Phenotypic and molecular insights into CASK-related disorders in males. Orphanet J Rare Dis 2015; 10:44. [PMID: 25886057 PMCID: PMC4449965 DOI: 10.1186/s13023-015-0256-3] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 03/20/2015] [Indexed: 12/05/2022] Open
Abstract
Background Heterozygous loss-of-function mutations in the X-linked CASK gene cause progressive microcephaly with pontine and cerebellar hypoplasia (MICPCH) and severe intellectual disability (ID) in females. Different CASK mutations have also been reported in males. The associated phenotypes range from nonsyndromic ID to Ohtahara syndrome with cerebellar hypoplasia. However, the phenotypic spectrum in males has not been systematically evaluated to date. Methods We identified a CASK alteration in 8 novel unrelated male patients by targeted Sanger sequencing, copy number analysis (MLPA and/or FISH) and array CGH. CASK transcripts were investigated by RT-PCR followed by sequencing. Immunoblotting was used to detect CASK protein in patient-derived cells. The clinical phenotype and natural history of the 8 patients and 28 CASK-mutation positive males reported previously were reviewed and correlated with available molecular data. Results CASK alterations include one nonsense mutation, one 5-bp deletion, one mutation of the start codon, and five partial gene deletions and duplications; seven were de novo, including three somatic mosaicisms, and one was familial. In three subjects, specific mRNA junction fragments indicated in tandem duplication of CASK exons disrupting the integrity of the gene. The 5-bp deletion resulted in multiple aberrant CASK mRNAs. In fibroblasts from patients with a CASK loss-of-function mutation, no CASK protein could be detected. Individuals who are mosaic for a severe CASK mutation or carry a hypomorphic mutation still showed detectable amount of protein. Conclusions Based on eight novel patients and all CASK-mutation positive males reported previously three phenotypic groups can be distinguished that represent a clinical continuum: (i) MICPCH with severe epileptic encephalopathy caused by hemizygous loss-of-function mutations, (ii) MICPCH associated with inactivating alterations in the mosaic state or a partly penetrant mutation, and (iii) syndromic/nonsyndromic mild to severe ID with or without nystagmus caused by CASK missense and splice mutations that leave the CASK protein intact but likely alter its function or reduce the amount of normal protein. Our findings facilitate focused testing of the CASK gene and interpreting sequence variants identified by next-generation sequencing in cases with a phenotype resembling either of the three groups. Electronic supplementary material The online version of this article (doi:10.1186/s13023-015-0256-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ute Moog
- Institute of Human Genetics, Heidelberg University, Heidelberg, Germany.
| | - Tatjana Bierhals
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany.
| | - Kristina Brand
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany.
| | - Jan Bautsch
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany.
| | | | - Thomas Brune
- Universitätskinderklinik, Universitätsklinikum Magdeburg, Magdeburg, Germany.
| | - Jonas Denecke
- Klinik und Poliklinik für Kinder- und Jugendmedizin, Neuropädiatrie, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany.
| | - Christine E de Die-Smulders
- Department of Clinical Genetics and School for Oncology & Developmental Biology (GROW), Maastricht UMC+, Maastricht, The Netherlands.
| | - Christina Evers
- Institute of Human Genetics, Heidelberg University, Heidelberg, Germany.
| | - Maja Hempel
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany.
| | - Marco Henneke
- Klinik für Kinder- und Jugendmedizin, Universitätsmedizin Göttingen, Göttingen, Germany.
| | - Helger Yntema
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Björn Menten
- Center for Medical Genetics, Ghent University, Ghent, Belgium.
| | - Joachim Pietz
- Section of Neuropediatrics, Center for Child and Adolescent Medicine, Heidelberg, Germany.
| | - Rolph Pfundt
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Jörg Schmidtke
- Institut für Humangenetik, Medizinische Hochschule Hannover, Hannover, Germany.
| | - Doris Steinemann
- Institut für Zell- und Molekularpathologie, Medizinische Hochschule Hannover, Hannover, Germany.
| | - Constance T Stumpel
- Department of Clinical Genetics and School for Oncology & Developmental Biology (GROW), Maastricht UMC+, Maastricht, The Netherlands.
| | | | - Kerstin Kutsche
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany.
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Hunter JM, Kiefer J, Balak CD, Jooma S, Ahearn ME, Hall JG, Baumbach-Reardon L. Review of X-linked syndromes with arthrogryposis or early contractures-aid to diagnosis and pathway identification. Am J Med Genet A 2015; 167A:931-73. [DOI: 10.1002/ajmg.a.36934] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 12/05/2014] [Indexed: 02/03/2023]
Affiliation(s)
- Jesse M. Hunter
- Integrated Functional Cancer Genomics; Translational Genomics Research Institute; Phoenix Arizona
| | - Jeff Kiefer
- Knowledge Mining; Translational Genomics Research Institute; Phoenix Arizona
| | - Christopher D. Balak
- Integrated Functional Cancer Genomics; Translational Genomics Research Institute; Phoenix Arizona
| | - Sonya Jooma
- Integrated Functional Cancer Genomics; Translational Genomics Research Institute; Phoenix Arizona
| | - Mary Ellen Ahearn
- Integrated Functional Cancer Genomics; Translational Genomics Research Institute; Phoenix Arizona
| | - Judith G. Hall
- Departments of Medical Genetics and Pediatrics; University of British Columbia and BC Children's Hospital Vancouver; British Columbia Canada
| | - Lisa Baumbach-Reardon
- Integrated Functional Cancer Genomics; Translational Genomics Research Institute; Phoenix Arizona
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Tohyama J, Nakashima M, Nabatame S, Gaik-Siew C, Miyata R, Rener-Primec Z, Kato M, Matsumoto N, Saitsu H. SPTAN1 encephalopathy: distinct phenotypes and genotypes. J Hum Genet 2015; 60:167-73. [PMID: 25631096 DOI: 10.1038/jhg.2015.5] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 12/26/2014] [Accepted: 01/06/2015] [Indexed: 12/23/2022]
Abstract
Recent progress in genetic analysis reveals that a significant proportion of cryptogenic epileptic encephalopathies are single-gene disorders. Mutations in numerous genes for early-onset epileptic encephalopathies have been rapidly identified, including in SPTAN1, which encodes α-II spectrin. The aim of this review is to delineate SPTAN1 encephalopathy as a distinct clinical syndrome. To date, a total of seven epileptic patients with four different in-frame SPTAN1 mutations have been identified. The major clinical features of SPTAN1 mutations include epileptic encephalopathy with hypsarrhythmia, no visual attention, acquired microcephaly, spastic quadriplegia and severe intellectual disability. Brainstem and cerebellar atrophy and cerebral hypomyelination, as observed by magnetic resonance imaging, are specific hallmarks of this condition. A milder variant is characterized by generalized epilepsy with pontocerebellar atrophy. Only in-frame SPTAN1 mutations in the last two spectrin repeats in the C-terminal region lead to dominant negative effects and these specific phenotypes. The last two spectrin repeats are required for α/β spectrin heterodimer associations and the mutations can alter heterodimer formation between the two spectrins. From these data we suggest that SPTAN1 encephalopathy is a distinct clinical syndrome owing to specific SPTAN1 mutations. It is important that this syndrome is recognized by pediatric neurologists to enable proper diagnostic work-up for patients.
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Affiliation(s)
- Jun Tohyama
- 1] Department of Child Neurology, Nishi-Niigata Chuo National Hospital, Niigata, Japan [2] Niigata University Medical and Dental Hospital, Niigata, Japan
| | - Mitsuko Nakashima
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Shin Nabatame
- Department of Pediatrics, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Ch'ng Gaik-Siew
- Department of Genetics, Kuala Lumpur Hospital, Kuala Lumpur, Malaysia
| | - Rie Miyata
- Department of Pediatrics, Tokyo Kita-Social Insurance Hospital, Tokyo, Japan
| | - Zvonka Rener-Primec
- Department of Pediatric Neurology, University Children's Hospital, Ljubljana, Slovenia
| | - Mitsuhiro Kato
- Department of Pediatrics, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Hirotomo Saitsu
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
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Abstract
Epileptic encephalopathies represent a group of devastating epileptic disorders that appear early in life and are characterized by pharmacoresistant generalized or focal seizures, persistent severe EEG abnormalities, and cognitive dysfunction or decline. The ictal and interictal epileptic discharges are age-specific and are either the main cause or contribute to cognitive deterioration in the idiopathic or symptomatic group respectively. Despite choosing the most appropriate anti-seizure drugs for the seizure-type and syndrome the results are often disappointing and polytherapy and/or alternative therapy becomes unavoidable. In those cases, consideration should be given to the quality of life of the child and carers. In this review we will discuss the clinical and EEG characteristics, evolution and management of age-related epileptic encephalopathies, recognized by the International League Against Epilepsy.
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Jiang T, Tan MS, Tan L, Yu JT. Application of next-generation sequencing technologies in Neurology. ANNALS OF TRANSLATIONAL MEDICINE 2015; 2:125. [PMID: 25568878 DOI: 10.3978/j.issn.2305-5839.2014.11.11] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/20/2013] [Accepted: 03/01/2013] [Indexed: 12/11/2022]
Abstract
Genetic risk factors that underlie many rare and common neurological diseases remain poorly understood because of the multi-factorial and heterogeneous nature of these disorders. Although genome-wide association studies (GWAS) have successfully uncovered numerous susceptibility genes for these diseases, odds ratios associated with risk alleles are generally low and account for only a small proportion of estimated heritability. These results implicated that there are rare (present in <5% of the population) but not causative variants exist in the pathogenesis of these diseases, which usually have large effect size and cannot be captured by GWAS. With the decreasing cost of next-generation sequencing (NGS) technologies, whole-genome sequencing (WGS) and whole-exome sequencing (WES) have enabled the rapid identification of rare variants with large effect size, which made huge progress in understanding the basis of many Mendelian neurological conditions as well as complex neurological diseases. In this article, recent NGS-based studies that aimed to investigate genetic causes for neurological diseases, including Alzheimer's disease, Parkinson's disease, epilepsy, multiple sclerosis, stroke, amyotrophic lateral sclerosis and spinocerebellar ataxias, have been reviewed. In addition, we also discuss the future directions of NGS applications in this article.
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Affiliation(s)
- Teng Jiang
- 1 Department of Neurology, Qingdao Municipal Hospital, Nanjing Medical University, Qingdao 266071, China ; 2 College of Medicine and Pharmaceutics, Ocean University of China, Qingdao 266071, China ; 3 Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao 266071, China
| | - Meng-Shan Tan
- 1 Department of Neurology, Qingdao Municipal Hospital, Nanjing Medical University, Qingdao 266071, China ; 2 College of Medicine and Pharmaceutics, Ocean University of China, Qingdao 266071, China ; 3 Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao 266071, China
| | - Lan Tan
- 1 Department of Neurology, Qingdao Municipal Hospital, Nanjing Medical University, Qingdao 266071, China ; 2 College of Medicine and Pharmaceutics, Ocean University of China, Qingdao 266071, China ; 3 Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao 266071, China
| | - Jin-Tai Yu
- 1 Department of Neurology, Qingdao Municipal Hospital, Nanjing Medical University, Qingdao 266071, China ; 2 College of Medicine and Pharmaceutics, Ocean University of China, Qingdao 266071, China ; 3 Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao 266071, China
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Novel approaches for targeting kinases: allosteric inhibition, allosteric activation and pseudokinases. Future Med Chem 2014; 6:541-61. [PMID: 24649957 DOI: 10.4155/fmc.13.216] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Protein kinases are involved in many essential cellular processes and their deregulation can lead to a variety of diseases, including cancer. The pharmaceutical industry has invested heavily in the identification of kinase inhibitors to modulate these disease-promoting pathways, resulting in several successful drugs. However, the field is challenging as it is difficult to identify novel selective inhibitors with good pharmacokinetic/pharmacodynamic properties. In addition, resistance to kinase inhibitor treatment frequently arises. The identification of non-ATP site targeting ('allosteric') inhibitors, the identification of kinase activators and the expansion of kinase target space to include the less studied members of the family, including atypical- and pseudo-kinases, are potential avenues to overcome these challenges. In this perspective, the opportunities and challenges of following these approaches and others will be discussed.
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Rossignol E, Kobow K, Simonato M, Loeb JA, Grisar T, Gilby KL, Vinet J, Kadam SD, Becker AJ. WONOEP appraisal: new genetic approaches to study epilepsy. Epilepsia 2014; 55:1170-86. [PMID: 24965021 PMCID: PMC4126888 DOI: 10.1111/epi.12692] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/13/2014] [Indexed: 12/19/2022]
Abstract
New genetic investigation techniques, including next-generation sequencing, epigenetic profiling, cell lineage mapping, targeted genetic manipulation of specific neuronal cell types, stem cell reprogramming, and optogenetic manipulations within epileptic networks are progressively unraveling the mysteries of epileptogenesis and ictogenesis. These techniques have opened new avenues to discover the molecular basis of epileptogenesis and to study the physiologic effects of mutations in epilepsy-associated genes on a multilayer level, from cells to circuits. This manuscript reviews recently published applications of these new genetic technologies in the study of epilepsy, as well as work presented by the authors at the genetic session of the XII Workshop on the Neurobiology of Epilepsy (WONOEP 2013) in Quebec, Canada. Next-generation sequencing is providing investigators with an unbiased means to assess the molecular causes of sporadic forms of epilepsy and has revealed the complexity and genetic heterogeneity of sporadic epilepsy disorders. To assess the functional impact of mutations in these newly identified genes on specific neuronal cell types during brain development, new modeling strategies in animals, including conditional genetics in mice and in utero knock-down approaches, are enabling functional validation with exquisite cell-type and temporal specificity. In addition, optogenetics, using cell-type-specific Cre recombinase driver lines, is enabling investigators to dissect networks involved in epilepsy. In addition, genetically encoded cell-type labeling is providing new means to assess the role of the nonneuronal components of epileptic networks such as glial cells. Furthermore, beyond its role in revealing coding variants involved in epileptogenesis, next-generation sequencing can be used to assess the epigenetic modifications that lead to sustained network hyperexcitability in epilepsy, including methylation changes in gene promoters and noncoding ribonucleic acid (RNA) involved in modifying gene expression following seizures. In addition, genetically based bioluminescent reporters are providing new opportunities to assess neuronal activity and neurotransmitter levels both in vitro and in vivo in the context of epilepsy. Finally, genetically rederived neurons generated from patient induced pluripotent stem cells and genetically modified zebrafish have become high-throughput means to investigate disease mechanisms and potential new therapies. Genetics has changed the field of epilepsy research considerably, and is paving the way for better diagnosis and therapies for patients with epilepsy.
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Affiliation(s)
- Elsa Rossignol
- Pediatric & Neuroscience Dept. & Brain Disease Research Group, CHU Ste-Justine, Montreal, Canada
| | - Katja Kobow
- Dept. of Neuropathology, Univ. Hospital Erlangen, Germany
| | - Michele Simonato
- Dept. of Medical Sciences (Pharmacology), Univ. of Ferrara, Italy
| | - Jeffrey A. Loeb
- Dept. of Neurology & Rehabilitation, Univ. of Illinois, Chicago, USA
| | | | - Krista L. Gilby
- Dept. of Medicine, Royal Hospital, The Melbourne Brain Centre, Univ. of Melbourne, Australia
| | - Jonathan Vinet
- Dept. of Neural, Biomedical, Metabolic & Neural Sciences, Univ. of Modena, Italy
| | - Shilpa D. Kadam
- Depts. of Neuroscience and Neurology, Kennedy Krieger & Johns Hopkins Univ. School of Medicine of Baltimore, USA
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