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Li YL, Lin J, Huang X, Zeng RH, Zhang G, Xu JN, Lin KJ, Chen XS, He MF, Qiao JD, Cheng X, Zhu D, Xiong ZQ, Chen WJ. Heterozygous Variants in KCNJ10 Cause Paroxysmal Kinesigenic Dyskinesia Via Haploinsufficiency. Ann Neurol 2024. [PMID: 38979912 DOI: 10.1002/ana.27018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 06/07/2024] [Accepted: 06/12/2024] [Indexed: 07/10/2024]
Abstract
OBJECTIVE Most paroxysmal kinesigenic dyskinesia (PKD) cases are hereditary, yet approximately 60% of patients remain genetically undiagnosed. We undertook the present study to uncover the genetic basis for undiagnosed PKD patients. METHODS Whole-exome sequencing was performed for 106 PRRT2-negative PKD probands. The functional impact of the genetic variants was investigated in HEK293T cells and Drosophila. RESULTS Heterozygous variants in KCNJ10 were identified in 11 individuals from 8 unrelated families, which accounted for 7.5% (8/106) of the PRRT2-negative probands. Both co-segregation of the identified variants and the significantly higher frequency of rare KCNJ10 variants in PKD cases supported impacts from the detected KCNJ10 heterozygous variants on PKD pathogenesis. Moreover, a KCNJ10 mutation-carrying father from a typical EAST/SeSAME family was identified as a PKD patient. All patients manifested dystonia attacks triggered by sudden movement with a short episodic duration. Patch-clamp recordings in HEK293T cells revealed apparent reductions in K+ currents of the patient-derived variants, indicating a loss-of-function. In Drosophila, milder hyperexcitability phenotypes were observed in heterozygous Irk2 knock-in flies compared to homozygotes, supporting haploinsufficiency as the mechanism for the detected heterozygous variants. Electrophysiological recordings showed that excitatory neurons in Irk2 haploinsufficiency flies exhibited increased excitability, and glia-specific complementation with human Kir4.1 rescued the Irk2 mutant phenotypes. INTERPRETATION Our study established haploinsufficiency resulting from heterozygous variants in KCNJ10 can be understood as a previously unrecognized genetic cause for PKD and provided evidence of glial involvement in the pathophysiology of PKD. ANN NEUROL 2024.
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Affiliation(s)
- Yun-Lu Li
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian, China
| | - Jingjing Lin
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian, China
| | - Xuejing Huang
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian, China
| | - Rui-Huang Zeng
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian, China
| | - Guangyu Zhang
- Department of Rehabilitation Medicine, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Jie-Ni Xu
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian, China
| | - Kai-Jun Lin
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian, China
| | - Xin-Shuo Chen
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian, China
| | - Ming-Feng He
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Jing-Da Qiao
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Xuewen Cheng
- Lingang Laboratory, Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, China
| | - Dengna Zhu
- Department of Rehabilitation Medicine, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Zhi-Qi Xiong
- Center for Excellence in Brain Science and Intelligence Technology, Institute of Neuroscience and State Key Laboratory of Neuroscience, Chinese Academy of Sciences, Shanghai, China
| | - Wan-Jin Chen
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian, China
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Burd SG, Lebedeva AV, Rubleva YV, Pantina NV, Yurchenko AV, Bogomazova MA, Kovaleva II, Karchevskaya AE. [Epilepsy syndromes associated with hearing loss]. Zh Nevrol Psikhiatr Im S S Korsakova 2023; 123:28-33. [PMID: 36719116 DOI: 10.17116/jnevro202312301128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Patients with epilepsy who have also hearing loss represent a distinct group of patients, often with aggravated medical history, comorbidities and high potential for disability. The etiopathogenetic factors of epilepsy and hearing loss may be common to these conditions (neuroinfections, craniocerebral injuries, cerebral circulatory disorders, perinatal pathology, etc.). In addition, these two syndromes may occur as part of hereditary diseases, so their timely recognition and genetic diagnosis are important for determining further medical and genetic prognosis. This article provides an overview of orphan genetic diseases associated with epilepsy and hearing loss - MERRF syndrome, MELAS syndrome, EAST syndrome, Ayme-Grippsyndrome, epilepsy, hearing loss and mental retardation syndromes, associated with mutations in SPATA5 gene, DOOR syndrome, Gustavson syndrome.
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Affiliation(s)
- S G Burd
- Federal Center of Brain Research and Neurotechnologies, Moscow, Russia.,Pirogov Russian National Research Medical University, Moscow, Russia
| | - A V Lebedeva
- Pirogov Russian National Research Medical University, Moscow, Russia
| | - Yu V Rubleva
- Federal Center of Brain Research and Neurotechnologies, Moscow, Russia
| | - N V Pantina
- Federal Center of Brain Research and Neurotechnologies, Moscow, Russia
| | - A V Yurchenko
- Federal Center of Brain Research and Neurotechnologies, Moscow, Russia
| | - M A Bogomazova
- Federal Center of Brain Research and Neurotechnologies, Moscow, Russia
| | - I I Kovaleva
- Federal Center of Brain Research and Neurotechnologies, Moscow, Russia
| | - A E Karchevskaya
- Federal Center of Brain Research and Neurotechnologies, Moscow, Russia
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Stee K, Van Poucke M, Pumarola M, Geerinckx L, Van Soens I, Bhatti SFM, Peelman L, Cornelis I. Spinocerebellar ataxia in the Bouvier des Ardennes breed is caused by a KCNJ10 missense variant. J Vet Intern Med 2022; 37:216-222. [PMID: 36426918 PMCID: PMC9889618 DOI: 10.1111/jvim.16594] [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: 07/22/2022] [Accepted: 11/17/2022] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND In Belgian Malinois, a KCNJ10 variant causes progressive spinocerebellar degeneration. HYPOTHESIS/OBJECTIVES Describe the clinical, diagnostic, pathological and genetic features of spinocerebellar degeneration in the Bouvier des Ardennes breed. ANIMALS Five affected Bouvier des Ardennes puppies with spinocerebellar ataxia (SCA), 8 healthy related dogs, and 63 healthy unrelated Bouvier des Ardennes. METHODS Sequential case study. RESULTS Clinical signs started at 6 weeks of age in 1 puppy with severe signs of cerebellar disease, and at 7 to 10 weeks of age in the 4 remaining puppies with milder signs of spinocerebellar disease. The first puppy displayed severe intention tremors and rapidly progressive generalized hypermetric ataxia, whereas the 4 others developed a milder progressive SCA. Euthanasia after progression to nonambulatory status was performed by 8 weeks of age in the first puppy, and before 11 months of age in the 4 remaining puppies. Histopathology revealed cerebellar spongy degeneration and a focal symmetrical demyelinating myelopathy. All cases were homozygous for KCNJ10 XM_545752.6:c.986T>C(p.(Leu329Pro)), which is pathogenic for SCA with (or without) myokymia, seizures or both (SAMS) and spongy degeneration and cerebellar ataxia (SDCA) 1 in Belgian Malinois dogs. All sampled parents were heterozygous and none of the healthy dogs were homozygous for this recessive variant. This variant has an allele frequency of 15% in the 63 healthy dogs studied. CONCLUSIONS AND CLINICAL IMPORTANCE Inherited spinocerebellar degeneration also affects the Bouvier des Ardennes breed and is caused by a KCNJ10 variant. It can present with a spectrum of severity grades, ranging from severe cerebellar to milder spinocerebellar signs.
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Affiliation(s)
- Kimberley Stee
- Small Animals Department, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Mario Van Poucke
- Department of Veterinary and Biosciences, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Martí Pumarola
- Mouse and Comparative Pathology Unit, Department of Animal Medicine and Surgery, Faculty of Veterinary MedicineUniversitat Autònoma de BarcelonaBellaterra (Barcelona)Spain
| | - Lise Geerinckx
- Department of Pathobiology, Pharmacology and Zoological Medicine, Faculty of Veterinary MedicineUniversity of GhentGhentBelgium
| | - Iris Van Soens
- Department of Companion Animal Clinical Sciences, Faculty of Veterinary MedicineUniversity of LiègeLiègeBelgium
| | - Sofie F. M. Bhatti
- Small Animals Department, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Luc Peelman
- Department of Veterinary and Biosciences, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Ine Cornelis
- Small Animals Department, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
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Staruschenko A, Hodges MR, Palygin O. Kir5.1 channels: potential role in epilepsy and seizure disorders. Am J Physiol Cell Physiol 2022; 323:C706-C717. [PMID: 35848616 PMCID: PMC9448276 DOI: 10.1152/ajpcell.00235.2022] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/06/2022] [Accepted: 07/08/2022] [Indexed: 11/22/2022]
Abstract
Inwardly rectifying potassium (Kir) channels are broadly expressed in many mammalian organ systems, where they contribute to critical physiological functions. However, the importance and function of the Kir5.1 channel (encoded by the KCNJ16 gene) have not been fully recognized. This review focuses on the recent advances in understanding the expression patterns and functional roles of Kir5.1 channels in fundamental physiological systems vital to potassium homeostasis and neurological disorders. Recent studies have described the role of Kir5.1-forming Kir channels in mouse and rat lines with mutations in the Kcnj16 gene. The animal research reveals distinct renal and neurological phenotypes, including pH and electrolyte imbalances, blunted ventilatory responses to hypercapnia/hypoxia, and seizure disorders. Furthermore, it was confirmed that these phenotypes are reminiscent of those in patient cohorts in which mutations in the KCNJ16 gene have also been identified, further suggesting a critical role for Kir5.1 channels in homeostatic/neural systems health and disease. Future studies that focus on the many functional roles of these channels, expanded genetic screening in human patients, and the development of selective small-molecule inhibitors for Kir5.1 channels, will continue to increase our understanding of this unique Kir channel family member.
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Affiliation(s)
- Alexander Staruschenko
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida
- Hypertension and Kidney Research Center, University of South Florida, Tampa, Florida
- James A. Haley Veterans Hospital, Tampa, Florida
| | - Matthew R Hodges
- Department of Physiology and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Oleg Palygin
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
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Lo J, Forst AL, Warth R, Zdebik AA. EAST/SeSAME Syndrome and Beyond: The Spectrum of Kir4.1- and Kir5.1-Associated Channelopathies. Front Physiol 2022; 13:852674. [PMID: 35370765 PMCID: PMC8965613 DOI: 10.3389/fphys.2022.852674] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 02/08/2022] [Indexed: 12/13/2022] Open
Abstract
In 2009, two groups independently linked human mutations in the inwardly rectifying K+ channel Kir4.1 (gene name KCNJ10) to a syndrome affecting the central nervous system (CNS), hearing, and renal tubular salt reabsorption. The autosomal recessive syndrome has been named EAST (epilepsy, ataxia, sensorineural deafness, and renal tubulopathy) or SeSAME syndrome (seizures, sensorineural deafness, ataxia, intellectual disability, and electrolyte imbalance), accordingly. Renal dysfunction in EAST/SeSAME patients results in loss of Na+, K+, and Mg2+ with urine, activation of the renin-angiotensin-aldosterone system, and hypokalemic metabolic alkalosis. Kir4.1 is highly expressed in affected organs: the CNS, inner ear, and kidney. In the kidney, it mostly forms heteromeric channels with Kir5.1 (KCNJ16). Biallelic loss-of-function mutations of Kir5.1 can also have disease significance, but the clinical symptoms differ substantially from those of EAST/SeSAME syndrome: although sensorineural hearing loss and hypokalemia are replicated, there is no alkalosis, but rather acidosis of variable severity; in contrast to EAST/SeSAME syndrome, the CNS is unaffected. This review provides a framework for understanding some of these differences and will guide the reader through the growing literature on Kir4.1 and Kir5.1, discussing the complex disease mechanisms and the variable expression of disease symptoms from a molecular and systems physiology perspective. Knowledge of the pathophysiology of these diseases and their multifaceted clinical spectrum is an important prerequisite for making the correct diagnosis and forms the basis for personalized therapies.
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Affiliation(s)
- Jacky Lo
- Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Anna-Lena Forst
- Medical Cell Biology, Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Richard Warth
- Medical Cell Biology, Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Anselm A. Zdebik
- Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
- Centre for Nephrology, University College London, London, United Kingdom
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Oluwole OG, James K, Yalcouye A, Wonkam A. Hearing loss and brain disorders: A review of multiple pathologies. Open Med (Wars) 2021; 17:61-69. [PMID: 34993346 PMCID: PMC8678477 DOI: 10.1515/med-2021-0402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 10/22/2021] [Accepted: 11/05/2021] [Indexed: 11/29/2022] Open
Abstract
Several causative factors are associated with hearing loss (HL) and brain disorders. However, there are many unidentified disease modifiers in these conditions. Our study summarised the most common brain disorders associated with HL and highlighted mechanisms of pathologies. We searched the literature for published articles on HL and brain disorders. Alzheimer's disease/dementia, Parkinson's disease, cognitive impairment, autism spectrum disorder, ataxia, epilepsy, stroke, and hypoxic-ischaemic encephalopathy majorly co-interact with HL. The estimated incidence rate was 113 per 10,000 person-years. Genetic, epigenetic, early life/neonatal stress, hypoxia, inflammation, nitric oxide infiltration, endoplasmic reticulum stress, and excess glutamate were the distinguished modifiers identified. Various mechanisms like adhesion molecules, transport proteins, hair cell apoptosis, and neurodegeneration have been implicated in these conditions and are serving as potential targets for therapies. To improve the quality of life of patients, these understandings will improve clinical diagnoses and management of HL and brain disorders.
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Affiliation(s)
- Oluwafemi Gabriel Oluwole
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, 3.14 Wernher & Beit North Building, P.O Box 7925, Cape Town, South Africa
| | - Kili James
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, 3.14 Wernher & Beit North Building, P.O Box 7925, Cape Town, South Africa
| | - Abdoulaye Yalcouye
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, 3.14 Wernher & Beit North Building, P.O Box 7925, Cape Town, South Africa
| | - Ambroise Wonkam
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, 3.14 Wernher & Beit North Building, P.O Box 7925, Cape Town, South Africa
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7
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Mérida I, Jung J, Bouvard S, Le Bars D, Lancelot S, Lavenne F, Bouillot C, Redouté J, Hammers A, Costes N. CERMEP-IDB-MRXFDG: a database of 37 normal adult human brain [ 18F]FDG PET, T1 and FLAIR MRI, and CT images available for research. EJNMMI Res 2021; 11:91. [PMID: 34529159 PMCID: PMC8446124 DOI: 10.1186/s13550-021-00830-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 08/15/2021] [Indexed: 01/05/2023] Open
Abstract
We present a database of cerebral PET FDG and anatomical MRI for 37 normal adult human subjects (CERMEP-IDB-MRXFDG). Thirty-nine participants underwent static [18F]FDG PET/CT and MRI, resulting in [18F]FDG PET, T1 MPRAGE MRI, FLAIR MRI, and CT images. Two participants were excluded after visual quality control. We describe the acquisition parameters, the image processing pipeline and provide participants' individual demographics (mean age 38 ± 11.5 years, range 23-65, 20 women). Volumetric analysis of the 37 T1 MRIs showed results in line with the literature. A leave-one-out assessment of the 37 FDG images using Statistical Parametric Mapping (SPM) yielded a low number of false positives after exclusion of artefacts. The database is stored in three different formats, following the BIDS common specification: (1) DICOM (data not processed), (2) NIFTI (multimodal images coregistered to PET subject space), (3) NIFTI normalized (images normalized to MNI space). Bona fide researchers can request access to the database via a short form.
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Affiliation(s)
- Inés Mérida
- CERMEP-Imagerie du Vivant, Lyon, France.
- CHU de Lyon HCL - GH Est, 59 Boulevard Pinel., 69677, Bron Cedex, France.
| | - Julien Jung
- INSERM U1028/CNRS UMR5292, Lyon Neuroscience Research Center, Lyon, France
- Hospices Civils de Lyon, University Hospitals, Lyon, France
| | - Sandrine Bouvard
- Université Claude Bernard Lyon 1, Lyon Neuroscience Research Center, INSERM, CNRS, Lyon, France
| | - Didier Le Bars
- CERMEP-Imagerie du Vivant, Lyon, France
- Hospices Civils de Lyon, University Hospitals, Lyon, France
| | - Sophie Lancelot
- CERMEP-Imagerie du Vivant, Lyon, France
- INSERM U1028/CNRS UMR5292, Lyon Neuroscience Research Center, Lyon, France
- Hospices Civils de Lyon, University Hospitals, Lyon, France
| | | | | | | | - Alexander Hammers
- School of Biomedical Engineering and Imaging Sciences, Kings' College London, King's College London and Guy's and St Thomas' PET Centre, London, UK
- Neurodis Foundation, Lyon, France
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8
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Naz S. Molecular genetic landscape of hereditary hearing loss in Pakistan. Hum Genet 2021; 141:633-648. [PMID: 34308486 DOI: 10.1007/s00439-021-02320-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 07/17/2021] [Indexed: 01/13/2023]
Abstract
Approximately 14.5 million Pakistani individuals have a hearing loss and half of these cases may be due to genetic causes. Though significant progress has been made in uncovering genetic variants for recessively inherited nonsyndromic deafness, Pendred syndrome, and Usher syndromes, the same is not true for dominantly inherited hearing loss, most syndromic cases and deafness with complex inheritance patterns. Variants of 57 genes have been reported to cause nonsyndromic recessive deafness in Pakistan, though most are rare. Variants of just five genes GJB2, HGF, MYO7A, SLC26A4, and TMC1 together explain 57% of profound deafness while those of GJB2, MYO15A, OTOF, SLC26A4, TMC1, and TMPRSS3 account for 47% of moderate to severe hearing loss. In contrast, although variants of at least 39 genes have been implicated in different deafness syndromes, their prevalence in the population and the spectrum of mutations have not been explored. Furthermore, research on genetics of deafness has mostly focused on individuals from the Punjab province and needs to be extended to other regions of Pakistan. Identifying the genes and their variants causing deafness in all ethnic groups is important as it will pinpoint rare as well as recurrent mutations. This information may ultimately help in offering genetic counseling and future treatments.
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Affiliation(s)
- Sadaf Naz
- School of Biological Sciences, University of the Punjab, Quaid-e-Azam Campus, Lahore, 54590, Pakistan.
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Moroni RF, Regondi MC, de Curtis M, Frassoni C, Librizzi L. Kir4.1 RNA Interference by In Utero Electroporation Fails to Affect Ictogenesis and Reveals a Possible role of Kir4.1 in Corticogenesis. Neuroscience 2020; 441:65-76. [PMID: 32590038 DOI: 10.1016/j.neuroscience.2020.06.020] [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: 02/11/2020] [Revised: 04/24/2020] [Accepted: 06/15/2020] [Indexed: 11/26/2022]
Abstract
Astrocyte dysfunction, and in particular impaired extracellular potassium spatial buffering, has been postulated to have a potential role in seizure susceptibility and ictogenesis. Inwardly rectifying potassium (Kir) channels, and specifically KIR4.1, have a predominant role in K+ homeostasis and their involvement in neuronal excitability control have been hypothesized. To avoid the severe side effects observed in Kir4.1 cKO, we studied the effects of Kir4.1 down-regulation in cortical astrocytes by using Kir4.1 RNA interference (RNAi) technique combined with in utero electroporation (IUE) at E16 and a piggyBac transposon system. Kir4.1 down-regulation was confirmed by immunohistochemistry and field fraction analysis. To investigate if Kir4.1 silencing affects 4AP-induced seizure threshold and extracellular potassium homeostasis, simultaneous in vitro field potential and extracellular K+ recordings were performed on somatosensory cortex slices obtained from rats electroporated with a piggyBac-Kir4.1-shRNA (Kir4.1-) and scrambled shRNA (Kir4.1Sc). Electrophysiological data revealed no significant differences in terms of seizure onset and seizure-induced extracellular K+ changes between Kir4.1- and Kir4.1Sc rats. Intriguingly, immunohistochemical analysis performed on slices studied with electrophysiology revealed a reduced number of neurons generated from radial glial cells in Kir4.1- rats. We conclude that focal down-regulation of Kir4.1 channel in cortical astrocytes by Kir4.1 RNAi technique combined with IUE is not effective in altering potassium homeostasis and seizure susceptibility. This technique revealed a possible role of Kir4.1 during corticogenesis.
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Affiliation(s)
- Ramona Frida Moroni
- Epilepsy Unit, Fondazione I.R.C.C.S. Istituto Neurologico "C. Besta", via Celoria 11, 20133 Milan, Italy.
| | - Maria Cristina Regondi
- Epilepsy Unit, Fondazione I.R.C.C.S. Istituto Neurologico "C. Besta", via Celoria 11, 20133 Milan, Italy.
| | - Marco de Curtis
- Epilepsy Unit, Fondazione I.R.C.C.S. Istituto Neurologico "C. Besta", via Celoria 11, 20133 Milan, Italy.
| | - Carolina Frassoni
- Epilepsy Unit, Fondazione I.R.C.C.S. Istituto Neurologico "C. Besta", via Celoria 11, 20133 Milan, Italy.
| | - Laura Librizzi
- Epilepsy Unit, Fondazione I.R.C.C.S. Istituto Neurologico "C. Besta", via Celoria 11, 20133 Milan, Italy.
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Bhowmick SS, Lang AE. Movement Disorders and Renal Diseases. Mov Disord Clin Pract 2020; 7:763-779. [PMID: 33043074 DOI: 10.1002/mdc3.13005] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 06/03/2020] [Accepted: 06/05/2020] [Indexed: 02/06/2023] Open
Abstract
Movement disorders often emerge from the interplay of complex pathophysiological processes involving the kidneys and the nervous system. Tremor, myoclonus, ataxia, chorea, and parkinsonism can occur in the context of renal dysfunction (azotemia and electrolyte abnormalities) or they can be part of complications of its management (dialysis and renal transplantation). On the other hand, myoglobinuria from rhabdomyolysis in status dystonicus and certain drugs used in the management of movement disorders can cause nephrotoxicity. Distinct from these well-recognized associations, it is important to appreciate that there are several inherited and acquired disorders in which movement abnormalities do not occur as a consequence of renal dysfunction or vice versa but are manifestations of common pathophysiological processes affecting the nervous system and the kidneys. These disorders are the emphasis of this review. Increasing awareness of these conditions among neurologists may help them to identify renal involvement earlier, take timely intervention by anticipating complications and focus on therapies targeting common mechanisms in addition to symptomatic management of movement disorders. Recognition of renal impairment in a patient with complex neurological presentation may narrow down the differentials and aid in reaching a definite diagnosis.
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Affiliation(s)
- Suvorit S Bhowmick
- Division of Neurology, Department of Medicine, Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital University Health Network Toronto Ontario Canada
| | - Anthony E Lang
- Division of Neurology, Department of Medicine, Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital University Health Network Toronto Ontario Canada
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Gawel K, Langlois M, Martins T, van der Ent W, Tiraboschi E, Jacmin M, Crawford AD, Esguerra CV. Seizing the moment: Zebrafish epilepsy models. Neurosci Biobehav Rev 2020; 116:1-20. [PMID: 32544542 DOI: 10.1016/j.neubiorev.2020.06.010] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 04/20/2020] [Accepted: 06/05/2020] [Indexed: 12/14/2022]
Abstract
Zebrafish are now widely accepted as a valuable animal model for a number of different central nervous system (CNS) diseases. They are suitable both for elucidating the origin of these disorders and the sequence of events culminating in their onset, and for use as a high-throughput in vivo drug screening platform. The availability of powerful and effective techniques for genome manipulation allows the rapid modelling of different genetic epilepsies and of conditions with seizures as a core symptom. With this review, we seek to summarize the current knowledge about existing epilepsy/seizures models in zebrafish (both pharmacological and genetic) and compare them with equivalent rodent and human studies. New findings obtained from the zebrafish models are highlighted. We believe that this comprehensive review will highlight the value of zebrafish as a model for investigating different aspects of epilepsy and will help researchers to use these models to their full extent.
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Affiliation(s)
- Kinga Gawel
- Chemical Neuroscience Group, Centre for Molecular Medicine Norway (NCMM), University of Oslo, Gaustadalléen 21, Forskningsparken, 0349, Oslo, Norway; Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Jaczewskiego St. 8b, 20-090, Lublin, Poland
| | | | - Teresa Martins
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Belval, Luxembourg
| | - Wietske van der Ent
- Chemical Neuroscience Group, Centre for Molecular Medicine Norway (NCMM), University of Oslo, Gaustadalléen 21, Forskningsparken, 0349, Oslo, Norway
| | - Ettore Tiraboschi
- Chemical Neuroscience Group, Centre for Molecular Medicine Norway (NCMM), University of Oslo, Gaustadalléen 21, Forskningsparken, 0349, Oslo, Norway; Neurophysics Group, Center for Mind/Brain Sciences, University of Trento, Piazza Manifattura 1, Building 14, 38068, Rovereto, TN, Italy
| | - Maxime Jacmin
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Belval, Luxembourg
| | - Alexander D Crawford
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Belval, Luxembourg; Faculty of Veterinary Medicine, Norwegian University of Life Sciences (NMBU), Oslo, Norway
| | - Camila V Esguerra
- Chemical Neuroscience Group, Centre for Molecular Medicine Norway (NCMM), University of Oslo, Gaustadalléen 21, Forskningsparken, 0349, Oslo, Norway.
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12
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Yaakub SN, Heckemann RA, Keller SS, McGinnity CJ, Weber B, Hammers A. On brain atlas choice and automatic segmentation methods: a comparison of MAPER & FreeSurfer using three atlas databases. Sci Rep 2020; 10:2837. [PMID: 32071355 PMCID: PMC7028906 DOI: 10.1038/s41598-020-57951-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 11/27/2019] [Indexed: 11/09/2022] Open
Abstract
Several automatic image segmentation methods and few atlas databases exist for analysing structural T1-weighted magnetic resonance brain images. The impact of choosing a combination has not hitherto been described but may bias comparisons across studies. We evaluated two segmentation methods (MAPER and FreeSurfer), using three publicly available atlas databases (Hammers_mith, Desikan-Killiany-Tourville, and MICCAI 2012 Grand Challenge). For each combination of atlas and method, we conducted a leave-one-out cross-comparison to estimate the segmentation accuracy of FreeSurfer and MAPER. We also used each possible combination to segment two datasets of patients with known structural abnormalities (Alzheimer's disease (AD) and mesial temporal lobe epilepsy with hippocampal sclerosis (HS)) and their matched healthy controls. MAPER was better than FreeSurfer at modelling manual segmentations in the healthy control leave-one-out analyses in two of the three atlas databases, and the Hammers_mith atlas database transferred to new datasets best regardless of segmentation method. Both segmentation methods reliably identified known abnormalities in each patient group. Better separation was seen for FreeSurfer in the AD and left-HS datasets, and for MAPER in the right-HS dataset. We provide detailed quantitative comparisons for multiple anatomical regions, thus enabling researchers to make evidence-based decisions on their choice of atlas and segmentation method.
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Affiliation(s)
- Siti Nurbaya Yaakub
- King's College London & Guy's and St Thomas' PET Centre, School of Biomedical Engineering & Imaging Sciences, King's College London, London, United Kingdom
| | - Rolf A Heckemann
- MedTech West at Sahlgrenska University Hospital Gothenburg, Gothenburg, Sweden
- Department of Radiation Physics, Institute of Clinical Sciences, Gothenburg University, Gothenburg, Sweden
- Division of Brain Sciences, Imperial College London, London, United Kingdom
| | - Simon S Keller
- Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
- Department of Neuroradiology, The Walton Centre NHS Foundation Trust, Liverpool, United Kingdom
| | - Colm J McGinnity
- King's College London & Guy's and St Thomas' PET Centre, School of Biomedical Engineering & Imaging Sciences, King's College London, London, United Kingdom
| | - Bernd Weber
- Center for Economics and Neuroscience, University of Bonn, Bonn, Germany
- Institute of Experimental Epileptology and Cognition Research, University Hospital Bonn, Bonn, Germany
| | - Alexander Hammers
- King's College London & Guy's and St Thomas' PET Centre, School of Biomedical Engineering & Imaging Sciences, King's College London, London, United Kingdom.
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13
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Morin M, Forst AL, Pérez-Torre P, Jiménez-Escrig A, Barca-Tierno V, García-Galloway E, Warth R, Lopez-Sendón Moreno JL, Moreno-Pelayo MA. Novel mutations in the KCNJ10 gene associated to a distinctive ataxia, sensorineural hearing loss and spasticity clinical phenotype. Neurogenetics 2020; 21:135-143. [PMID: 32062759 DOI: 10.1007/s10048-020-00605-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 02/01/2020] [Indexed: 12/31/2022]
Abstract
KCNJ10 encodes the inward-rectifying potassium channel (Kir4.1) that is expressed in the brain, inner ear, and kidney. Loss-of-function mutations in KCNJ10 gene cause a complex syndrome consisting of epilepsy, ataxia, intellectual disability, sensorineural deafness, and tubulopathy (EAST/SeSAME syndrome). Patients with EAST/SeSAME syndrome display renal salt wasting and electrolyte imbalance that resemble the clinical features of impaired distal tubular salt transport in Gitelman's syndrome. A key distinguishing feature between these two conditions is the additional neurological (extrarenal) manifestations found in EAST/SeSAME syndrome. Recent reports have further expanded the clinical and mutational spectrum of KCNJ10-related disorders including non-syndromic early-onset cerebellar ataxia. Here, we describe a kindred of three affected siblings with early-onset ataxia, deafness, and progressive spasticity without other prominent clinical features. By using targeted next-generation sequencing, we have identified two novel missense variants, c.488G>A (p.G163D) and c.512G>A (p.R171Q), in the KCNJ10 gene that, in compound heterozygosis, cause this distinctive EAST/SeSAME phenotype in our family. Electrophysiological characterization of these two variants confirmed their pathogenicity. When expressed in CHO cells, the R171Q mutation resulted in 50% reduction of currents compared to wild-type KCNJ10 and G163D showed a complete loss of function. Co-expression of G163D and R171Q had a more pronounced effect on currents and membrane potential than R171Q alone but less severe than single expression of G163D. Moreover, the effect of the mutations seemed less pronounced in the presence of Kir5.1 (encoded by KCNJ16), with whom the renal Kir4.1 channels form heteromers. This partial functional rescue by co-expression with Kir5.1 might explain the lack of renal symptoms in the patients. This report illustrates that a spectrum of disorders with distinct clinical symptoms may result from mutations in different parts of KCNJ10, a gene initially associated only with the EAST/SeSAME syndrome.
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Affiliation(s)
- Matias Morin
- Servicio de Genética, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS) and Hospital Universitario Ramón y Cajal, CIBERER, 28034, Madrid, Spain
| | - Anna-Lena Forst
- Medical Cell Biology, University of Regensburg, 93053, Regensburg, Germany
| | - Paula Pérez-Torre
- Servicio de Neurología, Hospital Universitario Ramón y Cajal, 28034, Madrid, Spain
| | | | - Verónica Barca-Tierno
- Servicio de Genética, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS) and Hospital Universitario Ramón y Cajal, CIBERER, 28034, Madrid, Spain
| | - Eva García-Galloway
- Servicio de Genética, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS) and Hospital Universitario Ramón y Cajal, CIBERER, 28034, Madrid, Spain
| | - Richard Warth
- Medical Cell Biology, University of Regensburg, 93053, Regensburg, Germany
| | | | - Miguel Angel Moreno-Pelayo
- Servicio de Genética, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS) and Hospital Universitario Ramón y Cajal, CIBERER, 28034, Madrid, Spain.
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14
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Papandreou A, Danti FR, Spaull R, Leuzzi V, Mctague A, Kurian MA. The expanding spectrum of movement disorders in genetic epilepsies. Dev Med Child Neurol 2020; 62:178-191. [PMID: 31784983 DOI: 10.1111/dmcn.14407] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/01/2019] [Indexed: 12/27/2022]
Abstract
An ever-increasing number of neurogenetic conditions presenting with both epilepsy and atypical movements are now recognized. These disorders within the 'genetic epilepsy-dyskinesia' spectrum are clinically and genetically heterogeneous. Increased clinical awareness is therefore necessary for a rational diagnostic approach. Furthermore, careful interpretation of genetic results is key to establishing the correct diagnosis and initiating disease-specific management strategies in a timely fashion. In this review we describe the spectrum of movement disorders associated with genetically determined epilepsies. We also propose diagnostic strategies and putative pathogenic mechanisms causing these complex syndromes associated with both seizures and atypical motor control. WHAT THIS PAPER ADDS: Implicated genes encode proteins with very diverse functions. Pathophysiological mechanisms by which epilepsy and movement disorder phenotypes manifest are often not clear. Early diagnosis of treatable disorders is essential and next generation sequencing may be required.
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Affiliation(s)
- Apostolos Papandreou
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neurology, Great Ormond Street Hospital, London, UK
| | - Federica Rachele Danti
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Human Neuroscience, Unit of Child Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy
| | - Robert Spaull
- Department of Paediatric Neurology, Bristol Royal Hospital for Children, Bristol, UK
- Bristol Medical School, University of Bristol, Bristol, UK
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, Unit of Child Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy
| | - Amy Mctague
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neurology, Great Ormond Street Hospital, London, UK
| | - Manju A Kurian
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neurology, Great Ormond Street Hospital, London, UK
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15
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Zhang H, Zhu L, Wang F, Wang R, Hong Y, Chen Y, Zhu B, Gao Y, Luo H, Zhang X, Sun H, Zhou Y, Yao Y, Wang X. Novel KCNJ10 Compound Heterozygous Mutations Causing EAST/SeSAME-Like Syndrome Compromise Potassium Channel Function. Front Genet 2019; 10:912. [PMID: 31781151 PMCID: PMC6856220 DOI: 10.3389/fgene.2019.00912] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 08/29/2019] [Indexed: 11/13/2022] Open
Abstract
Inwardly rectifying K+ channel 4.1 (Kir4.1), encoded by KCNJ10, is a member of the inwardly rectifying potassium channel family. In the brain, Kir4.1 is predominant in astrocytic glia and accounts for the spatial buffering of K+ released by neurons during action potential propagation. A number of studies have shown that mutations in KCNJ10 are associated with SeSAME/EAST syndrome, which is characterized by seizures, ataxia, sensorineural deafness, and electrolyte imbalance. Herein, we identified two siblings presenting with seizures and motor delays in one outbred kindred. Customized targeted-exome sequencing showed that both affected siblings are compound heterozygous for two KCNJ10 missense mutations (NM_002241.4: c.601G > A: p.A201T and c.626T > C: p.I209T). Prediction tools suggested that both amino acid substitutions were deleterious or disease causing. Further functional studies showed that Chinese hamster ovary (CHO) cells expressing either A201T and/or I209T Kir4.1 channels exhibited lower K+ currents, indicating compromised Kir4.1 biological function. Intriguingly, the A201T but not I209T mutation decreased total and cell surface Kir4.1 levels. Kir4.1 channels with the A201T mutation were unstable and degraded through lysosomal pathway. In conclusion, these data indicated that both A201T and I209T mutations disrupt Kir4.1 activity and are the cause of SeSAME/EAST-like syndrome in the siblings.
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Affiliation(s)
- Hongfeng Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Lin Zhu
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Fengpeng Wang
- Department of Functional Neurosurgery, Xiamen Humanity Hospital, Xiamen, China
| | - Ruimin Wang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Yujuan Hong
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Yangqin Chen
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Bin Zhu
- Departments of Neurosurgery, Dongfang Affliated Hospital of Xiamen University, Xiamen, China
| | - Yue Gao
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Hong Luo
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Xian Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Hao Sun
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Ying Zhou
- National Institute for Data Science in Health and Medicine, School of Medicine, Xiamen University, Xiamen, China
| | - Yi Yao
- Department of Functional Neurosurgery, Xiamen Humanity Hospital, Xiamen, China.,Department of Neurosurgery, Shenzhen Children's Hospital, Shenzhen, China
| | - Xin Wang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
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16
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Hamberis AO, Mehta CH, Dornhoffer JR, Meyer TA. Characteristics and progression of hearing loss in children with turner's syndrome. Laryngoscope 2019; 130:1540-1546. [DOI: 10.1002/lary.28264] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 07/23/2019] [Accepted: 08/12/2019] [Indexed: 01/11/2023]
Affiliation(s)
- Alexandra O. Hamberis
- Department of Otolaryngology–Head and Neck SurgeryMedical University of South Carolina Charleston South Carolina U.S.A
| | - Charmee H. Mehta
- Department of Otolaryngology–Head and Neck SurgeryMedical University of South Carolina Charleston South Carolina U.S.A
| | - James R. Dornhoffer
- Department of Otolaryngology–Head and Neck SurgeryMedical University of South Carolina Charleston South Carolina U.S.A
| | - Ted Albert Meyer
- Department of Otolaryngology–Head and Neck SurgeryMedical University of South Carolina Charleston South Carolina U.S.A
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17
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Mir A, Chaudhary M, Alkhaldi H, Alhazmi R, Albaradie R, Housawi Y. Epilepsy in patients with EAST syndrome caused by mutation in the KCNJ10. Brain Dev 2019; 41:706-715. [PMID: 30952461 DOI: 10.1016/j.braindev.2019.03.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 03/03/2019] [Accepted: 03/19/2019] [Indexed: 11/20/2022]
Abstract
OBJECTIVE EAST syndrome comprises of epilepsy, ataxia, sensorineural deafness, and tubulopathy. It is caused by a mutation in KCNJ10 gene. Less than thirty cases have been reported in the literature with emphasis on genetic mutation and renal tubulopathy. In this article, our goal is to present a comprehensive description of epilepsy and its management. A literature review is also presented to consolidate and compare our findings with the previously reported cases. METHODS Retrospective chart review was done to collect patient data. Research clinic was organized to obtain missing data. Molecular genetic testing was done at the CGC Genetics Laboratory. Electroencephalogram (EEG) was done for all patients and interpreted by a pediatric epileptologist and brain MRI was reviewed by a pediatric neuroradiologist. Developmental assessment was done by a developmental pediatrician using Griffiths Mental Developmental Scale. RESULTS In patients with EAST syndrome, seizure is the first symptom occurring around 3-4 months of age. Most common seizure type was generalized tonic clonic (GTC). Usually, the seizures were brief lasting <3 min but few patients also presented with status epilepticus especially when the medication was weaned. Carbamazepine (CBZ) was found to be effective in most cases. Lamotrigine (LTG), valproic acid (VPA), and topiramate (TPM) were also found to be helpful. Routine EEGs were usually normal or showed non-specific findings. In few patients, EEG showed background slowing. Brain MRI revealed hyperintensity in the dentate nuclei in some patients, and quantitative volumetric analysis studies showed volume loss in different regions of the brain especially the cerebellum. All our five patients have the same homozygous c.170C>T (p.Thr57Ile) missense mutation in KCNJ10 gene. CONCLUSION This article provides the readers with an understanding of the natural history of epilepsy in this syndrome to help in early recognition, avoid unnecessary investigations, and provide the best treatment for seizures. It also helps the physicians to share the prognosis of this rare syndrome with the parents.
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Affiliation(s)
- Ali Mir
- Pediatric Neurology Department, King Fahad Specialist Hospital, Dammam, Saudi Arabia.
| | - Mohammed Chaudhary
- Pediatric Neurology Department, King Fahad Specialist Hospital, Dammam, Saudi Arabia
| | - Hani Alkhaldi
- Pediatric Neurology Department, King Fahad Specialist Hospital, Dammam, Saudi Arabia
| | - Rami Alhazmi
- Medical Imaging Department, King Fahad Specialist Hospital, Dammam, Saudi Arabia
| | - Raidah Albaradie
- Pediatric Neurology Department, King Fahad Specialist Hospital, Dammam, Saudi Arabia
| | - Yousef Housawi
- Genetic and Metabolic Department, King Fahad Specialist Hospital, Dammam, Saudi Arabia
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18
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Min R, van der Knaap MS. Genetic defects disrupting glial ion and water homeostasis in the brain. Brain Pathol 2019; 28:372-387. [PMID: 29740942 PMCID: PMC8028498 DOI: 10.1111/bpa.12602] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 03/02/2018] [Indexed: 12/23/2022] Open
Abstract
Electrical activity of neurons in the brain, caused by the movement of ions between intracellular and extracellular compartments, is the basis of all our thoughts and actions. Maintaining the correct ionic concentration gradients is therefore crucial for brain functioning. Ion fluxes are accompanied by the displacement of osmotically obliged water. Since even minor brain swelling leads to severe brain damage and even death, brain ion and water movement has to be tightly regulated. Glial cells, in particular astrocytes, play a key role in ion and water homeostasis. They are endowed with specific channels, pumps and carriers to regulate ion and water flow. Glial cells form a large panglial syncytium to aid the uptake and dispersal of ions and water, and make extensive contacts with brain fluid barriers for disposal of excess ions and water. Genetic defects in glial proteins involved in ion and water homeostasis disrupt brain functioning, thereby leading to neurological diseases. Since white matter edema is often a hallmark disease feature, many of these diseases are characterized as leukodystrophies. In this review we summarize our current understanding of inherited glial diseases characterized by disturbed brain ion and water homeostasis by integrating findings from MRI, genetics, neuropathology and animal models for disease. We discuss how mutations in different glial proteins lead to disease, and highlight the similarities and differences between these diseases. To come to effective therapies for this group of diseases, a better mechanistic understanding of how glial cells shape ion and water movement in the brain is crucial.
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Affiliation(s)
- Rogier Min
- Department of Child Neurology, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, The Netherlands.,Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University, Amsterdam, The Netherlands
| | - Marjo S van der Knaap
- Department of Child Neurology, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, The Netherlands.,Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University, Amsterdam, The Netherlands
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19
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Schirmer L, Möbius W, Zhao C, Cruz-Herranz A, Ben Haim L, Cordano C, Shiow LR, Kelley KW, Sadowski B, Timmons G, Pröbstel AK, Wright JN, Sin JH, Devereux M, Morrison DE, Chang SM, Sabeur K, Green AJ, Nave KA, Franklin RJ, Rowitch DH. Oligodendrocyte-encoded Kir4.1 function is required for axonal integrity. eLife 2018; 7:36428. [PMID: 30204081 PMCID: PMC6167053 DOI: 10.7554/elife.36428] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 09/09/2018] [Indexed: 12/17/2022] Open
Abstract
Glial support is critical for normal axon function and can become dysregulated in white matter (WM) disease. In humans, loss-of-function mutations of KCNJ10, which encodes the inward-rectifying potassium channel KIR4.1, causes seizures and progressive neurological decline. We investigated Kir4.1 functions in oligodendrocytes (OLs) during development, adulthood and after WM injury. We observed that Kir4.1 channels localized to perinodal areas and the inner myelin tongue, suggesting roles in juxta-axonal K+ removal. Conditional knockout (cKO) of OL-Kcnj10 resulted in late onset mitochondrial damage and axonal degeneration. This was accompanied by neuronal loss and neuro-axonal dysfunction in adult OL-Kcnj10 cKO mice as shown by delayed visual evoked potentials, inner retinal thinning and progressive motor deficits. Axon pathologies in OL-Kcnj10 cKO were exacerbated after WM injury in the spinal cord. Our findings point towards a critical role of OL-Kir4.1 for long-term maintenance of axonal function and integrity during adulthood and after WM injury.
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Affiliation(s)
- Lucas Schirmer
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, California, United States.,Department of Pediatrics, University of California, San Francisco, San Francisco, United States.,Department of Paediatrics, University of Cambridge, Cambridge, United Kingdom.,Wellcome Trust-Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
| | - Wiebke Möbius
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - Chao Zhao
- Wellcome Trust-Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom.,Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Andrés Cruz-Herranz
- Department of Neurology, University of California, San Francisco, San Francisco, United States.,Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, United States
| | - Lucile Ben Haim
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, California, United States.,Department of Pediatrics, University of California, San Francisco, San Francisco, United States
| | - Christian Cordano
- Department of Neurology, University of California, San Francisco, San Francisco, United States.,Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, United States
| | - Lawrence R Shiow
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, California, United States.,Department of Pediatrics, University of California, San Francisco, San Francisco, United States
| | - Kevin W Kelley
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, California, United States.,Department of Pediatrics, University of California, San Francisco, San Francisco, United States
| | - Boguslawa Sadowski
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - Garrett Timmons
- Department of Neurology, University of California, San Francisco, San Francisco, United States.,Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, United States
| | - Anne-Katrin Pröbstel
- Department of Neurology, University of California, San Francisco, San Francisco, United States.,Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, United States
| | - Jackie N Wright
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, California, United States.,Department of Pediatrics, University of California, San Francisco, San Francisco, United States
| | - Jung Hyung Sin
- Department of Neurology, University of California, San Francisco, San Francisco, United States.,Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, United States
| | - Michael Devereux
- Department of Neurology, University of California, San Francisco, San Francisco, United States.,Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, United States
| | - Daniel E Morrison
- Wellcome Trust-Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom.,Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Sandra M Chang
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, California, United States.,Department of Pediatrics, University of California, San Francisco, San Francisco, United States
| | - Khalida Sabeur
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, California, United States.,Department of Pediatrics, University of California, San Francisco, San Francisco, United States
| | - Ari J Green
- Department of Neurology, University of California, San Francisco, San Francisco, United States.,Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, United States.,Department of Ophthalmology, University of California, San Francisco, San Francisco, United States
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - Robin Jm Franklin
- Wellcome Trust-Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom.,Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - David H Rowitch
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, California, United States.,Department of Pediatrics, University of California, San Francisco, San Francisco, United States.,Department of Paediatrics, University of Cambridge, Cambridge, United Kingdom.,Wellcome Trust-Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom.,Department of Neurosurgery, University of California, San Francisco, San Francisco, United States
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20
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Celmina M, Micule I, Inashkina I, Audere M, Kuske S, Pereca J, Stavusis J, Pelnena D, Strautmanis J. EAST/SeSAME syndrome: Review of the literature and introduction of four new Latvian patients. Clin Genet 2018; 95:63-78. [PMID: 29722015 DOI: 10.1111/cge.13374] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 04/12/2018] [Accepted: 04/23/2018] [Indexed: 11/28/2022]
Abstract
EAST (Epilepsy, Ataxia, Sensorineural deafness, Tubulopathy) or SeSAME (Seizures, Sensorineural deafness, Ataxia, Mental retardation, and Electrolyte imbalance) syndrome is a rare autosomal recessive syndrome first described in 2009 independently by Bockenhauer and Scholl. It is caused by mutations in KCNJ10, which encodes Kir4.1, an inwardly rectifying K+ channel found in the brain, inner ear, kidney and eye. To date, 16 mutations and at least 28 patients have been reported. In this paper, we review mutations causing EAST/SeSAME syndrome, clinical manifestations in detail, and efficacy of treatment in previously reported patients. We also report a new Latvian kindred with 4 patients. In contrast to the majority of previous reports, we found a progressive course of the disorder in terms of hearing impairment and neurologic deficit. The treatment is based on antiepileptic drugs, electrolyte replacement, hearing aids and mobility devices. Future research should concentrate on recognizing the lesions in the central nervous system to evaluate new potential diagnostic criteria and on formally evaluating intellectual disability.
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Affiliation(s)
- M Celmina
- Clinic for Pediatrics, Children's Clinical University Hospital, Riga, Latvia.,Faculty of Continuing Education, University of Latvia, Riga, Latvia
| | - I Micule
- Clinic for Medical Genetics and Prenatal Diagnostics, Children's Clinical University Hospital, Riga, Latvia
| | - I Inashkina
- Latvian Biomedical Research and Study Center, Riga, Latvia
| | - M Audere
- ENT Department, Children's Clinical University Hospital, Riga, Latvia
| | - S Kuske
- Latvian Children's Hearing Center, Riga, Latvia
| | - J Pereca
- Emergency Department, Royal Infirmary of Edinburg, Edinburgh, United Kingdom
| | - J Stavusis
- Latvian Biomedical Research and Study Center, Riga, Latvia
| | - D Pelnena
- Latvian Biomedical Research and Study Center, Riga, Latvia
| | - J Strautmanis
- Clinic for Pediatric Neurology and Neurosurgery, Children's Clinical University Hospital, Riga, Latvia
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Potassium dynamics and seizures: Why is potassium ictogenic? Epilepsy Res 2018; 143:50-59. [DOI: 10.1016/j.eplepsyres.2018.04.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 03/26/2018] [Accepted: 04/07/2018] [Indexed: 01/01/2023]
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Unusual white matter involvement in EAST syndrome associated with novel KCNJ10 mutations. J Neurol 2018; 265:1419-1425. [PMID: 29666984 DOI: 10.1007/s00415-018-8826-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 03/05/2018] [Accepted: 03/08/2018] [Indexed: 01/06/2023]
Abstract
BACKGROUND Epilepsy, ataxia, sensorineural deafness, and tubulopathy (EAST syndrome) is a rare channelopathy due to KCNJ10 mutations. So far, only mild cerebellar hypoplasia and/or dentate nuclei abnormalities have been reported as major neuroimaging findings in these patients. METHODS We analyzed the clinical and brain MRI features of two unrelated patients (aged 27 and 23 years) with EAST syndrome carrying novel homozygous frameshift mutations (p.Asn232Glnfs*14and p.Gly275Valfs*7) in KCNJ10, detected by whole exome sequencing. RESULTS Brain MRI examinations at 8 years in Patient 1 and at 13 years in Patient 2 revealed a peculiar brain and spinal cord involvement characterized by restricted diffusion of globi pallidi, thalami, brainstem, dentate nuclei, and cervical spinal cord in keeping with intramyelinic edema. The follow-up studies, performed, respectively, after 19 and 10 years, showed mild cerebellar atrophy and slight progression of the brain and spinal cord T2 signal abnormalities with increase of the restricted diffusion in the affected regions. CONCLUSION The present cases harboring novel homozygous frameshift mutations in KCNJ10 expand the spectrum of brain abnormalities in EAST syndrome, including mild cerebellar atrophy and intramyelinic edema, resulting from abnormal function of the Kir4.1 inwardly rectifying potassium channel at the astrocyte endfeet, with disruption of water-ion homeostasis.
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Kleta R, Bockenhauer D. Salt-Losing Tubulopathies in Children: What's New, What's Controversial? J Am Soc Nephrol 2018; 29:727-739. [PMID: 29237739 PMCID: PMC5827598 DOI: 10.1681/asn.2017060600] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Renal tubulopathies provide insights into the inner workings of the kidney, yet also pose therapeutic challenges. Because of the central nature of sodium in tubular transport physiology, disorders of sodium handling may affect virtually all aspects of the homeostatic functions of the kidney. Yet, owing to the rarity of these disorders, little clinical evidence regarding treatment exists. Consequently, treatment can vary widely between individual physicians and centers and is based mainly on understanding of renal physiology, reported clinical observations, and individual experiences. Salt-losing tubulopathies can affect all tubular segments, from the proximal tubule to the collecting duct. But the more frequently observed disorders are Bartter and Gitelman syndrome, which affect salt transport in the thick ascending limb of Henle's loop and/or the distal convoluted tubule, and these disorders generate the greatest controversies regarding management. Here, we review clinical and molecular aspects of salt-losing tubulopathies and discuss novel insights provided mainly by genetic investigations and retrospective clinical reviews. Additionally, we discuss controversial topics in the management of these disorders to highlight areas of importance for future clinical trials. International collaboration will be required to perform clinical studies to inform the treatment of these rare disorders.
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Affiliation(s)
- Robert Kleta
- UCL Centre for Nephrology and Great Ormond Street Hospital NHS Foundation Trust, London, United Kingdom
| | - Detlef Bockenhauer
- UCL Centre for Nephrology and Great Ormond Street Hospital NHS Foundation Trust, London, United Kingdom
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24
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Nicita F, Tasca G, Nardella M, Bellacchio E, Camponeschi I, Vasco G, Schirinzi T, Bertini E, Zanni G. Novel Homozygous KCNJ10 Mutation in a Patient with Non-syndromic Early-Onset Cerebellar Ataxia. THE CEREBELLUM 2018; 17:499-503. [DOI: 10.1007/s12311-018-0924-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Kreicher KL, Weir FW, Nguyen SA, Meyer TA. Characteristics and Progression of Hearing Loss in Children with Down Syndrome. J Pediatr 2018; 193:27-33.e2. [PMID: 29174076 DOI: 10.1016/j.jpeds.2017.09.053] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 09/18/2017] [Accepted: 09/21/2017] [Indexed: 12/15/2022]
Abstract
OBJECTIVES To evaluate hearing impairment in children with Down syndrome, and to describe the factors that influence the severity of hearing loss or changes in hearing over time. STUDY DESIGN Using the Audiological and Genetic Database (AudGenDB), audiograms of children with Down syndrome were analyzed retrospectively for type, severity, and laterality of hearing loss, as well as changes over time. Medical charts and imaging results were reviewed to identify factors influencing hearing loss. RESULTS Among the 1088 patients with Down syndrome included in the study, 921 had hearing loss in at least 1 ear, 91.1% had bilateral hearing loss, and 8.9% had unilateral hearing loss (1760 total ears with hearing loss). Of the ears with hearing loss, 18.8% (n = 180) had moderate or worse hearing loss. "Undefined" hearing loss and pure conductive hearing loss (CHL) were the most common types, followed by mixed hearing loss and sensorineural hearing loss (SNHL). Three-quarters (75.4%) of the children had experienced chronic otitis media or more than 2 episodes of acute otitis media. Patients with bilateral, mixed hearing loss or a history of seizures were at risk for more severe hearing loss. CHL, absence of cholesteatoma, and placement of first ear tubes before age 2 years were associated with greater improvement in hearing over time, whereas SNHL and mixed hearing loss were associated with progressive decline. CONCLUSION Children with Down syndrome who have bilateral, mixed hearing loss or a history of seizures are at risk for more severe hearing loss. SNHL and mixed hearing loss should not be overlooked in patients with CHL. All patients with Down syndrome will benefit from serial audiograms, especially those children with SNHL or mixed hearing loss, which is likely to worsen over time.
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Affiliation(s)
- Kathryn L Kreicher
- Department of Otolaryngology-Head and Neck Surgery, Medical University of South Carolina, Charleston, SC; Case Western Reserve University School of Medicine, Cleveland, OH.
| | - Forest W Weir
- Department of Otolaryngology-Head and Neck Surgery, Medical University of South Carolina, Charleston, SC
| | - Shaun A Nguyen
- Department of Otolaryngology-Head and Neck Surgery, Medical University of South Carolina, Charleston, SC
| | - Ted A Meyer
- Department of Otolaryngology-Head and Neck Surgery, Medical University of South Carolina, Charleston, SC
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Al Dhaibani MA, El-Hattab AW, Holroyd KB, Orthmann-Murphy J, Larson VA, Siddiqui KA, Szolics M, Schiess N. Novel mutation in the KCNJ10 gene in three siblings with seizures, ataxia and no electrolyte abnormalities. J Neurogenet 2017; 32:1-5. [PMID: 29191078 DOI: 10.1080/01677063.2017.1404057] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We report a consanguineous family with three affected siblings with novel mutation in the KCNJ10 gene. All three presented with central nervous system symptoms in the form of infantile focal seizures, ataxia, slurred speech with early developmental delay and intellectual disability in two siblings. None had any associated electrolyte abnormalities and no symptomatic hearing deficits were observed.
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Affiliation(s)
- Muna A Al Dhaibani
- a Department of Pediatrics , Tawam Hospital , Al Ain , United Arab Emirates
| | - Ayman W El-Hattab
- b Division of Clinical Genetics and Metabolic Disorders Pediatrics Department , Tawam Hospital , Al Ain , United Arab Emirates
| | | | | | - Valerie A Larson
- d Johns Hopkins Hospital and Health System , Baltimore , MD , USA
| | | | - Miklos Szolics
- f Department of Neurology , Al Tawam Hospital , Al Ain , United Arab Emirates
| | - Nicoline Schiess
- g Department of Neurology , Johns Hopkins University , Baltimore , MD , USA
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Papavasiliou A, Foska K, Ioannou J, Nagel M. Epilepsy, ataxia, sensorineural deafness, tubulopathy syndrome in a European child with KCNJ10 mutations: A case report. SAGE Open Med Case Rep 2017; 5:2050313X17723549. [PMID: 28835827 PMCID: PMC5536383 DOI: 10.1177/2050313x17723549] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 07/07/2017] [Indexed: 11/23/2022] Open
Abstract
Background: Epilepsy, ataxia, sensorineural deafness, tubulopathy syndrome is a multi-organ disorder that links to autosomal recessive mutations in the KCNJ10 gene, which encodes for the Kir4.1 potassium channel. It is mostly described in consanguineous, non-European families. Case Report: A European male of non-consanguineous birth, with early-onset, static ataxic motor disorder, intellectual disability and epilepsy, imitating cerebral palsy, presented with additional findings of renal tubulopathy, sensorineural deafness and normal neuroimaging leading to the diagnosis of epilepsy, ataxia, sensorineural deafness, tubulopathy syndrome. The patient was heterozygous for two KCNJ10 mutations: a missense mutation (p.R65C) that is already published and a not yet published duplication (p.F119GfsX25) that creates a premature truncation of the protein. Both mutations are likely damaging. Parental testing has not been performed, and therefore, we do not know for certain whether the mutations are on different alleles. This young man presents some clinical and laboratory features that differ from previously reported patients with epilepsy, ataxia, sensorineural deafness, tubulopathy syndrome. Conclusion: The necessity of accurate diagnosis through genetic testing in patients with static motor disorders resembling cerebral palsy phenotypes, atypical clinical features and noncontributory neuroimaging is emphasized.
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Affiliation(s)
| | - Katerina Foska
- Department of Pediatric Neurology, Pendeli Children's Hospital, Athens, Greece
| | - John Ioannou
- Department of Pediatric Neurology, Pendeli Children's Hospital, Athens, Greece
| | - Mato Nagel
- Laboratory for Molecular Diagnostics, Weisswasser, Germany
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Hasan S, Balobaid A, Grottesi A, Dabbagh O, Cenciarini M, Rawashdeh R, Al-Sagheir A, Bove C, Macchioni L, Pessia M, Al-Owain M, D'Adamo MC. Lethal digenic mutations in the K + channels Kir4.1 ( KCNJ10) and SLACK ( KCNT1) associated with severe-disabling seizures and neurodevelopmental delay. J Neurophysiol 2017; 118:2402-2411. [PMID: 28747464 DOI: 10.1152/jn.00284.2017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 07/05/2017] [Accepted: 07/21/2017] [Indexed: 01/14/2023] Open
Abstract
A 2-yr-old boy presented profound developmental delay, failure to thrive, ataxia, hypotonia, and tonic-clonic seizures that caused the death of the patient. Targeted and whole exome sequencing revealed two heterozygous missense variants: a novel mutation in the KCNJ10 gene that encodes for the inward-rectifying K+ channel Kir4.1 and another previously characterized mutation in KCNT1 that encodes for the Na+-activated K+ channel known as Slo2.2 or SLACK. The objectives of this study were to perform the clinical and genetic characterization of the proband and his family and to examine the functional consequence of the Kir4.1 mutation. The mutant and wild-type KCNJ10 constructs were generated and heterologously expressed in Xenopus laevis oocytes, and whole cell K+ currents were measured using the two-electrode voltage-clamp technique. The KCNJ10 mutation c.652C>T resulted in a p.L218F substitution at a highly conserved residue site. Wild-type KCNJ10 expression yielded robust Kir current, whereas currents from oocytes expressing the mutation were reduced, remarkably. Western Blot analysis revealed reduced protein expression by the mutation. Kir5.1 subunits display selective heteromultimerization with Kir4.1 constituting channels with unique kinetics. The effect of the mutation on Kir4.1/5.1 channel activity was twofold: a reduction in current amplitudes and an increase in the pH-dependent inhibition. We thus report a novel loss-of-function mutation in Kir4.1 found in a patient with a coexisting mutation in SLACK channels that results in a fatal disease.NEW & NOTEWORTHY We present and characterize a novel mutation in KCNJ10 Unlike previously reported EAST/SeSAME patients, our patient was heterozygous, and contrary to previous studies, mimicking the heterozygous state by coexpression resulted in loss of channel function. We report in the same patient co-occurrence of a KCNT1 mutation resulting in a more severe phenotype. This study provides new insights into the phenotypic spectrum and to the genotype-phenotype correlations associated with EAST/SeSAME and MMFSI.
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Affiliation(s)
- Sonia Hasan
- Department of Physiology, Faculty of Medicine, Kuwait University, Safat, Kuwait
| | - Ameera Balobaid
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | | | - Omar Dabbagh
- Department of Neurosciences, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Marta Cenciarini
- Section of Physiology and Biochemistry, Department of Experimental Medicine, School of Medicine, University of Perugia, Perugia, Italy
| | - Rifaat Rawashdeh
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Afaf Al-Sagheir
- Department of Pediatrics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Cecilia Bove
- Section of Physiology and Biochemistry, Department of Experimental Medicine, School of Medicine, University of Perugia, Perugia, Italy
| | - Lara Macchioni
- Section of Physiology and Biochemistry, Department of Experimental Medicine, School of Medicine, University of Perugia, Perugia, Italy
| | - Mauro Pessia
- Section of Physiology and Biochemistry, Department of Experimental Medicine, School of Medicine, University of Perugia, Perugia, Italy.,Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta
| | - Mohammed Al-Owain
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.,College of Medicine, AlFaisal University, Riyadh, Saudi Arabia; and
| | - Maria Cristina D'Adamo
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta; .,Fondazione Santa Lucia, IRCCS, Rome, Italy
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Viering DHHM, de Baaij JHF, Walsh SB, Kleta R, Bockenhauer D. Genetic causes of hypomagnesemia, a clinical overview. Pediatr Nephrol 2017; 32:1123-1135. [PMID: 27234911 PMCID: PMC5440500 DOI: 10.1007/s00467-016-3416-3] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 05/02/2016] [Accepted: 05/04/2016] [Indexed: 12/16/2022]
Abstract
Magnesium is essential to the proper functioning of numerous cellular processes. Magnesium ion (Mg2+) deficits, as reflected in hypomagnesemia, can cause neuromuscular irritability, seizures and cardiac arrhythmias. With normal Mg2+ intake, homeostasis is maintained primarily through the regulated reabsorption of Mg2+ by the thick ascending limb of Henle's loop and distal convoluted tubule of the kidney. Inadequate reabsorption results in renal Mg2+ wasting, as evidenced by an inappropriately high fractional Mg2+ excretion. Familial renal Mg2+ wasting is suggestive of a genetic cause, and subsequent studies in these hypomagnesemic families have revealed over a dozen genes directly or indirectly involved in Mg2+ transport. Those can be classified into four groups: hypercalciuric hypomagnesemias (encompassing mutations in CLDN16, CLDN19, CASR, CLCNKB), Gitelman-like hypomagnesemias (CLCNKB, SLC12A3, BSND, KCNJ10, FYXD2, HNF1B, PCBD1), mitochondrial hypomagnesemias (SARS2, MT-TI, Kearns-Sayre syndrome) and other hypomagnesemias (TRPM6, CNMM2, EGF, EGFR, KCNA1, FAM111A). Although identification of these genes has not yet changed treatment, which remains Mg2+ supplementation, it has contributed enormously to our understanding of Mg2+ transport and renal function. In this review, we discuss general mechanisms and symptoms of genetic causes of hypomagnesemia as well as the specific molecular mechanisms and clinical phenotypes associated with each syndrome.
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Affiliation(s)
- Daan H H M Viering
- Centre for Nephrology, University College London, London, UK
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jeroen H F de Baaij
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Stephen B Walsh
- Centre for Nephrology, University College London, London, UK
| | - Robert Kleta
- Centre for Nephrology, University College London, London, UK.
- Paediatric Nephrology, Great Ormond Street Hospital, London, UK.
| | - Detlef Bockenhauer
- Centre for Nephrology, University College London, London, UK
- Paediatric Nephrology, Great Ormond Street Hospital, London, UK
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Abstract
PURPOSE OF REVIEW Magnesium (Mg) imbalances are frequently overlooked. Hypermagnesemia usually occurs in preeclamptic women after Mg therapy or in end-stage renal disease patients, whereas hypomagnesemia is more common with a prevalence of up to 15% in the general population. Increasing evidence points toward a role for mild-to-moderate chronic hypomagnesemia in the pathogenesis of hypertension, type 2 diabetes mellitus, and metabolic syndrome. RECENT FINDINGS The kidneys are the major regulator of total body Mg homeostasis. Over the last decade, the identification of the responsible genes in rare genetic disorders has enhanced our understanding of how the kidney handles Mg. The different genetic disorders and medications contributing to abnormal Mg homeostasis are reviewed. SUMMARY As dysfunctional Mg homeostasis contributes to the development of many common human disorders, serum Mg deserves closer monitoring. Hypomagnesemic patients may be asymptomatic or may have mild symptoms. In severe hypomagnesemia, patients may present with neurological symptoms such as seizures, spasms, or cramps. Renal symptoms include nephrocalcinosis and impaired renal function. Most conditions affect tubular Mg reabsorption by disturbing the lumen-positive potential in the thick ascending limb or the negative membrane potential in the distal convoluted tubule.
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A Missense Variant in KCNJ10 in Belgian Shepherd Dogs Affected by Spongy Degeneration with Cerebellar Ataxia (SDCA1). G3-GENES GENOMES GENETICS 2017; 7:663-669. [PMID: 28007838 PMCID: PMC5295610 DOI: 10.1534/g3.116.038455] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Spongy degeneration with cerebellar ataxia (SDCA) is a severe neurodegenerative disease with monogenic autosomal recessive inheritance in Malinois dogs, one of the four varieties of the Belgian Shepherd breed. We performed a genetic investigation in six families and seven isolated cases of Malinois dogs with signs of cerebellar dysfunction. Linkage analysis revealed an unexpected genetic heterogeneity within the studied cases. The affected dogs from four families and one isolated case shared a ∼1.4 Mb common homozygous haplotype segment on chromosome 38. Whole genome sequence analysis of three affected and 140 control dogs revealed a missense variant in the KCNJ10 gene encoding a potassium channel (c.986T>C; p.Leu329Pro). Pathogenic variants in KCNJ10 were reported previously in humans, mice, and dogs with neurological phenotypes. Therefore, we consider KCNJ10:c.986T>C the most likely candidate causative variant for one subtype of SDCA in Malinois dogs, which we propose to term spongy degeneration with cerebellar ataxia 1 (SDCA1). However, our study also comprised samples from 12 Malinois dogs with cerebellar dysfunction which were not homozygous for this variant, suggesting a different genetic basis in these dogs. A retrospective detailed clinical and histopathological analysis revealed subtle neuropathological differences with respect to SDCA1-affected dogs. Thus, our study highlights the genetic and phenotypic complexity underlying cerebellar dysfunction in Malinois dogs and provides the basis for a genetic test to eradicate one specific neurodegenerative disease from the breeding population. These dogs represent an animal model for the human EAST syndrome.
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Van Poucke M, Stee K, Bhatti SFM, Vanhaesebrouck A, Bosseler L, Peelman LJ, Van Ham L. The novel homozygous KCNJ10 c.986T>C (p.(Leu329Pro)) variant is pathogenic for the SeSAME/EAST homologue in Malinois dogs. Eur J Hum Genet 2016; 25:222-226. [PMID: 27966545 DOI: 10.1038/ejhg.2016.157] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 09/21/2016] [Accepted: 09/29/2016] [Indexed: 12/31/2022] Open
Abstract
SeSAME/EAST syndrome is a multisystemic disorder in humans, characterised by seizures, sensorineural deafness, ataxia, developmental delay and electrolyte imbalance. It is exclusively caused by homozygous or compound heterozygous variations in the KCNJ10 gene. Here we describe a similar syndrome in two families belonging to the Malinois dog breed, based on clinical, neurological, electrodiagnostic and histopathological examination. Genetic analysis detected a novel pathogenic KCNJ10 c.986T>C (p.(Leu329Pro)) variant that is inherited in an autosomal recessive way. This variant has an allele frequency of 2.9% in the Belgian Malinois population, but is not found in closely related dog breeds or in dog breeds where similar symptoms have been already described. The canine phenotype is remarkably similar to humans, including ataxia and seizures. In addition, in half of the dogs clinical and electrophysiological signs of neuromyotonia were observed. Because there is currently no cure and treatment is nonspecific and unsatisfactory, this canine translational model could be used for further elucidating the genotype/phenotype correlation of this monogenic multisystem disorder and as an excellent intermediate step for drug safety testing and efficacy evaluations before initiating human studies.
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Affiliation(s)
- Mario Van Poucke
- Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Kimberley Stee
- Department of Small Animal Medicine and Clinical Biology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Sofie F M Bhatti
- Department of Small Animal Medicine and Clinical Biology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - An Vanhaesebrouck
- Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Leslie Bosseler
- Department of Pathology, Bacteriology and Poultry Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Luc J Peelman
- Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Luc Van Ham
- Department of Small Animal Medicine and Clinical Biology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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Marcián V, Filip P, Bareš M, Brázdil M. Cerebellar Dysfunction and Ataxia in Patients with Epilepsy: Coincidence, Consequence, or Cause? TREMOR AND OTHER HYPERKINETIC MOVEMENTS (NEW YORK, N.Y.) 2016; 6:376. [PMID: 27375960 PMCID: PMC4925921 DOI: 10.7916/d8kh0nbt] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Accepted: 05/05/2016] [Indexed: 12/15/2022]
Abstract
Basic epilepsy teachings assert that seizures arise from the cerebral cortex, glossing over infratentorial structures such as the cerebellum that are believed to modulate rather than generate seizures. Nonetheless, ataxia and other clinical findings in epileptic patients are slowly but inevitably drawing attention to this neural node. Tracing the evolution of this line of inquiry from the observed coincidence of cerebellar atrophy and cerebellar dysfunction (most apparently manifested as ataxia) in epilepsy to their close association, this review considers converging clinical, physiological, histological, and neuroimaging evidence that support incorporating the cerebellum into epilepsy pathology. We examine reports of still controversial cerebellar epilepsy, studies of cerebellar stimulation alleviating paroxysmal epileptic activity, studies and case reports of cerebellar lesions directly associated with seizures, and conditions in which ataxia is accompanied by epileptic seizures. Finally, the review substantiates the role of this complex brain structure in epilepsy whether by coincidence, as a consequence of deleterious cortical epileptic activity or antiepileptic drugs, or the very cause of the disease.
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Affiliation(s)
- Václav Marcián
- First Department of Neurology, St. Anne's University Hospital, Brno, Czech Republic; Medical Faculty of Masaryk University, Brno, Czech Republic.,First Department of Neurology, St. Anne's University Hospital, Brno, Czech Republic; Medical Faculty of Masaryk University, Brno, Czech Republic; Behavioral and Social Neuroscience Research Group, CEITEC (Central European Institute of Technology), Masaryk University, Brno, Czech Republic; Department of Neurology, School of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Pavel Filip
- First Department of Neurology, St. Anne's University Hospital, Brno, Czech Republic; Medical Faculty of Masaryk University, Brno, Czech Republic
| | - Martin Bareš
- First Department of Neurology, St. Anne's University Hospital, Brno, Czech Republic; Medical Faculty of Masaryk University, Brno, Czech Republic; Behavioral and Social Neuroscience Research Group, CEITEC (Central European Institute of Technology), Masaryk University, Brno, Czech Republic; Department of Neurology, School of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Milan Brázdil
- First Department of Neurology, St. Anne's University Hospital, Brno, Czech Republic; Medical Faculty of Masaryk University, Brno, Czech Republic; Behavioral and Social Neuroscience Research Group, CEITEC (Central European Institute of Technology), Masaryk University, Brno, Czech Republic
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Abdelhadi O, Iancu D, Tekman M, Stanescu H, Bockenhauer D, Kleta R. Founder mutation in KCNJ10 in Pakistani patients with EAST syndrome. Mol Genet Genomic Med 2016; 4:521-6. [PMID: 27652280 PMCID: PMC5023937 DOI: 10.1002/mgg3.227] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 05/05/2016] [Accepted: 05/09/2016] [Indexed: 11/11/2022] Open
Abstract
Background EAST syndrome is an autosomal recessive disorder caused by loss‐of‐function mutations in the gene KCNJ10. Among the 14 pathogenic mutations described so far, the p.R65P mutation stands out as the most frequent one and is particularly associated with patients of Pakistani origin. As a result we aimed to establish the existence of a potential founder effect in the Pakistani population. Methods To this end, we genotyped 12 patients from seven families and we compared disease haplotypes with ethnically matched control chromosomes. This haplotype was used together with demographic data for Pakistan to estimate the age of this founder mutation. Results We identified a small homozygous 0.694 Mb region around the KCNJ10 p.R65P mutation that had identical haplotypes in all of the patients which were completely absent in the control sample. Based on current demographic data and knowledge about disease frequency, we estimate that this particular p.R65P mutation arose 20 generations (about 500 years) ago. Conclusion By knowing the prevalent mutation in a given population more efficient diagnostics can be performed and the families can benefit from specific counseling.
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Affiliation(s)
- Ola Abdelhadi
- Centre for Nephrology University College London London UK
| | - Daniela Iancu
- Centre for Nephrology University College London London UK
| | - Mehmet Tekman
- Centre for Nephrology University College London London UK
| | - Horia Stanescu
- Centre for Nephrology University College London London UK
| | | | - Robert Kleta
- Centre for Nephrology University College London London UK
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Abdelhadi O, Iancu D, Stanescu H, Kleta R, Bockenhauer D. EAST syndrome: Clinical, pathophysiological, and genetic aspects of mutations in KCNJ10. Rare Dis 2016; 4:e1195043. [PMID: 27500072 PMCID: PMC4961265 DOI: 10.1080/21675511.2016.1195043] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 05/02/2016] [Accepted: 05/24/2016] [Indexed: 11/04/2022] Open
Abstract
EAST syndrome is a recently described autosomal recessive disorder secondary to mutations in KCNJ10 (Kir4.1), a gene encoding a potassium channel expressed in the brain, eye, ear and kidney. This condition is characterized by 4 cardinal features; Epilepsy, Ataxia, Sensorineural deafness, and (a renal salt-wasting) Tubulopathy, hence the acronym EAST syndrome. Here we review reported clinical manifestations, in particular the neurological signs and symptoms which typically have the most impact on the quality of life of patients. In addition we review the pathophysiology and genetic aspects of the disease. So far 14 different KCNJ10 mutations have been published which either directly affect channel function or may lead to mislocalisation. Investigations of the pathophysiology may provide clues to potential treatments.
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Affiliation(s)
- Ola Abdelhadi
- Center for Nephrology, University College London, London, UK
| | - Daniela Iancu
- Center for Nephrology, University College London, London, UK
| | - Horia Stanescu
- Center for Nephrology, University College London, London, UK
| | - Robert Kleta
- Center for Nephrology, University College London, London, UK
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Imbrici P, Liantonio A, Camerino GM, De Bellis M, Camerino C, Mele A, Giustino A, Pierno S, De Luca A, Tricarico D, Desaphy JF, Conte D. Therapeutic Approaches to Genetic Ion Channelopathies and Perspectives in Drug Discovery. Front Pharmacol 2016; 7:121. [PMID: 27242528 PMCID: PMC4861771 DOI: 10.3389/fphar.2016.00121] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Accepted: 04/25/2016] [Indexed: 12/21/2022] Open
Abstract
In the human genome more than 400 genes encode ion channels, which are transmembrane proteins mediating ion fluxes across membranes. Being expressed in all cell types, they are involved in almost all physiological processes, including sense perception, neurotransmission, muscle contraction, secretion, immune response, cell proliferation, and differentiation. Due to the widespread tissue distribution of ion channels and their physiological functions, mutations in genes encoding ion channel subunits, or their interacting proteins, are responsible for inherited ion channelopathies. These diseases can range from common to very rare disorders and their severity can be mild, disabling, or life-threatening. In spite of this, ion channels are the primary target of only about 5% of the marketed drugs suggesting their potential in drug discovery. The current review summarizes the therapeutic management of the principal ion channelopathies of central and peripheral nervous system, heart, kidney, bone, skeletal muscle and pancreas, resulting from mutations in calcium, sodium, potassium, and chloride ion channels. For most channelopathies the therapy is mainly empirical and symptomatic, often limited by lack of efficacy and tolerability for a significant number of patients. Other channelopathies can exploit ion channel targeted drugs, such as marketed sodium channel blockers. Developing new and more specific therapeutic approaches is therefore required. To this aim, a major advancement in the pharmacotherapy of channelopathies has been the discovery that ion channel mutations lead to change in biophysics that can in turn specifically modify the sensitivity to drugs: this opens the way to a pharmacogenetics strategy, allowing the development of a personalized therapy with increased efficacy and reduced side effects. In addition, the identification of disease modifiers in ion channelopathies appears an alternative strategy to discover novel druggable targets.
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Affiliation(s)
- Paola Imbrici
- Department of Pharmacy - Drug Sciences, University of Bari "Aldo Moro" Bari, Italy
| | - Antonella Liantonio
- Department of Pharmacy - Drug Sciences, University of Bari "Aldo Moro" Bari, Italy
| | - Giulia M Camerino
- Department of Pharmacy - Drug Sciences, University of Bari "Aldo Moro" Bari, Italy
| | - Michela De Bellis
- Department of Pharmacy - Drug Sciences, University of Bari "Aldo Moro" Bari, Italy
| | - Claudia Camerino
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari "Aldo Moro" Bari, Italy
| | - Antonietta Mele
- Department of Pharmacy - Drug Sciences, University of Bari "Aldo Moro" Bari, Italy
| | - Arcangela Giustino
- Department of Biomedical Sciences and Human Oncology, University of Bari "Aldo Moro" Bari, Italy
| | - Sabata Pierno
- Department of Pharmacy - Drug Sciences, University of Bari "Aldo Moro" Bari, Italy
| | - Annamaria De Luca
- Department of Pharmacy - Drug Sciences, University of Bari "Aldo Moro" Bari, Italy
| | - Domenico Tricarico
- Department of Pharmacy - Drug Sciences, University of Bari "Aldo Moro" Bari, Italy
| | - Jean-Francois Desaphy
- Department of Biomedical Sciences and Human Oncology, University of Bari "Aldo Moro" Bari, Italy
| | - Diana Conte
- Department of Pharmacy - Drug Sciences, University of Bari "Aldo Moro" Bari, Italy
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Psychiatric Manifestation of EAST Syndrome: Case Report and a Critical Assessment of Psychiatric Issues. J Clin Psychopharmacol 2016; 36:185-7. [PMID: 26862828 DOI: 10.1097/jcp.0000000000000468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Sethi G, Chopra G, Samudrala R. Multiscale modelling of relationships between protein classes and drug behavior across all diseases using the CANDO platform. Mini Rev Med Chem 2016; 15:705-17. [PMID: 25694071 DOI: 10.2174/1389557515666150219145148] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 10/30/2014] [Accepted: 11/25/2014] [Indexed: 01/27/2023]
Abstract
We have examined the effect of eight different protein classes (channels, GPCRs, kinases, ligases, nuclear receptors, proteases, phosphatases, transporters) on the benchmarking performance of the CANDO drug discovery and repurposing platform (http://protinfo.org/cando). The first version of the CANDO platform utilizes a matrix of predicted interactions between 48278 proteins and 3733 human ingestible compounds (including FDA approved drugs and supplements) that map to 2030 indications/diseases using a hierarchical chem and bio-informatic fragment based docking with dynamics protocol (> one billion predicted interactions considered). The platform uses similarity of compound-proteome interaction signatures as indicative of similar functional behavior and benchmarking accuracy is calculated across 1439 indications/diseases with more than one approved drug. The CANDO platform yields a significant correlation (0.99, p-value < 0.0001) between the number of proteins considered and benchmarking accuracy obtained indicating the importance of multitargeting for drug discovery. Average benchmarking accuracies range from 6.2 % to 7.6 % for the eight classes when the top 10 ranked compounds are considered, in contrast to a range of 5.5 % to 11.7 % obtained for the comparison/control sets consisting of 10, 100, 1000, and 10000 single best performing proteins. These results are generally two orders of magnitude better than the average accuracy of 0.2% obtained when randomly generated (fully scrambled) matrices are used. Different indications perform well when different classes are used but the best accuracies (up to 11.7% for the top 10 ranked compounds) are achieved when a combination of classes are used containing the broadest distribution of protein folds. Our results illustrate the utility of the CANDO approach and the consideration of different protein classes for devising indication specific protocols for drug repurposing as well as drug discovery.
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Affiliation(s)
| | | | - Ram Samudrala
- Department of Biomedical Informatics, School of Medicine and Biomedical Sciences, State University of New York (SUNY), 923 Main Street, Buffalo, NY 14203, USA.
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Kumar P, Kumar D, Jha SK, Jha NK, Ambasta RK. Ion Channels in Neurological Disorders. ION CHANNELS AS THERAPEUTIC TARGETS, PART A 2016; 103:97-136. [DOI: 10.1016/bs.apcsb.2015.10.006] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Grondin Y, Bortoni ME, Sepulveda R, Ghelfi E, Bartos A, Cotanche D, Clifford RE, Rogers RA. Genetic Polymorphisms Associated with Hearing Threshold Shift in Subjects during First Encounter with Occupational Impulse Noise. PLoS One 2015; 10:e0130827. [PMID: 26121033 PMCID: PMC4488244 DOI: 10.1371/journal.pone.0130827] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 05/26/2015] [Indexed: 12/20/2022] Open
Abstract
Noise-induced hearing loss (NIHL) is the most significant occupational health issue worldwide. We conducted a genome-wide association study to identify single-nucleotide polymorphisms (SNPs) associated with hearing threshold shift in young males undergoing their first encounter with occupational impulse noise. We report a significant association of SNP rs7598759 (p < 5 x 10(-7); p = 0.01 after permutation and correction; Odds Ratio = 12.75) in the gene coding for nucleolin, a multifunctional phosphoprotein involved in the control of senescence and protection against apoptosis. Interestingly, nucleolin has been shown to mediate the anti-apoptotic effect of HSP70, a protein found to prevent ototoxicity and whose polymorphisms have been associated with susceptibility to NIHL. Increase in nucleolin expression has also been associated with the prevention of apoptosis in cells undergoing oxidative stress, a well-known metabolic sequela of noise exposure. To assess the potential role of nucleolin in hearing loss, we tested down-regulation of nucleolin in cochlear sensory cells HEI-OC1 under oxidative stress conditions and report increased sensitivity to cisplatin, a chemotherapeutic drug with ototoxic side effects. Additional SNPs were found with suggestive association (p < 5 x 10(-4)), of which 7 SNPs were located in genes previously reported to be related to NIHL and 43 of them were observed in 36 other genes previously not reported to be associated with NIHL. Taken together, our GWAS data and in vitro studies reported herein suggest that nucleolin is a potential candidate associated with NIHL in this population.
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Affiliation(s)
- Yohann Grondin
- Molecular and Integrative Physiological Sciences Program, Department of Environmental Health, Harvard School of Public Health, 665 Huntington Ave, Boston, MA, 02115, United States of America
| | - Magda E. Bortoni
- Molecular and Integrative Physiological Sciences Program, Department of Environmental Health, Harvard School of Public Health, 665 Huntington Ave, Boston, MA, 02115, United States of America
| | - Rosalinda Sepulveda
- Molecular and Integrative Physiological Sciences Program, Department of Environmental Health, Harvard School of Public Health, 665 Huntington Ave, Boston, MA, 02115, United States of America
| | - Elisa Ghelfi
- Molecular and Integrative Physiological Sciences Program, Department of Environmental Health, Harvard School of Public Health, 665 Huntington Ave, Boston, MA, 02115, United States of America
| | - Adam Bartos
- Molecular and Integrative Physiological Sciences Program, Department of Environmental Health, Harvard School of Public Health, 665 Huntington Ave, Boston, MA, 02115, United States of America
| | - Douglas Cotanche
- Molecular and Integrative Physiological Sciences Program, Department of Environmental Health, Harvard School of Public Health, 665 Huntington Ave, Boston, MA, 02115, United States of America
| | - Royce E. Clifford
- Molecular and Integrative Physiological Sciences Program, Department of Environmental Health, Harvard School of Public Health, 665 Huntington Ave, Boston, MA, 02115, United States of America
- Department of Otolaryngology-Head and Neck Surgery, 34800 Bob Wilson Dr., Suite 200, Naval Medical Center, San Diego, CA, 92134, United States of America
| | - Rick A. Rogers
- Molecular and Integrative Physiological Sciences Program, Department of Environmental Health, Harvard School of Public Health, 665 Huntington Ave, Boston, MA, 02115, United States of America
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de Baaij JHF, Hoenderop JGJ, Bindels RJM. Magnesium in man: implications for health and disease. Physiol Rev 2015; 95:1-46. [PMID: 25540137 DOI: 10.1152/physrev.00012.2014] [Citation(s) in RCA: 870] [Impact Index Per Article: 96.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Magnesium (Mg(2+)) is an essential ion to the human body, playing an instrumental role in supporting and sustaining health and life. As the second most abundant intracellular cation after potassium, it is involved in over 600 enzymatic reactions including energy metabolism and protein synthesis. Although Mg(2+) availability has been proven to be disturbed during several clinical situations, serum Mg(2+) values are not generally determined in patients. This review aims to provide an overview of the function of Mg(2+) in human health and disease. In short, Mg(2+) plays an important physiological role particularly in the brain, heart, and skeletal muscles. Moreover, Mg(2+) supplementation has been shown to be beneficial in treatment of, among others, preeclampsia, migraine, depression, coronary artery disease, and asthma. Over the last decade, several hereditary forms of hypomagnesemia have been deciphered, including mutations in transient receptor potential melastatin type 6 (TRPM6), claudin 16, and cyclin M2 (CNNM2). Recently, mutations in Mg(2+) transporter 1 (MagT1) were linked to T-cell deficiency underlining the important role of Mg(2+) in cell viability. Moreover, hypomagnesemia can be the consequence of the use of certain types of drugs, such as diuretics, epidermal growth factor receptor inhibitors, calcineurin inhibitors, and proton pump inhibitors. This review provides an extensive and comprehensive overview of Mg(2+) research over the last few decades, focusing on the regulation of Mg(2+) homeostasis in the intestine, kidney, and bone and disturbances which may result in hypomagnesemia.
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Affiliation(s)
- Jeroen H F de Baaij
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Joost G J Hoenderop
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - René J M Bindels
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
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Gilliam D, O'Brien DP, Coates JR, Johnson GS, Johnson GC, Mhlanga-Mutangadura T, Hansen L, Taylor JF, Schnabel RD. A homozygous KCNJ10 mutation in Jack Russell Terriers and related breeds with spinocerebellar ataxia with myokymia, seizures, or both. J Vet Intern Med 2014; 28:871-7. [PMID: 24708069 PMCID: PMC4238845 DOI: 10.1111/jvim.12355] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Revised: 02/14/2014] [Accepted: 03/03/2014] [Indexed: 12/21/2022] Open
Abstract
Background Juvenile‐onset spinocerebellar ataxia has been recognized in Jack Russell Terriers and related Russell group terriers (RGTs) for over 40 years. Ataxia occurs with varying combinations of myokymia, seizures, and other signs of neurologic disease. More than 1 form of the disease has been suspected. Hypothesis/Objectives The objective was to identify the mutation causing the spinocerebellar ataxia associated with myokymia, seizures, or both and distinguish the phenotype from other ataxias in the RGTs. Animals DNA samples from 16 RGTs with spinocerebellar ataxia beginning from 2 to 12 months of age, 640 control RGTs, and 383 dogs from 144 other breeds along with the medical records of affected dogs were studied. Methods This case‐control study compared the frequencies of a KCNJ10 allele in RGTs with spinocerebellar ataxia versus control RGTs. This allele was identified in a whole‐genome sequence of a single RGT with spinocerebellar ataxia and myokymia by comparison to whole‐genome sequences from 81 other canids that were normal or had other diseases. Results A missense mutation in the gene coding for the inwardly rectifying potassium channel Kir4.1 (KCNJ10:c.627C>G) was significantly (P < .001) associated with the disease. Dogs homozygous for the mutant allele all had spinocerebellar ataxia with varying combinations of myokymia and seizures. Conclusions and Clinical Importance Identification of the KCNJ10 mutation in dogs with spinocerebellar ataxia with myokymia, seizures, or both clarifies the multiple forms of ataxia seen in these breeds and provides a DNA test to identify carriers.
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Affiliation(s)
- D Gilliam
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO
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Stivaros S. How the imaging investigation of EAST syndrome points towards the future of radiological multi-parametric phenotyping of a genetic disease. Dev Med Child Neurol 2013; 55:783-4. [PMID: 23924081 DOI: 10.1111/dmcn.12189] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Stavros Stivaros
- Royal Manchester Children's Hospital, Academic Department of Paediatric Neuroradiology & The University of Manchester, UK
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