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Tian M, Li R, Yang F, Shu X, Li J, Chen J, Peng L, Yu X, Yang C. Phenotypic expansion of KCNH1-associated disorders to include isolated epilepsy and its associations with genotypes and molecular sub-regional locations. CNS Neurosci Ther 2022; 29:270-281. [PMID: 36285361 PMCID: PMC9804083 DOI: 10.1111/cns.14001] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 09/20/2022] [Accepted: 09/29/2022] [Indexed: 02/06/2023] Open
Abstract
PURPOSE Genotype-phenotypic correlation of KCNH1 variant remains elusive. This study aimed to expand the phenotypic spectrum of KCNH1 and explore the correlations between epilepsy and molecular sub-regional locations. METHODS We performed whole-exome sequencing in a cohort of 98 patients with familiar febrile seizure (FS) or epilepsy with unexplained etiologies. The damaging effects of variants were predicted by protein modeling and multiple in silico tools. All reported patients with KCNH1 pathogenic variants with detailed neurological phenotypes were analyzed to evaluate the genotype-phenotype correlation. RESULTS Two novel KCNH1 variants were identified in three cases, including two patients with FS with inherited variant (p.Ile113Thr) and one boy with epilepsy with de novo variant (p.Arg357Trp). Variant Ile113Thr was located within the eag domain, and variant p.Arg357Trp was located in transmembrane domain 4 of KCNH1, respectively. Two patients experienced refractory status epilepticus (SE), of which one patient died of acute encephalopathy induced by SE. Further analysis of 30 variants in 51 patients demonstrated that de novo variants were associated with epileptic encephalopathy, while mosaic/somatic or germline variants cause isolated epilepsy/FS. All hotspot variants associated with epileptic encephalopathy clustered in transmembrane domain (S4 and S6), while those with isolated epilepsy/seizures or TBS/ZLS without epilepsy were scattered in the KCNH1. CONCLUSIONS We found two novel missense variants of KCNH1 in three individuals with isolated FS/epilepsy. Variants in the KCNH1 cause a spectrum of epileptic disorders ranging from a benign form of genetic isolated epilepsy/FS to intractable form of epileptic encephalopathy. The genotypes and variant locations help explaining the phenotypic variation of patients with KCNH1 variant.
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Affiliation(s)
- Mao‐Qiang Tian
- Department of PediatricsAffiliated Hospital of Zunyi Medical UniversityZunyiChina,Department of PediatricsGuizhou Children's HospitalZunyiChina
| | - Ren‐Ke Li
- Department of PediatricsAffiliated Hospital of Zunyi Medical UniversityZunyiChina,Department of PediatricsGuizhou Children's HospitalZunyiChina
| | | | - Xiao‐Mei Shu
- Department of PediatricsAffiliated Hospital of Zunyi Medical UniversityZunyiChina,Department of PediatricsGuizhou Children's HospitalZunyiChina
| | - Juan Li
- Department of PediatricsAffiliated Hospital of Zunyi Medical UniversityZunyiChina,Department of PediatricsGuizhou Children's HospitalZunyiChina
| | - Jing Chen
- Department of PediatricsAffiliated Hospital of Zunyi Medical UniversityZunyiChina,Department of PediatricsGuizhou Children's HospitalZunyiChina
| | - Long‐Ying Peng
- Department of PediatricsAffiliated Hospital of Zunyi Medical UniversityZunyiChina,Department of PediatricsGuizhou Children's HospitalZunyiChina
| | - Xiao‐Hua Yu
- Department of PediatricsAffiliated Hospital of Zunyi Medical UniversityZunyiChina,Department of PediatricsGuizhou Children's HospitalZunyiChina
| | - Chang‐Jian Yang
- Department of PediatricsAffiliated Hospital of Zunyi Medical UniversityZunyiChina,Department of PediatricsGuizhou Children's HospitalZunyiChina
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2
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Gripp KW, Smithson SF, Scurr IJ, Baptista J, Majumdar A, Pierre G, Williams M, Henderson LB, Wentzensen IM, McLaughlin H, Leeuwen L, Simon MEH, van Binsbergen E, Dinulos MBP, Kaplan JD, McRae A, Superti-Furga A, Good JM, Kutsche K. Syndromic disorders caused by gain-of-function variants in KCNH1, KCNK4, and KCNN3-a subgroup of K + channelopathies. Eur J Hum Genet 2021; 29:1384-1395. [PMID: 33594261 PMCID: PMC8440610 DOI: 10.1038/s41431-021-00818-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/18/2021] [Accepted: 01/22/2021] [Indexed: 12/13/2022] Open
Abstract
Decreased or increased activity of potassium channels caused by loss-of-function and gain-of-function (GOF) variants in the corresponding genes, respectively, underlies a broad spectrum of human disorders affecting the central nervous system, heart, kidney, and other organs. While the association of epilepsy and intellectual disability (ID) with variants affecting function in genes encoding potassium channels is well known, GOF missense variants in K+ channel encoding genes in individuals with syndromic developmental disorders have only recently been recognized. These syndromic phenotypes include Zimmermann–Laband and Temple–Baraitser syndromes, caused by dominant variants in KCNH1, FHEIG syndrome due to dominant variants in KCNK4, and the clinical picture associated with dominant variants in KCNN3. Here we review the presentation of these individuals, including five newly reported with variants in KCNH1 and three additional individuals with KCNN3 variants, all variants likely affecting function. There is notable overlap in the phenotypic findings of these syndromes associated with dominant KCNN3, KCNH1, and KCNK4 variants, sharing developmental delay and/or ID, coarse facial features, gingival enlargement, distal digital hypoplasia, and hypertrichosis. We suggest to combine the phenotypes and define a new subgroup of potassium channelopathies caused by increased K+ conductance, referred to as syndromic neurodevelopmental K+ channelopathies due to dominant variants in KCNH1, KCNK4, or KCNN3.
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Affiliation(s)
- Karen W Gripp
- Division of Medical Genetics, Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - Sarah F Smithson
- Department of Clinical Genetics, University Hospitals Bristol and Weston, Bristol, UK
| | - Ingrid J Scurr
- Department of Clinical Genetics, University Hospitals Bristol and Weston, Bristol, UK
| | - Julia Baptista
- Exeter Genomics Laboratory, Royal Devon & Exeter NHS Foundation Trust, Exeter, UK.,College of Medicine and Health, University of Exeter, Exeter, UK
| | - Anirban Majumdar
- Department of Paediatric Neurology, Bristol Royal Hospital for Children, Bristol, UK
| | - Germaine Pierre
- Department of Paediatric Metabolic Medicine, Bristol Royal Hospital for Children, Bristol, UK
| | - Maggie Williams
- Bristol Genetics Laboratory, North Bristol NHS Trust, Bristol, UK
| | | | | | | | - Lisette Leeuwen
- Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Marleen E H Simon
- Department of Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Ellen van Binsbergen
- Department of Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Mary Beth P Dinulos
- Section of Genetics and Child Development, Children's Hospital at Dartmouth, Lebanon, NH, USA
| | - Julie D Kaplan
- Division of Medical Genetics, Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - Anne McRae
- Division of Genetics, Birth Defects and Metabolism, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
| | - Andrea Superti-Furga
- Division of Genetic Medicine, Lausanne University Hospital, Lausanne, Switzerland
| | - Jean-Marc Good
- Division of Genetic Medicine, Lausanne University Hospital, Lausanne, Switzerland
| | - Kerstin Kutsche
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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3
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Kortüm F, Niceta M, Magliozzi M, Dumic Kubat K, Robertson SP, Moresco A, Dentici ML, Baban A, Leoni C, Onesimo R, Obregon MG, Digilio MC, Zampino G, Novelli A, Tartaglia M, Kutsche K. Cantú syndrome versus Zimmermann-Laband syndrome: Report of nine individuals with ABCC9 variants. Eur J Med Genet 2020; 63:103996. [PMID: 32622958 DOI: 10.1016/j.ejmg.2020.103996] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 06/23/2020] [Accepted: 06/28/2020] [Indexed: 11/17/2022]
Abstract
Cantú syndrome (CS) is a rare developmental disorder characterized by a coarse facial appearance, macrocephaly, hypertrichosis, skeletal and cardiovascular anomalies and caused by heterozygous gain-of-function variants in ABCC9 and KCNJ8, encoding subunits of heterooctameric ATP-sensitive potassium (KATP) channels. CS shows considerable clinical overlap with Zimmermann-Laband syndrome (ZLS), a rare condition with coarse facial features, hypertrichosis, gingival overgrowth, intellectual disability of variable degree, and hypoplasia or aplasia of terminal phalanges and/or nails. ZLS is caused by heterozygous gain-of-function variants in KCNH1 or KCNN3, and gain-of-function KCNK4 variants underlie the clinically similar FHEIG (facial dysmorphism, hypertrichosis, epilepsy, intellectual disability/developmental delay, and gingival overgrowth) syndrome; KCNH1, KCNN3 and KCNK4 encode potassium channels. Within our research project on ZLS, we performed targeted Sanger sequencing of ABCC9 in 15 individuals tested negative for a mutation in the ZLS-associated genes and found two individuals harboring a heterozygous pathogenic ABCC9 missense variant. Through a collaborative effort, we identified a total of nine individuals carrying a monoallelic ABCC9 variant: five sporadic patients and four members of two unrelated families. Among the six detected ABCC9 missense variants, four [p.(Pro252Leu), p.(Thr259Lys), p.(Ala1064Pro), and p.(Arg1197His)] were novel. Systematic assessment of the clinical features in the nine cases with an ABCC9 variant highlights the significant clinical overlap between ZLS and CS that includes early developmental delay, hypertrichosis, gingival overgrowth, joint laxity, and hypoplasia of terminal phalanges and nails. Gain of K+ channel activity possibly accounts for significant clinical similarities of CS, ZLS and FHEIG syndrome and defines a new subgroup of potassium channelopathies.
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Affiliation(s)
- Fanny Kortüm
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Marcello Niceta
- Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Monia Magliozzi
- Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | | | - Stephen P Robertson
- Department of Women's and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Angelica Moresco
- Paediatric Hospital Dr. Juan P. Garrahan, Buenos Aires, Argentina
| | - Maria Lisa Dentici
- Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Anwar Baban
- The European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart - ERN GUARD-Heart, Pediatric Cardiology and Arrhythmia/Syncope Units, Bambino Gesù Children Hospital and Research Institute, Rome, Italy
| | - Chiara Leoni
- Center of Rare Diseases and Congenital Defects, Fondazione Policlinico Universitario A. Gemelli, IRCCS, Rome, Italy
| | - Roberta Onesimo
- Center of Rare Diseases and Congenital Defects, Fondazione Policlinico Universitario A. Gemelli, IRCCS, Rome, Italy
| | | | - Maria Cristina Digilio
- Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Giuseppe Zampino
- Center of Rare Diseases and Congenital Defects, Fondazione Policlinico Universitario A. Gemelli, IRCCS, Rome, Italy
| | - Antonio Novelli
- Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Marco Tartaglia
- Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Kerstin Kutsche
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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4
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"Electrifying dysmorphology": Potassium channelopathies causing dysmorphic syndromes. ADVANCES IN GENETICS 2020; 105:137-174. [PMID: 32560786 DOI: 10.1016/bs.adgen.2020.03.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Potassium channels are a heterogeneous group of membrane-bound proteins, whose functions support a diverse range of biological processes. Genetic disorders arising from mutations in potassium channels are classically recognized by symptoms arising from acute channel dysfunction, such as periodic paralysis, ataxia, seizures, or cardiac conduction abnormalities, often in a patient with otherwise normal examination findings. In this chapter, we review a distinct subgroup of rare potassium channelopathies whose presentations are instead suggestive of a developmental disorder, with features including intellectual disability, craniofacial dysmorphism or other physical anomalies. Known conditions within this subgroup are: Andersen-Tawil syndrome, Birk-Barel syndrome, Cantú syndrome, Keppen-Lubinsky syndrome, Temple-Baraitser syndrome, Zimmerman-Laband syndrome and a very similar disorder called Bauer-Tartaglia or FHEIG syndrome. Ion channelopathies are unlikely to be routinely considered in the differential diagnosis of children presenting with developmental concerns, and so detailed description and photographs of the clinical phenotype are provided to aid recognition. For several of these disorders, functional characterization of the genetic mutations responsible has led to identification of candidate therapies, including drugs already commonly used for other indications, which adds further impetus to their prompt recognition. Together, these cases illustrate the potential for mechanistic insights gained from genetic diagnosis to drive translational work toward targeted, disease-modifying therapies for rare disorders.
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5
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Costa CRR, Braz SV, de Toledo IP, Martelli-Júnior H, Mazzeu JF, Guerra ENS, Coletta RD, Acevedo AC. Syndromes with gingival fibromatosis: A systematic review. Oral Dis 2020; 27:881-893. [PMID: 32335995 DOI: 10.1111/odi.13369] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 04/03/2020] [Accepted: 04/16/2020] [Indexed: 12/13/2022]
Abstract
OBJECTIVE The aim of systematic review was to describe the phenotypes and molecular profiles of syndromes with gingival fibromatosis (GF). METHODS A comprehensive search of PubMed, LILACS, Livivo, Scopus, and Web of Science was conducted using key terms relevant to the research questions and supplemented by a gray literature search. The Methodological Quality and Synthesis of Case Series and Case Reports in association with the Case Series and Prevalence Studies from the Joanna Briggs Institute critical appraisal tools were used for the risk of bias. We followed the PRISMA checklist guidelines. RESULTS Eighty-four studies reporting GF as an oral manifestation of a syndrome were identified in this review. Enamel renal syndrome was the most frequently reported syndrome with GF, represented by 54 individuals in 19 studies, followed by Zimmermann-Laband syndrome with 24 individuals in 15 studies and Costello syndrome, which was presented in a case series study with 41 individuals. Among reported cases, other clinical manifestations such as hypertrichosis, ectopic gingival calcification, and cherubism were described. CONCLUSIONS The results emphasize the need of systematic oro-dental-facial phenotyping for future descriptions as well as further molecular analysis in order to better understand the occurrence of syndromic GF.
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Affiliation(s)
- Cláudio Rodrigues Rezende Costa
- Laboratory of Oral Histopathology, Health Sciences Faculty, University of Brasília, Brasília, Brazil.,Faculty of Dentistry, University of Rio Verde, Rio Verde, Brazil
| | - Shélida Vasconcelos Braz
- Laboratory of Oral Histopathology, Health Sciences Faculty, University of Brasília, Brasília, Brazil.,Laboratory of Medical Genetics, Faculty of Medicine, University of Brasília, Brasília, Brazil
| | - Isabela Porto de Toledo
- Laboratory of Oral Histopathology, Health Sciences Faculty, University of Brasília, Brasília, Brazil
| | - Hercilio Martelli-Júnior
- Dental School, Stomatology Clinic, State University of Montes Claros, Montes Claros, Brazil.,Center for Rehabilitation of Craniofacial Anomalies, Dental School, University of José Rosario Vellano, Alfenas, Brazil
| | - Juliana Forte Mazzeu
- Laboratory of Medical Genetics, Faculty of Medicine, University of Brasília, Brasília, Brazil
| | - Eliete Neves Silva Guerra
- Laboratory of Oral Histopathology, Health Sciences Faculty, University of Brasília, Brasília, Brazil
| | - Ricardo D Coletta
- Department of Oral Diagnosis, School of Dentistry, University of Campinas, Piracicaba, Brazil
| | - Ana Carolina Acevedo
- Laboratory of Oral Histopathology, Health Sciences Faculty, University of Brasília, Brasília, Brazil.,Oral Care Center for Inherited Diseases, Health Sciences Faculty, Division of Dentistry, University Hospital of Brasilia, University of Brasilia, Brasília, Brazil
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6
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Gain-of-Function Mutations in KCNN3 Encoding the Small-Conductance Ca 2+-Activated K + Channel SK3 Cause Zimmermann-Laband Syndrome. Am J Hum Genet 2019; 104:1139-1157. [PMID: 31155282 DOI: 10.1016/j.ajhg.2019.04.012] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 04/15/2019] [Indexed: 01/16/2023] Open
Abstract
Zimmermann-Laband syndrome (ZLS) is characterized by coarse facial features with gingival enlargement, intellectual disability (ID), hypertrichosis, and hypoplasia or aplasia of nails and terminal phalanges. De novo missense mutations in KCNH1 and KCNK4, encoding K+ channels, have been identified in subjects with ZLS and ZLS-like phenotype, respectively. We report de novo missense variants in KCNN3 in three individuals with typical clinical features of ZLS. KCNN3 (SK3/KCa2.3) constitutes one of three members of the small-conductance Ca2+-activated K+ (SK) channels that are part of a multiprotein complex consisting of the pore-forming channel subunits, the constitutively bound Ca2+ sensor calmodulin, protein kinase CK2, and protein phosphatase 2A. CK2 modulates Ca2+ sensitivity of the channels by phosphorylating SK-bound calmodulin. Patch-clamp whole-cell recordings of KCNN3 channel-expressing CHO cells demonstrated that disease-associated mutations result in gain of function of the mutant channels, characterized by increased Ca2+ sensitivity leading to faster and more complete activation of KCNN3 mutant channels. Pretreatment of cells with the CK2 inhibitor 4,5,6,7-tetrabromobenzotriazole revealed basal inhibition of wild-type and mutant KCNN3 channels by CK2. Analogous experiments with the KCNN3 p.Val450Leu mutant previously identified in a family with portal hypertension indicated basal constitutive channel activity and thus a different gain-of-function mechanism compared to the ZLS-associated mutant channels. With the report on de novo KCNK4 mutations in subjects with facial dysmorphism, hypertrichosis, epilepsy, ID, and gingival overgrowth, we propose to combine the phenotypes caused by mutations in KCNH1, KCNK4, and KCNN3 in a group of neurological potassium channelopathies caused by an increase in K+ conductance.
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7
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Cázares-Ordoñez V, Pardo L. Kv10.1 potassium channel: from the brain to the tumors. Biochem Cell Biol 2017; 95:531-536. [DOI: 10.1139/bcb-2017-0062] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The KCNH1 gene encodes the Kv10.1 (Eag1) ion channel, a member of the EAG (ether-à-go-go) family of voltage-gated potassium channels. Recent studies have demonstrated that KCHN1 mutations are implicated in Temple–Baraitser and Zimmermann–Laband syndromes and other forms of developmental deficits that all present with mental retardation and epilepsy, suggesting that Kv10.1 might be important for cognitive development in humans. Although the Kv10.1 channel is mainly expressed in the mammalian brain, its ectopic expression occurs in 70% of human cancers. Cancer cells and tumors expressing Kv10.1 acquire selective advantages that favor cancer progression through molecular mechanisms that involve several cellular pathways, indicating that protein–protein interactions may be important for Kv10.1 influence in cell proliferation and tumorigenesis. Several studies on transcriptional and post-transcriptional regulation of Kv10.1 expression have shown interesting mechanistic insights about Kv10.1 role in oncogenesis, increasing the importance of identifying the cellular factors that regulate Kv10.1 expression in tumors.
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Affiliation(s)
- V. Cázares-Ordoñez
- Oncophysiology Group, Max Planck Institute of Experimental Medicine, Hermann-Rein-Strasse 3, 37075 Göttingen, Germany
- Oncophysiology Group, Max Planck Institute of Experimental Medicine, Hermann-Rein-Strasse 3, 37075 Göttingen, Germany
| | - L.A. Pardo
- Oncophysiology Group, Max Planck Institute of Experimental Medicine, Hermann-Rein-Strasse 3, 37075 Göttingen, Germany
- Oncophysiology Group, Max Planck Institute of Experimental Medicine, Hermann-Rein-Strasse 3, 37075 Göttingen, Germany
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8
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Eag1 K + Channel: Endogenous Regulation and Functions in Nervous System. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:7371010. [PMID: 28367272 PMCID: PMC5358448 DOI: 10.1155/2017/7371010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 12/27/2016] [Accepted: 01/31/2017] [Indexed: 02/04/2023]
Abstract
Ether-à-go-go1 (Eag1, Kv10.1, KCNH1) K+ channel is a member of the voltage-gated K+ channel family mainly distributed in the central nervous system and cancer cells. Like other types of voltage-gated K+ channels, the EAG1 channels are regulated by a variety of endogenous signals including reactive oxygen species, rendering the EAG1 to be in the redox-regulated ion channel family. The role of EAG1 channels in tumor development and its therapeutic significance have been well established. Meanwhile, the importance of hEAG1 channels in the nervous system is now increasingly appreciated. The present review will focus on the recent progress on the channel regulation by endogenous signals and the potential functions of EAG1 channels in normal neuronal signaling as well as neurological diseases.
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9
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Lubinsky M, Kantaputra PN. Syndromes with supernumerary teeth. Am J Med Genet A 2016; 170:2611-6. [DOI: 10.1002/ajmg.a.37763] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 05/12/2016] [Indexed: 01/24/2023]
Affiliation(s)
| | - Piranit Nik Kantaputra
- Center of Excellence in Medical Genetics Research; Chiang Mai University; Chiang Mai Thailand
- Division of Pediatric Dentistry; Faculty of Dentistry; Department of Orthodontics and Pediatric Dentistry; Chiang Mai University; Chiang Mai Thailand
- Dentaland Clinic; Chiang Mai Thailand
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10
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Gawron K, Łazarz-Bartyzel K, Potempa J, Chomyszyn-Gajewska M. Gingival fibromatosis: clinical, molecular and therapeutic issues. Orphanet J Rare Dis 2016; 11:9. [PMID: 26818898 PMCID: PMC4729029 DOI: 10.1186/s13023-016-0395-1] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 01/20/2016] [Indexed: 12/28/2022] Open
Abstract
Gingival fibromatosis is a rare and heterogeneous group of disorders that develop as slowly progressive, local or diffuse enlargements within marginal and attached gingiva or interdental papilla. In severe cases, the excess tissue may cover the crowns of the teeth, thus causing functional, esthetic, and periodontal problems, such as bone loss and bleeding, due to the presence of pseudopockets and plaque accumulation. It affects both genders equally. Hereditary, drug-induced, and idiopathic gingival overgrowth have been reported. Hereditary gingival fibromatosis can occur as an isolated condition or as part of a genetic syndrome. The pathologic manifestation of gingival fibromatosis comprises excessive accumulation of extracellular matrix proteins, of which collagen type I is the most prominent example. Mutation in the Son-of-Sevenless-1 gene has been suggested as one possible etiological cause of isolated (non-syndromic) hereditary gingival fibromatosis, but mutations in other genes are also likely to be involved, given the heterogeneity of this condition. The most attractive concept of mechanism for drug-induced gingival overgrowth is epithelial-to-mesenchymal transition, a process in which interactions between gingival cells and the extracellular matrix are weakened as epithelial cells transdifferentiate into fibrogenic fibroblast-like cells. The diagnosis is mainly made on the basis of the patient's history and clinical features, and on histopathological evaluation of affected gingiva. Early diagnosis is important, mostly to exclude oral malignancy. Differential diagnosis comprises all pathologies in the mouth with excessive gingival overgrowth. Hereditary gingival fibromatosis may present as an autosomal-dominant or less commonly autosomal-recessive mode of inheritance. If a systemic disease or syndrome is suspected, the patient is directed to a geneticist for additional clinical examination and specialized diagnostic tests. Treatments vary according to the type of overgrowth and the extent of disease progression, thus, scaling of teeth is sufficient in mild cases, while in severe cases surgical intervention is required. Prognosis is precarious and the risk of recurrence exists.
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Affiliation(s)
- Katarzyna Gawron
- Microbiology Department, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387, Krakow, Poland.
| | - Katarzyna Łazarz-Bartyzel
- Department of Periodontology and Oral Medicine, Jagiellonian University, Medical College, Institute of Dentistry, 30-387, Krakow, Poland.
| | - Jan Potempa
- Microbiology Department, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387, Krakow, Poland.
- Oral Health and Systemic Disease Research Group, School of Dentistry, University of Louisville, Louisville, KY, USA.
| | - Maria Chomyszyn-Gajewska
- Department of Periodontology and Oral Medicine, Jagiellonian University, Medical College, Institute of Dentistry, 30-387, Krakow, Poland.
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11
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Pezzani L, Milani D, Tadini G. Intellectual Disability: When the Hypertrichosis Is a Clue. J Pediatr Genet 2015; 4:154-8. [PMID: 27617126 DOI: 10.1055/s-0035-1564442] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 06/17/2015] [Indexed: 01/18/2023]
Abstract
The skin and the central and peripheral nervous system both derive from the ectoderm ridge. Therefore, several syndromes characterized by the presence of intellectual disability (ID) can be associated with specific congenital cutaneous manifestations. In this review, we list some of the most frequent diseases characterized by the presence of ID associated with hirsutism, which might be an incentive for the clinicians to pay attention to the ectodermal annexes in patients with ID.
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Affiliation(s)
- Lidia Pezzani
- Pathology Unit, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy
| | - Donatella Milani
- Pediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy
| | - Gianluca Tadini
- Pediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy; Unit of Dermatology, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy
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12
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'Splitting versus lumping': Temple-Baraitser and Zimmermann-Laband Syndromes. Hum Genet 2015; 134:1089-97. [PMID: 26264464 DOI: 10.1007/s00439-015-1590-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 08/03/2015] [Indexed: 10/23/2022]
Abstract
KCNH1 mutations have recently been described in six individuals with Temple-Baraitser syndrome (TMBTS) and six individuals with Zimmermann-Laband syndrome (ZLS). TMBTS is characterized by intellectual disability (ID), epilepsy, dysmorphic facial features, broad thumbs and great toes with absent/hypoplastic nails. ZLS is characterized by facial dysmorphism including coarsening of the face and a large nose, gingival enlargement, ID, hypoplasia of terminal phalanges and nails and hypertrichosis. In this study, we present four additional unrelated individuals with de novo KCNH1 mutations from ID cohorts. We report on a novel recurrent pathogenic KCNH1 variant in three individuals and add a fourth individual with a previously TMBTS-associated KCNH1 variant. Neither TMBTS nor ZLS was suspected clinically. KCNH1 encodes a voltage-gated potassium channel, which is not only highly expressed in the central nervous system, but also seems to play an important role during development. Clinical evaluation of our mutation-positive individuals revealed that one of the main characteristics of TMBTS/ZLS, namely the pronounced nail hypoplasia of the great toes and thumbs, can be mild and develop over time. Clinical comparison of all published KCNH1 mutation-positive individuals revealed a similar facial but variable limb phenotype. KCNH1 mutation-positive individuals present with severe ID, neonatal hypotonia, hypertelorism, broad nasal tip, wide mouth, nail a/hypoplasia, a proximal implanted and long thumb and long great toes. In summary, we show that the phenotypic variability of individuals with KCNH1 mutations is more pronounced than previously expected, and we discuss whether KCNH1 mutations allow for "lumping" or for "splitting" of TMBTS and ZLS.
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Kortüm F, Caputo V, Bauer CK, Stella L, Ciolfi A, Alawi M, Bocchinfuso G, Flex E, Paolacci S, Dentici ML, Grammatico P, Korenke GC, Leuzzi V, Mowat D, Nair LDV, Nguyen TTM, Thierry P, White SM, Dallapiccola B, Pizzuti A, Campeau PM, Tartaglia M, Kutsche K. Mutations in KCNH1 and ATP6V1B2 cause Zimmermann-Laband syndrome. Nat Genet 2015; 47:661-7. [DOI: 10.1038/ng.3282] [Citation(s) in RCA: 139] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 03/23/2015] [Indexed: 12/16/2022]
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Castori M, Valiante M, Pascolini G, Leuzzi V, Pizzuti A, Grammatico P. Clinical and genetic study of two patients with Zimmermann-Laband syndrome and literature review. Eur J Med Genet 2013; 56:570-6. [PMID: 23994350 DOI: 10.1016/j.ejmg.2013.08.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 08/13/2013] [Indexed: 10/26/2022]
Abstract
Zimmermann-Laband syndrome (ZLS) is a rare MCA/MR condition mainly characterized by gingival hypertrophy, hypo/aplastic nails and distal phalanges, hypertrichosis and intellectual disability. The molecular basis of ZLS is unknown. Most patients are sporadic, although familial aggregation is also observed with different inheritance patterns. We report on two unrelated children with full-blown characteristics of ZLS. Remarkable variability in expression included severity of neurocognitive involvement and extent of appendicular and facial features. In both, comparative genome hybridization array at a ~ 75 Mb resolution resulted negative, while aminoacid metabolic screening revealed high plasma levels of hypoxanthine and xanthine in one. Literature review identified 50 previously published patients (27 females, 23 males), including 14 familial, clustered in four pedigrees, and 37 sporadic. Tabulation of clinical features confirmed the core phenotype and identified developmental delay as the unique major clinical problem (occurring in 40% of the cases) with a moderately high risk of epilepsy (13%). Segregation analysis in the 20 sporadic patients with available data on healthy sibs and a single pedigree with affected sibs was significantly in contrast with an autosomal recessive mutation. An autosomal dominant mutation with high mutation rate and rare instances of germinal mosaicism seems the most likely inheritance pattern. This work may represent a starting point for future molecular studies aimed at identifying the molecular basis of ZLS.
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Affiliation(s)
- Marco Castori
- Division of Medical Genetics, Department of Molecular Medicine, Sapienza University, San Camillo-Forlanini Hospital, Rome, Italy.
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