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Zaytseva AK, Kulichik OE, Kostareva AA, Zhorov BS. Biophysical mechanisms of myocardium sodium channelopathies. Pflugers Arch 2024; 476:735-753. [PMID: 38424322 DOI: 10.1007/s00424-024-02930-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 02/15/2024] [Accepted: 02/16/2024] [Indexed: 03/02/2024]
Abstract
Genetic variants of gene SCN5A encoding the alpha-subunit of cardiac voltage-gated sodium channel Nav1.5 are associated with various diseases, including long QT syndrome (LQT3), Brugada syndrome (BrS1), and progressive cardiac conduction disease (PCCD). In the last decades, the great progress in understanding molecular and biophysical mechanisms of these diseases has been achieved. The LQT3 syndrome is associated with gain-of-function of sodium channels Nav1.5 due to impaired inactivation, enhanced activation, accelerated recovery from inactivation or the late current appearance. In contrast, BrS1 and PCCD are associated with the Nav1.5 loss-of-function, which in electrophysiological experiments can be manifested as reduced current density, enhanced fast or slow inactivation, impaired activation, or decelerated recovery from inactivation. Genetic variants associated with congenital arrhythmias can also disturb interactions of the Nav1.5 channel with different proteins or drugs and cause unexpected reactions to drug administration. Furthermore, mutations can affect post-translational modifications of the channels and their sensitivity to pH and temperature. Here we briefly review the current knowledge on biophysical mechanisms of LQT3, BrS1 and PCCD. We focus on limitations of studies that use heterologous expression systems and induced pluripotent stem cells (iPSC) derived cardiac myocytes and summarize our understanding of genotype-phenotype relations of SCN5A mutations.
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Affiliation(s)
- Anastasia K Zaytseva
- Almazov National Medical Research Centre, St. Petersburg, Russia.
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia.
| | - Olga E Kulichik
- Almazov National Medical Research Centre, St. Petersburg, Russia
| | | | - Boris S Zhorov
- Almazov National Medical Research Centre, St. Petersburg, Russia
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
- McMaster University, Hamilton, Canada
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Chinthalapudi K, Biswas R, López-Serrano A, Huang HL, Ramirez-Navarro A, Grandinetti G, Heissler S, Deschênes I. Structural basis of human Na v1.5 gating mechanisms. RESEARCH SQUARE 2024:rs.3.rs-3985999. [PMID: 38659812 PMCID: PMC11042394 DOI: 10.21203/rs.3.rs-3985999/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Voltage-gated Nav1.5 channels are central to the generation and propagation of cardiac action potentials1. Aberrations in their function are associated with a wide spectrum of cardiac diseases including arrhythmias and heart failure2-5. Despite decades of progress in Nav1.5 biology6-8, the lack of structural insights into intracellular regions has hampered our understanding of its gating mechanisms. Here we present three cryo-EM structures of human Nav1.5 in previously unanticipated open states, revealing sequential conformational changes in gating charges of the voltage-sensing domains (VSDs) and several intracellular regions. Despite the channel being in the open state, these structures show the IFM motif repositioned in the receptor site but not dislodged. In particular, our structural findings highlight a dynamic C-terminal domain (CTD) and III-IV linker interaction, which regulates the conformation of VSDs and pore opening. Electrophysiological studies confirm that disrupting this interaction results in the fast inactivation of Nav1.5. Together, our structure-function studies establish a foundation for understanding the gating mechanisms of Nav1.5 and the mechanisms underlying CTD-related channelopathies.
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Chen B, Tan L, Chen D, Wang X, Liu J, Huang X, Wang Y, Huang S, Mao F, Lian J. KCNH2A561V Heterozygous Mutation Inhibits KCNH2 Protein Expression via The Activation of UPR Mediated by ATF6. Physiol Res 2023; 72:621-631. [PMID: 38015761 PMCID: PMC10751050 DOI: 10.33549/physiolres.935095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 05/26/2023] [Indexed: 01/05/2024] Open
Abstract
The potassium channel protein KCNH2 is encoded by KCNH2 gene, and there are more than 300 mutations of KCNH2. Unfolded protein response (UPR) is typically initiated in response to an accumulation of unfolded and/or misfolded proteins in the endoplasmic reticulum (ER). The present study aimed to explore the UPR process and the role of activating transcription factor 6 (ATF6) in the abnormal expression of potassium voltage-gated channel subfamily H member 2 (KCNH2)A561V. The wild-type (wt) KCNH2 and A561V mutant KCNH2 was constructed with his-tag. The 293 cells were used and divided into KCNH2wt+KCNH2A561V, KCNH2wt and KCNH2A561V groups. The expression levels of ATF6 and KCNH2 in different groups were detected by Western blotting, reverse transcription-quantitative PCR, immunofluorescence and immuno-coprecipitation assays. The protein types and abundance of immuno-coprecipitation samples were analyzed by mass spectrometry. The proteomic analysis of the mass spectrometry results was carried out by using the reactome database and GO (Gene Ontology) tool. The mRNA expression levels of KCNH2 and ATF6 in the KCNH2wt+KCNH2A561V group were higher compared with the KCNH2A561V group. However, the full-length protein expression of ATF6 was inhibited, indicating that ATF6 was highly activated and a substantial number of ATF6 was sheared in KCNH2wt+KCNH2A561V group compared with control group. Furthermore, A561V-KCNH2 mutation leading to the accumulation of the immature form of KCNH2 (135 kDa bands) in ER, resulting in the reduction of the ratio of 155 kDa/135 kDa. In addition, the abundance of UPR-related proteins in the KCNH2A561V group was higher compared with the KCNH2wt+KCNH2A561V group. The 'cysteine biosynthetic activity' of GO:0019344 process and the 'positive regulation of cytoplasmic translation activity' of GO:2000767 process in the KCNH2A561V group were higher compared with the KCNH2wt+KCNH2A561V group. Hence, co-expression of wild-type and A561V mutant KCNH2 in 293 cells activated the UPR process, which led to the inhibition of protein translation and synthesis, in turn inhibiting the expression of KCNH2. These results provided a theoretical basis for clinical treatment of Long QT syndrome.
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Affiliation(s)
- B Chen
- Emergency Medical Center, Ningbo Yinzhou No. 2 Hospital, Ningbo, Zhejiang, China; Department of General Surgery, Ningbo No.2 Hospital, Ningbo, China. ; Department of Cardiology, Ningbo Medical Center LiHuiLi Hospital, Ningbo, China.
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Moras E, Gandhi K, Narasimhan B, Brugada R, Brugada J, Brugada P, Krittanawong C. Genetic and Molecular Mechanisms in Brugada Syndrome. Cells 2023; 12:1791. [PMID: 37443825 PMCID: PMC10340412 DOI: 10.3390/cells12131791] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 06/30/2023] [Accepted: 07/03/2023] [Indexed: 07/15/2023] Open
Abstract
Brugada syndrome is a rare hereditary arrhythmia disorder characterized by a distinctive electrocardiogram pattern and an elevated risk of ventricular arrhythmias and sudden cardiac death in young adults. Despite recent advances, it remains a complex condition, encompassing mechanisms, genetics, diagnosis, arrhythmia risk stratification, and management. The underlying electrophysiological mechanism of Brugada syndrome requires further investigation, with current theories focusing on abnormalities in repolarization, depolarization, and current-load match. The genetic basis of the syndrome is strong, with mutations found in genes encoding subunits of cardiac sodium, potassium, and calcium channels, as well as genes involved in channel trafficking and regulation. While the initial discovery of mutations in the SCN5A gene provided valuable insights, Brugada syndrome is now recognized as a multifactorial disease influenced by several loci and environmental factors, challenging the traditional autosomal dominant inheritance model. This comprehensive review aims to provide a current understanding of Brugada syndrome, focusing on its pathophysiology, genetic mechanisms, and novel models of risk stratification. Advancements in these areas hold the potential to facilitate earlier diagnosis, improve risk assessments, and enable more targeted therapeutic interventions.
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Affiliation(s)
- Errol Moras
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Kruti Gandhi
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Bharat Narasimhan
- Debakey Cardiovascular Institute, Houston Methodist Hospital, Houston, TX 77030, USA
| | - Ramon Brugada
- Cardiology, Cardiac Genetics Clinical Unit, Hospital Universitari Josep Trueta, Hospital Santa Caterina, 17007 Girona, Spain
- Cardiovascular Genetics Center and Clinical Diagnostic Laboratory, Institut d’Investigació Biomèdica Girona-IdIBGi, 17190 Salt, Spain
| | - Josep Brugada
- Cardiovascular Institute, Hospital Clínic, 08036 Barcelona, Spain
- Pediatric Arrhythmia Unit, Hospital Sant Joan de Déu, 08950 Barcelona, Spain
- Department of Medicine, University of Barcelona, 08036 Barcelona, Spain
| | - Pedro Brugada
- Cardiovascular Division, Free University of Brussels (UZ Brussel) VUB, B-1050 Brussels, Belgium
- Medical Centre Prof. Brugada, B-9300 Aalst, Belgium
- Arrhythmia Unit, Helicopteros Sanitarios Hospital (HSH), Puerto Banús, 29603 Marbella, Spain
| | - Chayakrit Krittanawong
- Cardiology Division, NYU Langone Health and NYU School of Medicine, New York, NY 10016, USA
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5
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Hu X, Kong J, Niu T, Chen L, Yang J. Single coronary artery presenting dilated cardiomyopathy and hyperlipidemia with the SCN5A and APOA5 gene mutation: A case report and review of the literature. Front Cardiovasc Med 2023; 10:1113886. [PMID: 37288251 PMCID: PMC10242075 DOI: 10.3389/fcvm.2023.1113886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 03/23/2023] [Indexed: 06/09/2023] Open
Abstract
We present a 55-year-old man with chest tightness and dyspnoea after activity lasting for 2 months who was diagnosed with single coronary artery (SCA) and presented with dilated cardiomyopathy (DCM) with the c.1858C > T mutation in the SCN5A gene. The computed tomography coronary angiogram (CTCA) showed congenital absence of the right coronary artery (RCA), and the right heart was nourished by the left coronary artery branch with no apparent stenosis. Transthoracic echocardiography (TTE) revealed enlargement of the left heart and cardiomyopathy. Cardiac magnetic resonance imaging (CMR) revealed DCM. Genetic testing showed that the c.1858C > T variant of the SCN5A gene could lead to Brugada syndrome and DCM. SCA is a rare congenital anomaly of the coronary anatomy, and this case reported as SCA accompanied by DCM is even rarer. We present a rare case of a 55-year-old man with DCM with the c.1858C > T (p. Arg620Cys)/c.1008G > A (p.(Pro336=) variant of the SCN5A gene, congenital absence of RCA, and c.990_993delAACA (p. Asp332Valfs*5) variant of the APOA5 gene. To our knowledge, this is the first report of DCM combined with the SCN5A gene mutation in SCA after searching the PubMed, CNKI and Wanfang databases.
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Affiliation(s)
- Xiaoxia Hu
- Department of Cardiology, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Jing Kong
- Department of Cardiology, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Tingting Niu
- Department of Medical Technology, Jinan Vocational College of Nursing, Jinan, Shandong, China
| | - Liang Chen
- Department of Emergency Medicine, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Jingjing Yang
- Department of Emergency Medicine, Qilu Hospital of Shandong University, Jinan, Shandong, China
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Melgari D, Calamaio S, Frosio A, Prevostini R, Anastasia L, Pappone C, Rivolta I. Automated Patch-Clamp and Induced Pluripotent Stem Cell-Derived Cardiomyocytes: A Synergistic Approach in the Study of Brugada Syndrome. Int J Mol Sci 2023; 24:ijms24076687. [PMID: 37047659 PMCID: PMC10095337 DOI: 10.3390/ijms24076687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 03/29/2023] [Accepted: 03/30/2023] [Indexed: 04/07/2023] Open
Abstract
The development of high-throughput automated patch-clamp technology is a recent breakthrough in the field of Brugada syndrome research. Brugada syndrome is a heart disorder marked by abnormal electrocardiographic readings and an elevated risk of sudden cardiac death due to arrhythmias. Various experimental models, developed either in animals, cell lines, human tissue or computational simulation, play a crucial role in advancing our understanding of this condition, and developing effective treatments. In the perspective of the pathophysiological role of ion channels and their pharmacology, automated patch-clamp involves a robotic system that enables the simultaneous recording of electrical activity from multiple single cells at once, greatly improving the speed and efficiency of data collection. By combining this approach with the use of patient-derived cardiomyocytes, researchers are gaining a more comprehensive view of the underlying mechanisms of heart disease. This has led to the development of more effective treatments for those affected by cardiovascular conditions.
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Affiliation(s)
- Dario Melgari
- Institute of Molecular and Translational Cardiology (IMTC), San Donato Milanese, 20097 Milan, Italy
| | - Serena Calamaio
- Institute of Molecular and Translational Cardiology (IMTC), San Donato Milanese, 20097 Milan, Italy
| | - Anthony Frosio
- Institute of Molecular and Translational Cardiology (IMTC), San Donato Milanese, 20097 Milan, Italy
| | - Rachele Prevostini
- Institute of Molecular and Translational Cardiology (IMTC), San Donato Milanese, 20097 Milan, Italy
| | - Luigi Anastasia
- Institute of Molecular and Translational Cardiology (IMTC), San Donato Milanese, 20097 Milan, Italy
- Faculty of Medicine, Vita-Salute San Raffaele University, 20132 Milan, Italy
| | - Carlo Pappone
- Institute of Molecular and Translational Cardiology (IMTC), San Donato Milanese, 20097 Milan, Italy
- Faculty of Medicine, Vita-Salute San Raffaele University, 20132 Milan, Italy
- Arrhythmology Department, IRCCS Policlinico San Donato, San Donato Milanese, 20097 Milan, Italy
| | - Ilaria Rivolta
- Institute of Molecular and Translational Cardiology (IMTC), San Donato Milanese, 20097 Milan, Italy
- School of Medicine and Surgery, University of Milano-Bicocca, Via Cadore, 48, 20900 Monza, Italy
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7
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Bersell KR, Yang T, Mosley JD, Glazer AM, Hale AT, Kryshtal DO, Kim K, Steimle JD, Brown JD, Salem JE, Campbell CC, Hong CC, Wells QS, Johnson AN, Short L, Blair MA, Behr ER, Petropoulou E, Jamshidi Y, Benson MD, Keyes MJ, Ngo D, Vasan RS, Yang Q, Gerszten RE, Shaffer C, Parikh S, Sheng Q, Kannankeril PJ, Moskowitz IP, York JD, Wang TJ, Knollmann BC, Roden DM. Transcriptional Dysregulation Underlies Both Monogenic Arrhythmia Syndrome and Common Modifiers of Cardiac Repolarization. Circulation 2023; 147:824-840. [PMID: 36524479 PMCID: PMC9992308 DOI: 10.1161/circulationaha.122.062193] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 11/03/2022] [Indexed: 12/23/2022]
Abstract
BACKGROUND Brugada syndrome (BrS) is an inherited arrhythmia syndrome caused by loss-of-function variants in the cardiac sodium channel gene SCN5A (sodium voltage-gated channel alpha subunit 5) in ≈20% of subjects. We identified a family with 4 individuals diagnosed with BrS harboring the rare G145R missense variant in the cardiac transcription factor TBX5 (T-box transcription factor 5) and no SCN5A variant. METHODS We generated induced pluripotent stem cells (iPSCs) from 2 members of a family carrying TBX5-G145R and diagnosed with Brugada syndrome. After differentiation to iPSC-derived cardiomyocytes (iPSC-CMs), electrophysiologic characteristics were assessed by voltage- and current-clamp experiments (n=9 to 21 cells per group) and transcriptional differences by RNA sequencing (n=3 samples per group), and compared with iPSC-CMs in which G145R was corrected by CRISPR/Cas9 approaches. The role of platelet-derived growth factor (PDGF)/phosphoinositide 3-kinase (PI3K) pathway was elucidated by small molecule perturbation. The rate-corrected QT (QTc) interval association with serum PDGF was tested in the Framingham Heart Study cohort (n=1893 individuals). RESULTS TBX5-G145R reduced transcriptional activity and caused multiple electrophysiologic abnormalities, including decreased peak and enhanced "late" cardiac sodium current (INa), which were entirely corrected by editing G145R to wild-type. Transcriptional profiling and functional assays in genome-unedited and -edited iPSC-CMs showed direct SCN5A down-regulation caused decreased peak INa, and that reduced PDGF receptor (PDGFRA [platelet-derived growth factor receptor α]) expression and blunted signal transduction to PI3K was implicated in enhanced late INa. Tbx5 regulation of the PDGF axis increased arrhythmia risk due to disruption of PDGF signaling and was conserved in murine model systems. PDGF receptor blockade markedly prolonged normal iPSC-CM action potentials and plasma levels of PDGF in the Framingham Heart Study were inversely correlated with the QTc interval (P<0.001). CONCLUSIONS These results not only establish decreased SCN5A transcription by the TBX5 variant as a cause of BrS, but also reveal a new general transcriptional mechanism of arrhythmogenesis of enhanced late sodium current caused by reduced PDGF receptor-mediated PI3K signaling.
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Affiliation(s)
- Kevin R Bersell
- Departments of Pharmacology (K.R.B., A.M.G., D.O.K., K.K., J-E.S., C.C.C., Q.S.W., S.P., B.C.K., D.M.R.), Vanderbilt University, Nashville, TN
| | - Tao Yang
- Medicine (T.Y., J.D.M., J.D.B., J-E.S., Q.S.W., L.S., M.A.B., C.S., T.J.W., B.C.K., D.M.R.), Vanderbilt University, Nashville, TN
| | - Jonathan D Mosley
- Departments of Pharmacology (K.R.B., A.M.G., D.O.K., K.K., J-E.S., C.C.C., Q.S.W., S.P., B.C.K., D.M.R.), Vanderbilt University, Nashville, TN
| | - Andrew M Glazer
- Departments of Pharmacology (K.R.B., A.M.G., D.O.K., K.K., J-E.S., C.C.C., Q.S.W., S.P., B.C.K., D.M.R.), Vanderbilt University, Nashville, TN
| | - Andrew T Hale
- Biochemistry (A.T.H., J.D.Y.), Vanderbilt University, Nashville, TN
| | - Dmytro O Kryshtal
- Departments of Pharmacology (K.R.B., A.M.G., D.O.K., K.K., J-E.S., C.C.C., Q.S.W., S.P., B.C.K., D.M.R.), Vanderbilt University, Nashville, TN
| | - Kyungsoo Kim
- Departments of Pharmacology (K.R.B., A.M.G., D.O.K., K.K., J-E.S., C.C.C., Q.S.W., S.P., B.C.K., D.M.R.), Vanderbilt University, Nashville, TN
| | - Jeffrey D Steimle
- Departments of Pediatrics, Pathology, and Human Genetics, University of Chicago, IL (J.D.S., I.P.M.)
| | - Jonathan D Brown
- Medicine (T.Y., J.D.M., J.D.B., J-E.S., Q.S.W., L.S., M.A.B., C.S., T.J.W., B.C.K., D.M.R.), Vanderbilt University, Nashville, TN
| | - Joe-Elie Salem
- Departments of Pharmacology (K.R.B., A.M.G., D.O.K., K.K., J-E.S., C.C.C., Q.S.W., S.P., B.C.K., D.M.R.), Vanderbilt University, Nashville, TN
- Medicine (T.Y., J.D.M., J.D.B., J-E.S., Q.S.W., L.S., M.A.B., C.S., T.J.W., B.C.K., D.M.R.), Vanderbilt University, Nashville, TN
- Assistance Publique - Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Department of Pharmacology, CIC-1901, Sorbonne University, Paris, France (J-E.S.)
- Sorbonne Universités, UPMC Univ Paris 06, Faculty of Medicine, France (J-E.S.)
| | - Courtney C Campbell
- Departments of Pharmacology (K.R.B., A.M.G., D.O.K., K.K., J-E.S., C.C.C., Q.S.W., S.P., B.C.K., D.M.R.), Vanderbilt University, Nashville, TN
| | - Charles C Hong
- Department of Medicine, University of Maryland School of Medicine, Baltimore (C.C.H.)
| | - Quinn S Wells
- Departments of Pharmacology (K.R.B., A.M.G., D.O.K., K.K., J-E.S., C.C.C., Q.S.W., S.P., B.C.K., D.M.R.), Vanderbilt University, Nashville, TN
- Medicine (T.Y., J.D.M., J.D.B., J-E.S., Q.S.W., L.S., M.A.B., C.S., T.J.W., B.C.K., D.M.R.), Vanderbilt University, Nashville, TN
- Biomedical Informatics (Q.S.W., D.M.R.), Vanderbilt University, Nashville, TN
| | - Amanda N Johnson
- Molecular Physiology and Biophysics (A.N.J.), Vanderbilt University, Nashville, TN
| | - Laura Short
- Medicine (T.Y., J.D.M., J.D.B., J-E.S., Q.S.W., L.S., M.A.B., C.S., T.J.W., B.C.K., D.M.R.), Vanderbilt University, Nashville, TN
| | - Marcia A Blair
- Medicine (T.Y., J.D.M., J.D.B., J-E.S., Q.S.W., L.S., M.A.B., C.S., T.J.W., B.C.K., D.M.R.), Vanderbilt University, Nashville, TN
| | | | - Evmorfia Petropoulou
- Cardiology Clinical Academic Group, Molecular and Clinical Sciences Institute, St George's, University of London and St George's University Hospitals National Health Service Foundation Trust, London, UK (E.P., Y.J.)
| | - Yalda Jamshidi
- Cardiology Clinical Academic Group, Molecular and Clinical Sciences Institute, St George's, University of London and St George's University Hospitals National Health Service Foundation Trust, London, UK (E.P., Y.J.)
| | - Mark D Benson
- Cardiovascular Research Center (E.J.B., M.D.B., M.J.K., R.E.G.), Beth Israel Deaconess Hospital, Boston, MA
- Division of Cardiovascular Medicine, Brigham and Women's Hospital, Boston, MA (M.D.B.)
| | - Michelle J Keyes
- Cardiovascular Research Center (E.J.B., M.D.B., M.J.K., R.E.G.), Beth Israel Deaconess Hospital, Boston, MA
| | - Debby Ngo
- Division of Pulmonary and Cardiovascular Medicine (D.N., R.E.G.), Beth Israel Deaconess Hospital, Boston, MA
| | | | - Qiong Yang
- Boston University School of Medicine, MA (R.S.V., Q.Y.)
| | - Robert E Gerszten
- Cardiovascular Research Center (E.J.B., M.D.B., M.J.K., R.E.G.), Beth Israel Deaconess Hospital, Boston, MA
- Division of Pulmonary and Cardiovascular Medicine (D.N., R.E.G.), Beth Israel Deaconess Hospital, Boston, MA
| | - Christian Shaffer
- Medicine (T.Y., J.D.M., J.D.B., J-E.S., Q.S.W., L.S., M.A.B., C.S., T.J.W., B.C.K., D.M.R.), Vanderbilt University, Nashville, TN
| | - Shan Parikh
- Departments of Pharmacology (K.R.B., A.M.G., D.O.K., K.K., J-E.S., C.C.C., Q.S.W., S.P., B.C.K., D.M.R.), Vanderbilt University, Nashville, TN
| | | | | | - Ivan P Moskowitz
- Departments of Pediatrics, Pathology, and Human Genetics, University of Chicago, IL (J.D.S., I.P.M.)
| | - John D York
- Biochemistry (A.T.H., J.D.Y.), Vanderbilt University, Nashville, TN
| | - Thomas J Wang
- Medicine (T.Y., J.D.M., J.D.B., J-E.S., Q.S.W., L.S., M.A.B., C.S., T.J.W., B.C.K., D.M.R.), Vanderbilt University, Nashville, TN
| | - Bjorn C Knollmann
- Departments of Pharmacology (K.R.B., A.M.G., D.O.K., K.K., J-E.S., C.C.C., Q.S.W., S.P., B.C.K., D.M.R.), Vanderbilt University, Nashville, TN
- Medicine (T.Y., J.D.M., J.D.B., J-E.S., Q.S.W., L.S., M.A.B., C.S., T.J.W., B.C.K., D.M.R.), Vanderbilt University, Nashville, TN
| | - Dan M Roden
- Departments of Pharmacology (K.R.B., A.M.G., D.O.K., K.K., J-E.S., C.C.C., Q.S.W., S.P., B.C.K., D.M.R.), Vanderbilt University, Nashville, TN
- Medicine (T.Y., J.D.M., J.D.B., J-E.S., Q.S.W., L.S., M.A.B., C.S., T.J.W., B.C.K., D.M.R.), Vanderbilt University, Nashville, TN
- Biomedical Informatics (Q.S.W., D.M.R.), Vanderbilt University, Nashville, TN
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8
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Gamal El-Din TM. When the Gates Swing Open Only: Arrhythmia Mutations That Target the Fast Inactivation Gate of Na v1.5. Cells 2022; 11:cells11233714. [PMID: 36496974 PMCID: PMC9735811 DOI: 10.3390/cells11233714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/17/2022] [Accepted: 11/17/2022] [Indexed: 11/23/2022] Open
Abstract
Nav1.5 is the main voltage-gated sodium channel found in cardiac muscle, where it facilitates the fast influx of Na+ ions across the cell membrane, resulting in the fast depolarization phase-phase 0 of the cardiac action potential. As a result, it plays a major role in determining the amplitude and the upstroke velocity of the cardiac impulse. Quantitively, cardiac sodium channel activates in less than a millisecond to trigger the cardiac action potential and inactivates within 2-3 ms to facilitate repolarization and return to the resting state in preparation for firing the next action potential. Missense mutations in the gene that encodes Nav1.5 (SCN5A), change these time constants which leads to a wide spectrum of cardiac diseases ranging from long QT syndrome type 3 (LQT3) to sudden cardiac death. In this mini-review I will focus on the missense mutations in the inactivation gate of Nav1.5 that results in arrhythmia, attempting to correlate the location of the missense mutation to their specific phenotype.
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9
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Anderson CL, Munawar S, Reilly L, Kamp TJ, January CT, Delisle BP, Eckhardt LL. How Functional Genomics Can Keep Pace With VUS Identification. Front Cardiovasc Med 2022; 9:900431. [PMID: 35859585 PMCID: PMC9291992 DOI: 10.3389/fcvm.2022.900431] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 06/09/2022] [Indexed: 01/03/2023] Open
Abstract
Over the last two decades, an exponentially expanding number of genetic variants have been identified associated with inherited cardiac conditions. These tremendous gains also present challenges in deciphering the clinical relevance of unclassified variants or variants of uncertain significance (VUS). This review provides an overview of the advancements (and challenges) in functional and computational approaches to characterize variants and help keep pace with VUS identification related to inherited heart diseases.
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Affiliation(s)
- Corey L. Anderson
- Cellular and Molecular Arrythmias Program, Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin-Madison, Madison, WI, United States
| | - Saba Munawar
- Cellular and Molecular Arrythmias Program, Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin-Madison, Madison, WI, United States
| | - Louise Reilly
- Cellular and Molecular Arrythmias Program, Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin-Madison, Madison, WI, United States
| | - Timothy J. Kamp
- Cellular and Molecular Arrythmias Program, Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin-Madison, Madison, WI, United States
| | - Craig T. January
- Cellular and Molecular Arrythmias Program, Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin-Madison, Madison, WI, United States
| | - Brian P. Delisle
- Department of Physiology, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Lee L. Eckhardt
- Cellular and Molecular Arrythmias Program, Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin-Madison, Madison, WI, United States
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10
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Abstract
Brugada syndrome is a heritable channelopathy characterized by a peculiar electrocardiogram (ECG) pattern and increased risk of cardiac arrhythmias and sudden death. The arrhythmias originate because of an imbalance between the repolarizing and depolarizing currents that modulate the cardiac action potential. Even if an overt structural cardiomyopathy is not typical of Brugada syndrome, fibrosis and structural changes in the right ventricle contribute to a conduction slowing, which ultimately facilitates ventricular arrhythmias. Currently, Mendelian autosomal dominant transmission is detected in less than 25% of all clinical confirmed cases. Although 23 genes have been associated with the condition, only SCN5A, encoding the cardiac sodium channel, is considered clinically actionable and disease causing. The limited monogenic inheritance has pointed toward new perspectives on the possible complex genetic architecture of the disease, involving polygenic inheritance and a polygenic risk score that can influence penetrance and risk stratification. Expected final online publication date for the Annual Review of Genomics and Human Genetics, Volume 23 is October 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Marina Cerrone
- Leon H. Charney Division of Cardiology, Grossman School of Medicine, New York University, New York, NY, USA;
| | - Sarah Costa
- Department of Internal Medicine, Kantonsspital Baden, Baden, Switzerland
| | - Mario Delmar
- Leon H. Charney Division of Cardiology, Grossman School of Medicine, New York University, New York, NY, USA;
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11
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Soh MS, Bagnall RD, Semsarian C, Scheffer IE, Berkovic SF, Reid CA. Rare SUDEP SCN5A variants cause changes in channel function implicating cardiac arrhythmia as a cause of death. Epilepsia 2022; 63:e57-e62. [PMID: 35397174 DOI: 10.1111/epi.17254] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 04/06/2022] [Accepted: 04/07/2022] [Indexed: 11/29/2022]
Abstract
Sudden Unexpected Death in Epilepsy (SUDEP) is a leading cause of premature death in epilepsy. The underlying pathological mechanisms are likely to be multi-factorial. Cardiac arrhythmia has been suggested as a cause of death in some patients with SUDEP. SCN5A encodes the cardiac Nav 1.5 sodium channel. SCN5A variants that result in either loss or gain of channel function cause cardiac arrhythmias. Rare SCN5A variants have been reported in SUDEP cases but the impact of these variants on channel function is unknown. Here we use whole-cell voltage clamp recordings to perform functional analyses of rare SCN5A SUDEP variants, p.V223G, p.I397V and p.R523C. Expression and biophysical properties including activation, inactivation and recovery from inactivation were probed. Each SCN5A variant significantly impacted human NaV 1.5 channel function indicating that they could cause cardiac arrhythmias. The patient carrying the p.R523C variant was on lamotrigine, an antiseizure medication implicated in SUDEP. Therapeutic concentration of lamotrigine caused a slowing of the rate of recovery from inactivation and a hyperpolarizing shift in the voltage of inactivation of human NaV 1.5 wild-type, but not p.R523C channels, implicating a gene-by-drug interaction. These data suggest that SCN5A arrhythmogenic variants may confer increased risk of sudden death in individuals with epilepsy.
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Affiliation(s)
- Ming S Soh
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia
| | - Richard D Bagnall
- Agnes Ginges Centre for Molecular Cardiology at Centenary Institute, The University of Sydney, Sydney, NSW, Australia.,Faculty of Medicine and Health, The University of Sydney, NSW, Australia
| | - Christopher Semsarian
- Agnes Ginges Centre for Molecular Cardiology at Centenary Institute, The University of Sydney, Sydney, NSW, Australia.,Faculty of Medicine and Health, The University of Sydney, NSW, Australia
| | - Ingrid E Scheffer
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia.,Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC, Australia.,Murdoch Children's Research Institute, The Royal Children's Hospital, Parkville, VIC, Australia.,Department of Paediatrics, University of Melbourne, Royal Children's Hospital, VIC, Australia
| | - Samuel F Berkovic
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC, Australia
| | - Christopher A Reid
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia.,Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC, Australia
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12
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Kahlig KM, Scott L, Hatch RJ, Griffin A, Martinez Botella G, Hughes ZA, Wittmann M. The novel persistent sodium current inhibitor PRAX-562 has potent anticonvulsant activity with improved protective index relative to standard of care sodium channel blockers. Epilepsia 2022; 63:697-708. [PMID: 35037706 PMCID: PMC9304232 DOI: 10.1111/epi.17149] [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: 03/29/2021] [Revised: 12/03/2021] [Accepted: 12/06/2021] [Indexed: 11/28/2022]
Abstract
OBJECTIVE This study investigates the effects of PRAX-562 on sodium current (INa ), intrinsic neuronal excitability, and protection from evoked seizures to determine whether a preferential persistent INa inhibitor would exhibit improved preclinical efficacy and tolerability compared to two standard voltage-gated sodium channel (NaV ) blockers. METHODS Inhibition of INa was characterized using patch clamp analysis. The effect on intrinsic excitability was measured using evoked action potentials recorded from hippocampal CA1 pyramidal neurons in mouse brain slices. Anticonvulsant activity was evaluated using the maximal electroshock seizure (MES) model, and tolerability was assessed by measuring spontaneous locomotor activity (sLMA). RESULTS PRAX-562 potently and preferentially inhibited persistent INa induced by ATX-II or the SCN8A mutation N1768D (half-maximal inhibitory concentration [IC50 ] = 141 and 75 nmol·L-1 , respectively) relative to peak INa tonic/resting block (60× preference). PRAX-562 also exhibited potent use-dependent block (31× preference to tonic block). This profile is considerably different from standard NaV blockers, including carbamazepine (CBZ; persistent INa IC50 = 77 500 nmol·L-1 , preference ratios of 30× [tonic block], less use-dependent block observed at various frequencies). In contrast to CBZ, PRAX-562 reduced neuronal intrinsic excitability with only a minor reduction in action potential amplitude. PRAX-562 (10 mg/kg po) completely prevented evoked seizures without affecting sLMA (MES unbound brain half-maximal efficacious concentration = 4.3 nmol·L-1 , sLMA half-maximal tolerated concentration = 69.7 nmol·L-1 , protective index [PI] = 16×). In contrast, CBZ and lamotrigine (LTG) had PIs of approximately 5.5×, with significant overlap between doses that were anticonvulsant and that reduced locomotor activity. SIGNIFICANCE PRAX-562 demonstrated robust preclinical anticonvulsant activity similar to CBZ but improved compared to LTG. PRAX-562 exhibited significantly improved preclinical tolerability compared with standard NaV blockers (CBZ and LTG), potentially due to the preference for persistent INa . Preferential targeting of persistent INa may represent a differentiated therapeutic option for diseases of hyperexcitability, where standard NaV blockers have demonstrated efficacy but poor tolerability.
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Affiliation(s)
| | - Liam Scott
- Praxis Precision Medicines, Boston, Massachusetts, USA
| | - Robert J Hatch
- Praxis Precision Medicines, Boston, Massachusetts, USA.,Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia
| | | | | | - Zoë A Hughes
- Praxis Precision Medicines, Boston, Massachusetts, USA
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13
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Monasky MM, Micaglio E, D'Imperio S, Pappone C. The Mechanism of Ajmaline and Thus Brugada Syndrome: Not Only the Sodium Channel! Front Cardiovasc Med 2022; 8:782596. [PMID: 35004896 PMCID: PMC8733296 DOI: 10.3389/fcvm.2021.782596] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 11/29/2021] [Indexed: 12/12/2022] Open
Abstract
Ajmaline is an anti-arrhythmic drug that is used to unmask the type-1 Brugada syndrome (BrS) electrocardiogram pattern to diagnose the syndrome. Thus, the disease is defined at its core as a particular response to this or other drugs. Ajmaline is usually described as a sodium-channel blocker, and most research into the mechanism of BrS has centered around this idea that the sodium channel is somehow impaired in BrS, and thus the genetics research has placed much emphasis on sodium channel gene mutations, especially the gene SCN5A, to the point that it has even been suggested that only the SCN5A gene should be screened in BrS patients. However, pathogenic rare variants in SCN5A are identified in only 20–30% of cases, and recent data indicates that SCN5A variants are actually, in many cases, prognostic rather than diagnostic, resulting in a more severe phenotype. Furthermore, the misconception by some that ajmaline only influences the sodium current is flawed, in that ajmaline actually acts additionally on potassium and calcium currents, as well as mitochondria and metabolic pathways. Clinical studies have implicated several candidate genes in BrS, encoding not only for sodium, potassium, and calcium channel proteins, but also for signaling-related, scaffolding-related, sarcomeric, and mitochondrial proteins. Thus, these proteins, as well as any proteins that act upon them, could prove absolutely relevant in the mechanism of BrS.
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Affiliation(s)
- Michelle M Monasky
- Arrhythmology Department, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy
| | - Emanuele Micaglio
- Arrhythmology Department, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy
| | - Sara D'Imperio
- Arrhythmology Department, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy
| | - Carlo Pappone
- Arrhythmology Department, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy.,Vita-Salute San Raffaele University, Milan, Italy
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14
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Clinical Spectrum of SCN5A Channelopathy in Children with Primary Electrical Disease and Structurally Normal Hearts. Genes (Basel) 2021; 13:genes13010016. [PMID: 35052356 PMCID: PMC8774384 DOI: 10.3390/genes13010016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 12/11/2021] [Accepted: 12/18/2021] [Indexed: 12/19/2022] Open
Abstract
Sodium voltage-gated channel α subunit 5 (SCN5A)-mutations may cause an array of arrhythmogenic syndromes most frequently as an autosomal dominant trait, with incomplete penetrance, variable expressivity and male predominance. In the present study, we retrospectively describe a group of Mexican patients with SCN5A-disease causing variants in whom the onset of symptoms occurred in the pediatric age range. The study included 17 patients with clinical diagnosis of primary electrical disease, at least one SCN5A pathogenic or likely pathogenic mutation and age of onset <18 years, and all available first- and second-degree relatives. Fifteen patients (88.2%) were male, and sixteen independent variants were found (twelve missense, three truncating and one complex inframe deletion/insertion). The frequency of compound heterozygosity was remarkably high (3/17, 17.6%), with early childhood onset and severe disease. Overall, 70.6% of pediatric patients presented with overlap syndrome, 11.8% with isolated sick sinus syndrome, 11.8% with isolated Brugada syndrome (BrS) and 5.9% with isolated type 3 long QT syndrome (LQTS). A total of 24/45 SCN5A mutation carriers were affected (overall penetrance 53.3%), and penetrance was higher in males (63.3%, 19 affected/30 mutation carriers) than in females (33.3%, 5 affected/15 carriers). In conclusion, pediatric patients with SCNA-disease causing variants presented mainly as overlap syndrome, with predominant loss-of-function phenotypes of sick sinus syndrome (SSS), progressive cardiac conduction disease (PCCD) and ventricular arrhythmias.
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15
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Korkosh VS, Zaytseva AK, Kostareva AA, Zhorov BS. Intersegment Contacts of Potentially Damaging Variants of Cardiac Sodium Channel. Front Pharmacol 2021; 12:756415. [PMID: 34803699 PMCID: PMC8600069 DOI: 10.3389/fphar.2021.756415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 10/18/2021] [Indexed: 11/30/2022] Open
Abstract
Over 1,500 missense variants of sodium channel hNav1.5, which are reported in the ClinVar database, are associated with cardiac diseases. For most of the variants, the clinical significance is uncertain (VUS), not provided (NP), or has conflicting interpretations of pathogenicity (CIP). Reclassifying these variants as pathogenic/likely pathogenic (P/LP) variants is important for diagnosing genotyped patients. In our earlier work, several bioinformatics tools and paralogue annotation method consensually predicted that 74 VUS/NP/CIP variants of 54 wild type residues (set w54) are potentially damaging variants (PDVs). Atomic mechanisms underlying dysfunction of the PDVs are unknown. Here we employed a recent cryo-EM structure of the hNav1.5 channel with likely inactivated pore domain (PD) and activated voltage-sensing domains (VSDs), and ad hoc models of the closed and open PD and resting VSDs to explore intersegment contacts of w54 residues. We found that 44 residues from set w54 contact 84 residues with 118 disease missense variants. These include 104 VUS/NP/CIP variants, most of which are associated with the loss-of-function Brugada syndrome (BrS1) or gain-of-function long QT syndrome (LQT3). Matrix representation of the PDVs and their contact variants facilitated recognition of coupled mutations associated with the same disease. In particular, BrS1-associated coupled mutations, which disturb the P-loops region with the selectivity filter slow inactivation gate, would cause the channel dysfunction. Other likely causes of the channel dysfunction include coupled BrS1-associated variants within VSDs that would destabilize their activated states and coupled LQT3-associated variants, which would stabilize the open PD or activated VSDs. Our study proposes mechanisms of channel dysfunction for scores of BrS1- and LQT3-associated variants, confirms status for 82% of PDVs, and suggests damaging status for their contact variants, which are currently categorized as VUS/NP/CIP variants.
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Affiliation(s)
- Vyacheslav S Korkosh
- Almazov National Medical Research Centre, St. Petersburg, Russia.,Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Anastasia K Zaytseva
- Almazov National Medical Research Centre, St. Petersburg, Russia.,Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Anna A Kostareva
- Almazov National Medical Research Centre, St. Petersburg, Russia.,Department of Women's and Children's Health, Karolinska Institute, Solna, Sweden
| | - Boris S Zhorov
- Almazov National Medical Research Centre, St. Petersburg, Russia.,Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia.,Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
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16
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Ca2+-dependent modulation of voltage-gated myocyte sodium channels. Biochem Soc Trans 2021; 49:1941-1961. [PMID: 34643236 PMCID: PMC8589445 DOI: 10.1042/bst20200604] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 08/01/2021] [Accepted: 08/31/2021] [Indexed: 12/19/2022]
Abstract
Voltage-dependent Na+ channel activation underlies action potential generation fundamental to cellular excitability. In skeletal and cardiac muscle this triggers contraction via ryanodine-receptor (RyR)-mediated sarcoplasmic reticular (SR) Ca2+ release. We here review potential feedback actions of intracellular [Ca2+] ([Ca2+]i) on Na+ channel activity, surveying their structural, genetic and cellular and functional implications, translating these to their possible clinical importance. In addition to phosphorylation sites, both Nav1.4 and Nav1.5 possess potentially regulatory binding sites for Ca2+ and/or the Ca2+-sensor calmodulin in their inactivating III–IV linker and C-terminal domains (CTD), where mutations are associated with a range of skeletal and cardiac muscle diseases. We summarize in vitro cell-attached patch clamp studies reporting correspondingly diverse, direct and indirect, Ca2+ effects upon maximal Nav1.4 and Nav1.5 currents (Imax) and their half-maximal voltages (V1/2) characterizing channel gating, in cellular expression systems and isolated myocytes. Interventions increasing cytoplasmic [Ca2+]i down-regulated Imax leaving V1/2 constant in native loose patch clamped, wild-type murine skeletal and cardiac myocytes. They correspondingly reduced action potential upstroke rates and conduction velocities, causing pro-arrhythmic effects in intact perfused hearts. Genetically modified murine RyR2-P2328S hearts modelling catecholaminergic polymorphic ventricular tachycardia (CPVT), recapitulated clinical ventricular and atrial pro-arrhythmic phenotypes following catecholaminergic challenge. These accompanied reductions in action potential conduction velocities. The latter were reversed by flecainide at RyR-blocking concentrations specifically in RyR2-P2328S as opposed to wild-type hearts, suggesting a basis for its recent therapeutic application in CPVT. We finally explore the relevance of these mechanisms in further genetic paradigms for commoner metabolic and structural cardiac disease.
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17
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Milman A, Behr ER, Gray B, Johnson DC, Andorin A, Hochstadt A, Gourraud JB, Maeda S, Takahashi Y, Jm Juang J, Kim SH, Kamakura T, Aiba T, Postema PG, Mizusawa Y, Denjoy I, Giustetto C, Conte G, Huang Z, Sarquella-Brugada G, Mazzanti A, Jespersen CH, Arbelo E, Brugada R, Calo L, Corrado D, Casado-Arroyo R, Allocca G, Takagi M, Delise P, Brugada J, Tfelt-Hansen J, Priori SG, Veltmann C, Yan GX, Brugada P, Gaita F, Leenhardt A, Wilde AAM, Kusano KF, Nam GB, Hirao K, Probst V, Belhassen B. Genotype-Phenotype Correlation of SCN5A Genotype in Patients With Brugada Syndrome and Arrhythmic Events: Insights From the SABRUS in 392 Probands. CIRCULATION. GENOMIC AND PRECISION MEDICINE 2021; 14:e003222. [PMID: 34461752 DOI: 10.1161/circgen.120.003222] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Brugada syndrome (BrS) is associated with mutations in the cardiac sodium channel gene, SCN5A. However, genetic studies of patients with BrS with arrhythmic events have been limited. We sought to compare various clinical, ECG, and electrophysiological parameters according to SCN5A genotype in a large cohort of BrS probands with first arrhythmic event. METHODS Survey on Arrhythmic Events in Brugada Syndrome is a survey of 10 Western and 4 Asian countries, gathering 678 patients with BrS with first arrhythmic event. Only probands were included, and SCN5A genotype adjudicated. Patients without appropriate genetic data were excluded. Associations of genotype with clinical features were analyzed. RESULTS The study group comprised 392 probands: 92 (23.5%) SCN5A+(44 pathogenic/likely pathogenic [P/LP] and 48 variants of unknown significance) and 300 (76.5%) SCN5A-.SCN5A missense variants and the patients hosting them were similar regardless of adjudication. A higher proportion of patients with P/LP were pediatric (<16 years) compared with SCN5A- (11.4% versus 3%, P=0.023). The proportion of females was higher among patients with P/LP compared with SCN5A- (18.2% versus 6.3%, P=0.013). P/LP probands were more likely to have a family history of sudden cardiac death compared with SCN5A- (41.9% versus 16.8%, P<0.001). A higher proportion of patients with P/LP were White compared with SCN5A- (87.5% versus 47%, P<0.001). Ethnicity (odds ratio, 5.41 [2.8-11.19], P<0.001) and family history of sudden cardiac death (odds ratio, 2.73 [1.28-5.82], P=0.009) were independent variables associated with P/LP genotype following logistic regression. CONCLUSIONS The genetic basis of BrS has a complex relationship with gender, ethnicity, and age. Probands hosting a P/LP variant tended to experience their first arrhythmic event at a younger age and to have events triggered by fever compared with patients with SCN5A-. In addition, they were more likely to be White and to have family history of sudden cardiac death. Among females, a P/LP variant suggests an increased risk of being symptomatic. This association should be further studied on an ethnically specific basis in large prospectively collected international cohorts.
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Affiliation(s)
- Anat Milman
- Leviev Heart Institute, The Chaim Sheba Medical Center, Tel Hashomer, Israel (A. Milman)
- Sackler School of Medicine, Tel Aviv University, Israel (A. Milman, A.H., B.B.)
| | - Elijah R Behr
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart (E.R.B., D.C.J., A.A., J.-B.G., P.G.P., Y.M., A. Mazzanti, C.H.J., D.C., J.T.-H., S.G.P., A.A.M.W., V.P.)
- Cardiovascular Clinical Academic Group, St George's, University of London & St. George's University Hospitals NHS Foundation Trust, United Kingdom (E.R.B., B.G., D.C.J.)
| | - Belinda Gray
- Cardiovascular Clinical Academic Group, St George's, University of London & St. George's University Hospitals NHS Foundation Trust, United Kingdom (E.R.B., B.G., D.C.J.)
| | - David C Johnson
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart (E.R.B., D.C.J., A.A., J.-B.G., P.G.P., Y.M., A. Mazzanti, C.H.J., D.C., J.T.-H., S.G.P., A.A.M.W., V.P.)
- Cardiovascular Clinical Academic Group, St George's, University of London & St. George's University Hospitals NHS Foundation Trust, United Kingdom (E.R.B., B.G., D.C.J.)
| | - Antoine Andorin
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart (E.R.B., D.C.J., A.A., J.-B.G., P.G.P., Y.M., A. Mazzanti, C.H.J., D.C., J.T.-H., S.G.P., A.A.M.W., V.P.)
- Service de Cardiologie, CHU de Nantes, France (A.A., J.-B.G., V.P.)
| | - Aviram Hochstadt
- Sackler School of Medicine, Tel Aviv University, Israel (A. Milman, A.H., B.B.)
- Department of Cardiology, Tel-Aviv Sourasky Medical Center, Israel (A.H.)
| | - Jean-Baptiste Gourraud
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart (E.R.B., D.C.J., A.A., J.-B.G., P.G.P., Y.M., A. Mazzanti, C.H.J., D.C., J.T.-H., S.G.P., A.A.M.W., V.P.)
- Service de Cardiologie, CHU de Nantes, France (A.A., J.-B.G., V.P.)
| | - Shingo Maeda
- Heart Rhythm Center, Tokyo Medical and Dental University, Tokyo, Japan (S.M., Y.T., K.H.)
| | - Yoshihide Takahashi
- Heart Rhythm Center, Tokyo Medical and Dental University, Tokyo, Japan (S.M., Y.T., K.H.)
| | - Jimmy Jm Juang
- Cardiovascular Center and Division of Cardiology, National Taiwan University Hospital & University College of Medicine, Taipei (J.J.M.J.)
| | - Sung-Hwan Kim
- Division of Cardiology, College of Medicine, The Catholic University of Korea, Seoul, Korea (S.-H.K.)
| | - Tsukasa Kamakura
- Division of Arrhythmia and Electrophysiology, National Cerebral and Cardiovascular Center, Osaka, Japan (T.K., T.A., K.F.K.)
| | - Takeshi Aiba
- Division of Arrhythmia and Electrophysiology, National Cerebral and Cardiovascular Center, Osaka, Japan (T.K., T.A., K.F.K.)
| | - Pieter G Postema
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart (E.R.B., D.C.J., A.A., J.-B.G., P.G.P., Y.M., A. Mazzanti, C.H.J., D.C., J.T.-H., S.G.P., A.A.M.W., V.P.)
- Amsterdam UMC, University of Amsterdam, Heart Center; Department of Clinical & Experimental Cardiology, the Netherlands (P.G.P., Y.M., A.A.M.W.)
| | - Yuka Mizusawa
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart (E.R.B., D.C.J., A.A., J.-B.G., P.G.P., Y.M., A. Mazzanti, C.H.J., D.C., J.T.-H., S.G.P., A.A.M.W., V.P.)
- Amsterdam UMC, University of Amsterdam, Heart Center; Department of Clinical & Experimental Cardiology, the Netherlands (P.G.P., Y.M., A.A.M.W.)
| | - Isabelle Denjoy
- Service de Cardiologie et CNMR Maladies Cardiaques Héréditaires Rares, Hôpital Bichat & Université Paris Diderot, Sorbonne, France (I.D., A.L.)
| | - Carla Giustetto
- Division of Cardiology, University of Torino, Department of Medical Sciences, Città della Salute e della Scienza Hospital, Italy (C.G., F.G.)
- Heart Rhythm Management Centre, UZ-VUB, Brussels, Belgium (G.C., P.B.)
| | | | - Zhengrong Huang
- Department of Cardiology, the First Affiliated Hospital of Xiamen University, Fujian, China (Z.H.)
| | - Georgia Sarquella-Brugada
- Pediatric Arrhythmias, Electrophysiology and Sudden Death Unit Cardiology, Department Hospital Sant Joan de Déu, Barcelona - Universitat de Barcelona, Spain (G.S.-B.)
| | - Andrea Mazzanti
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart (E.R.B., D.C.J., A.A., J.-B.G., P.G.P., Y.M., A. Mazzanti, C.H.J., D.C., J.T.-H., S.G.P., A.A.M.W., V.P.)
- Molecular Cardiology, Istituti Clinici Scientifici Maugeri IRCCS, Pavia, Italy (A. Mazzanti, S.G.P.)
| | - Camilla H Jespersen
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart (E.R.B., D.C.J., A.A., J.-B.G., P.G.P., Y.M., A. Mazzanti, C.H.J., D.C., J.T.-H., S.G.P., A.A.M.W., V.P.)
- The Heart Centre, Copenhagen University Hospital, Denmark (C.H.J., J.T.-H.)
- Department of Forensic Medicine, Faculty of Medical Sciences, University of Copenhagen, Denmark (C.H.J., J.T.-H.)
| | - Elena Arbelo
- Cardiovascular Institute, Hospital Clinic and IDIBAPS, Barcelona, Catalonia, Spain (E.A., J.B.)
| | - Ramon Brugada
- Cardiovascular Genetics Center, University of Girona-IDIBGI, Spain (R.B.)
- Medical Science Department, School of Medicine, University of Girona, Spain (R.B.)
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain (R.B.)
| | - Leonardo Calo
- Division of Cardiology, Policlinico Casilino, Roma, Italy (L.C.)
| | - Domenico Corrado
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart (E.R.B., D.C.J., A.A., J.-B.G., P.G.P., Y.M., A. Mazzanti, C.H.J., D.C., J.T.-H., S.G.P., A.A.M.W., V.P.)
- Department of Cardiac, Thoracic and Vascular Sciences University of Padova, Italy (D.C.)
| | - Ruben Casado-Arroyo
- Department of Cardiology, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium (R.C.-A.)
| | - Giuseppe Allocca
- Division of Cardiology, Hospital of Peschiera del Garda, Veneto, Italy (G.A., P.D.)
| | - Masahiko Takagi
- Division of Cardiac Arrhythmia, Kansai Medical University Medical Center, Moriguchi, Japan (M.T.)
| | - Pietro Delise
- Division of Cardiology, Hospital of Peschiera del Garda, Veneto, Italy (G.A., P.D.)
| | - Josep Brugada
- Cardiovascular Institute, Hospital Clinic and IDIBAPS, Barcelona, Catalonia, Spain (E.A., J.B.)
| | - Jacob Tfelt-Hansen
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart (E.R.B., D.C.J., A.A., J.-B.G., P.G.P., Y.M., A. Mazzanti, C.H.J., D.C., J.T.-H., S.G.P., A.A.M.W., V.P.)
- The Heart Centre, Copenhagen University Hospital, Denmark (C.H.J., J.T.-H.)
- Department of Forensic Medicine, Faculty of Medical Sciences, University of Copenhagen, Denmark (C.H.J., J.T.-H.)
| | - Silvia G Priori
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart (E.R.B., D.C.J., A.A., J.-B.G., P.G.P., Y.M., A. Mazzanti, C.H.J., D.C., J.T.-H., S.G.P., A.A.M.W., V.P.)
- Molecular Cardiology, Istituti Clinici Scientifici Maugeri IRCCS, Pavia, Italy (A. Mazzanti, S.G.P.)
| | - Christian Veltmann
- Hannover Heart Rhythm Center, Department of Cardiology & Angiology, Hannover Medical School, Hannover, Germany (C.V.)
| | - Gan-Xin Yan
- Lankenau Medical Center, Wynnewood, PA (G.-X.Y.)
| | - Pedro Brugada
- Heart Rhythm Management Centre, UZ-VUB, Brussels, Belgium (G.C., P.B.)
| | - Fiorenzo Gaita
- Division of Cardiology, University of Torino, Department of Medical Sciences, Città della Salute e della Scienza Hospital, Italy (C.G., F.G.)
| | - Antoine Leenhardt
- Service de Cardiologie et CNMR Maladies Cardiaques Héréditaires Rares, Hôpital Bichat & Université Paris Diderot, Sorbonne, France (I.D., A.L.)
| | - Arthur A M Wilde
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart (E.R.B., D.C.J., A.A., J.-B.G., P.G.P., Y.M., A. Mazzanti, C.H.J., D.C., J.T.-H., S.G.P., A.A.M.W., V.P.)
- Amsterdam UMC, University of Amsterdam, Heart Center; Department of Clinical & Experimental Cardiology, the Netherlands (P.G.P., Y.M., A.A.M.W.)
| | - Kengo F Kusano
- Division of Arrhythmia and Electrophysiology, National Cerebral and Cardiovascular Center, Osaka, Japan (T.K., T.A., K.F.K.)
| | - Gi-Byoung Nam
- Division of Cardiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea (G.-B.N.)
| | - Kenzo Hirao
- Heart Rhythm Center, Tokyo Medical and Dental University, Tokyo, Japan (S.M., Y.T., K.H.)
| | - Vincent Probst
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart (E.R.B., D.C.J., A.A., J.-B.G., P.G.P., Y.M., A. Mazzanti, C.H.J., D.C., J.T.-H., S.G.P., A.A.M.W., V.P.)
- Service de Cardiologie, CHU de Nantes, France (A.A., J.-B.G., V.P.)
| | - Bernard Belhassen
- Sackler School of Medicine, Tel Aviv University, Israel (A. Milman, A.H., B.B.)
- Heart Institute, Hadassah University Hospital, Jerusalem, Israel (B.B.)
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18
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Comparative structural analysis of human Na v1.1 and Na v1.5 reveals mutational hotspots for sodium channelopathies. Proc Natl Acad Sci U S A 2021; 118:2100066118. [PMID: 33712547 DOI: 10.1073/pnas.2100066118] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Among the nine subtypes of human voltage-gated sodium (Nav) channels, the brain and cardiac isoforms, Nav1.1 and Nav1.5, each carry more than 400 missense mutations respectively associated with epilepsy and cardiac disorders. High-resolution structures are required for structure-function relationship dissection of the disease variants. We report the cryo-EM structures of the full-length human Nav1.1-β4 complex at 3.3 Å resolution here and the Nav1.5-E1784K variant in the accompanying paper. Up to 341 and 261 disease-related missense mutations in Nav1.1 and Nav1.5, respectively, are resolved. Comparative structural analysis reveals several clusters of disease mutations that are common to both Nav1.1 and Nav1.5. Among these, the majority of mutations on the extracellular loops above the pore domain and the supporting segments for the selectivity filter may impair structural integrity, while those on the pore domain and the voltage-sensing domains mostly interfere with electromechanical coupling and fast inactivation. Our systematic structural delineation of these mutations provides important insight into their pathogenic mechanism, which will facilitate the development of precise therapeutic interventions against various sodium channelopathies.
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19
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Wilde AAM, Wu CI. Does function trump bioinformatics in Brugada syndrome-associated SCN5A mutation calling? Patients, computers, and patches. Eur Heart J 2021; 42:2864-2865. [PMID: 34333601 PMCID: PMC8325777 DOI: 10.1093/eurheartj/ehab292] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- Arthur A M Wilde
- Amsterdam UMC, University of Amsterdam, Heart Center, Department of Clinical and Experimental Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Cheng-I Wu
- Amsterdam UMC, University of Amsterdam, Heart Center, Department of Clinical and Experimental Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands.,Heart Rhythm Center, Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
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20
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Ishikawa T, Kimoto H, Mishima H, Yamagata K, Ogata S, Aizawa Y, Hayashi K, Morita H, Nakajima T, Nakano Y, Nagase S, Murakoshi N, Kowase S, Ohkubo K, Aiba T, Morimoto S, Ohno S, Kamakura S, Nogami A, Takagi M, Karakachoff M, Dina C, Schott JJ, Yoshiura KI, Horie M, Shimizu W, Nishimura K, Kusano K, Makita N. Functionally validated SCN5A variants allow interpretation of pathogenicity and prediction of lethal events in Brugada syndrome. Eur Heart J 2021; 42:2854-2863. [PMID: 34219138 DOI: 10.1093/eurheartj/ehab254] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 01/09/2021] [Accepted: 04/14/2021] [Indexed: 02/06/2023] Open
Abstract
AIMS The prognostic value of genetic variants for predicting lethal arrhythmic events (LAEs) in Brugada syndrome (BrS) remains controversial. We investigated whether the functional curation of SCN5A variations improves prognostic predictability. METHODS AND RESULTS Using a heterologous expression system and whole-cell patch clamping, we functionally characterized 22 variants of unknown significance (VUSs) among 55 SCN5A mutations previously curated using in silico prediction algorithms in the Japanese BrS registry (n = 415). According to the loss-of-function (LOF) properties, SCN5A mutation carriers (n = 60) were divided into two groups: LOF-SCN5A mutations and non-LOF SCN5A variations. Functionally proven LOF-SCN5A mutation carriers (n = 45) showed significantly severer electrocardiographic conduction abnormalities and worse prognosis associated with earlier manifestations of LAEs (7.9%/year) than in silico algorithm-predicted SCN5A carriers (5.1%/year) or all BrS probands (2.5%/year). Notably, non-LOF SCN5A variation carriers (n = 15) exhibited no LAEs during the follow-up period. Multivariate analysis demonstrated that only LOF-SCN5A mutations and a history of aborted cardiac arrest were significant predictors of LAEs. Gene-based association studies using whole-exome sequencing data on another independent SCN5A mutation-negative BrS cohort (n = 288) showed no significant enrichment of rare variants in 16 985 genes including 22 non-SCN5A BrS-associated genes as compared with controls (n = 372). Furthermore, rare variations of non-SCN5A BrS-associated genes did not affect LAE-free survival curves. CONCLUSION In vitro functional validation is key to classifying the pathogenicity of SCN5A VUSs and for risk stratification of genetic predictors of LAEs. Functionally proven LOF-SCN5A mutations are genetic burdens of sudden death in BrS, but evidence for other BrS-associated genes is elusive.
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Affiliation(s)
- Taisuke Ishikawa
- Omics Research Center, National Cerebral and Cardiovascular Center, 6-1 Kishibe-Shimmachi, Suita 5648565, Japan
| | - Hiroki Kimoto
- Department of Molecular Physiology, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki 8528523, Japan
| | - Hiroyuki Mishima
- Department of Human Genetics, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki 8528523, Japan
| | - Kenichiro Yamagata
- Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, 6-1 Kishibe-Shimmachi, Suita 5648565, Japan
| | - Soshiro Ogata
- Department of Preventive Medicine and Epidemiology, National Cerebral and Cardiovascular Center, 6-1 Kishibe-Shimmachi, Suita 5648565, Japan
| | - Yoshiyasu Aizawa
- Department of Cardiovascular Medicine, International University of Health and Welfare, 4-3 Kozunomori, Narita 2860048, Japan
| | - Kenshi Hayashi
- Department of Cardiovascular Medicine, Kanazawa University Graduate School of Medical Sciences, 13-1 Takaramachi, Kanazawa 9208641, Japan
| | - Hiroshi Morita
- Department of Cardiovascular Therapeutics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama 7008558, Japan
| | - Tadashi Nakajima
- Department of Cardiovascular Medicine, Gunma University Graduate School of Medicine, 3-39-22 Showamachi, Maebashi 3710034, Japan
| | - Yukiko Nakano
- Department of Cardiovascular Medicine, Hiroshima University, 1-2-3 Kasumi, Hiroshima 7348551, Japan
| | - Satoshi Nagase
- Department of Advanced Arrhythmia and Translational Medical Science, National Cerebral and Cardiovascular Center, 6-1 Kishibe-Shimmachi, Suita 5648565, Japan
| | - Nobuyuki Murakoshi
- Department of Cardiology, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 3058575, Japan
| | - Shinya Kowase
- Department of Heart Rhythm Management, Yokohama Rosai Hospital, 3211 Kozukue-Cho, Yokohama 2220036, Japan
| | - Kimie Ohkubo
- Division of Cardiology, Department of Medicine, Nihon University School of Medicine, 30-1 Oyaguchi-kamimachi, Tokyo 1738610, Japan
| | - Takeshi Aiba
- Department of Clinical Laboratory, National Cerebral and Cardiovascular Center, 6-1 Kishibe-Shimmachi, Suita 5648565, Japan
| | - Shimpei Morimoto
- Innovation Platform & Office for Precision Medicine, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki 8528501, Japan
| | - Seiko Ohno
- Department of Bioscience and Genetics, National Cerebral and Cardiovascular Center, 6-1 Kishibe-Shimmachi, Suita 5648565, Japan
| | - Shiro Kamakura
- Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, 6-1 Kishibe-Shimmachi, Suita 5648565, Japan
| | - Akihiko Nogami
- Department of Cardiology, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 3058575, Japan
| | - Masahiko Takagi
- Division of Cardiac Arrhythmia, Kansai Medical University, 10-15 Fumizonomachi, Moriguchi 5708507, Japan
| | - Matilde Karakachoff
- L'institut du Thorax, CHU Nantes, 1 Place Alexis-Ricordeau, Nantes 44007, France
| | - Christian Dina
- L'institut du Thorax, INSERM, CNRS, UNIV Nantes, 8 Quai Moncousu, Nantes 44007, France
| | - Jean-Jacques Schott
- L'institut du Thorax, INSERM, CNRS, UNIV Nantes, 8 Quai Moncousu, Nantes 44007, France
| | - Koh-Ichiro Yoshiura
- Department of Human Genetics, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki 8528523, Japan
| | - Minoru Horie
- Center for Epidemiologic Research in Asia, Shiga University of Medical Science, Setatsukiwa-cho, Ohtsu 5202192, Japan
| | - Wataru Shimizu
- Department of Cardiovascular Medicine, Nippon Medical School, 1-1-5 Sendagi, Tokyo 1138603, Japan
| | - Kunihiro Nishimura
- Department of Preventive Medicine and Epidemiology, National Cerebral and Cardiovascular Center, 6-1 Kishibe-Shimmachi, Suita 5648565, Japan
| | - Kengo Kusano
- Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, 6-1 Kishibe-Shimmachi, Suita 5648565, Japan
| | - Naomasa Makita
- Omics Research Center, National Cerebral and Cardiovascular Center, 6-1 Kishibe-Shimmachi, Suita 5648565, Japan
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21
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Behr ER, Ben-Haim Y, Ackerman MJ, Krahn AD, Wilde AAM. Brugada syndrome and reduced right ventricular outflow tract conduction reserve: a final common pathway? Eur Heart J 2021; 42:1073-1081. [PMID: 33421051 DOI: 10.1093/eurheartj/ehaa1051] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 11/04/2020] [Accepted: 12/09/2020] [Indexed: 12/19/2022] Open
Abstract
Brugada syndrome (BrS) was first described as a primary electrical disorder predisposing to the risk of sudden cardiac death and characterized by right precordial lead ST elevation. Early description of right ventricular structural abnormalities and of right ventricular outflow tract (RVOT) conduction delay in BrS patients set the stage for the current controversy over the pathophysiology underlying the syndrome: channelopathy or cardiomyopathy; repolarization or depolarization. This review examines the current understanding of the BrS substrate, its genetic and non-genetic basis, theories of pathophysiology, and the clinical implications thereof. We propose that the final common pathway for BrS could be viewed as a disease of 'reduced RVOT conduction reserve'.
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Affiliation(s)
- Elijah R Behr
- Cardiovascular Clinical Academic Group, Molecular and Clinical Sciences Research Institute, St. George's University of London, Cranmer Terrace, London SW17 0RE, UK.,St. George's University Hospitals NHS Foundation Trust, Cranmer Terrace, London SW17 0RE, UK.,European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart: ERN GUARD-Heart (ERN GUARDHEART http://guardheart.ern-net.eu).,European Cardiac Arrhythmia Genetics Focus Group (ECGen), EHRA
| | - Yael Ben-Haim
- Cardiovascular Clinical Academic Group, Molecular and Clinical Sciences Research Institute, St. George's University of London, Cranmer Terrace, London SW17 0RE, UK.,St. George's University Hospitals NHS Foundation Trust, Cranmer Terrace, London SW17 0RE, UK.,European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart: ERN GUARD-Heart (ERN GUARDHEART http://guardheart.ern-net.eu)
| | - Michael J Ackerman
- Division of Heart Rhythm Services and the Windland Smith Rice Genetic Heart Rhythm Clinic, Department of Cardiovascular Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.,Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.,Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
| | - Andrew D Krahn
- Heart Rhythm Services, Division of Cardiology, Department of Medicine, University of British Columbia, 2775 Laurel Street, Vancouver, BC V5Z 1M9, Canada
| | - Arthur A M Wilde
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart: ERN GUARD-Heart (ERN GUARDHEART http://guardheart.ern-net.eu).,European Cardiac Arrhythmia Genetics Focus Group (ECGen), EHRA.,Heart Center, Department of Clinical and Experimental Cardiology, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, Amsterdam 1105 AZ, The Netherlands
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22
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Ghaffari T, Mirhosseini Motlagh N, Daraei A, Tafrihi M, Saravi M, Sabour D. Novel SCN5A variants identified in a group of Iranian Brugada syndrome patients. Funct Integr Genomics 2021; 21:331-340. [PMID: 33641026 DOI: 10.1007/s10142-021-00778-9] [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: 06/16/2020] [Revised: 01/26/2021] [Accepted: 02/14/2021] [Indexed: 10/22/2022]
Abstract
Brugada syndrome (BrS) is a rare hereditary arrhythmia syndrome that increases an individual's risk for sudden cardiac death (SCD) due to ventricular fibrillation. This disorder is regarded as a notable cause of death in individuals aged less than 40 years, responsible for up to 40% of sudden deaths in cases without structural heart disease, and is reported to be an endemic in Asian countries. Mutations in SCN5A are found in approximately 30% of patients with Brugada syndrome. This study aimed to investigate mutations in the SCN5A gene in a group of Iranian Brugada syndrome patients. Nine probands (n = 9, male, mean age = 39) diagnosed with Brugada syndrome were enrolled in this study. Exon 2 to 29 were amplified by PCR and subjected to direct sequencing. Eight in silico prediction tools were used to anticipate the effects of non-synonymous variants. Seven known polymorphisms and 2 previously reported disease-causing mutations, including H558R and G1406R, were found in the studied cases. Twenty novel variants were identified: 15 missense, 2 frameshift, 2 synonymous, and one nonsense variants. In silico tools predicted 11 non-synonymous variants to have damaging effects, whereas frameshift and nonsense variants were considered inherently pathogenic. The novel variants identified in this study, alongside previously reported mutations, are highly likely to be the cause of the Brugada syndrome phenotype observed in the patient group. Further analysis is required to understand the physiological effects caused by these variants.
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Affiliation(s)
- Taraneh Ghaffari
- Molecular and Cell Biology Research Lab2, Department of Molecular and Cell Biology, Faculty of Basic Sciences, University of Mazandaran, Babolsar, 47416-95447, Iran.,Department of Laboratory Science, Faculty of Paramedicine, Babol University of Medical Sciences, Ganjafrooz St, Babol, 47176-47745, Iran.,Dermatology Research Institute, Suite 310, 8500 Blackfoot Trial SE, Calgary, Alberta, T2J 7E1, Canada
| | - Naser Mirhosseini Motlagh
- Department of Cancer Medicine, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Isar 11 St, Babol, 47138-18983, Iran
| | - Abdolreza Daraei
- Department of Genetics, Faculty of Medicine, Babol University of Medical Sciences, Ganjafrooz St, Babol, 47176-47745, Iran
| | - Majid Tafrihi
- Molecular and Cell Biology Research Lab2, Department of Molecular and Cell Biology, Faculty of Basic Sciences, University of Mazandaran, Babolsar, 47416-95447, Iran
| | - Mehrdad Saravi
- Department of Cardiology, Faculty of Medicine, Rohani Hospital, Babol University of Medical Sciences, Ganjafrooz St, Babol, 47176-47745, Iran
| | - Davood Sabour
- Department of Cancer Medicine, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Isar 11 St, Babol, 47138-18983, Iran. .,Department of Genetics, Faculty of Medicine, Babol University of Medical Sciences, Ganjafrooz St, Babol, 47176-47745, Iran.
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23
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Steinberg C, Pilote S, Philippon F, Laksman ZW, Champagne J, Simard C, Krahn AD, Drolet B. SCN5A-C683R exhibits combined gain-of-function and loss-of-function properties related to adrenaline-triggered ventricular arrhythmia. Exp Physiol 2021; 106:683-699. [PMID: 33480457 DOI: 10.1113/ep089088] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 01/11/2021] [Indexed: 12/14/2022]
Abstract
NEW FINDINGS What is the role of SCN5A-C683R? SCN5A-C683R is a novel variant associated with an uncommon phenotype of adrenaline-triggered ventricular arrhythmia in the absence of a distinct ECG phenotype. What is the main finding and its importance? Functional studies demonstrated that NaV 1.5/C683R results in a mixed electrophysiological phenotype with gain-of-function (GOF) and loss-of-function (LOF) properties compared with NaV 1.5/wild type. Gain-of-function properties are characterized by a significant increase of the maximal current density and a hyperpolarizing shift of the steady-state activation. The LOF effect of NaV 1.5/C683R is characterized by increased closed-state inactivation. Electrophysiological properties and clinical manifestation of SCN5A-C683R are different from long-QT-3 or Brugada syndrome and might represent a distinct inherited arrhythmia syndrome. ABSTRACT Mutations of SCN5Ahave been identified as the genetic substrate of various inherited arrhythmia syndromes, including long-QT-3 and Brugada syndrome. We recently identified a novel SCN5A variant (C683R) in two genetically unrelated families. The index patients of both families experienced adrenaline-triggered ventricular arrhythmia with cardiac arrest but did not show a specific ECG phenotype, raising the hypothesis that SCN5A-C683R might be a susceptibility variant and the genetic substrate of distinct inherited arrhythmia. We conducted functional cellular studies to characterize the electrophysiological properties of NaV 1.5/C683R in order to explore the potential pathogenicity of this novel variant. The C683R variant was engineered by site-directed mutagenesis. NaV 1.5/wild type (WT) and NaV 1.5/C683R were expressed in tsA201 cells. Electrophysiological characterization of C683R was performed using the whole-cell patch-clamp technique. Adrenergic stimulation was mimicked by exposure to the protein kinase A activator 8-CPT-cAMP. The impact of β-blockers was tested by exposing NaV 1.5/WT and NaV 1.5/C683R currents to propranolol and nadolol. C683R resulted in a co-association of gain-of-function and loss-of-function properties of NaV 1.5. Gain-of-function properties were characterized by a significant increase of the maximal NaV 1.5 current density compared with NaV 1.5/WT (861 ± 309 vs. 627 ± 489 pA/pF; P < 0.05, n ≥ 9) that was potentiated in NaV 1.5/C683R with 8-CPT-cAMP stimulation (869 ± 287 vs. 607 ± 320 pA/pF; P < 0.05, n ≥ 12). C683R also resulted in a significant hyperpolarizing shift in the voltage of steady-state activation (-65.4 ± 3.0 vs. -57.2 ± 4.8 mV; P < 0.001), resulting in an increased window current compared with WT. The loss-of-function effect of NaV 1.5/C683R was characterized by significantly increased closed-state inactivation compared with NaV 1.5/WT (P < 0.05). C683R is a novel SCN5A variant resulting in a co-association of gain-of-function and loss-of-function properties of the cardiac sodium channel NaV 1.5. The phenotype is characterized by adrenaline-triggered ventricular arrhythmias. Electrophysiological properties and clinical manifestations are different from long-QT-3 or Brugada syndrome and might represent a distinct inherited arrhythmia syndrome.
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Affiliation(s)
- Christian Steinberg
- Division of Cardiology, Electrophysiology Service, Institut universitaire de cardiologie et de pneumologie de Québec, IUCPQ-UL), Laval University, Québec, QC, Canada.,IUCPQ-UL Research Center, Laval University, Québec, QC, Canada
| | - Sylvie Pilote
- IUCPQ-UL Research Center, Laval University, Québec, QC, Canada.,Faculty of Pharmacy, Laval University, Québec, QC, Canada
| | - François Philippon
- Division of Cardiology, Electrophysiology Service, Institut universitaire de cardiologie et de pneumologie de Québec, IUCPQ-UL), Laval University, Québec, QC, Canada.,IUCPQ-UL Research Center, Laval University, Québec, QC, Canada
| | - Zachary W Laksman
- Heart Rhythm Services, St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Jean Champagne
- Division of Cardiology, Electrophysiology Service, Institut universitaire de cardiologie et de pneumologie de Québec, IUCPQ-UL), Laval University, Québec, QC, Canada.,IUCPQ-UL Research Center, Laval University, Québec, QC, Canada
| | - Chantale Simard
- IUCPQ-UL Research Center, Laval University, Québec, QC, Canada.,Faculty of Pharmacy, Laval University, Québec, QC, Canada
| | - Andrew D Krahn
- Heart Rhythm Services, St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Benoît Drolet
- IUCPQ-UL Research Center, Laval University, Québec, QC, Canada.,Faculty of Pharmacy, Laval University, Québec, QC, Canada
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24
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Pearman CM, Denham NC, Mills RW, Ding WY, Modi SS, Hall MCS, Todd DM, Mahida S. Relationship between sodium channel function and clinical phenotype in SCN5A variants associated with Brugada syndrome. Hum Mutat 2020; 41:2195-2204. [PMID: 33131149 PMCID: PMC7756571 DOI: 10.1002/humu.24128] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 09/23/2020] [Accepted: 10/09/2020] [Indexed: 12/19/2022]
Abstract
The identification of a pathogenic SCN5A variant confers an increased risk of conduction defects and ventricular arrhythmias (VA) in Brugada syndrome (BrS). However, specific aspects of sodium channel function that influence clinical phenotype have not been defined. A systematic literature search identified SCN5A variants associated with BrS. Sodium current (INa) functional parameters (peak current, decay, steady‐state activation and inactivation, and recovery from inactivation) and clinical features (conduction abnormalities [CA], spontaneous VA or family history of sudden cardiac death [SCD], and spontaneous BrS electrocardiogram [ECG]) were extracted. A total of 561 SCN5A variants associated with BrS were identified, for which data on channel function and clinical phenotype were available in 142. In the primary analysis, no relationship was found between any aspect of channel function and CA, VA/SCD, or spontaneous BrS ECG pattern. Sensitivity analyses including only variants graded pathogenic or likely pathogenic suggested that reduction in peak current and positive shift in steady‐state activation were weakly associated with CA and VA/SCD, although sensitivity and specificity remained low. The relationship between in vitro assessment of channel function and BrS clinical phenotype is weak. The assessment of channel function does not enhance risk stratification. Caution is needed when extrapolating functional testing to the likelihood of variant pathogenicity.
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Affiliation(s)
- Charles M Pearman
- Department of Cardiac Electrophysiology and Inherited Cardiac Conditions, Liverpool Heart and Chest Hospital, Liverpool, UK.,Unit of Cardiac Physiology, Division of Cardiovascular Sciences, Manchester Academic Health Science Centre, Core Technology Facility, University of Manchester, Manchester, UK
| | - Nathan C Denham
- Department of Cardiac Electrophysiology and Inherited Cardiac Conditions, Liverpool Heart and Chest Hospital, Liverpool, UK.,Unit of Cardiac Physiology, Division of Cardiovascular Sciences, Manchester Academic Health Science Centre, Core Technology Facility, University of Manchester, Manchester, UK
| | - Robert W Mills
- Cardiovascular Research Center, Massachusetts General Hospital, Charlestown, Massachusetts, USA
| | - Wern Y Ding
- Department of Cardiac Electrophysiology and Inherited Cardiac Conditions, Liverpool Heart and Chest Hospital, Liverpool, UK.,Liverpool Centre for Cardiovascular Science, Faculty of Life Sciences, University of Liverpool, Liverpool, UK
| | - Simon S Modi
- Department of Cardiac Electrophysiology and Inherited Cardiac Conditions, Liverpool Heart and Chest Hospital, Liverpool, UK
| | - Mark C S Hall
- Department of Cardiac Electrophysiology and Inherited Cardiac Conditions, Liverpool Heart and Chest Hospital, Liverpool, UK
| | - Derick M Todd
- Department of Cardiac Electrophysiology and Inherited Cardiac Conditions, Liverpool Heart and Chest Hospital, Liverpool, UK
| | - Saagar Mahida
- Department of Cardiac Electrophysiology and Inherited Cardiac Conditions, Liverpool Heart and Chest Hospital, Liverpool, UK.,Liverpool Centre for Cardiovascular Science, Faculty of Life Sciences, University of Liverpool, Liverpool, UK
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25
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Abrams J, Roybal D, Chakouri N, Katchman AN, Weinberg R, Yang L, Chen BX, Zakharov SI, Hennessey JA, Avula UMR, Diaz J, Wang C, Wan EY, Pitt GS, Ben-Johny M, Marx SO. Fibroblast growth factor homologous factors tune arrhythmogenic late NaV1.5 current in calmodulin binding-deficient channels. JCI Insight 2020; 5:141736. [PMID: 32870823 PMCID: PMC7566708 DOI: 10.1172/jci.insight.141736] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 08/26/2020] [Indexed: 12/19/2022] Open
Abstract
The Ca2+-binding protein calmodulin has emerged as a pivotal player in tuning Na+ channel function, although its impact in vivo remains to be resolved. Here, we identify the role of calmodulin and the NaV1.5 interactome in regulating late Na+ current in cardiomyocytes. We created transgenic mice with cardiac-specific expression of human NaV1.5 channels with alanine substitutions for the IQ motif (IQ/AA). The mutations rendered the channels incapable of binding calmodulin to the C-terminus. The IQ/AA transgenic mice exhibited normal ventricular repolarization without arrhythmias and an absence of increased late Na+ current. In comparison, transgenic mice expressing a lidocaine-resistant (F1759A) human NaV1.5 demonstrated increased late Na+ current and prolonged repolarization in cardiomyocytes, with spontaneous arrhythmias. To determine regulatory factors that prevent late Na+ current for the IQ/AA mutant channel, we considered fibroblast growth factor homologous factors (FHFs), which are within the NaV1.5 proteomic subdomain shown by proximity labeling in transgenic mice expressing NaV1.5 conjugated to ascorbate peroxidase. We found that FGF13 diminished late current of the IQ/AA but not F1759A mutant cardiomyocytes, suggesting that endogenous FHFs may serve to prevent late Na+ current in mouse cardiomyocytes. Leveraging endogenous mechanisms may furnish an alternative avenue for developing novel pharmacology that selectively blunts late Na+ current.
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Affiliation(s)
| | | | - Nourdine Chakouri
- Department of Physiology and Cellular Biophysics, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | | | | | - Lin Yang
- Division of Cardiology, Department of Medicine
| | | | | | | | | | - Johanna Diaz
- Department of Physiology and Cellular Biophysics, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Chaojian Wang
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina, USA
| | | | - Geoffrey S. Pitt
- Cardiovascular Research Institute, Weill Cornell Medical College, New York, New York, USA
| | - Manu Ben-Johny
- Department of Physiology and Cellular Biophysics, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Steven O. Marx
- Division of Cardiology, Department of Medicine
- Department of Pharmacology, and
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26
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Mahdieh N, Khorgami M, Soveizi M, Seyed Aliakbar S, Dalili M, Rabbani B. Genetic homozygosity in a diverse population: An experience of long QT syndrome. Int J Cardiol 2020; 316:117-124. [PMID: 32470535 DOI: 10.1016/j.ijcard.2020.05.056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 05/02/2020] [Accepted: 05/18/2020] [Indexed: 11/20/2022]
Abstract
BACKGROUND Genomic variations have shown an ethnic-specific pattern within various cohorts. Genetic variants of KCNQ1, KCNH2, SCN5A and KCNE1 causing LQT syndrome have been described in many populations. In this article the spectrum of variants of these genes is presented in Iranian patients. METHODS 102 unrelated individuals diagnosed with LQT were enrolled in this study. Clinical and electrocardiogram (ECG) data of 95 patients were documented, and analyzed by expert pediatric cardiologists. Coding regions and exon-intron boundaries were amplified and sequenced. Segregation analysis was done for novel variants as well as in silico analyses. RESULTS Sixty nine of 95 cases (73%) had Schwartz score of ≥3.5. The causal variants were found in 31 cases (9 novel variants). 21 patients had KCNQ1 (LQTS1) of which15 patients were homozygous for KCNQ1 variants, 9 of these patients (29%) had a Jervell and Lange-Nielsen phenotype. 4 patients had KCNH2 (LQTS2) variants, 7 cases had SCN5A had heterozygous variants, and 2 cases had heterozygous variants in KCNE1 (LQTS5). 19 variants were missense, 3 were nonsense, and 3 were frameshifts. There was one large deletion and 3 intronic variants. CONCLUSION The yield of genetic testing and the genotype profile of LQTS patients in Iran is different from reports elsewhere, with lower overall yield and with 48% having homozygous states.
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Affiliation(s)
- Nejat Mahdieh
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran; Growth and development research center, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammadrafi Khorgami
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Mahdieh Soveizi
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Saranaz Seyed Aliakbar
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Dalili
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran.
| | - Bahareh Rabbani
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran; Growth and development research center, Tehran University of Medical Sciences, Tehran, Iran.
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27
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Glazer AM, Wada Y, Li B, Muhammad A, Kalash OR, O'Neill MJ, Shields T, Hall L, Short L, Blair MA, Kroncke BM, Capra JA, Roden DM. High-Throughput Reclassification of SCN5A Variants. Am J Hum Genet 2020; 107:111-123. [PMID: 32533946 PMCID: PMC7332654 DOI: 10.1016/j.ajhg.2020.05.015] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 05/19/2020] [Indexed: 12/19/2022] Open
Abstract
Partial or complete loss-of-function variants in SCN5A are the most common genetic cause of the arrhythmia disorder Brugada syndrome (BrS1). However, the pathogenicity of SCN5A variants is often unknown or disputed; 80% of the 1,390 SCN5A missense variants observed in at least one individual to date are variants of uncertain significance (VUSs). The designation of VUS is a barrier to the use of sequence data in clinical care. We selected 83 variants: 10 previously studied control variants, 10 suspected benign variants, and 63 suspected Brugada syndrome-associated variants, selected on the basis of their frequency in the general population and in individuals with Brugada syndrome. We used high-throughput automated patch clamping to study the function of the 83 variants, with the goal of reclassifying variants with functional data. The ten previously studied controls had functional properties concordant with published manual patch clamp data. All 10 suspected benign variants had wild-type-like function. 22 suspected BrS variants had loss of channel function (<10% normalized peak current) and 22 variants had partial loss of function (10%-50% normalized peak current). The previously unstudied variants were initially classified as likely benign (n = 2), likely pathogenic (n = 10), or VUSs (n = 61). After the patch clamp studies, 16 variants were benign/likely benign, 45 were pathogenic/likely pathogenic, and only 12 were still VUSs. Structural modeling identified likely mechanisms for loss of function including altered thermostability and disruptions to alpha helices, disulfide bonds, or the permeation pore. High-throughput patch clamping enabled reclassification of the majority of tested VUSs in SCN5A.
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Affiliation(s)
- Andrew M Glazer
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Yuko Wada
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Bian Li
- Department of Biological Sciences, Center for Structural Biology, and Vanderbilt Genetics Institute, Vanderbilt University, Nashville, TN 37235, USA
| | - Ayesha Muhammad
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Olivia R Kalash
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Matthew J O'Neill
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Tiffany Shields
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Lynn Hall
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Laura Short
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Marcia A Blair
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Brett M Kroncke
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - John A Capra
- Department of Biological Sciences, Center for Structural Biology, and Vanderbilt Genetics Institute, Vanderbilt University, Nashville, TN 37235, USA
| | - Dan M Roden
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
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28
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Kroncke BM, Smith DK, Zuo Y, Glazer AM, Roden DM, Blume JD. A Bayesian method to estimate variant-induced disease penetrance. PLoS Genet 2020; 16:e1008862. [PMID: 32569262 PMCID: PMC7347235 DOI: 10.1371/journal.pgen.1008862] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 07/09/2020] [Accepted: 05/14/2020] [Indexed: 01/09/2023] Open
Abstract
A major challenge emerging in genomic medicine is how to assess best disease risk from rare or novel variants found in disease-related genes. The expanding volume of data generated by very large phenotyping efforts coupled to DNA sequence data presents an opportunity to reinterpret genetic liability of disease risk. Here we propose a framework to estimate the probability of disease given the presence of a genetic variant conditioned on features of that variant. We refer to this as the penetrance, the fraction of all variant heterozygotes that will present with disease. We demonstrate this methodology using a well-established disease-gene pair, the cardiac sodium channel gene SCN5A and the heart arrhythmia Brugada syndrome. From a review of 756 publications, we developed a pattern mixture algorithm, based on a Bayesian Beta-Binomial model, to generate SCN5A penetrance probabilities for the Brugada syndrome conditioned on variant-specific attributes. These probabilities are determined from variant-specific features (e.g. function, structural context, and sequence conservation) and from observations of affected and unaffected heterozygotes. Variant functional perturbation and structural context prove most predictive of Brugada syndrome penetrance.
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Affiliation(s)
- Brett M. Kroncke
- Department of Medicine Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Department of Pharmacology Vanderbilt University, Nashville, Tennessee, United States of America
| | - Derek K. Smith
- Department of Biostatistics Vanderbilt University, Nashville, Tennessee, United States of America
| | - Yi Zuo
- Department of Biostatistics Vanderbilt University, Nashville, Tennessee, United States of America
| | - Andrew M. Glazer
- Department of Medicine Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Dan M. Roden
- Department of Medicine Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Department of Pharmacology Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Biomedical Informatics Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Jeffrey D. Blume
- Department of Biostatistics Vanderbilt University, Nashville, Tennessee, United States of America
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29
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Barake W, Giudicessi JR, Asirvatham SJ, Ackerman MJ. Purkinje system hyperexcitability and ventricular arrhythmia risk in type 3 long QT syndrome. Heart Rhythm 2020; 17:1768-1776. [PMID: 32454217 DOI: 10.1016/j.hrthm.2020.05.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 05/01/2020] [Accepted: 05/11/2020] [Indexed: 01/20/2023]
Abstract
BACKGROUND Gain-of-function variants in the SCN5A-encoded Nav1.5 sodium channel cause type 3 long QT syndrome (LQT3) and multifocal ectopic Purkinje-related premature contractions. Although the Purkinje system is uniquely sensitive to the action potential-prolonging effects of LQT3-causative variants, the existence of additional Purkinje phenotype(s) in LQT3 is unknown. OBJECTIVE The purpose of this study was to determine the prevalence and clinical implications of frequent fascicular/Purkinje-related premature ventricular contractions (PVCs) and short-coupled ventricular arrhythmias (VAs), suggestive of Purkinje system hyperexcitability (PSH), in a single-center LQT3 cohort. METHODS A retrospective analysis of 177 SCN5A-positive patients was performed to identify individuals with a LQT3 phenotype. Available electrocardiographic, electrophysiology study, device, and genetic data from 91 individuals with LQT3 were reviewed for evidence of presumed fascicular PVCs and short-coupled VAs. The relationship between PSH and ventricular fibrillation events was assessed by Kaplan-Meier and Cox regression analyses. RESULTS Overall, 30 of 91 patients with LQT3 (33%) exhibited evidence of presumed PSH (fascicular PVCs 30 of 30 [100%]; short-coupled VAs 17 of 30 [56%]). Kaplan-Meier and Cox regression analyses demonstrated an increased risk of ventricular fibrillation events in individuals with LQT3 and PSH (log-rank, P < .03; hazard ratio 3.95; 95% confidence interval 1.15-15.7; P = .03). Interestingly, variants in the voltage-sensing domain regions of Nav1.5 were more frequently observed in patients with LQT3 and PSH than those without (19 of 30 [63%] vs 9 of 61 [15%]; P < .0001). CONCLUSION This study demonstrates that a discernible Purkinje phenotype is present in one-third of LQT3 cases and increases the risk of potentially lethal VAs. Further study is needed to determine whether a distinct cellular electrophysiology phenotype underlies this phenomenon.
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Affiliation(s)
- Walid Barake
- Division of Heart Rhythm Services, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota
| | - John R Giudicessi
- Clinician Investigator Training Program, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota; Windland Smith Rice Sudden Death Genomics Laboratory, Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota
| | - Samuel J Asirvatham
- Division of Heart Rhythm Services, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota; Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota
| | - Michael J Ackerman
- Division of Heart Rhythm Services, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota; Windland Smith Rice Sudden Death Genomics Laboratory, Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota; Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota.
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30
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Fouda MA, Ghovanloo MR, Ruben PC. Cannabidiol protects against high glucose-induced oxidative stress and cytotoxicity in cardiac voltage-gated sodium channels. Br J Pharmacol 2020; 177:2932-2946. [PMID: 32077098 DOI: 10.1111/bph.15020] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 12/23/2019] [Accepted: 01/14/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND AND PURPOSE Cardiovascular complications are the major cause of mortality in diabetic patients. However, the molecular mechanisms underlying diabetes-associated arrhythmias are unclear. We hypothesized that high glucose could adversely affect Nav 1.5, the major cardiac sodium channel isoform of the heart, at least partially via oxidative stress. We further hypothesized that cannabidiol (CBD), one of the main constituents of Cannabis sativa, through its effects on Nav 1.5, could protect against high glucose-elicited oxidative stress and cytotoxicity. EXPERIMENTAL APPROACH To test these ideas, we used CHO cells transiently co-transfected with cDNA encoding human Nav 1.5 α-subunit under control and high glucose conditions (50 or 100 mM for 24 hr). Several experimental and computational techniques were used, including voltage clamp of heterologous expression systems, cell viability assays, fluorescence assays and action potential modelling. KEY RESULTS High glucose evoked cell death associated with elevation in reactive oxygen species (ROS) right shifted the voltage dependence of conductance and steady-state fast inactivation, and increased persistent current leading to computational prolongation of action potential (hyperexcitability) which could result in long QT3 arrhythmia. CBD mitigated all the deleterious effects provoked by high glucose. Perfusion with lidocaine (a well-known sodium channel inhibitor with antioxidant effects) or co-incubation of Tempol (a well-known antioxidant) elicited protection, comparable to CBD, against the deleterious effects of high glucose. CONCLUSION AND IMPLICATIONS These findings suggest that, through its favourable antioxidant and sodium channel inhibitory effects, CBD may protect against high glucose-induced arrhythmia and cytotoxicity.
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Affiliation(s)
- Mohamed A Fouda
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada.,Department of Pharmacology and Toxicology, Alexandria University, Alexandria, Egypt
| | - Mohammad-Reza Ghovanloo
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Peter C Ruben
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada
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31
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Gade AR, Marx SO, Pitt GS. An interaction between the III-IV linker and CTD in NaV1.5 confers regulation of inactivation by CaM and FHF. J Gen Physiol 2020; 152:e201912434. [PMID: 31865383 PMCID: PMC7062510 DOI: 10.1085/jgp.201912434] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 11/25/2019] [Indexed: 12/19/2022] Open
Abstract
Voltage gated sodium channel (VGSC) activation drives the action potential upstroke in cardiac myocytes, skeletal muscles, and neurons. After opening, VGSCs rapidly enter a non-conducting, inactivated state. Impaired inactivation causes persistent inward current and underlies cardiac arrhythmias. VGSC auxiliary proteins calmodulin (CaM) and fibroblast growth factor homologous factors (FHFs) bind to the channel's C-terminal domain (CTD) and limit pathogenic persistent currents. The structural details and mechanisms mediating these effects are not clear. Building on recently published cryo-EM structures, we show that CaM and FHF limit persistent currents in the cardiac NaV1.5 VGSC by stabilizing an interaction between the channel's CTD and III-IV linker region. Perturbation of this intramolecular interaction increases persistent current and shifts the voltage dependence of steady-state inactivation. Interestingly, the NaV1.5 residues involved in the interaction are sites mutated in the arrhythmogenic long QT3 syndrome (LQT3). Along with electrophysiological investigations of this interaction, we present structural models that suggest how CaM and FHF stabilize the interaction and thereby limit the persistent current. The critical residues at the interaction site are conserved among VGSC isoforms, and subtle substitutions provide an explanation for differences in inactivation among the isoforms.
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Affiliation(s)
- Aravind R. Gade
- Cardiovascular Research Institute, Weill Cornell Medicine, New York, NY
| | - Steven O. Marx
- Division of Cardiology, Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
- Department of Pharmacology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
| | - Geoffrey S. Pitt
- Cardiovascular Research Institute, Weill Cornell Medicine, New York, NY
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32
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Tarnovskaya SI, Korkosh VS, Zhorov BS, Frishman D. Predicting novel disease mutations in the cardiac sodium channel. Biochem Biophys Res Commun 2020; 521:603-611. [DOI: 10.1016/j.bbrc.2019.10.142] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 10/20/2019] [Indexed: 12/22/2022]
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33
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Mattivi CL, Ye D, Tester DJ, Clemens DJ, Zhou W, Giudicessi JR, Ackerman MJ. Utilization of the genome aggregation database, in silico tools, and heterologous expression patch-clamp studies to identify and demote previously published type 2 long QT syndrome: Causative variants from pathogenic to likely benign. Heart Rhythm 2019; 17:315-323. [PMID: 31493592 DOI: 10.1016/j.hrthm.2019.08.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Indexed: 10/26/2022]
Abstract
BACKGROUND Loss-of-function variants in the KCNH2-encoded Kv11.1 potassium channel cause long QT syndrome (LQTS) type 2 (LQT2). Presently, hundreds of KCNH2 missense variants (MVs) have been published as "disease-causative." However, an estimated 10% of rare published LQTS MVs may be "false positives." OBJECTIVE The purpose of this study was to determine which published KCNH2 MVs are likely false positives and warrant demotion to "likely benign" status. METHODS A list of 337 LQT2-associated MVs from 6 large compendia was compiled. MV frequency within the Genome Aggregation Database (gnomAD) (n = 141,352 individuals) was assessed, and MVs were analyzed with 8 in silico tools. Variants with minor allele frequency (MAF) >7*10E-6, the calculated maximum credible frequency of LQT2, and predicted "benign" by all tools were demoted to "likely benign." Ultra-rare variants (n = 8) absent in gnomAD but predicted "benign" by all tools were considered as potential false positives and were characterized functionally using whole-cell patch clamp. RESULTS Overall, 14 of 337 published KCNH2 MVs (4%) were observed at MAF >7*10E-6, whereas 252 of 337 (75%) were absent in gnomAD. Among the latter, 8 variants (I96V, G187S, A203T, P241L, H254Q, G314S, P935S, P963T) were predicted benign by 8 tools and lacked characterization. Patch clamp showed no functional perturbation for these 8 MVs. CONCLUSION This study offers compelling evidence for the demotion of 22 of 337 KCNH2 variants (6.5%) in the literature. Meticulous "pruning" of compendia using exome/genome databases, in silico tools, and in vitro functional studies must be conducted not only for putatively pathogenic LQTS MVs but for the entire field of genetic heart disease.
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Affiliation(s)
- Connor L Mattivi
- Mayo Clinic Graduate School of Biomedical Sciences, Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota
| | - Dan Ye
- Mayo Clinic Graduate School of Biomedical Sciences, Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota
| | - David J Tester
- Mayo Clinic Graduate School of Biomedical Sciences, Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota; Department of Cardiovascular Medicine, Division of Heart Rhythm Services, Mayo Clinic, Rochester, Minnesota
| | - Daniel J Clemens
- Mayo Clinic Graduate School of Biomedical Sciences, Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota
| | - Wei Zhou
- Mayo Clinic Graduate School of Biomedical Sciences, Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota
| | - John R Giudicessi
- Department of Cardiovascular Medicine, Division of Heart Rhythm Services, Mayo Clinic, Rochester, Minnesota
| | - Michael J Ackerman
- Mayo Clinic Graduate School of Biomedical Sciences, Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota; Department of Pediatric and Adolescent Medicine, Division of Pediatric Cardiology, Mayo Clinic, Rochester, Minnesota.
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34
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Holland KD, Bouley TM, Horn PS. Location: A surrogate for personalized treatment of sodium channelopathies. Ann Neurol 2019; 84:1-9. [PMID: 30048009 DOI: 10.1002/ana.25268] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 05/23/2018] [Accepted: 05/31/2018] [Indexed: 11/11/2022]
Abstract
Voltage-gated sodium channels have been implicated in numerous inherited paroxysmal disorders of the nervous system, muscle, and heart. Our goal is to provide a framework that helps neurologists understand the clinical and treatment implications of sodium channel variants they encounter in clinical practice. This will be accomplished through our objectives of (1) recognizing the relationship between location of a missense sodium channel gene variant and its effect on channel function, and (2) categorizing clinical phenotype based on functional effect of a variant. The relationship between location, function, and treatment response is also discussed. These interactions can be illustrated by the sodium channelopathies seen in people with epilepsy but generalize beyond that disorder. Ann Neurol 2018;83:1-9.
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Affiliation(s)
- Katherine D Holland
- Division of Child Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
| | - Thomas M Bouley
- McMicken College of Arts and Sciences, University of Cincinnati, Cincinnati, OH
| | - Paul S Horn
- Division of Child Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
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35
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Gray B, Ackerman MJ, Semsarian C, Behr ER. Evaluation After Sudden Death in the Young. Circ Arrhythm Electrophysiol 2019; 12:e007453. [DOI: 10.1161/circep.119.007453] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Sudden cardiac death is defined as a death occurring usually within an hour of onset of symptoms, arising from an underlying cardiac disease. Sudden cardiac death is a complication of a number of cardiovascular diseases and is often unexpected. In individuals aged <35 years, unexplained sudden cardiac death is the most common presentation. A significant proportion of sudden cardiac death in the young (≤35 years) events may be precipitated by underlying inherited cardiac conditions, including both heritable cardiomyopathies and inherited arrhythmia syndromes (also known as cardiac channelopathies). Tragically, sudden death may be the first manifestation of the disease in a family and, therefore, clinical and genetic evaluation of surviving family members forms a key role in diagnosing the underlying inherited cardiac condition in the family. This is particularly relevant when considering that most inherited cardiac conditions are inherited in an autosomal dominant manner meaning that surviving family members have a 50% chance of inheriting the same disease substrate. This review will outline the underlying causes of sudden cardiac death in the young and outline our universal approach to familial evaluation following a young person’s sudden death.
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Affiliation(s)
- Belinda Gray
- Cardiology Clinical Academic Group, St. George’s University of London (B.G., E.R.B.)
- St George’s University Hospitals NHS Foundation Trust, London, United Kingdom (B.G., E.R.B.)
- Agnes Ginges Centre for Molecular Cardiology, Centenary Institute (B.G., C.S.)
- Faculty of Health and Medical Sciences, University of Sydney, NSW, Australia (B.G., C.S.)
| | - Michael J. Ackerman
- Departments of Cardiovascular Medicine, Pediatric and Adolescent Medicine, and Molecular Pharmacology and Experimental Therapeutics, Divisions of Heart Rhythm Services and Pediatric Cardiology, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN (M.J.A.)
- Department of Cardiology, Royal Prince Alfred Hospital, NSW, Australia (M.J.A.)
| | - Christopher Semsarian
- Agnes Ginges Centre for Molecular Cardiology, Centenary Institute (B.G., C.S.)
- Faculty of Health and Medical Sciences, University of Sydney, NSW, Australia (B.G., C.S.)
| | - Elijah R. Behr
- Cardiology Clinical Academic Group, St. George’s University of London (B.G., E.R.B.)
- St George’s University Hospitals NHS Foundation Trust, London, United Kingdom (B.G., E.R.B.)
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Giudicessi JR. Machine Learning and Rare Variant Adjudication in Type 1 Long QT Syndrome. ACTA ACUST UNITED AC 2019; 10:CIRCGENETICS.117.001944. [PMID: 29021308 DOI: 10.1161/circgenetics.117.001944] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- John R Giudicessi
- From the Departments of Cardiovascular Medicine and Internal Medicine (Clinician-Investigator Training Program), Mayo Clinic, Rochester, MN.
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Nof E, Vysochek L, Meisel E, Burashnikov E, Antzelevitch C, Clatot J, Beinart R, Luria D, Glikson M, Oz S. Mutations in Na V1.5 Reveal Calcium-Calmodulin Regulation of Sodium Channel. Front Physiol 2019; 10:700. [PMID: 31231243 PMCID: PMC6560087 DOI: 10.3389/fphys.2019.00700] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 05/20/2019] [Indexed: 12/02/2022] Open
Abstract
Mutations in the SCN5A gene, encoding the cardiac voltage-gated sodium channel NaV1.5, are associated with inherited cardiac arrhythmia and conduction disease. Ca2+-dependent mechanisms and the involvement of β-subunit (NaVβ) in NaV1.5 regulation are not fully understood. A patient with severe sinus-bradycardia and cardiac conduction-disease was genetically evaluated and compound heterozygosity in the SCN5A gene was found. Mutations were identified in the cytoplasmic DIII-IV linker (K1493del) and the C-terminus (A1924T) of NaV1.5, both are putative CaM-binding domains. These mutants were functionally studied in human embryonic kidney (HEK) cells and HL-1 cells using whole-cell patch clamp technique. Calmodulin (CaM) interaction and cell-surface expression of heterologously expressed NaV1.5 mutants were studied by pull-down and biotinylation assays. The mutation K1493del rendered NaV1.5 non-conductive. NaV1.5K1493del altered the gating properties of co-expressed functional NaV1.5, in a Ca2+ and NaVβ1-dependent manner. NaV1.5A1924T impaired NaVβ1-dependent gating regulation. Ca2+-dependent CaM-interaction with NaV1.5 was blunted in NaV1.5K1493del. Electrical charge substitution at position 1493 did not affect CaM-interaction and channel functionality. Arrhythmia and conduction-disease -associated mutations revealed Ca2+-dependent gating regulation of NaV1.5 channels. Our results highlight the role of NaV1.5 DIII-IV linker in the CaM-binding complex and channel function, and suggest that the Ca2+-sensing machinery of NaV1.5 involves NaVβ1.
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Affiliation(s)
- Eyal Nof
- Heart Center, Sheba Medical Center, Ramat Gan, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | | | - Eshcar Meisel
- Heart Center, Sheba Medical Center, Ramat Gan, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Elena Burashnikov
- Lankenau Institute for Medical Research, Wynnewood, PA, United States
| | - Charles Antzelevitch
- Lankenau Institute for Medical Research, Wynnewood, PA, United States.,Lankenau Heart Institute, Wynnewood, PA, United States.,Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, United States
| | - Jerome Clatot
- Lankenau Institute for Medical Research, Wynnewood, PA, United States
| | - Roy Beinart
- Heart Center, Sheba Medical Center, Ramat Gan, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - David Luria
- Heart Center, Sheba Medical Center, Ramat Gan, Israel
| | - Michael Glikson
- Heart Center, Sheba Medical Center, Ramat Gan, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shimrit Oz
- Heart Center, Sheba Medical Center, Ramat Gan, Israel
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38
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Kapplinger JD, Pundi KN, Larson NB, Callis TE, Tester DJ, Bikker H, Wilde AAM, Ackerman MJ. Yield of the RYR2 Genetic Test in Suspected Catecholaminergic Polymorphic Ventricular Tachycardia and Implications for Test Interpretation. CIRCULATION-GENOMIC AND PRECISION MEDICINE 2019; 11:e001424. [PMID: 29453246 DOI: 10.1161/circgen.116.001424] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 12/18/2017] [Indexed: 11/16/2022]
Abstract
BACKGROUND Pathogenic RYR2 variants account for ≈60% of clinically definite cases of catecholaminergic polymorphic ventricular tachycardia. However, the rate of rare benign RYR2 variants identified in the general population remains a challenge for genetic test interpretation. Therefore, we examined the results of the RYR2 genetic test among patients referred for commercial genetic testing and examined factors impacting variant interpretability. METHODS Frequency and location comparisons were made for RYR2 variants identified among 1355 total patients of varying clinical certainty and 60 706 Exome Aggregation Consortium controls. The impact of the clinical phenotype on the yield of RYR2 variants was examined. Six in silico tools were assessed using patient- and control-derived variants. RESULTS A total of 18.2% (218/1200) of patients referred for commercial testing hosted rare RYR2 variants, statistically less than the 59% (46/78) yield among clinically definite cases, resulting in a much higher potential genetic false discovery rate among referrals considering the 3.2% background rate of rare, benign RYR2 variants. Exclusion of clearly putative pathogenic variants further complicates the interpretation of the next novel RYR2 variant. Exonic/topologic analyses revealed overrepresentation of patient variants in exons covering only one third of the protein. In silico tools largely failed to show evidence toward enhancement of variant interpretation. CONCLUSIONS Current expert recommendations have resulted in increased use of RYR2 genetic testing in patients with questionable clinical phenotypes. Using the largest to date catecholaminergic polymorphic ventricular tachycardia patient versus control comparison, this study highlights important variables in the interpretation of variants to overcome the 3.2% background rate that confounds RYR2 variant interpretation.
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Affiliation(s)
- Jamie D Kapplinger
- From the Mayo Clinic School of Medicine (J.D.K., M.J.A.), Medical Scientist Training Program (J.D.K., M.J.A.), Mayo Clinic Graduate School of Biomedical Sciences, Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory (J.D.K., D.J.T., M.J.A.), Division of Biomedical Statistics and Informatics, Department of Health Sciences Research (N.B.L.), Division of Heart Rhythm Services, Department of Cardiovascular Diseases (D.J.T., M.J.A.), and Division of Pediatric Cardiology, Department of Pediatrics (M.J.A.), Mayo Clinic, Rochester, MN; Department of Medicine, Stanford University, Stanford, CA (K.N.P.); Transgenomic Inc, New Haven, CT (T.E.C.); and Department of Clinical Genetics (H.B.) and Heart Centre, Department of Clinical and Experimental Cardiology (A.A.M.W.), Academic Medical Center, University of Amsterdam, The Netherlands
| | - Krishna N Pundi
- From the Mayo Clinic School of Medicine (J.D.K., M.J.A.), Medical Scientist Training Program (J.D.K., M.J.A.), Mayo Clinic Graduate School of Biomedical Sciences, Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory (J.D.K., D.J.T., M.J.A.), Division of Biomedical Statistics and Informatics, Department of Health Sciences Research (N.B.L.), Division of Heart Rhythm Services, Department of Cardiovascular Diseases (D.J.T., M.J.A.), and Division of Pediatric Cardiology, Department of Pediatrics (M.J.A.), Mayo Clinic, Rochester, MN; Department of Medicine, Stanford University, Stanford, CA (K.N.P.); Transgenomic Inc, New Haven, CT (T.E.C.); and Department of Clinical Genetics (H.B.) and Heart Centre, Department of Clinical and Experimental Cardiology (A.A.M.W.), Academic Medical Center, University of Amsterdam, The Netherlands
| | - Nicholas B Larson
- From the Mayo Clinic School of Medicine (J.D.K., M.J.A.), Medical Scientist Training Program (J.D.K., M.J.A.), Mayo Clinic Graduate School of Biomedical Sciences, Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory (J.D.K., D.J.T., M.J.A.), Division of Biomedical Statistics and Informatics, Department of Health Sciences Research (N.B.L.), Division of Heart Rhythm Services, Department of Cardiovascular Diseases (D.J.T., M.J.A.), and Division of Pediatric Cardiology, Department of Pediatrics (M.J.A.), Mayo Clinic, Rochester, MN; Department of Medicine, Stanford University, Stanford, CA (K.N.P.); Transgenomic Inc, New Haven, CT (T.E.C.); and Department of Clinical Genetics (H.B.) and Heart Centre, Department of Clinical and Experimental Cardiology (A.A.M.W.), Academic Medical Center, University of Amsterdam, The Netherlands
| | - Thomas E Callis
- From the Mayo Clinic School of Medicine (J.D.K., M.J.A.), Medical Scientist Training Program (J.D.K., M.J.A.), Mayo Clinic Graduate School of Biomedical Sciences, Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory (J.D.K., D.J.T., M.J.A.), Division of Biomedical Statistics and Informatics, Department of Health Sciences Research (N.B.L.), Division of Heart Rhythm Services, Department of Cardiovascular Diseases (D.J.T., M.J.A.), and Division of Pediatric Cardiology, Department of Pediatrics (M.J.A.), Mayo Clinic, Rochester, MN; Department of Medicine, Stanford University, Stanford, CA (K.N.P.); Transgenomic Inc, New Haven, CT (T.E.C.); and Department of Clinical Genetics (H.B.) and Heart Centre, Department of Clinical and Experimental Cardiology (A.A.M.W.), Academic Medical Center, University of Amsterdam, The Netherlands
| | - David J Tester
- From the Mayo Clinic School of Medicine (J.D.K., M.J.A.), Medical Scientist Training Program (J.D.K., M.J.A.), Mayo Clinic Graduate School of Biomedical Sciences, Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory (J.D.K., D.J.T., M.J.A.), Division of Biomedical Statistics and Informatics, Department of Health Sciences Research (N.B.L.), Division of Heart Rhythm Services, Department of Cardiovascular Diseases (D.J.T., M.J.A.), and Division of Pediatric Cardiology, Department of Pediatrics (M.J.A.), Mayo Clinic, Rochester, MN; Department of Medicine, Stanford University, Stanford, CA (K.N.P.); Transgenomic Inc, New Haven, CT (T.E.C.); and Department of Clinical Genetics (H.B.) and Heart Centre, Department of Clinical and Experimental Cardiology (A.A.M.W.), Academic Medical Center, University of Amsterdam, The Netherlands
| | - Hennie Bikker
- From the Mayo Clinic School of Medicine (J.D.K., M.J.A.), Medical Scientist Training Program (J.D.K., M.J.A.), Mayo Clinic Graduate School of Biomedical Sciences, Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory (J.D.K., D.J.T., M.J.A.), Division of Biomedical Statistics and Informatics, Department of Health Sciences Research (N.B.L.), Division of Heart Rhythm Services, Department of Cardiovascular Diseases (D.J.T., M.J.A.), and Division of Pediatric Cardiology, Department of Pediatrics (M.J.A.), Mayo Clinic, Rochester, MN; Department of Medicine, Stanford University, Stanford, CA (K.N.P.); Transgenomic Inc, New Haven, CT (T.E.C.); and Department of Clinical Genetics (H.B.) and Heart Centre, Department of Clinical and Experimental Cardiology (A.A.M.W.), Academic Medical Center, University of Amsterdam, The Netherlands
| | - Arthur A M Wilde
- From the Mayo Clinic School of Medicine (J.D.K., M.J.A.), Medical Scientist Training Program (J.D.K., M.J.A.), Mayo Clinic Graduate School of Biomedical Sciences, Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory (J.D.K., D.J.T., M.J.A.), Division of Biomedical Statistics and Informatics, Department of Health Sciences Research (N.B.L.), Division of Heart Rhythm Services, Department of Cardiovascular Diseases (D.J.T., M.J.A.), and Division of Pediatric Cardiology, Department of Pediatrics (M.J.A.), Mayo Clinic, Rochester, MN; Department of Medicine, Stanford University, Stanford, CA (K.N.P.); Transgenomic Inc, New Haven, CT (T.E.C.); and Department of Clinical Genetics (H.B.) and Heart Centre, Department of Clinical and Experimental Cardiology (A.A.M.W.), Academic Medical Center, University of Amsterdam, The Netherlands
| | - Michael J Ackerman
- From the Mayo Clinic School of Medicine (J.D.K., M.J.A.), Medical Scientist Training Program (J.D.K., M.J.A.), Mayo Clinic Graduate School of Biomedical Sciences, Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory (J.D.K., D.J.T., M.J.A.), Division of Biomedical Statistics and Informatics, Department of Health Sciences Research (N.B.L.), Division of Heart Rhythm Services, Department of Cardiovascular Diseases (D.J.T., M.J.A.), and Division of Pediatric Cardiology, Department of Pediatrics (M.J.A.), Mayo Clinic, Rochester, MN; Department of Medicine, Stanford University, Stanford, CA (K.N.P.); Transgenomic Inc, New Haven, CT (T.E.C.); and Department of Clinical Genetics (H.B.) and Heart Centre, Department of Clinical and Experimental Cardiology (A.A.M.W.), Academic Medical Center, University of Amsterdam, The Netherlands.
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Giudicessi JR, Roden DM, Wilde AAM, Ackerman MJ. Classification and Reporting of Potentially Proarrhythmic Common Genetic Variation in Long QT Syndrome Genetic Testing. Circulation 2019; 137:619-630. [PMID: 29431662 DOI: 10.1161/circulationaha.117.030142] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The acquired and congenital forms of long QT syndrome represent 2 distinct but clinically and genetically intertwined disorders of cardiac repolarization characterized by the shared final common pathway of QT interval prolongation and risk of potentially life-threatening arrhythmias. Over the past 2 decades, our understanding of the spectrum of genetic variation that (1) perturbs the function of cardiac ion channel macromolecular complexes and intracellular calcium-handling proteins, (2) underlies acquired/congenital long QT syndrome susceptibility, and (3) serves as a determinant of QT interval duration in the general population has grown exponentially. In turn, these molecular insights led to the development and increased utilization of clinically impactful genetic testing for congenital long QT syndrome. However, the widespread adoption and potential misinterpretation of the 2015 American College of Medical Genetics and Genomics variant classification and reporting guidelines may have contributed unintentionally to the reduced reporting of common genetic variants, with compelling epidemiological and functional evidence to support a potentially proarrhythmic role in patients with congenital and acquired long QT syndrome. As a result, some genetic testing reports may fail to convey the full extent of a patient's genetic susceptibility for a potentially life-threatening arrhythmia to the ordering healthcare professional. In this white paper, we examine the current classification and reporting (or lack thereof) of potentially proarrhythmic common genetic variants and investigate potential mechanisms to facilitate the reporting of these genetic variants without increasing the risk of diagnostic miscues.
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Affiliation(s)
- John R Giudicessi
- Departments of Cardiovascular Medicine and Internal Medicine, Clinician-Investigator Training Program, Mayo Clinic, Rochester, MN (J.R.G)
| | - Dan M Roden
- Departments of Biomedical Informatics, Medicine, and Pharmacology, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN (D.M.R.)
| | - Arthur A M Wilde
- Department of Clinical and Experimental Cardiology, Academic Medical Center, University of Amsterdam, The Netherlands (A.A.M.W.)
| | - Michael J Ackerman
- Departments of Cardiovascular Diseases, Pediatrics, and Molecular Pharmacology and Experimental Therapeutics, Divisions of Heart Rhythm Services and Pediatric Cardiology, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN (M.J.A.)
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40
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Urrutia J, Aguado A, Muguruza-Montero A, Núñez E, Malo C, Casis O, Villarroel A. The Crossroad of Ion Channels and Calmodulin in Disease. Int J Mol Sci 2019; 20:ijms20020400. [PMID: 30669290 PMCID: PMC6359610 DOI: 10.3390/ijms20020400] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 01/11/2019] [Accepted: 01/16/2019] [Indexed: 01/21/2023] Open
Abstract
Calmodulin (CaM) is the principal Ca2+ sensor in eukaryotic cells, orchestrating the activity of hundreds of proteins. Disease causing mutations at any of the three genes that encode identical CaM proteins lead to major cardiac dysfunction, revealing the importance in the regulation of excitability. In turn, some mutations at the CaM binding site of ion channels cause similar diseases. Here we provide a summary of the two sides of the partnership between CaM and ion channels, describing the diversity of consequences of mutations at the complementary CaM binding domains.
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Affiliation(s)
- Janire Urrutia
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country, 48940 Leioa, Spain.
| | - Alejandra Aguado
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country, 48940 Leioa, Spain.
| | | | - Eider Núñez
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country, 48940 Leioa, Spain.
| | - Covadonga Malo
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country, 48940 Leioa, Spain.
| | - Oscar Casis
- Departamento de Fisiología, Facultad de Farmacia, Universidad del País Vasco (UPV/EHU), 01006 Vitoria-Gasteiz, Spain.
| | - Alvaro Villarroel
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country, 48940 Leioa, Spain.
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41
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42
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Walsh R, Wilde AAM. SCN5A variants in Brugada syndrome: True, true false, or false true. J Cardiovasc Electrophysiol 2018; 30:128-131. [PMID: 30375078 DOI: 10.1111/jce.13774] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Roddy Walsh
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam
| | - Arthur A M Wilde
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam
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43
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Denham NC, Pearman CM, Ding WY, Waktare J, Gupta D, Snowdon R, Hall M, Cooper R, Modi S, Todd D, Mahida S. Systematic re-evaluation of SCN5A variants associated with Brugada syndrome. J Cardiovasc Electrophysiol 2018; 30:118-127. [PMID: 30203441 DOI: 10.1111/jce.13740] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 09/01/2018] [Accepted: 09/07/2018] [Indexed: 12/19/2022]
Abstract
BACKGROUND A large number of SCN5A variants have been reported to underlie Brugada syndrome (BrS). However, the evidence supporting individual variants is highly heterogeneous. OBJECTIVE We systematically re-evaluated all SCN5A variants reported in BrS using the 2015 American college of medical genetics and genomics and the association for molecular pathology (ACMG-AMP) guidelines. METHODS A PubMed/Embase search was performed to identify all reported SCN5A variants in BrS. Standardized bioinformatic re-analysis (SIFT, PolyPhen, Mutation Taster, Mutation assessor, FATHMM, GERP, PhyloP, and SiPhy) and re-evaluation of frequency in the gnomAD database were performed. Fourteen ACMG-AMP rules were deemed applicable for SCN5A variant analysis. RESULTS Four hundred and eighty unique SCN5A variants were identified, the majority of which 425 (88%) were coding variants. One hundred and fifty-six of 425 (37%) variants were classified as pathogenic/likely pathogenic. Two hundred and fifty-eight (60%) were classified as variants of uncertain significance, while a further 11 (3%) were classified as benign/likely benign. When considering the subset of variants that were considered "null" variants separately, 95% fulfilled criteria for pathogenicity/likely pathogenicity. In contrast, only 17% of missense variants fulfilled criteria for pathogenicity/likely pathogenicity. Importantly, however, only 25% of missense variants had available functional data, which was a major score driver for pathogenic classification. CONCLUSION Based on contemporary ACMG-AMP guidelines, only a minority of SCN5A variants implicated in BrS fulfill the criteria for pathogenicity or likely pathogenicity.
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Affiliation(s)
- Nathan C Denham
- Department of Cardiac Electrophysiology, Liverpool Heart and Chest Hospital, Liverpool, UK.,Department of Inherited Cardiac Diseases, Liverpool Heart and Chest Hospital, Liverpool, UK.,Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK
| | - Charles M Pearman
- Department of Cardiac Electrophysiology, Liverpool Heart and Chest Hospital, Liverpool, UK.,Department of Inherited Cardiac Diseases, Liverpool Heart and Chest Hospital, Liverpool, UK.,Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK
| | - Wern Yew Ding
- Department of Cardiac Electrophysiology, Liverpool Heart and Chest Hospital, Liverpool, UK
| | - Johan Waktare
- Department of Cardiac Electrophysiology, Liverpool Heart and Chest Hospital, Liverpool, UK
| | - Dhiraj Gupta
- Department of Cardiac Electrophysiology, Liverpool Heart and Chest Hospital, Liverpool, UK
| | - Richard Snowdon
- Department of Cardiac Electrophysiology, Liverpool Heart and Chest Hospital, Liverpool, UK.,Department of Inherited Cardiac Diseases, Liverpool Heart and Chest Hospital, Liverpool, UK
| | - Mark Hall
- Department of Cardiac Electrophysiology, Liverpool Heart and Chest Hospital, Liverpool, UK
| | - Robert Cooper
- Department of Inherited Cardiac Diseases, Liverpool Heart and Chest Hospital, Liverpool, UK
| | - Simon Modi
- Department of Cardiac Electrophysiology, Liverpool Heart and Chest Hospital, Liverpool, UK.,Department of Inherited Cardiac Diseases, Liverpool Heart and Chest Hospital, Liverpool, UK
| | - Derick Todd
- Department of Cardiac Electrophysiology, Liverpool Heart and Chest Hospital, Liverpool, UK.,Department of Inherited Cardiac Diseases, Liverpool Heart and Chest Hospital, Liverpool, UK
| | - Saagar Mahida
- Department of Cardiac Electrophysiology, Liverpool Heart and Chest Hospital, Liverpool, UK.,Department of Inherited Cardiac Diseases, Liverpool Heart and Chest Hospital, Liverpool, UK
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44
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Hosseini SM, Kim R, Udupa S, Costain G, Jobling R, Liston E, Jamal SM, Szybowska M, Morel CF, Bowdin S, Garcia J, Care M, Sturm AC, Novelli V, Ackerman MJ, Ware JS, Hershberger RE, Wilde AA, Gollob MH. Reappraisal of Reported Genes for Sudden Arrhythmic Death: Evidence-Based Evaluation of Gene Validity for Brugada Syndrome. Circulation 2018; 138:1195-1205. [PMID: 29959160 PMCID: PMC6147087 DOI: 10.1161/circulationaha.118.035070] [Citation(s) in RCA: 218] [Impact Index Per Article: 36.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 06/11/2018] [Indexed: 12/26/2022]
Abstract
BACKGROUND Implicit in the genetic evaluation of patients with suspected genetic diseases is the assumption that the genes evaluated are causative for the disease based on robust scientific and statistical evidence. However, in the past 20 years, considerable variability has existed in the study design and quality of evidence supporting reported gene-disease associations, raising concerns of the validity of many published disease-causing genes. Brugada syndrome (BrS) is an arrhythmia syndrome with a risk of sudden death. More than 20 genes have been reported to cause BrS and are assessed routinely on genetic testing panels in the absence of a systematic, evidence-based evaluation of the evidence supporting the causality of these genes. METHODS We evaluated the clinical validity of genes tested by diagnostic laboratories for BrS by assembling 3 gene curation teams. Using an evidence-based semiquantitative scoring system of genetic and experimental evidence for gene-disease associations, curation teams independently classified genes as demonstrating limited, moderate, strong, or definitive evidence for disease causation in BrS. The classification of curator teams was reviewed by a clinical domain expert panel that could modify the classifications based on their independent review and consensus. RESULTS Of 21 genes curated for clinical validity, biocurators classified only 1 gene ( SCN5A) as definitive evidence, whereas all other genes were classified as limited evidence. After comprehensive review by the clinical domain Expert panel, all 20 genes classified as limited evidence were reclassified as disputed with regard to any assertions of disease causality for BrS. CONCLUSIONS Our results contest the clinical validity of all but 1 gene clinically tested and reported to be associated with BrS. These findings warrant a systematic, evidence-based evaluation for reported gene-disease associations before use in patient care.
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Affiliation(s)
- S. Mohsen Hosseini
- Ted Rogers Cardiac Genome Clinic (S.M.H., R.K., R.J., E.L., S.B.), The Hospital for Sick Children, Toronto, Ontario, Canada
- * Drs Hosseini, Kim, and Udupa contributed equally
| | - Raymond Kim
- Ted Rogers Cardiac Genome Clinic (S.M.H., R.K., R.J., E.L., S.B.), The Hospital for Sick Children, Toronto, Ontario, Canada
- Division of Clinical and Metabolic Genetics (R.K., G.C., R.J., E.L., S.M.J., S.B.), The Hospital for Sick Children, Toronto, Ontario, Canada
- Fred A. Litwin Family Center in Genetic Medicine, University Health Network, Toronto, Ontario, Canada (R.K., M.S., C.F.M.)
- * Drs Hosseini, Kim, and Udupa contributed equally
| | - Sharmila Udupa
- Toronto General Hospital Research Institute, University of Toronto, Ontario, Canada (S.U., M.H.G.)
- * Drs Hosseini, Kim, and Udupa contributed equally
| | - Gregory Costain
- Division of Clinical and Metabolic Genetics (R.K., G.C., R.J., E.L., S.M.J., S.B.), The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Rebekah Jobling
- Ted Rogers Cardiac Genome Clinic (S.M.H., R.K., R.J., E.L., S.B.), The Hospital for Sick Children, Toronto, Ontario, Canada
- Division of Clinical and Metabolic Genetics (R.K., G.C., R.J., E.L., S.M.J., S.B.), The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Eriskay Liston
- Ted Rogers Cardiac Genome Clinic (S.M.H., R.K., R.J., E.L., S.B.), The Hospital for Sick Children, Toronto, Ontario, Canada
- Division of Clinical and Metabolic Genetics (R.K., G.C., R.J., E.L., S.M.J., S.B.), The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Seema M. Jamal
- Division of Clinical and Metabolic Genetics (R.K., G.C., R.J., E.L., S.M.J., S.B.), The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Marta Szybowska
- Fred A. Litwin Family Center in Genetic Medicine, University Health Network, Toronto, Ontario, Canada (R.K., M.S., C.F.M.)
| | - Chantal F. Morel
- Fred A. Litwin Family Center in Genetic Medicine, University Health Network, Toronto, Ontario, Canada (R.K., M.S., C.F.M.)
| | - Sarah Bowdin
- Ted Rogers Cardiac Genome Clinic (S.M.H., R.K., R.J., E.L., S.B.), The Hospital for Sick Children, Toronto, Ontario, Canada
- Division of Clinical and Metabolic Genetics (R.K., G.C., R.J., E.L., S.M.J., S.B.), The Hospital for Sick Children, Toronto, Ontario, Canada
| | - John Garcia
- Invitae Corporation, San Francisco, CA (J.G.)
| | - Melanie Care
- Peter Munk Cardiac Centre, Department of Medicine (M.C., M.H.G.), Toronto General Hospital, University of Toronto, Ontario, Canada
| | - Amy C. Sturm
- Geisinger Health System Genomic Medicine Institute, Danville, PA (A.C.S.)
| | - Valeria Novelli
- Centro Benito Stirpe per la Morte Improvvisa del Giovane Atleta, Fondazione Policlinico Universitario Agostino Gemelli, Catholic University of the Sacred Heart, Rome, Italy (V.N.)
| | - Michael J. Ackerman
- Departments of Cardiovascular Diseases, Pediatrics, and Molecular Pharmacology and Experimental Therapeutics, Divisions of Heart Rhythm Services and Pediatric Cardiology, Windland Smith Rice Sudden Death Genomics Laboratory, Rochester, MN (M.J.A.)
| | - James S. Ware
- National Heart and Lung Institute, MRC London Institute of Medical Sciences, Imperial College London, Royal Brompton & Harefield Hospitals, United Kingdom (J.S.W.)
| | - Ray E. Hershberger
- Department of Internal Medicine, Division of Human Genetics and Cardiovascular Division, Ohio State University, Columbus (R.E.H.)
| | - Arthur A.M. Wilde
- AMC Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands (A.A.M.W.)
- Princess Al-Jawhara Al-Brahim Centre of Excellence in Research of Hereditary Disorders, Jeddah, Saudi Arabia (A.A.M.W.). Columbia University Irving Medical Centre, New York (A.A.M.W.)
| | - Michael H. Gollob
- Toronto General Hospital Research Institute, University of Toronto, Ontario, Canada (S.U., M.H.G.)
- Peter Munk Cardiac Centre, Department of Medicine (M.C., M.H.G.), Toronto General Hospital, University of Toronto, Ontario, Canada
- Department of Physiology, Peter Munk Cardiovascular Molecular Medicine Laboratory (M.H.G.), Toronto General Hospital, University of Toronto, Ontario, Canada
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Gray B, Behr ER. New Insights Into the Genetic Basis of Inherited Arrhythmia Syndromes. ACTA ACUST UNITED AC 2018; 9:569-577. [PMID: 27998945 DOI: 10.1161/circgenetics.116.001571] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Belinda Gray
- From the Department of Cardiology, Royal Prince Alfred Hospital, New South Wales, Australia (B.G.); Sydney Medical School, University of Sydney, Australia (B.G.), Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, New South Wales, Australia (B.G.); Cardiology Clinical Academic Group, St George's University of London, United Kingdom (E.R.B.); and St George's University Hospitals NHS Foundation Trust, London, United Kingdom (E.R.B.)
| | - Elijah R Behr
- From the Department of Cardiology, Royal Prince Alfred Hospital, New South Wales, Australia (B.G.); Sydney Medical School, University of Sydney, Australia (B.G.), Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, New South Wales, Australia (B.G.); Cardiology Clinical Academic Group, St George's University of London, United Kingdom (E.R.B.); and St George's University Hospitals NHS Foundation Trust, London, United Kingdom (E.R.B.).
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Frasier CR, Zhang H, Offord J, Dang LT, Auerbach DS, Shi H, Chen C, Goldman AM, Eckhardt LL, Bezzerides VJ, Parent JM, Isom LL. Channelopathy as a SUDEP Biomarker in Dravet Syndrome Patient-Derived Cardiac Myocytes. Stem Cell Reports 2018; 11:626-634. [PMID: 30146492 PMCID: PMC6135724 DOI: 10.1016/j.stemcr.2018.07.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 07/23/2018] [Accepted: 07/26/2018] [Indexed: 12/31/2022] Open
Abstract
Dravet syndrome (DS) is a severe developmental and epileptic encephalopathy with a high incidence of sudden unexpected death in epilepsy (SUDEP). Most DS patients carry de novo variants in SCN1A, resulting in Nav1.1 haploinsufficiency. Because SCN1A is expressed in heart and in brain, we proposed that cardiac arrhythmia contributes to SUDEP in DS. We generated DS patient and control induced pluripotent stem cell-derived cardiac myocytes (iPSC-CMs). We observed increased sodium current (INa) and spontaneous contraction rates in DS patient iPSC-CMs versus controls. For the subject with the largest increase in INa, cardiac abnormalities were revealed upon clinical evaluation. Generation of a CRISPR gene-edited heterozygous SCN1A deletion in control iPSCs increased INa density in iPSC-CMs similar to that seen in patient cells. Thus, the high risk of SUDEP in DS may result from a predisposition to cardiac arrhythmias in addition to seizures, reflecting expression of SCN1A in heart and brain.
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Affiliation(s)
- Chad R Frasier
- Department of Pharmacology, University of Michigan Medical School, 2301E MSRB III, Ann Arbor, MI 48109, USA
| | - Helen Zhang
- Department of Neurology, University of Michigan Medical School, 5021 BSRB, Ann Arbor, MI 48109, USA
| | - James Offord
- Department of Pharmacology, University of Michigan Medical School, 2301E MSRB III, Ann Arbor, MI 48109, USA
| | - Louis T Dang
- Division of Pediatric Neurology, Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - David S Auerbach
- Department of Pharmacology, University of Michigan Medical School, 2301E MSRB III, Ann Arbor, MI 48109, USA
| | - Huilin Shi
- Department of Neurology, University of Michigan Medical School, 5021 BSRB, Ann Arbor, MI 48109, USA
| | - Chunling Chen
- Department of Pharmacology, University of Michigan Medical School, 2301E MSRB III, Ann Arbor, MI 48109, USA
| | - Alica M Goldman
- Ann Arbor VA Healthcare System, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Department of Neurology, Baylor College of Medicine, Houston, TX 77030, USA
| | - L Lee Eckhardt
- Cellular and Molecular Arrhythmia Research Program, Division of Cardiovascular Medicine, University of Wisconsin, Madison, WI 53705, USA
| | - Vassilios J Bezzerides
- Cardiology, Electrophysiology Division, Boston Children's Hospital, Boston, MA 02115, USA
| | - Jack M Parent
- Department of Neurology, University of Michigan Medical School, 5021 BSRB, Ann Arbor, MI 48109, USA; Ann Arbor VA Healthcare System, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
| | - Lori L Isom
- Department of Pharmacology, University of Michigan Medical School, 2301E MSRB III, Ann Arbor, MI 48109, USA; Department of Neurology, University of Michigan Medical School, 5021 BSRB, Ann Arbor, MI 48109, USA.
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Predicting changes to I Na from missense mutations in human SCN5A. Sci Rep 2018; 8:12797. [PMID: 30143662 PMCID: PMC6109095 DOI: 10.1038/s41598-018-30577-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 07/23/2018] [Indexed: 11/08/2022] Open
Abstract
Mutations in SCN5A can alter the cardiac sodium current INa and increase the risk of potentially lethal conditions such as Brugada and long-QT syndromes. The relation between mutations and their clinical phenotypes is complex, and systems to predict clinical severity of unclassified SCN5A variants perform poorly. We investigated if instead we could predict changes to INa, leaving the link from INa to clinical phenotype for mechanistic simulation studies. An exhaustive list of nonsynonymous missense mutations and resulting changes to INa was compiled. We then applied machine-learning methods to this dataset, and found that changes to INa could be predicted with higher sensitivity and specificity than most existing predictors of clinical significance. The substituted residues’ location on the protein correlated with channel function and strongly contributed to predictions, while conservedness and physico-chemical properties did not. However, predictions were not sufficiently accurate to form a basis for mechanistic studies. These results show that changes to INa, the mechanism through which SCN5A mutations create cardiac risk, are already difficult to predict using purely in-silico methods. This partly explains the limited success of systems to predict clinical significance of SCN5A variants, and underscores the need for functional studies of INa in risk assessment.
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Baruteau AE, Kyndt F, Behr ER, Vink AS, Lachaud M, Joong A, Schott JJ, Horie M, Denjoy I, Crotti L, Shimizu W, Bos JM, Stephenson EA, Wong L, Abrams DJ, Davis AM, Winbo A, Dubin AM, Sanatani S, Liberman L, Kaski JP, Rudic B, Kwok SY, Rieubland C, Tfelt-Hansen J, Van Hare GF, Guyomarc’h-Delasalle B, Blom NA, Wijeyeratne YD, Gourraud JB, Le Marec H, Ozawa J, Fressart V, Lupoglazoff JM, Dagradi F, Spazzolini C, Aiba T, Tester DJ, Zahavich LA, Beauséjour-Ladouceur V, Jadhav M, Skinner JR, Franciosi S, Krahn AD, Abdelsayed M, Ruben PC, Yung TC, Ackerman MJ, Wilde AA, Schwartz PJ, Probst V. SCN5A mutations in 442 neonates and children: genotype–phenotype correlation and identification of higher-risk subgroups. Eur Heart J 2018; 39:2879-2887. [DOI: 10.1093/eurheartj/ehy412] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 07/01/2018] [Indexed: 01/20/2023] Open
Affiliation(s)
- Alban-Elouen Baruteau
- Cardiology Clinical Academic Group, Molecular and Clinical Sciences Research Institute, St George’s University of London, London, UK
- Department of Congenital Cardiology, Evelina London Children’s Hospital, Guy’s and St Thomas’ NHS Foundation Trust, London, UK
- M3C CHU de Nantes, Fédération des Cardiopathies Congénitales, Nantes, F-44000, France
- L’institut du thorax, INSERM, CNRS, UNIV Nantes, CHU Nantes, Nantes, France
| | - Florence Kyndt
- L’institut du thorax, INSERM, CNRS, UNIV Nantes, CHU Nantes, Nantes, France
| | - Elijah R Behr
- Cardiology Clinical Academic Group, Molecular and Clinical Sciences Research Institute, St George’s University of London, London, UK
| | - Arja S Vink
- Department of Pediatric Cardiology, Academic Medical Center, Amsterdam, The Netherlands
- Department of Clinical and Experimental Cardiology, Heart Centre, Academic Medical Center, Amsterdam, The Netherlands
| | - Matthias Lachaud
- L’institut du thorax, INSERM, CNRS, UNIV Nantes, CHU Nantes, Nantes, France
| | - Anna Joong
- Division of Pediatric Cardiology, Morgan Stanley Children’s Hospital, New York Presbyterian Hospital, Columbia University Medical Center, New York, NY, USA
| | | | - Minoru Horie
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Sciences, Otsu, Japan
| | - Isabelle Denjoy
- AP-HP, Hôpital Bichat, Service de Cardiologie, Université Denis Diderot, Paris, France
| | - Lia Crotti
- Center for Cardiac Arrhythmias of Genetic Origin, IRCCS Istituto Auxologico Italiano, Milano, Italy
| | - Wataru Shimizu
- Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan
- Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan
| | - Johan M Bos
- Division of Heart Rhythm Services, Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN, USA
- Division of Pediatric Cardiology, Department of Pediatrics, Mayo Clinic, Rochester, MN, USA
- Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN, USA
| | - Elizabeth A Stephenson
- The Hospital for Sick Children, Labbatt Family, Heart Centre, University of Toronto, Toronto, Canada
| | - Leonie Wong
- Cardiology Clinical Academic Group, Molecular and Clinical Sciences Research Institute, St George’s University of London, London, UK
| | - Dominic J Abrams
- Inherited Cardiac Arrhythmia Program, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Andrew M Davis
- Department of Cardiology, The Royal Children's Hospital, Melbourne, Australia
- Murdoch Children’s Research Institute and University of Melbourne, Melbourne, Australia
| | - Annika Winbo
- Greenlane Paediatric and Congenital Cardiac Services, Starship Childrens Hospital, Auckland, New Zealand
- Department of Congenital Cardiology, Evelina London Children’s Hospital, Guy’s and St Thomas’ NHS Foundation Trust, London, UK
- Cardiology Clinical Academic Group, Molecular and Clinical Sciences Research Institute, St George’s University of London, London, UK
| | - Anne M Dubin
- Division of Pediatric Electrophysiology, Lucile Packard Children’s Hospital, Stanford University, Palo Alto, CA, USA
| | - Shubhayan Sanatani
- Divisions of Cardiology, Department of Pediatrics and Medicine, British Columbia Children’s Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Leonardo Liberman
- Division of Pediatric Cardiology, Morgan Stanley Children’s Hospital, New York Presbyterian Hospital, Columbia University Medical Center, New York, NY, USA
| | - Juan Pablo Kaski
- Department of Cardiology, Centre for Inherited Cardiovascular Diseases, Great Ormond Street Hospital for Children, London, UK
- Institute of Cardiovascular Science, University College London, London, UK
| | - Boris Rudic
- Medical Faculty Mannheim of the University of Heidelberg, 1st Department of Medicine, Mannheim, Germany
- DZHK (German Centre for Cardiovascular Research), Mannheim, Germany
| | - Sit Yee Kwok
- Department of Paediatric Cardiology, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China
| | - Claudine Rieubland
- Division of Human Genetics, Department of Pediatrics, Inselspital, University of Bern, Switzerland
| | - Jacob Tfelt-Hansen
- Faculty of Health and Medical Science, Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
- Department of Forensic Medicine, Faculty of Medical Sciences, University of Copenhagen, Denmark
| | - George F Van Hare
- Division of Cardiology, Department of Pediatrics, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | | | - Nico A Blom
- Department of Pediatric Cardiology, Academic Medical Center, Amsterdam, The Netherlands
| | - Yanushi D Wijeyeratne
- Cardiology Clinical Academic Group, Molecular and Clinical Sciences Research Institute, St George’s University of London, London, UK
| | | | - Hervé Le Marec
- L’institut du thorax, INSERM, CNRS, UNIV Nantes, CHU Nantes, Nantes, France
| | - Junichi Ozawa
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Sciences, Otsu, Japan
| | - Véronique Fressart
- AP-HP, Hôpital Pitié Salpétrière, Service de Biologie Moléculaire, Paris, France
| | | | - Federica Dagradi
- Center for Cardiac Arrhythmias of Genetic Origin, IRCCS Istituto Auxologico Italiano, Milano, Italy
| | - Carla Spazzolini
- Center for Cardiac Arrhythmias of Genetic Origin, IRCCS Istituto Auxologico Italiano, Milano, Italy
| | - Takeshi Aiba
- Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan
| | - David J Tester
- Division of Heart Rhythm Services, Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN, USA
- Division of Pediatric Cardiology, Department of Pediatrics, Mayo Clinic, Rochester, MN, USA
- Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN, USA
| | - Laura A Zahavich
- The Hospital for Sick Children, Labbatt Family, Heart Centre, University of Toronto, Toronto, Canada
| | | | - Mangesh Jadhav
- Department of Cardiology, The Royal Children's Hospital, Melbourne, Australia
| | - Jonathan R Skinner
- Greenlane Paediatric and Congenital Cardiac Services, Starship Childrens Hospital, Auckland, New Zealand
- Department of Paediatrics, Child and Youth Health, University of Auckland, Auckland, New Zealand
| | - Sonia Franciosi
- Divisions of Cardiology, Department of Pediatrics and Medicine, British Columbia Children’s Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Andrew D Krahn
- Divisions of Cardiology, Department of Pediatrics and Medicine, British Columbia Children’s Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Mena Abdelsayed
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, Canada
| | - Peter C Ruben
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, Canada
| | - Tak-Cheung Yung
- Department of Paediatric Cardiology, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China
| | - Michael J Ackerman
- Division of Heart Rhythm Services, Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN, USA
- Division of Pediatric Cardiology, Department of Pediatrics, Mayo Clinic, Rochester, MN, USA
- Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN, USA
| | - Arthur A Wilde
- Department of Clinical and Experimental Cardiology, Heart Centre, Academic Medical Center, Amsterdam, The Netherlands
- Princess Al-Jawhara Al-Brahim Centre of Excellence in Research of Hereditary Disorders, Jeddah, Kingdom of Saudi Arabia
| | - Peter J Schwartz
- Center for Cardiac Arrhythmias of Genetic Origin, IRCCS Istituto Auxologico Italiano, Milano, Italy
| | - Vincent Probst
- L’institut du thorax, INSERM, CNRS, UNIV Nantes, CHU Nantes, Nantes, France
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A novel three base-pair deletion in domain two of the cardiac sodium channel causes Brugada syndrome. J Electrocardiol 2018; 51:667-673. [PMID: 29997009 DOI: 10.1016/j.jelectrocard.2018.03.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 03/12/2018] [Accepted: 03/21/2018] [Indexed: 11/21/2022]
Abstract
INTRODUCTION Mutations within SCN5A are found in a significant proportion (15-30%) of Brugada syndrome (BrS) cases and impair sodium transport across excitable cardiac cells that mediate ventricular contractions. Genetic testing offers a means to clinically assess and manage affected individuals and their family members. METHODS AND RESULTS The proband at age 44 years old exhibited a syncopal event during exercise, and presented later with a spontaneous type-I BrS pattern on 12‑lead resting electrocardiogram (ECG). Mutational analysis performed across all SCN5A exons revealed a unique three base-pair deletion p.M741_T742delinsI (c.2223_2225delGAC), in a heterozygous state in the proband and 2 siblings. This mutation was not seen in a cohort of 105 ethnicity-matched controls or in public genome databases. Patch clamp electrophysiology study conducted in TSA201 cells showed an abolishment of sodium current (INa). The proband, and several relatives, also harboured a known SCN5A variant, p.R1193Q (c.3578G>A). CONCLUSION Our study has demonstrated the deleterious effect of a novel SCN5A mutation p.M741_T742delinsI (c.2223_2225delGAC). The findings highlight the complex effects of gender and age in phenotype manifestation. It also offers insights into improving the long-term management of BrS, and the utility of cascade genetic screening for risk stratification.
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50
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Stallmeyer B, Dittmann S, Schulze-Bahr E. Genetische Diagnostik zur Vermeidung des plötzlichen Herztods. Internist (Berl) 2018; 59:776-789. [DOI: 10.1007/s00108-018-0462-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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