51
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Giudicessi JR, Ackerman MJ. Role of genetic heart disease in sentinel sudden cardiac arrest survivors across the age spectrum. Int J Cardiol 2018; 270:214-220. [PMID: 29884292 DOI: 10.1016/j.ijcard.2018.05.100] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 05/08/2018] [Accepted: 05/25/2018] [Indexed: 11/18/2022]
Abstract
BACKGROUND Sudden cardiac arrest (SCA) may be the sentinel expression of a sudden cardiac death-predisposing genetic heart disease (GHD). Although shown to underlie many unexplained SCAs in the young, the contribution of GHDs to sentinel SCA has never been quantified across the age spectrum. Thus, we sought to determine the contribution of GHDs in single-center referral cohort of non-ischemic SCA survivors. METHODS AND RESULTS Retrospective analysis of 3037 patients was used to identify all individuals who experienced a sentinel event of SCA. Following exclusion of patients with ischemic or complex congenital heart disease, cases were classified by clinical diagnoses. Overall, 180 (5.9%) referral patients experienced a sentinel SCA (average age at SCA 28 ± 15 years, 99 females). An etiology was identified in 113/180 patients (62.8%) including channelopathies in 26.7%, arrhythmogenic bileaflet mitral valve prolapse in 10.6%, cardiomyopathies in 9.4%, other etiologies in 6.7%, acquired long QT syndrome in 6.7%, and multiple disorders in 2.8%. The remaining 67/180 (37.2%) cases were classified as idiopathic ventricular fibrillation (IVF). Interestingly, the contribution of GHDs declined precipitously after the first decade of life [90.0% (age 0-9; n = 20), 58.7% (age 10-19; n = 46), 28.1% (age 20-29; n = 32), 23.8% (age 30-39; n = 42), 16.7% (age 40-49; n = 24), and 12.5% (age 50+; n = 16)]. CONCLUSIONS Within a referral population enriched for GHDs, the ability of a comprehensive cardiac evaluation, including genetic testing, to elucidate a root cause in non-ischemic SCA survivors declined with age. Although rare, GHDs can underlie SCA into adulthood and merit consideration across the age spectrum.
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Affiliation(s)
- John R Giudicessi
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, United States; Department of Internal Medicine (Clinician-Investigator Training Program), Mayo Clinic, Rochester, MN, United States
| | - Michael J Ackerman
- Department of Cardiovascular Medicine (Division of Heart Rhythm Services), Mayo Clinic, Rochester, MN, United States; Department of Pediatric and Adolescent Medicine (Division of Pediatric Cardiology), Mayo Clinic, Rochester, MN, United States; Department of Molecular Pharmacology & Experimental Therapeutics (Windland Smith Rice Sudden Death Genomics Laboratory), Mayo Clinic, Rochester, MN, United States.
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52
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Roberts JD. Predicting Penetrance of SCN5A Rare Variants: Peering Beyond the Black and White and Into the Shades of Grey. CIRCULATION-GENOMIC AND PRECISION MEDICINE 2018; 11:e002166. [PMID: 29728398 DOI: 10.1161/circgen.118.002166] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Jason D Roberts
- Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, ON, Canada.
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53
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Robyns T, Nuyens D, Vandenberk B, Kuiperi C, Corveleyn A, Breckpot J, Garweg C, Ector J, Willems R. Genotype-phenotype relationship and risk stratification in loss-of-function SCN5A mutation carriers. Ann Noninvasive Electrocardiol 2018; 23:e12548. [PMID: 29709101 DOI: 10.1111/anec.12548] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 02/12/2018] [Indexed: 02/06/2023] Open
Abstract
INTRODUCTION Loss-of-function (LoF) mutations in the SCN5A gene cause multiple phenotypes including Brugada Syndrome (BrS) and a diffuse cardiac conduction defect. Markers of increased risk for sudden cardiac death (SCD) in LoF SCN5A mutation carriers are ill defined. We hypothesized that late potentials and fragmented QRS would be more prevalent in SCN5A mutation carriers compared to SCN5A-negative BrS patients and evaluated risk markers for SCD in SCN5A mutation carriers. METHODS We included all SCN5A loss-of-function mutation carriers and SCN5A-negative BrS patients from our center. A combined arrhythmic endpoint was defined as appropriate ICD shock or SCD. RESULTS Late potentials were more prevalent in 79 SCN5A mutation carriers compared to 39 SCN5A-negative BrS patients (66% versus 44%, p = .021), while there was no difference in the prevalence of fragmented QRS. PR interval prolongation was the only parameter that predicted the presence of a SCN5A mutation in BrS (OR 1.08; p < .001). Four SCN5A mutation carriers, of whom three did not have a diagnostic type 1 ECG either spontaneously or after provocation with a sodium channel blocker, reached the combined arrhythmic endpoint during a follow-up of 44 ± 52 months resulting in an annual incidence rate of 1.37%. CONCLUSION LP were more frequently observed in SCN5A mutation carriers, while fQRS was not. In SCN5A mutation carriers, the annual incidence rate of SCD was non-negligible, even in the absence of a spontaneous or induced type 1 ECG. Therefore, proper follow-up of SCN5A mutation carriers without Brugada syndrome phenotype is warranted.
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Affiliation(s)
- Tomas Robyns
- Department of Cardiovascular Diseases, University Hospitals Leuven, Leuven, Belgium.,Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium
| | - Dieter Nuyens
- Department of Cardiology, Ziekenhuis Oost Limburg, Genk, Belgium
| | - Bert Vandenberk
- Department of Cardiovascular Diseases, University Hospitals Leuven, Leuven, Belgium.,Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium
| | - Cuno Kuiperi
- Department of Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Anniek Corveleyn
- Department of Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Jeroen Breckpot
- Department of Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Christophe Garweg
- Department of Cardiovascular Diseases, University Hospitals Leuven, Leuven, Belgium.,Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium
| | - Joris Ector
- Department of Cardiovascular Diseases, University Hospitals Leuven, Leuven, Belgium.,Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium
| | - Rik Willems
- Department of Cardiovascular Diseases, University Hospitals Leuven, Leuven, Belgium.,Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium
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54
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Abstract
INTRODUCTION AND OBJECTIVES The importance of sodium channels for the normal electrical activity of the heart is emphasized by the fact that mutations (inherited or de novo) in genes that encode for these channels or their associated proteins cause arrhythmogenic syndromes such as the Brugada syndrome and the long QT syndrome (LQTS). The aim of this study is to conduct a review of the literature on the mutations in the sodium channel complex responsible for heart disease and the implications of a close relationship between genetics and the clinical aspects of the main cardiac channelopathies, namely at the level of diagnosis, risk stratification, prognosis, screening of family members and treatment. METHODS The online Pubmed® database was used to search for articles published in this field in indexed journals. The MeSH database was used to define the following query: "Mutation [Mesh] AND Sodium Channels [Mesh] AND Heart Diseases [Mesh]", and articles published in the last 15 years, written in English or Portuguese and referring to research in human beings were included. CONCLUSIONS In the past few years, significant advances have been made to clarify the genetic and molecular basis of these syndromes. A greater understanding of the underlying pathophysiological mechanisms showed the importance of the relationship between genotype and phenotype and led to progress in the clinical approach to these patients. However, it is still necessary to improve diagnostic capacity, optimize risk stratification, and develop new specific treatments according to the genotype-phenotype binomial.
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55
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Fonseca DJ, Vaz da Silva MJ. Cardiac channelopathies: The role of sodium channel mutations. REVISTA PORTUGUESA DE CARDIOLOGIA (ENGLISH EDITION) 2018. [DOI: 10.1016/j.repce.2017.11.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
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56
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Whiffin N, Walsh R, Govind R, Edwards M, Ahmad M, Zhang X, Tayal U, Buchan R, Midwinter W, Wilk AE, Najgebauer H, Francis C, Wilkinson S, Monk T, Brett L, O'Regan DP, Prasad SK, Morris-Rosendahl DJ, Barton PJR, Edwards E, Ware JS, Cook SA. CardioClassifier: disease- and gene-specific computational decision support for clinical genome interpretation. Genet Med 2018; 20:1246-1254. [PMID: 29369293 DOI: 10.1038/gim.2017.258] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 12/05/2017] [Indexed: 11/10/2022] Open
Abstract
PURPOSE Internationally adopted variant interpretation guidelines from the American College of Medical Genetics and Genomics (ACMG) are generic and require disease-specific refinement. Here we developed CardioClassifier ( http://www.cardioclassifier.org ), a semiautomated decision-support tool for inherited cardiac conditions (ICCs). METHODS CardioClassifier integrates data retrieved from multiple sources with user-input case-specific information, through an interactive interface, to support variant interpretation. Combining disease- and gene-specific knowledge with variant observations in large cohorts of cases and controls, we refined 14 computational ACMG criteria and created three ICC-specific rules. RESULTS We benchmarked CardioClassifier on 57 expertly curated variants and show full retrieval of all computational data, concordantly activating 87.3% of rules. A generic annotation tool identified fewer than half as many clinically actionable variants (64/219 vs. 156/219, Fisher's P = 1.1 × 10-18), with important false positives, illustrating the critical importance of disease and gene-specific annotations. CardioClassifier identified putatively disease-causing variants in 33.7% of 327 cardiomyopathy cases, comparable with leading ICC laboratories. Through addition of manually curated data, variants found in over 40% of cardiomyopathy cases are fully annotated, without requiring additional user-input data. CONCLUSION CardioClassifier is an ICC-specific decision-support tool that integrates expertly curated computational annotations with case-specific data to generate fast, reproducible, and interactive variant pathogenicity reports, according to best practice guidelines.
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Affiliation(s)
- Nicola Whiffin
- National Heart & Lung Institute, Imperial College London, London, UK. .,Cardiovascular Research Centre at Royal Brompton and Harefield NHS Foundation Trust, London, UK. .,MRC London Institute of Medical Sciences, Imperial College London, London, UK.
| | - Roddy Walsh
- National Heart & Lung Institute, Imperial College London, London, UK.,Cardiovascular Research Centre at Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Risha Govind
- National Heart & Lung Institute, Imperial College London, London, UK.,Cardiovascular Research Centre at Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Matthew Edwards
- Clinical Genetics and Genomics Laboratory, Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Mian Ahmad
- National Heart & Lung Institute, Imperial College London, London, UK.,Cardiovascular Research Centre at Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Xiaolei Zhang
- National Heart & Lung Institute, Imperial College London, London, UK.,Cardiovascular Research Centre at Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Upasana Tayal
- National Heart & Lung Institute, Imperial College London, London, UK.,Cardiovascular Research Centre at Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Rachel Buchan
- National Heart & Lung Institute, Imperial College London, London, UK.,Cardiovascular Research Centre at Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - William Midwinter
- National Heart & Lung Institute, Imperial College London, London, UK.,Cardiovascular Research Centre at Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Alicja E Wilk
- National Heart & Lung Institute, Imperial College London, London, UK.,Cardiovascular Research Centre at Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Hanna Najgebauer
- National Heart & Lung Institute, Imperial College London, London, UK.,Cardiovascular Research Centre at Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Catherine Francis
- National Heart & Lung Institute, Imperial College London, London, UK.,Cardiovascular Research Centre at Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Sam Wilkinson
- Clinical Genetics and Genomics Laboratory, Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Thomas Monk
- Clinical Genetics and Genomics Laboratory, Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Laura Brett
- Clinical Genetics and Genomics Laboratory, Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Declan P O'Regan
- MRC London Institute of Medical Sciences, Imperial College London, London, UK
| | - Sanjay K Prasad
- National Heart & Lung Institute, Imperial College London, London, UK.,Cardiovascular Research Centre at Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Deborah J Morris-Rosendahl
- National Heart & Lung Institute, Imperial College London, London, UK.,Clinical Genetics and Genomics Laboratory, Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Paul J R Barton
- National Heart & Lung Institute, Imperial College London, London, UK.,Cardiovascular Research Centre at Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Elizabeth Edwards
- National Heart & Lung Institute, Imperial College London, London, UK.,Cardiovascular Research Centre at Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - James S Ware
- National Heart & Lung Institute, Imperial College London, London, UK.,Cardiovascular Research Centre at Royal Brompton and Harefield NHS Foundation Trust, London, UK.,MRC London Institute of Medical Sciences, Imperial College London, London, UK
| | - Stuart A Cook
- National Heart & Lung Institute, Imperial College London, London, UK.,Cardiovascular Research Centre at Royal Brompton and Harefield NHS Foundation Trust, London, UK.,National Heart Centre Singapore, Singapore, Singapore.,Duke-National University of Singapore, Singapore, Singapore
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57
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Paquin A, Ye D, Tester DJ, Kapplinger JD, Zimmermann MT, Ackerman MJ. Even pore-localizing missense variants at highly conserved sites in KCNQ1-encoded K v7.1 channels may have wild-type function and not cause type 1 long QT syndrome: Do not rely solely on the genetic test company's interpretation. HeartRhythm Case Rep 2017; 4:37-44. [PMID: 29876285 PMCID: PMC5988472 DOI: 10.1016/j.hrcr.2017.04.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 03/20/2017] [Accepted: 04/12/2017] [Indexed: 11/17/2022] Open
Affiliation(s)
- Ashley Paquin
- Mayo Clinic School of Medicine, Mayo Clinic, Rochester, Minnesota
| | - Dan Ye
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, Minnesota
- Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota
- Division of Heart Rhythm Services, Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota
| | - David J. Tester
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, Minnesota
- Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota
- Division of Heart Rhythm Services, Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota
| | - Jamie D. Kapplinger
- Mayo Clinic School of Medicine, Mayo Clinic, Rochester, Minnesota
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, Minnesota
| | | | - Michael J. Ackerman
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, Minnesota
- Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota
- Division of Heart Rhythm Services, Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota
- Division of Pediatric Cardiology, Department of Pediatrics, Mayo Clinic, Rochester, Minnesota
- Address reprint requests and correspondence: Dr Michael J. Ackerman, Mayo Clinic Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Guggenheim 501, 200 First St SW, Rochester, MN 55905.
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58
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Clemens DJ, Lentino AR, Kapplinger JD, Ye D, Zhou W, Tester DJ, Ackerman MJ. Using the genome aggregation database, computational pathogenicity prediction tools, and patch clamp heterologous expression studies to demote previously published long QT syndrome type 1 mutations from pathogenic to benign. Heart Rhythm 2017; 15:555-561. [PMID: 29197658 DOI: 10.1016/j.hrthm.2017.11.032] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Indexed: 12/31/2022]
Abstract
BACKGROUND Mutations in the KCNQ1-encoded Kv7.1 potassium channel cause long QT syndrome (LQTS) type 1 (LQT1). It has been suggested that ∼10%-20% of rare LQTS case-derived variants in the literature may have been published erroneously as LQT1-causative mutations and may be "false positives." OBJECTIVE The purpose of this study was to determine which previously published KCNQ1 case variants are likely false positives. METHODS A list of all published, case-derived KCNQ1 missense variants (MVs) was compiled. The occurrence of each MV within the Genome Aggregation Database (gnomAD) was assessed. Eight in silico tools were used to predict each variant's pathogenicity. Case-derived variants that were either (1) too frequently found in gnomAD or (2) absent in gnomAD but predicted to be pathogenic by ≤2 tools were considered potential false positives. Three of these variants were characterized functionally using whole-cell patch clamp technique. RESULTS Overall, there were 244 KCNQ1 case-derived MVs. Of these, 29 (12%) were seen in ≥10 individuals in gnomAD and are demotable. However, 157 of 244 MVs (64%) were absent in gnomAD. Of these, 7 (4%) were predicted to be pathogenic by ≤2 tools, 3 of which we characterized functionally. There was no significant difference in current density between heterozygous KCNQ1-F127L, -P477L, or -L619M variant-containing channels compared to KCNQ1-WT. CONCLUSION This study offers preliminary evidence for the demotion of 32 (13%) previously published LQT1 MVs. Of these, 29 were demoted because of their frequent sighting in gnomAD. Additionally, in silico analysis and in vitro functional studies have facilitated the demotion of 3 ultra-rare MVs (F127L, P477L, L619M).
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Affiliation(s)
- 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
| | - Anne R Lentino
- Mayo Clinic Graduate School of Biomedical Sciences, Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota
| | - Jamie D Kapplinger
- Mayo Clinic Graduate School of Biomedical Sciences, Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota; Mayo Clinic School of Medicine, 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; Department of Cardiovascular Diseases, Division of Heart Rhythm Services, 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; Department of Cardiovascular Diseases, Division of Heart Rhythm Services, 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 Diseases, 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; Mayo Clinic School of Medicine, Mayo Clinic, Rochester, Minnesota; Department of Cardiovascular Diseases, Division of Heart Rhythm Services, Mayo Clinic, Rochester, Minnesota; Department of Pediatrics, Division of Pediatric Cardiology, Mayo Clinic, Rochester, Minnesota.
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59
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Massively Parallel Sequencing of Genes Implicated in Heritable Cardiac Disorders: A Strategy for a Small Diagnostic Laboratory. Med Sci (Basel) 2017; 5:medsci5040022. [PMID: 29099038 PMCID: PMC5753651 DOI: 10.3390/medsci5040022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 09/20/2017] [Accepted: 10/02/2017] [Indexed: 12/16/2022] Open
Abstract
Sudden cardiac death (SCD) in people before the age of 35 years is a devastating event for any family. The causes of SCD in the young can be broadly divided into two groups: heritable cardiac disorders that affect the heart structure (cardiomyopathies) and primary electrical disorders (cardiac ion channelopathies). Genetic testing is vital as those suffering from cardiac ion channelopathies have structurally normal hearts, and those with cardiomyopathies may only show subtle abnormalities in the heart and these signs may not be detected during an autopsy. Post-mortem genetic testing of SCD victims is important to identify the underlying genetic cause. This is important as family cascade screening may be undertaken to identify those who may be at risk and provide vital information about risk stratification and clinical management. The development of massively parallel sequencing (MPS) has made it possible for the simultaneous screening of multiple patients for hundreds of genes. In light of this, we opted to develop an MPS approach for SCD analysis that would allow us to screen for mutations in genes implicated in cardiomyopathies and cardiac ion channelopathies. The rationale behind this panel was to limit it to genes carrying the greatest mutation load. If no likely pathogenic gene variant were found then testing could cascade to whole exome/genome sequencing as a gene-discovery exercise. The overarching aim was to design and validate a custom-cardiac panel that satisfies the diagnostic requirements of LabPLUS (Auckland City Hospital, Auckland, NZ) and the guidelines provided by the Royal College of Pathologists of Australasia and the Association for Clinical Genetic Science.
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60
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Repeat genetic testing with targeted capture sequencing in primary arrhythmia syndrome and cardiomyopathy. Eur J Hum Genet 2017; 25:1313-1323. [PMID: 29255176 DOI: 10.1038/s41431-017-0004-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 08/01/2017] [Accepted: 08/04/2017] [Indexed: 11/09/2022] Open
Abstract
In inherited primary arrhythmia syndromes (PAS) and cardiomyopathies (CMP), the yield of genetic testing varies between 20 and 75% in different diseases according to studies performed in the pre next-generation sequencing (NGS) era. It is unknown whether retesting historical negative samples with NGS techniques is worthwhile. Therefore, we assessed the value of NGS-based panel testing in previously genotype negative-phenotype positive probands. We selected 107 patients (47 PAS and 60 CMP) with a clear phenotype who remained genotype negative after genetic analysis of the main genes implicated in their specific phenotype. Targeted sequencing of the coding regions of 71 PAS- and CMP-related genes was performed. Variant interpretation and classification was done according to a cardiology-specific scoring algorithm ('Amsterdam criteria') and the ACMG-AMP criteria. Co-segregation analysis was performed when DNA and clinical data of family members were available. Finally, a genetic diagnosis could be established in 21 patients (20%), 5 PAS (11%) and 16 CMP (27%) patients, respectively. The increased detection rate was due to sequencing of novel genes in 52% of the cases and due to technical failures with the historical analysis in 48%. A total of 118 individuals were informed about their carrier state and either reassured or scheduled for proper follow-up. To conclude, genetic retesting in clinically overt PAS and CMP cases, who were genotype negative with older techniques, resulted in an additional genetic diagnosis in up to 20% of the cases. This clearly supports a policy for genetic retesting with NGS-based panels.
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61
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Therasse D, Sacher F, Petit B, Babuty D, Mabo P, Martins R, Jesel L, Maury P, Pasquie JL, Mansourati J, Dupuis JM, Kyndt F, Thollet A, Guyomarch B, Barc J, Schott JJ, Le Marec H, Redon R, Probst V, Gourraud JB. Sodium-channel blocker challenge in the familial screening of Brugada syndrome: Safety and predictors of positivity. Heart Rhythm 2017; 14:1442-1448. [DOI: 10.1016/j.hrthm.2017.06.031] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Indexed: 10/19/2022]
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62
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Wilde AA, Semsarian C. In search of the holy grail in the channelopathy field: Proving pathogenicity of long QT syndrome–associated variants? Heart Rhythm 2017; 14:1180-1181. [DOI: 10.1016/j.hrthm.2017.05.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Indexed: 12/11/2022]
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63
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Genotype-Phenotype Correlation of
SCN5A
Mutation for the Clinical and Electrocardiographic Characteristics of Probands With Brugada Syndrome. Circulation 2017; 135:2255-2270. [DOI: 10.1161/circulationaha.117.027983] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 03/13/2017] [Indexed: 01/27/2023]
Abstract
Background:
The genotype-phenotype correlation of
SCN5A
mutations as a predictor of cardiac events in Brugada syndrome remains controversial. We aimed to establish a registry limited to probands, with a long follow-up period, so that the genotype-phenotype correlation of
SCN5A
mutations in Brugada syndrome can be examined without patient selection bias.
Methods:
This multicenter registry enrolled 415 probands (n=403; men, 97%; age, 46±14 years) diagnosed with Brugada syndrome whose
SCN5A
gene was analyzed for mutations.
Results:
During a mean follow-up period of 72 months, the overall cardiac event rate was 2.5%/y. In comparison with probands without mutations (
SCN5A
(–), n=355), probands with
SCN5A
mutations (
SCN5A
(+), n=60) experienced their first cardiac event at a younger age (34 versus 42 years,
P
=0.013), had a higher positive rate of late potentials (89% versus 73%,
P
=0.016), exhibited longer P-wave, PQ, and QRS durations, and had a higher rate of cardiac events (
P
=0.017 by log-rank). Multivariate analysis indicated that only
SCN5A
mutation and history of aborted cardiac arrest were significant predictors of cardiac events (
SCN5A
(+) versus
SCN5A
(–): hazard ratio, 2.0 and
P
=0.045; history of aborted cardiac arrest versus no such history: hazard ratio, 6.5 and
P
<0.001).
Conclusions:
Brugada syndrome patients with
SCN5A
mutations exhibit more conduction abnormalities on ECG and have higher risk for cardiac events.
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64
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Hata Y, Kinoshita K, Nishida N. An Autopsy Case of Sudden Unexpected Death of a Young Adult in a Hot Bath: Molecular Analysis Using Next-Generation DNA Sequencing. CLINICAL MEDICINE INSIGHTS-CASE REPORTS 2017; 10:1179547617702884. [PMID: 28469501 PMCID: PMC5398417 DOI: 10.1177/1179547617702884] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 02/11/2017] [Indexed: 11/17/2022]
Abstract
We report a case of sudden unexpected death of a young woman who was found in a bathtub of hot water. The autopsy concluded that all possible causes of sudden loss of consciousness, except cardiac origin, could be excluded. However, the heart did not show any obvious pathological changes. We used next-generation DNA sequencing (NGS) to examine 73 genes and detected 3 rare, potentially pathogenic variants with minor allele frequencies ⩽1.0%. The pathogenicity of these variants was evaluated using 8 in silico predictive algorithms, and SCN5A_p.Gly289Ser, CACNB2_p.Ser502Leu, and MYH11_p.Lys1573Glu were detected as possible pathogenic variants. Inherited heart disease is a likely cause of sudden unexpected deaths of young people in hot baths, even before the clinical manifestation of the disease. In the future, molecular analysis by NGS may help to predict young to early middle-aged people who could be at risk of sudden arrhythmogenic fatality in hot baths.
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Affiliation(s)
- Yukiko Hata
- Department of Legal Medicine, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Koshi Kinoshita
- Department of Legal Medicine, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Naoki Nishida
- Department of Legal Medicine, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
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Antzelevitch C, Yan GX, Ackerman MJ, Borggrefe M, Corrado D, Guo J, Gussak I, Hasdemir C, Horie M, Huikuri H, Ma C, Morita H, Nam GB, Sacher F, Shimizu W, Viskin S, Wilde AA. J-Wave syndromes expert consensus conference report: Emerging concepts and gaps in knowledge. Europace 2017; 19:665-694. [PMID: 28431071 PMCID: PMC5834028 DOI: 10.1093/europace/euw235] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Affiliation(s)
| | - Gan-Xin Yan
- Lankenau Medical Center, Wynnewood, Pennsylvania
| | - Michael J. Ackerman
- Departments of Cardiovascular Diseases, Pediatrics, and Molecular Pharmacology & Experimental Therapeutics, Divisions of Heart Rhythm Services and Pediatric Cardiology, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester,Minnesota
| | - Martin Borggrefe
- 1st Department of Medicine–Cardiology, University Medical Centre Mannheim, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Mannheim, Germany
| | - Domenico Corrado
- Department of Cardiac, Thoracic and Vascular Sciences, University of Padua Medical School, Padua, Italy
| | - Jihong Guo
- Division of Cardiology, Peking University of People's Hospital, Beijing, China
| | - Ihor Gussak
- Rutgers University, New Brunswick, New Jersey
| | - Can Hasdemir
- Department of Cardiology, Ege University School of Medicine, Izmir, Turkey
| | - Minoru Horie
- Shiga University of Medical Sciences, Ohtsu, Shiga, Japan
| | - Heikki Huikuri
- Research Unit of Internal Medicine, Medical Research Center, Oulu University Hospital, and University of Oulu, Oulu, Finland
| | - Changsheng Ma
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, National Clinical Research Center for Cardiovascular Diseases, Beijing, China
| | - Hiroshi Morita
- Department of Cardiovascular Therapeutics, Okayama University Graduate School of Medicine, Okayama, Japan
| | - Gi-Byoung Nam
- Heart Institute, Asan Medical Center, and Department of Internal Medicine, University of Ulsan College of Medicine Seoul, Seoul, Korea
| | - Frederic Sacher
- Bordeaux University Hospital, LIRYC Institute/INSERM 1045, Bordeaux, France
| | - Wataru Shimizu
- Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan
| | - Sami Viskin
- Tel-Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Arthur A.M. Wilde
- Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, University of Amsterdam, the Netherlands and Princess Al-Jawhara Al-Brahim Centre of Excellence in Research of Hereditary Disorders, Jeddah, Kingdom of Saudi Arabia
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66
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Giudicessi JR, Kullo IJ, Ackerman MJ. Precision Cardiovascular Medicine: State of Genetic Testing. Mayo Clin Proc 2017; 92:642-662. [PMID: 28385198 PMCID: PMC6364981 DOI: 10.1016/j.mayocp.2017.01.015] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 12/23/2016] [Accepted: 01/30/2017] [Indexed: 01/11/2023]
Abstract
In the 15 years following the release of the first complete human genome sequences, our understanding of rare and common genetic variation as determinants of cardiovascular disease susceptibility, prognosis, and therapeutic response has grown exponentially. As such, the use of genomics to enhance the care of patients with cardiovascular diseases has garnered increased attention from clinicians, researchers, and regulatory agencies eager to realize the promise of precision genomic medicine. However, owing to a large burden of "complex" common diseases, emphasis on evidence-based practice, and a degree of unfamiliarity/discomfort with the language of genomic medicine, the development and implementation of genomics-guided approaches designed to further individualize the clinical management of a variety of cardiovascular disorders remains a challenge. In this review, we detail a practical approach to genetic testing initiation and interpretation as well as review the current state of cardiovascular genetic and pharmacogenomic testing in the context of relevant society and regulatory agency recommendations/guidelines.
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Affiliation(s)
- John R Giudicessi
- Department of Internal Medicine, Internal Medicine Residency Program, Clinician-Investigator Training Program, Mayo Clinic, Rochester, MN
| | - Iftikhar J Kullo
- Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN; Gonda Vascular Center, Mayo Clinic, Rochester, MN.
| | - Michael J Ackerman
- Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN; Division of Heart Rhythm Services, Mayo Clinic, Rochester, MN; Department of Pediatric and Adolescent Medicine, Division of Pediatric Cardiology, Mayo Clinic, Rochester, MN; Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN.
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67
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Yan H, Wang C, Marx SO, Pitt GS. Calmodulin limits pathogenic Na+ channel persistent current. J Gen Physiol 2017; 149:277-293. [PMID: 28087622 PMCID: PMC5299624 DOI: 10.1085/jgp.201611721] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 12/13/2016] [Accepted: 12/19/2016] [Indexed: 01/29/2023] Open
Abstract
The molecular mechanisms controlling “persistent” current through voltage-gated Na+ channels are poorly understood. Yan et al. show that apocalmodulin binding to the intracellular C-terminal domain limits persistent Na+ flux and accelerates inactivation across the voltage-gated Na+ channel family. Increased “persistent” current, caused by delayed inactivation, through voltage-gated Na+ (NaV) channels leads to cardiac arrhythmias or epilepsy. The underlying molecular contributors to these inactivation defects are poorly understood. Here, we show that calmodulin (CaM) binding to multiple sites within NaV channel intracellular C-terminal domains (CTDs) limits persistent Na+ current and accelerates inactivation across the NaV family. Arrhythmia or epilepsy mutations located in NaV1.5 or NaV1.2 channel CTDs, respectively, reduce CaM binding either directly or by interfering with CTD–CTD interchannel interactions. Boosting the availability of CaM, thus shifting its binding equilibrium, restores wild-type (WT)–like inactivation in mutant NaV1.5 and NaV1.2 channels and likewise diminishes the comparatively large persistent Na+ current through WT NaV1.6, whose CTD displays relatively low CaM affinity. In cerebellar Purkinje neurons, in which NaV1.6 promotes a large physiological persistent Na+ current, increased CaM diminishes the persistent Na+ current, suggesting that the endogenous, comparatively weak affinity of NaV1.6 for apoCaM is important for physiological persistent current.
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Affiliation(s)
- Haidun Yan
- Ion Channel Research Unit, Duke University Medical Center, Durham, NC 27710
| | - Chaojian Wang
- Ion Channel Research Unit, Duke University Medical Center, Durham, NC 27710
| | - Steven O Marx
- Division of Cardiology, Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032.,Department of Pharmacology, College of Physicians and Surgeons, Columbia University, New York, NY 10032
| | - Geoffrey S Pitt
- Ion Channel Research Unit, Duke University Medical Center, Durham, NC 27710
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68
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Aromolaran AS, Chahine M, Boutjdir M. Regulation of Cardiac Voltage-Gated Sodium Channel by Kinases: Roles of Protein Kinases A and C. Handb Exp Pharmacol 2017; 246:161-184. [PMID: 29032483 DOI: 10.1007/164_2017_53] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
In the heart, voltage-gated sodium (Nav) channel (Nav1.5) is defined by its pore-forming α-subunit and its auxiliary β-subunits, both of which are important for its critical contribution to the initiation and maintenance of the cardiac action potential (AP) that underlie normal heart rhythm. The physiological relevance of Nav1.5 is further marked by the fact that inherited or congenital mutations in Nav1.5 channel gene SCN5A lead to altered functional expression (including expression, trafficking, and current density), and are generally manifested in the form of distinct cardiac arrhythmic events, epilepsy, neuropathic pain, migraine, and neuromuscular disorders. However, despite significant advances in defining the pathophysiology of Nav1.5, the molecular mechanisms that underlie its regulation and contribution to cardiac disorders are poorly understood. It is rapidly becoming evident that the functional expression (localization, trafficking and gating) of Nav1.5 may be under modulation by post-translational modifications that are associated with phosphorylation. We review here the molecular basis of cardiac Na channel regulation by kinases (PKA and PKC) and the resulting functional consequences. Specifically, we discuss: (1) recent literature on the structural, molecular, and functional properties of cardiac Nav1.5 channels; (2) how these properties may be altered by phosphorylation in disease states underlain by congenital mutations in Nav1.5 channel and/or subunits such as long QT and Brugada syndromes. Our expectation is that understanding the roles of these distinct and complex phosphorylation processes on the functional expression of Nav1.5 is likely to provide crucial mechanistic insights into Na channel associated arrhythmogenic events and will facilitate the development of novel therapeutic strategies.
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Affiliation(s)
- Ademuyiwa S Aromolaran
- Cardiovascular Research Program, VA New York Harbor Healthcare System, Brooklyn, NY, USA
- Departments of Medicine, Cell Biology and Pharmacology, State University of New York Downstate Medical Center, Brooklyn, NY, USA
| | - Mohamed Chahine
- CERVO Brain Research Center, Institut Universitaire en Santé Mentale de Québec, Quebec City, QC, Canada
- Department of Medicine, Université Laval, Quebec City, QC, Canada
| | - Mohamed Boutjdir
- Cardiovascular Research Program, VA New York Harbor Healthcare System, Brooklyn, NY, USA.
- Departments of Medicine, Cell Biology and Pharmacology, State University of New York Downstate Medical Center, Brooklyn, NY, USA.
- Department of Medicine, New York University School of Medicine, New York, NY, USA.
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69
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Antzelevitch C, Yan GX, Ackerman MJ, Borggrefe M, Corrado D, Guo J, Gussak I, Hasdemir C, Horie M, Huikuri H, Ma C, Morita H, Nam GB, Sacher F, Shimizu W, Viskin S, Wilde AA. J-Wave syndromes expert consensus conference report: Emerging concepts and gaps in knowledge. J Arrhythm 2016; 32:315-339. [PMID: 27761155 PMCID: PMC5063270 DOI: 10.1016/j.joa.2016.07.002] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Affiliation(s)
| | - Gan-Xin Yan
- Lankenau Medical Center, Wynnewood, PA, United States
| | - Michael J. Ackerman
- Departments of Cardiovascular Diseases, Pediatrics, and Molecular Pharmacology & Experimental Therapeutics, Divisions of Heart Rhythm Services and Pediatric Cardiology, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN, United States
| | - Martin Borggrefe
- 1st Department of Medicine–Cardiology, University Medical Centre Mannheim, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Mannheim, Germany
| | - Domenico Corrado
- Department of Cardiac, Thoracic and Vascular Sciences, University of Padua Medical School, Padua, Italy
| | - Jihong Guo
- Division of Cardiology, Peking University of People׳s Hospital, Beijing, China
| | - Ihor Gussak
- Rutgers University, New Brunswick, NJ, United States
| | - Can Hasdemir
- Department of Cardiology, Ege University School of Medicine, Izmir, Turkey
| | - Minoru Horie
- Shiga University of Medical Sciences, Ohtsu, Shiga, Japan
| | - Heikki Huikuri
- Research Unit of Internal Medicine, Medical Research Center, Oulu University Hospital, and University of Oulu, Oulu, Finland
| | - Changsheng Ma
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, National Clinical Research Center for Cardiovascular Diseases, Beijing, China
| | - Hiroshi Morita
- Department of Cardiovascular Therapeutics, Okayama University Graduate School of Medicine, Okayama, Japan
| | - Gi-Byoung Nam
- Heart Institute, Asian Medical Center, and Department of Internal Medicine, University of Ulsan College of Medicine Seoul, Seoul, South Korea
| | - Frederic Sacher
- Bordeaux University Hospital, LIRYC Institute/INSERM 1045, Bordeaux, France
| | - Wataru Shimizu
- Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan
| | - Sami Viskin
- Tel-Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Arthur A.M. Wilde
- Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, University of Amsterdam, The Netherlands
- Jawhara Al-Brahim Centre of Excellence in Research of Hereditary Disorders, Jeddah, Saudi Arabia
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70
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Antzelevitch C, Yan GX, Ackerman MJ, Borggrefe M, Corrado D, Guo J, Gussak I, Hasdemir C, Horie M, Huikuri H, Ma C, Morita H, Nam GB, Sacher F, Shimizu W, Viskin S, Wilde AAM. J-Wave syndromes expert consensus conference report: Emerging concepts and gaps in knowledge. Heart Rhythm 2016; 13:e295-324. [PMID: 27423412 PMCID: PMC5035208 DOI: 10.1016/j.hrthm.2016.05.024] [Citation(s) in RCA: 222] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Indexed: 12/16/2022]
Affiliation(s)
| | - Gan-Xin Yan
- Lankenau Medical Center, Wynnewood, Pennsylvania
| | - Michael J Ackerman
- Departments of Cardiovascular Diseases, Pediatrics, and Molecular Pharmacology & Experimental Therapeutics, Divisions of Heart Rhythm Services and Pediatric Cardiology, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester,Minnesota
| | - Martin Borggrefe
- 1st Department of Medicine-Cardiology, University Medical Centre Mannheim, and DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Mannheim, Germany
| | - Domenico Corrado
- Department of Cardiac, Thoracic and Vascular Sciences, University of Padua Medical School, Padua, Italy
| | - Jihong Guo
- Division of Cardiology, Peking University of People's Hospital, Beijing, China
| | - Ihor Gussak
- Rutgers University, New Brunswick, New Jersey
| | - Can Hasdemir
- Department of Cardiology, Ege University School of Medicine, Izmir, Turkey
| | - Minoru Horie
- Shiga University of Medical Sciences, Ohtsu, Shiga, Japan
| | - Heikki Huikuri
- Research Unit of Internal Medicine, Medical Research Center, Oulu University Hospital, and University of Oulu, Oulu, Finland
| | - Changsheng Ma
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, National Clinical Research Center for Cardiovascular Diseases, Beijing, China
| | - Hiroshi Morita
- Department of Cardiovascular Therapeutics, Okayama University Graduate School of Medicine, Okayama, Japan
| | - Gi-Byoung Nam
- Heart Institute, Asan Medical Center, and Department of Internal Medicine, University of Ulsan College of Medicine Seoul, Seoul, Korea
| | - Frederic Sacher
- Bordeaux University Hospital, LIRYC Institute/INSERM 1045, Bordeaux, France
| | - Wataru Shimizu
- Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan
| | - Sami Viskin
- Tel-Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Arthur A M Wilde
- Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, University of Amsterdam, the Netherlands and Princess Al-Jawhara Al-Brahim Centre of Excellence in Research of Hereditary Disorders, Jeddah, Kingdom of Saudi Arabia
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71
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Hata Y, Yoshida K, Kinoshita K, Nishida N. Epilepsy-related sudden unexpected death: targeted molecular analysis of inherited heart disease genes using next-generation DNA sequencing. Brain Pathol 2016; 27:292-304. [PMID: 27135274 DOI: 10.1111/bpa.12390] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 04/11/2016] [Accepted: 04/21/2016] [Indexed: 11/27/2022] Open
Abstract
Inherited heart disease causing electric instability in the heart has been suggested to be a risk factor for sudden unexpected death in epilepsy (SUDEP). The purpose of this study was to reveal the correlation between epilepsy-related sudden unexpected death (SUD) and inherited heart disease. Twelve epilepsy-related SUD cases (seven males and five females, aged 11-78 years) were examined. Nine cases fulfilled the criteria of SUDEP, and three cases died by drowning. In addition to examining three major epilepsy-related genes, we used next-generation sequencing (NGS) to examine 73 inherited heart disease-related genes. We detected both known pathogenic variants and rare variants with minor allele frequencies of <0.5%. The pathogenicity of these variants was evaluated and graded by eight in silico predictive algorithms. Six known and six potential rare variants were detected. Among these, three known variants of LDB3, DSC2 and KCNE1 and three potential rare variants of MYH6, DSP and DSG2 were predicted by in silico analysis as possibly highly pathogenic in three of the nine SUDEP cases. Two of three cases with desmosome-related variants showed mild but possible significant right ventricular dysplasia-like pathology. A case with LDB3 and MYH6 variants showed hypertrabeculation of the left ventricle and severe fibrosis of the cardiac conduction system. In the three drowning death cases, one case with mild prolonged QT interval had two variants in ANK2. This study shows that inherited heart disease may be a significant risk factor for SUD in some epilepsy cases, even if pathological findings of the heart had not progressed to an advanced stage of the disease. A combination of detailed pathological examination of the heart and gene analysis using NGS may be useful for evaluating arrhythmogenic potential of epilepsy-related SUD.
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Affiliation(s)
- Yukiko Hata
- Department of Legal Medicine, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Koji Yoshida
- Department of Neurology, Toyama University Hospital, Toyama, Japan
| | - Koshi Kinoshita
- Department of Legal Medicine, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Naoki Nishida
- Department of Legal Medicine, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
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Abstract
Approximately 80 genes in the human genome code for pore-forming subunits of potassium (K(+)) channels. Rare variants (mutations) in K(+) channel-encoding genes may cause heritable arrhythmia syndromes. Not all rare variants in K(+) channel-encoding genes are necessarily disease-causing mutations. Common variants in K(+) channel-encoding genes are increasingly recognized as modifiers of phenotype in heritable arrhythmia syndromes and in the general population. Although difficult, distinguishing pathogenic variants from benign variants is of utmost importance to avoid false designations of genetic variants as disease-causing mutations.
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Affiliation(s)
- Ahmad S Amin
- Department of Clinical and Experimental Cardiology, Heart Centre, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam 1105 AZ, The Netherlands
| | - Arthur A M Wilde
- Department of Clinical and Experimental Cardiology, Heart Centre, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam 1105 AZ, The Netherlands; King Abdulaziz University, Princess Al-Jawhara Al-Brahim Centre of Excellence in Research of Hereditary Disorders, PO Box 80200, Jeddah 21589, Kingdom of Saudi Arabia.
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73
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Lahrouchi N, Behr ER, Bezzina CR. Next-Generation Sequencing in Post-mortem Genetic Testing of Young Sudden Cardiac Death Cases. Front Cardiovasc Med 2016; 3:13. [PMID: 27303672 PMCID: PMC4885007 DOI: 10.3389/fcvm.2016.00013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 05/02/2016] [Indexed: 12/19/2022] Open
Abstract
Sudden cardiac death (SCD) in the young (<40 years) occurs in the setting of a variety of rare inherited cardiac disorders and is a disastrous event for family members. Establishing the cause of SCD is important as it permits the pre-symptomatic identification of relatives at risk of SCD. Sudden arrhythmic death syndrome (SADS) is defined as SCD in the setting of negative autopsy findings and toxicological analysis. In such cases, reaching a diagnosis is even more challenging and post-mortem genetic testing can crucially contribute to the identification of the underlying cause of death. In this review, we will discuss the current achievements of “the molecular autopsy” in young SADS cases and provide an overview of key challenges in assessing pathogenicity (i.e., causality) of genetic variants identified through next-generation sequencing.
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Affiliation(s)
- Najim Lahrouchi
- Department of Clinical and Experimental Cardiology, Heart Center, AMC , Amsterdam , Netherlands
| | - Elijah R Behr
- Cardiology Clinical Academic Group, St George's University of London , London , UK
| | - Connie R Bezzina
- Department of Clinical and Experimental Cardiology, Heart Center, AMC , Amsterdam , Netherlands
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74
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Abstract
Ventricular repolarization is a complex electrical phenomenon which represents a crucial stage in electrical cardiac activity. It is expressed on the surface electrocardiogram by the interval between the start of the QRS complex and the end of the T wave or U wave (QT). Several physiological, pathological and iatrogenic factors can influence ventricular repolarization. It has been demonstrated that small perturbations in this process can be a potential trigger of malignant arrhythmias, therefore the analysis of ventricular repolarization represents an interesting tool to implement risk stratification of arrhythmic events in different clinical settings. The aim of this review is to critically revise the traditional methods of static analysis of ventricular repolarization as well as those for dynamic evaluation, their prognostic significance and the possible application in daily clinical practice.
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75
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The role of genetic testing in unexplained sudden death. Transl Res 2016; 168:59-73. [PMID: 26143861 DOI: 10.1016/j.trsl.2015.06.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2015] [Revised: 06/08/2015] [Accepted: 06/11/2015] [Indexed: 12/19/2022]
Abstract
Most sudden deaths are because of a cardiac etiology and are termed sudden cardiac death (SCD). In younger individuals coronary artery disease is less prevalent and cardiac genetic disorders are more common. If sudden death is unexplained despite an appropriate autopsy and toxicologic assessment the term sudden arrhythmic death syndrome (SADS) may be used. This is an umbrella term and common underlying etiologies are primary arrhythmia syndromes with a familial basis such as Brugada syndrome, long QT syndrome, and subtle forms of cardiomyopathy. The first clinical presentation of these conditions is often SCD, which makes identification, screening, and risk stratification crucial to avert further deaths. This review will focus on genetic testing in the context of family screening. It will address the role of the "molecular autopsy" alongside current postmortem practices in the evaluation of SADS deaths. We describe the current data underlying genetic testing in these conditions, explore the potential for next-generation sequencing, and discuss the inherent diagnostic problems in determination of pathogenicity.
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76
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Chapter Five - Ubiquitination of Ion Channels and Transporters. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2016; 141:161-223. [DOI: 10.1016/bs.pmbts.2016.02.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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77
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Veerman CC, Wilde AAM, Lodder EM. The cardiac sodium channel gene SCN5A and its gene product NaV1.5: Role in physiology and pathophysiology. Gene 2015; 573:177-87. [PMID: 26361848 DOI: 10.1016/j.gene.2015.08.062] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Revised: 07/31/2015] [Accepted: 08/27/2015] [Indexed: 12/18/2022]
Abstract
The gene SCN5A encodes the main cardiac sodium channel NaV1.5. This channel predominates the cardiac sodium current, INa, which underlies the fast upstroke of the cardiac action potential. As such, it plays a crucial role in cardiac electrophysiology. Over the last 60years a tremendous amount of knowledge regarding its function at the electrophysiological and molecular level has been acquired. Furthermore, genetic studies have shown that mutations in SCN5A are associated with multiple cardiac diseases (e.g. Brugada syndrome, Long QT syndrome, conduction disease and cardiomyopathy), while genetic variation in the general population has been associated with differences in cardiac conduction and risk of arrhythmia through genome wide association studies. In this review we aim to give an overview of the current knowledge (and the gaps therein) on SCN5A and NaV1.5.
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Affiliation(s)
- Christiaan C Veerman
- Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands
| | - Arthur A M Wilde
- Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands.
| | - Elisabeth M Lodder
- Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands.
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78
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Brion M, Sobrino B, Martinez M, Blanco-Verea A, Carracedo A. Massive parallel sequencing applied to the molecular autopsy in sudden cardiac death in the young. Forensic Sci Int Genet 2015; 18:160-70. [PMID: 26243589 DOI: 10.1016/j.fsigen.2015.07.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 07/06/2015] [Accepted: 07/13/2015] [Indexed: 12/18/2022]
Abstract
Sudden cardiac death in the young is a very traumatic event that occurs often in apparently healthy individuals without an explainable cause of death after a comprehensive medico-legal investigation. Knowledge about the pathologies with a risk of sudden death is increasingly showing a greater underlying genetic heterogeneity, which provides one of the main handicaps for molecular autopsy. On the other hand the enormous technological advances in sequencing technologies, allow us to analyse as many genes as we want at a cost increasingly reduced. The sum of these two factors (increased knowledge of genetics and available technologies) allow us to make an individualized study of the causes of sudden cardiac death in young adults, through massive sequencing of all potential genes involved in the process. We define this approach as massive genomic autopsy, and with this review we will try to explain the possible scenarios and methods available for its implementation.
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Affiliation(s)
- M Brion
- Xenética de Enfermidades Cardiovasculares, Instituto de Investigación Sanitaria de Santiago, Red de Investigación Cardiovascular (RIC), Santiago De Compostela, Spain; Grupo de Medicina Xenómica, University of Santiago de Compostela. Fundación Pública Galega de Medicina Xenómica, SERGAS, Santiago de Compostela, Spain.
| | - B Sobrino
- Grupo de Medicina Xenómica, University of Santiago de Compostela. Fundación Pública Galega de Medicina Xenómica, SERGAS, Santiago de Compostela, Spain
| | - M Martinez
- Xenética de Enfermidades Cardiovasculares, Instituto de Investigación Sanitaria de Santiago, Red de Investigación Cardiovascular (RIC), Santiago De Compostela, Spain; Grupo de Medicina Xenómica, University of Santiago de Compostela. Fundación Pública Galega de Medicina Xenómica, SERGAS, Santiago de Compostela, Spain
| | - A Blanco-Verea
- Xenética de Enfermidades Cardiovasculares, Instituto de Investigación Sanitaria de Santiago, Red de Investigación Cardiovascular (RIC), Santiago De Compostela, Spain; Grupo de Medicina Xenómica, University of Santiago de Compostela. Fundación Pública Galega de Medicina Xenómica, SERGAS, Santiago de Compostela, Spain
| | - A Carracedo
- Grupo de Medicina Xenómica, University of Santiago de Compostela. Fundación Pública Galega de Medicina Xenómica, SERGAS, Santiago de Compostela, Spain; Centro de Investigación Biomédica en Red de Enfermedades Rara (CIBERER), Spain; Center of Excellence in Genomic Medicine, King Abdulaziz University, Jeddah, KSA, Saudi Arabia
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