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Greiner AM, Mehdi H, Cevan C, Gutmann R, London B. The role of GPD1L, a sodium channel interacting gene, in the pathogenesis of Brugada Syndrome. Front Med (Lausanne) 2024; 10:1159586. [PMID: 38962240 PMCID: PMC11221213 DOI: 10.3389/fmed.2023.1159586] [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: 02/06/2023] [Accepted: 03/06/2023] [Indexed: 07/05/2024] Open
Abstract
Background Brugada Syndrome (BrS) is an inherited arrhythmia syndrome in which mutations in the cardiac sodium channel SCN5A (NaV1.5) account for approximately 20% of cases. Mutations in sodium channel-modifying genes may account for additional BrS cases, though BrS may be polygenic given common SNPs associated with BrS have been identified. Recent analysis, however, has suggested that SCN5A should be regarded as the sole monogenic cause of BrS. Objective We sought to re-assess the genetic underpinnings of BrS in a large mutligenerational family with a putative mutation in GPD1L that affects surface membrane expression of NaV1.5 in vitro. Methods Fine linkage mapping was performed in the family using the Illumina Global Screening Array. Whole exome sequencing of the proband was performed to identify rare variants and mutations, and Sanger sequencing was used to assay previously-reported risk single nucleotide polymorphsims (SNPs) for BrS. Results Linkage analysis decreased the size of the previously-reported microsatellite linkage region to approximately 3 Mb. GPD1L-A280V was the only coding non-synonymous variation present at less than 1% allele frequency in the proband within the linkage region. No rare non-synonymous variants were present outside the linkage area in affected individuals in genes associated with BrS. Risk SNPs known to predispose to BrS were overrepresented in affected members of the family. Conclusion Together, our data suggest GPD1L-A280V remains the most likely cause of BrS in this large multigenerational family. While care should be taken in interpreting variant pathogenicity given the genetic uncertainty of BrS, our data support inclusion of other putative BrS genes in clinical genetic panels.
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Affiliation(s)
- Alexander M. Greiner
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, United States
- Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, United States
- University of Iowa Interdisciplinary Graduate Program in Genetics, Interdisciplinary Graduate Program in Genetics, University of Iowa, Iowa City, IA, United States
| | - Haider Mehdi
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, United States
- Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Chloe Cevan
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Rebecca Gutmann
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Barry London
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, United States
- Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, United States
- University of Iowa Interdisciplinary Graduate Program in Genetics, Interdisciplinary Graduate Program in Genetics, University of Iowa, Iowa City, IA, United States
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Kaufman R, Schupmann W, Timmermans S, Raz A. High risk, mixed reward: Making genetic test results actionable in cardiology. Soc Sci Med 2024; 354:117049. [PMID: 38950492 DOI: 10.1016/j.socscimed.2024.117049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Revised: 05/09/2024] [Accepted: 06/10/2024] [Indexed: 07/03/2024]
Abstract
Professional organizations point to the underutilization of genetic testing in cardiology as a lack of genetic literacy. Yet, few studies have examined the interpretive work required from clinicians to make results clinically actionable. Based on interviews with twenty-nine cardiologists, we find that although genetic testing may provide epistemic closure by substantiating a suspected diagnosis at the molecular level, genetic testing often disrupted cardiologists' diagnostic inferential processes. These epistemic disruptions were not intrinsic to a particular genetic result type (positive, negative, or VUS), but arose from reconciling genetic results with the patient's symptoms and medical and family history. Drawing from the sociology of diagnosis and professional expertise, we examine how cardiologists resolved epistemic disruptions by either sidelining or repairing genetic test results. However, such attempts at making genetic test results actionable for diagnosis may not resolve epistemic disruptions. We argue that rather than clinicians lacking individual literacy, the limited uptake of genetic test results reflects a collective problem of gaps in the genetic knowledge base that leads to medical agnosis, or an inability to make sense of a patient's symptoms uncertainty, rather than diagnosis.
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Affiliation(s)
- Rebecca Kaufman
- Department of Sociology, University of California, Los Angeles, CA, USA
| | - Will Schupmann
- Department of Sociology, University of California, Los Angeles, CA, USA
| | - Stefan Timmermans
- Department of Sociology, University of California, Los Angeles, CA, USA.
| | - Aviad Raz
- Department of Sociology & Anthropology, Ben-Gurion University of the Nagev, Beersheba, Israel
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Leung HT, Kwok SY, Kwong KY, Shih FY, Tsao S, Chung BHY. Prioritize Variant Reclassification in Pediatric Long QT Syndrome-Time to Revisit. Pediatr Cardiol 2024; 45:1023-1035. [PMID: 38565666 DOI: 10.1007/s00246-024-03461-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 02/26/2024] [Indexed: 04/04/2024]
Abstract
Congenital long QT syndrome (LQTS) is an inherited arrhythmia syndrome associated with sudden cardiac death. Accurate interpretation and classification of genetic variants in LQTS patients are crucial for effective management. All patients with LQTS with a positive genetic test over the past 18 years (2002-2020) in our single tertiary pediatric cardiac center were identified. Reevaluation of the reported variants in LQTS genes was conducted using the American College of Genetics and Genomics (ACMG) guideline after refinement by the US ClinGen SVI working group and guideline by Walsh et al. on genetic variant reclassification, under multidisciplinary input. Among the 59 variants identified. 18 variants (30.5%) were reclassified. A significant larger portion of variants of unknown significance (VUS) were reclassified compared to likely pathogenic (LP)/pathogenic (P) variants (57.7% vs 9.1%, p < 0.001). The rate of reclassification was significantly higher in the limited/disputed evidence group compared to the definite/moderate evidence group (p = 0.0006). All LP/P variants were downgraded in the limited/disputed evidence group (p = 0.0057). VUS upgrades are associated with VUS located in genes within the definite/moderate evidence group (p = 0.0403) and with VUS present in patients exhibiting higher corrected QT intervals (QTc) (p = 0.0445). A significant number of pediatric LQTS variants were reclassified, particularly for VUS. The strength of the gene-disease association of the genes influences the reclassification performance. The study provides important insights and guidance for pediatricians to seek for reclassification of "outdated variants" in order to facilitate contemporary precision medicine.
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Affiliation(s)
- Hei-To Leung
- Department of Paediatrics & Adolescent Medicine, Hong Kong Children's Hospital, 1 Shing Cheong Rd, Ngau Tau Kok, Hong Kong SAR, China
| | - Sit-Yee Kwok
- Department of Paediatrics & Adolescent Medicine, Hong Kong Children's Hospital, 1 Shing Cheong Rd, Ngau Tau Kok, Hong Kong SAR, China.
| | - Ka-Yee Kwong
- Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR, China
| | - Fong-Ying Shih
- Clinical Genetics Service Unit, Hong Kong Children's Hospital, Kowloon Bay, Hong Kong SAR, China
| | - Sabrina Tsao
- Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR, China
| | - Brian Hon-Yin Chung
- Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR, China
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Ackerman MJ, Giudicessi JR. Continuous variant reclassification: An effective tool in the ongoing quest to escape genetic purgatory. Heart Rhythm 2024; 21:911-912. [PMID: 38307312 DOI: 10.1016/j.hrthm.2024.01.050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 01/26/2024] [Indexed: 02/04/2024]
Affiliation(s)
- Michael J Ackerman
- Department of Cardiovascular Medicine, Windland Smith Rice Genetic Heart Rhythm Clinic, Mayo Clinic, Rochester, Minnesota; Department of Molecular Pharmacology and 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
| | - John R Giudicessi
- Department of Cardiovascular Medicine, Windland Smith Rice Genetic Heart Rhythm Clinic, Mayo Clinic, Rochester, Minnesota; Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota.
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Weizman O, Gandjbakhch E, Magnin-Poull I, Proukhnitzky J, Bordet C, Palmyre A, Bloch A, Fressart V, Charron P. Molecular genetic screening after non-ischaemic sudden cardiac arrest and no overt cardiomyopathy in real life: A major tool for the aetiological diagnostic work-up. Arch Cardiovasc Dis 2024; 117:382-391. [PMID: 38670870 DOI: 10.1016/j.acvd.2024.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 02/22/2024] [Accepted: 02/26/2024] [Indexed: 04/28/2024]
Abstract
BACKGROUND With the development of advanced sequencing techniques, genetic testing has emerged as a valuable tool for the work-up of non-ischaemic sudden cardiac arrest (SCA). AIMS To evaluate the effectiveness of genetic testing in patients with unexplained SCA, according to clinical phenotype. METHODS All patients who underwent molecular genetic testing for non-ischaemic SCA with no left ventricular cardiomyopathy between 2012 and 2021 in two French university hospitals were included. RESULTS Of 66 patients (mean age 36.7±11.9years, 54.5% men), 21 (31.8%; 95% confidence interval 22.4-45.3%) carried a genetic variant: eight (12.1%) had a pathogenic or likely pathogenic (P/LP) variant and 13 (19.7%) had a variant of uncertain significance (VUS). Among 37 patients (56.1%) with no phenotypic clues, genetic testing identified a P/LP variant in five (13.5%), mainly in RYR2 (n=3) and SCN5A (n=2), and a VUS in nine (24.3%). None of the nine patients with phenotypic evidence of channelopathies had P/LP variants, but two had VUS in RYR2 and NKX2.5. Among the 20 patients with suspected arrhythmogenic cardiomyopathy, three P/LP variants (15.0%) and two VUS (10.0%) were found in DSC2, PKP2, SCN5A and DSG2, TRPM4, respectively. Genetic testing was performed sooner after cardiac arrest (P<0.001) and results were obtained more rapidly (P=0.02) after versus before 2016. CONCLUSION This study highlights the utility of molecular genetic testing with a genetic variant of interest identified in one-third of patients with unexplained SCA. Genetic testing was beneficial even in patients without phenotypic clues, with one-fourth of patients carrying a P/LP variant that could have direct implications.
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Affiliation(s)
- Orianne Weizman
- Cardiology department, Nancy university hospital, Nancy, France; AP-HP, unité de génétique médicale, CHU Ambroise-Paré, 92100 Boulogne-Billancourt, France.
| | - Estelle Gandjbakhch
- AP-HP, cardiology department, Institute of cardiology, Institute for cardiometabolism and nutrition (ICAN), Pitié-Salpêtrière hospital, Paris, France; Sorbonne université, Inserm 1166, Paris, France; AP-HP, département de génétique, Centre de référence des maladies cardiaques héréditaires ou rares, Pitié-Salpêtrière hospital, Paris, France
| | | | - Julie Proukhnitzky
- AP-HP, cardiology department, Institute of cardiology, Institute for cardiometabolism and nutrition (ICAN), Pitié-Salpêtrière hospital, Paris, France; Sorbonne université, Inserm 1166, Paris, France; AP-HP, département de génétique, Centre de référence des maladies cardiaques héréditaires ou rares, Pitié-Salpêtrière hospital, Paris, France
| | - Céline Bordet
- AP-HP, département de génétique, Centre de référence des maladies cardiaques héréditaires ou rares, Pitié-Salpêtrière hospital, Paris, France
| | - Aurélien Palmyre
- AP-HP, unité de génétique médicale, CHU Ambroise-Paré, 92100 Boulogne-Billancourt, France
| | - Adrien Bloch
- AP-HP, Biochemistry department, molecular cardiogenetics unit, Pitié-Salpêtrière hospital, Paris, France
| | - Véronique Fressart
- AP-HP, Biochemistry department, molecular cardiogenetics unit, Pitié-Salpêtrière hospital, Paris, France
| | - Philippe Charron
- AP-HP, unité de génétique médicale, CHU Ambroise-Paré, 92100 Boulogne-Billancourt, France; AP-HP, cardiology department, Institute of cardiology, Institute for cardiometabolism and nutrition (ICAN), Pitié-Salpêtrière hospital, Paris, France; Sorbonne université, Inserm 1166, Paris, France; AP-HP, département de génétique, Centre de référence des maladies cardiaques héréditaires ou rares, Pitié-Salpêtrière hospital, Paris, France.
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Beqaj H, Sittenfeld L, Chang A, Miotto M, Dridi H, Willson G, Jorge CM, Li JA, Reiken S, Liu Y, Dai Z, Marks AR. Location of ryanodine receptor type 2 mutation predicts age of onset of sudden death in catecholaminergic polymorphic ventricular tachycardia - A systematic review and meta-analysis of case-based literature. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.03.15.24304349. [PMID: 38559077 PMCID: PMC10980137 DOI: 10.1101/2024.03.15.24304349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Background Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare inherited arrhythmia caused by mutations in the ryanodine receptor type 2 (RyR2). Diagnosis of CPVT often occurs after a major cardiac event, thus posing a severe threat to the patient's health. Methods Publication databases, including PubMed, Scopus, and Embase, were searched for articles on patients with RyR2-CPVT mutations and their associated clinical presentation. Articles were reviewed by two independent reviewers and mutations were analyzed for demographic information, mutation distribution, and therapeutics. The human RyR2 cryo-EM structure was used to model CPVT mutations and predict the diagnosis and outcomes of CPVT patients. Findings We present a database of 1008 CPVT patients from 227 papers. Data analyses revealed that patients most often experienced exercise-induced syncope in their early teenage years but the diagnosis of CPVT took a decade. Mutations located near key regulatory sites in the channel were associated with earlier onset of CPVT symptoms including sudden cardiac death. Interpretation The present study provides a road map for predicting clinical outcomes based on the location of RyR2 mutations in CPVT patients. The study was partially limited by the inconsistency in the depth of information provided in each article, but nevertheless is an important contribution to the understanding of the clinical and molecular basis of CPVT and suggests the need for early diagnosis and creative approaches to disease management. Funding The work was supported by grant NIH R01HL145473, P01 HL164319 R25HL156002, T32 HL120826.
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7
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Agaoglu NB, Unal B, Hayes CP, Walker M, Ng OH, Doganay L, Can ND, Rana HQ, Ghazani AA. Genomic disparity impacts variant classification of cancer susceptibility genes in Turkish breast cancer patients. Cancer Med 2024; 13:e6852. [PMID: 38308423 PMCID: PMC10905328 DOI: 10.1002/cam4.6852] [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: 05/20/2023] [Revised: 11/23/2023] [Accepted: 12/10/2023] [Indexed: 02/04/2024] Open
Abstract
OBJECTIVE Turkish genome is underrepresented in large genomic databases. This study aims to evaluate the effect of allele frequency in the Turkish population in determining the clinical utility of germline findings in breast cancer, including invasive lobular carcinoma (ILC), mixed invasive ductal and lobular carcinoma (IDC-L), and ductal carcinoma (DC). METHODS Two clinic-based cohorts from the Umraniye Research and Training Hospital (URTH) were used in this study: a cohort consisting of 132 women with breast cancer and a non-cancer cohort consisting of 492 participants. The evaluation of the germline landscape was performed by analysis of 27 cancer genes. The frequency and type of variants in the breast cancer cohort were compared to those in the non-cancer cohort to investigate the effect of population genetics. The variant allele frequencies in Turkish Variome and gnomAD were statistically evaluated. RESULTS The genetic analysis identified 121 variants in the breast cancer cohort (actionable = 32, VUS = 89) and 223 variants in the non-cancer cohort (actionable = 25, VUS = 188). The occurrence of 21 variants in both suggested a possible genetic population effect. Evaluation of allele frequency of 121 variants from the breast cancer cohort showed 22% had a significantly higher value in Turkish Variome compared to gnomAD (p < 0.0001, 95% CI) with a mean difference of 60 times (ranging from 1.37-354.4). After adjusting for variant allele frequency using the ancestry-appropriate database, 6.7% (5/75) of VUS was reclassified to likely benign. CONCLUSION To our knowledge, this is the first study of population genetic effects in breast cancer subtypes in Turkish women. Our findings underscore the need for a large genomic database representing Turkish population-specific variants. It further highlights the significance of the ancestry-appropriate population database for accurate variant assessment in clinical settings.
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Affiliation(s)
- Nihat B. Agaoglu
- Department of Medical Genetics, Division of Cancer GeneticsUmraniye Training and Research HospitalIstanbulTurkey
| | - Busra Unal
- Department of Medical Genetics, Division of Cancer GeneticsUmraniye Training and Research HospitalIstanbulTurkey
- Division of GeneticsBrigham and Women's HospitalBostonMassachusettsUSA
| | - Connor P. Hayes
- Division of GeneticsBrigham and Women's HospitalBostonMassachusettsUSA
| | - McKenzie Walker
- Division of GeneticsBrigham and Women's HospitalBostonMassachusettsUSA
| | - Ozden Hatirnaz Ng
- Department of Medical Biology, School of MedicineAcibadem UniversityIstanbulTurkey
| | - Levent Doganay
- Department of Medical Genetics, Division of Cancer GeneticsUmraniye Training and Research HospitalIstanbulTurkey
| | - Nisan D. Can
- Department of Molecular Biology Genetics and BiotechnologyIstanbul Technical UniversityIstanbulTurkey
| | - Huma Q. Rana
- Division of Cancer Genetics and PreventionDana‐Farber Cancer InstituteBostonMassachusettsUSA
- Department of MedicineBrigham and Women's HospitalBostonMassachusettsUSA
- Harvard Medical SchoolBostonMassachusettsUSA
| | - Arezou A. Ghazani
- Division of GeneticsBrigham and Women's HospitalBostonMassachusettsUSA
- Department of MedicineBrigham and Women's HospitalBostonMassachusettsUSA
- Harvard Medical SchoolBostonMassachusettsUSA
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8
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Ma JG, O’Neill MJ, Richardson E, Thomson KL, Ingles J, Muhammad A, Solus JF, Davogustto G, Anderson KC, Benjamin Shoemaker M, Stergachis AB, Floyd BJ, Dunn K, Parikh VN, Chubb H, Perrin MJ, Roden DM, Vandenberg JI, Ng CA, Glazer AM. Multi-site validation of a functional assay to adjudicate SCN5A Brugada Syndrome-associated variants. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.12.19.23299592. [PMID: 38196587 PMCID: PMC10775332 DOI: 10.1101/2023.12.19.23299592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2024]
Abstract
Brugada Syndrome (BrS) is an inheritable arrhythmia condition that is associated with rare, loss-of-function variants in the cardiac sodium channel gene, SCN5A. Interpreting the pathogenicity of SCN5A missense variants is challenging and ~79% of SCN5A missense variants in ClinVar are currently classified as Variants of Uncertain Significance (VUS). An in vitro SCN5A-BrS automated patch clamp assay was generated for high-throughput functional studies of NaV1.5. The assay was independently studied at two separate research sites - Vanderbilt University Medical Center and Victor Chang Cardiac Research Institute - revealing strong correlations, including peak INa density (R2=0.86). The assay was calibrated according to ClinGen Sequence Variant Interpretation recommendations using high-confidence variant controls (n=49). Normal and abnormal ranges of function were established based on the distribution of benign variant assay results. The assay accurately distinguished benign controls (24/25) from pathogenic controls (23/24). Odds of Pathogenicity values derived from the experimental results yielded 0.042 for normal function (BS3 criterion) and 24.0 for abnormal function (PS3 criterion), resulting in up to strong evidence for both ACMG criteria. The calibrated assay was then used to study SCN5A VUS observed in four families with BrS and other arrhythmia phenotypes associated with SCN5A loss-of-function. The assay revealed loss-of-function for three of four variants, enabling reclassification to likely pathogenic. This validated APC assay provides clinical-grade functional evidence for the reclassification of current VUS and will aid future SCN5A-BrS variant classification.
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Affiliation(s)
- Joanne G. Ma
- Mark Cowley Lidwill Research Program in Cardiac Electrophysiology, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia
- School of Clinical Medicine, UNSW Sydney, Darlinghurst, NSW, Australia
| | | | - Ebony Richardson
- Clinical Genomics Laboratory, Centre for Population Genomics, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia and Murdoch Children Research Institute, Melbourne, Australia
| | - Kate L. Thomson
- Oxford Genetics Laboratories, Churchill Hospital, Oxford, UK
| | - Jodie Ingles
- Clinical Genomics Laboratory, Centre for Population Genomics, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia and Murdoch Children Research Institute, Melbourne, Australia
| | - Ayesha Muhammad
- Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Joseph F. Solus
- Vanderbilt Center for Arrhythmia Research and Therapeutics (VanCART), Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Giovanni Davogustto
- Division of Cardiovascular Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Katherine C. Anderson
- Division of Cardiovascular Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - M. Benjamin Shoemaker
- Division of Cardiovascular Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Andrew B. Stergachis
- University of Washington School of Medicine, Department of Medicine, Seattle, WA, USA
| | - Brendan J. Floyd
- Stanford Center for Inherited Cardiovascular Disease, Stanford University School of Medicine, Stanford, CA, USA
| | - Kyla Dunn
- Stanford Center for Inherited Cardiovascular Disease, Stanford University School of Medicine, Stanford, CA, USA
| | - Victoria N. Parikh
- Stanford Center for Inherited Cardiovascular Disease, Stanford University School of Medicine, Stanford, CA, USA
| | - Henry Chubb
- Stanford Center for Inherited Cardiovascular Disease, Stanford University School of Medicine, Stanford, CA, USA
| | - Mark J. Perrin
- Department of Genomic Medicine, Royal Melbourne Hospital, Victoria, Australia
| | - Dan M. Roden
- Vanderbilt Center for Arrhythmia Research and Therapeutics (VanCART), Departments of Medicine, Pharmacology, and Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jamie I. Vandenberg
- Mark Cowley Lidwill Research Program in Cardiac Electrophysiology, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia
- School of Clinical Medicine, UNSW Sydney, Darlinghurst, NSW, Australia
| | - Chai-Ann Ng
- Mark Cowley Lidwill Research Program in Cardiac Electrophysiology, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia
- School of Clinical Medicine, UNSW Sydney, Darlinghurst, NSW, Australia
| | - Andrew M. Glazer
- Vanderbilt Center for Arrhythmia Research and Therapeutics (VanCART), Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
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Tarnovskaya SI, Kostareva AA, Zhorov BS. In silico analysis of TRPM4 variants of unknown clinical significance. PLoS One 2023; 18:e0295974. [PMID: 38100498 PMCID: PMC10723691 DOI: 10.1371/journal.pone.0295974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 12/02/2023] [Indexed: 12/17/2023] Open
Abstract
BACKGROUND TRPM4 is a calcium-activated channel that selectively permeates monovalent cations. Genetic variants of the channel in cardiomyocytes are associated with various heart disorders, such as progressive familial heart block and Brugada syndrome. About97% of all known TRPM4 missense variants are classified as variants of unknown clinical significance (VUSs). The very large number of VUSs is a serious problem in diagnostics and treatment of inherited heart diseases. METHODS AND RESULTS We collected 233 benign or pathogenic missense variants in the superfamily of TRP channels from databases ClinVar, Humsavar and Ensembl Variation to compare performance of 22 algorithms that predict damaging variants. We found that ClinPred is the best-performing tool for TRP channels. We also used the paralogue annotation method to identify disease variants across the TRP family. In the set of 565 VUSs of hTRPM4, ClinPred predicted pathogenicity of 299 variants. Among these, 12 variants are also categorized as LP/P variants in at least one paralogue of hTRPM4. We further used the cryo-EM structure of hTRPM4 to find scores of contact pairs between parental (wild type) residues of VUSs for which ClinPred predicts a high probability of pathogenicity of variants for both contact partners. We propose that 68 respective missense VUSs are also likely pathogenic variants. CONCLUSIONS ClinPred outperformed other in-silico tools in predicting damaging variants of TRP channels. ClinPred, the paralogue annotation method, and analysis of residue contacts the hTRPM4 cryo-EM structure collectively suggest pathogenicity of 80 TRPM4 VUSs.
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Affiliation(s)
- Svetlana I. Tarnovskaya
- Almazov National Medical Research Centre, St. Petersburg, Russia
- Sechenov Institute of Evolutionary Physiology & 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 and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Boris S. Zhorov
- Almazov National Medical Research Centre, St. Petersburg, Russia
- Sechenov Institute of Evolutionary Physiology & Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Canada
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10
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Asatryan B, Bleijendaal H, Wilde AAM. Toward advanced diagnosis and management of inherited arrhythmia syndromes: Harnessing the capabilities of artificial intelligence and machine learning. Heart Rhythm 2023; 20:1399-1407. [PMID: 37442407 DOI: 10.1016/j.hrthm.2023.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/20/2023] [Accepted: 07/02/2023] [Indexed: 07/15/2023]
Abstract
The use of advanced computational technologies, such as artificial intelligence (AI), is now exerting a significant influence on various aspects of life, including health care and science. AI has garnered remarkable public notice with the release of deep learning models that can model anything from artwork to academic papers with minimal human intervention. Machine learning, a method that uses algorithms to extract information from raw data and represent it in a model, and deep learning, a method that uses multiple layers to progressively extract higher-level features from the raw input with minimal human intervention, are increasingly leveraged to tackle problems in the health sector, including utilization for clinical decision support in cardiovascular medicine. Inherited arrhythmia syndromes are a clinical domain where multiple unanswered questions remain despite unprecedented progress over the past 2 decades with the introduction of large panel genetic testing and the first steps in precision medicine. In particular, AI tools can help address gaps in clinical diagnosis by identifying individuals with concealed or transient phenotypes; enhance risk stratification by elevating recognition of underlying risk burden beyond widely recognized risk factors; improve prediction of response to therapy, and further prognostication. In this contemporary review, we provide a summary of the AI models developed to solve challenges in inherited arrhythmia syndromes and also outline gaps that can be filled with the development of intelligent AI models.
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Affiliation(s)
- Babken Asatryan
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland.
| | - Hidde Bleijendaal
- University of Amsterdam, Heart Center; Department of Clinical and Experimental Cardiology, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Amsterdam, The Netherlands; Department of Clinical Epidemiology, Biostatistics and Bioinformatics, University of Amsterdam, Amsterdam, The Netherlands
| | - Arthur A M Wilde
- University of Amsterdam, Heart Center; Department of Clinical and Experimental Cardiology, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Amsterdam, The Netherlands; Department of Clinical Epidemiology, Biostatistics and Bioinformatics, University of Amsterdam, Amsterdam, The Netherlands; European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart (ERN GUARD-Heart)
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11
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Kotta M, Torchio M, Bayliss P, Cohen MC, Quarrell O, Wheeldon N, Marton T, Gentilini D, Crotti L, Coombs RC, Schwartz PJ. Cardiac Genetic Investigation of Sudden Infant and Early Childhood Death: A Study From Victims to Families. J Am Heart Assoc 2023; 12:e029100. [PMID: 37589201 PMCID: PMC10547337 DOI: 10.1161/jaha.122.029100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 06/27/2023] [Indexed: 08/18/2023]
Abstract
Background Sudden infant death syndrome (SIDS) is the leading cause of death up to age 1. Sudden unexplained death in childhood (SUDC) is similar but affects mostly toddlers aged 1 to 4. SUDC is rarer than SIDS, and although cardiogenetic testing (molecular autopsy) identifies an underlying cause in a fraction of SIDS, less is known about SUDC. Methods and Results Seventy-seven SIDS and 16 SUDC cases underwent molecular autopsy with 25 definitive-evidence arrhythmia-associated genes. In 18 cases, another 76 genes with varying degrees of evidence were analyzed. Parents were offered cascade screening. Double-blind review of clinical-genetic data established genotype-phenotype correlations. The yield of likely pathogenic variants in the 25 genes was higher in SUDC than in SIDS (18.8% [3/16] versus 2.6% [2/77], respectively; P=0.03), whereas novel/ultra-rare variants of uncertain significance were comparably represented. Rare variants of uncertain significance and likely benign variants were found only in SIDS. In cases with expanded analyses, likely pathogenic/likely benign variants stemmed only from definitive-evidence genes, whereas all other genes contributed only variants of uncertain significance. Among 24 parents screened, variant status and phenotype largely agreed, and 3 cases positively correlated for cardiac channelopathies. Genotype-phenotype correlations significantly aided variant adjudication. Conclusions Genetic yield is higher in SUDC than in SIDS although, in both, it is contributed only by definitive-evidence genes. SIDS/SUDC cascade family screening facilitates establishment or dismissal of a diagnosis through definitive variant adjudication indicating that anonymity is no longer justifiable. Channelopathies may underlie a relevant fraction of SUDC. Binary classifications of genetic causality (pathogenic versus benign) could not always be adequate.
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Affiliation(s)
- Maria‐Christina Kotta
- Center for Cardiac Arrhythmias of Genetic Origin and Laboratory of Cardiovascular GeneticsIRCCS Istituto Auxologico ItalianoMilanItaly
| | - Margherita Torchio
- Center for Cardiac Arrhythmias of Genetic Origin and Laboratory of Cardiovascular GeneticsIRCCS Istituto Auxologico ItalianoMilanItaly
| | - Pauline Bayliss
- Department of Clinical GeneticsSheffield Children’s NHS Foundation TrustSheffieldUnited Kingdom
| | - Marta C. Cohen
- Department of HistopathologySheffield Children’s NHS Foundation TrustSheffieldUnited Kingdom
| | - Oliver Quarrell
- Sheffield Children’s Hospital NHS Foundation TrustSheffieldUnited Kingdom
- Department of NeurosciencesUniversity of SheffieldSheffieldUnited Kingdom
| | - Nigel Wheeldon
- Cardiothoracic CentreNorthern General Hospital, Sheffield Teaching Hospitals NHS TrustSheffieldUnited Kingdom
| | - Tamás Marton
- Cellular Pathology DepartmentBirmingham Women’s and Children’s HospitalBirminghamUnited Kingdom
| | - Davide Gentilini
- Bioinformatics and Statistical Genetics UnitIRCCS Istituto Auxologico ItalianoMilanItaly
| | - Lia Crotti
- Center for Cardiac Arrhythmias of Genetic Origin and Laboratory of Cardiovascular GeneticsIRCCS Istituto Auxologico ItalianoMilanItaly
- Department of Medicine and SurgeryUniversity of Milano‐BicoccaMilanItaly
| | - Robert C. Coombs
- Department of NeonatologySheffield Teaching Hospitals. NHS TrustSheffieldUnited Kingdom
| | - Peter J. Schwartz
- Center for Cardiac Arrhythmias of Genetic Origin and Laboratory of Cardiovascular GeneticsIRCCS Istituto Auxologico ItalianoMilanItaly
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12
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Morales A, Goehringer J, Sanoudou D. Evolving cardiovascular genetic counseling needs in the era of precision medicine. Front Cardiovasc Med 2023; 10:1161029. [PMID: 37424912 PMCID: PMC10325680 DOI: 10.3389/fcvm.2023.1161029] [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: 02/07/2023] [Accepted: 06/05/2023] [Indexed: 07/11/2023] Open
Abstract
In the era of Precision Medicine the approach to disease diagnosis, treatment, and prevention is being transformed across medical specialties, including Cardiology, and increasingly involves genomics approaches. The American Heart Association endorses genetic counseling as an essential component in the successful delivery of cardiovascular genetics care. However, with the dramatic increase in the number of available cardiogenetic tests, the demand, and the test result complexity, there is a need not only for a greater number of genetic counselors but more importantly, for highly specialized cardiovascular genetic counselors. Consequently, there is a pressing need for advanced cardiovascular genetic counseling training, along with innovative online services, telemedicine, and patient-facing digital tools, as the most effective way forward. The speed of implementation of these reforms will be of essence in the translation of scientific advancements into measurable benefits for patients with heritable cardiovascular disease and their families.
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Affiliation(s)
- Ana Morales
- Translational Health Sciences Program, School of Medicine and Health Sciences, The George Washington University, Washington, DC, United States
| | | | - Despina Sanoudou
- Clinical Genomics and Pharmacogenomics Unit, 4th Department of Internal Medicine, ‘Attikon’ Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
- Center for New Biotechnologies and Precision Medicine, Medical School, National and Kapodistrian University of Athens, Athens, Greece
- Molecular Biology Division, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
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13
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Kelly KL, Lin PT, Basso C, Bois M, Buja LM, Cohle SD, d'Amati G, Duncanson E, Fallon JT, Firchau D, Fishbein G, Giordano C, Leduc C, Litovsky SH, Mackey-Bojack S, Maleszewski JJ, Michaud K, Padera RF, Papadodima SA, Parsons S, Radio SJ, Rizzo S, Roe SJ, Romero M, Sheppard MN, Stone JR, Tan CD, Thiene G, van der Wal AC, Veinot JP. Sudden cardiac death in the young: A consensus statement on recommended practices for cardiac examination by pathologists from the Society for Cardiovascular Pathology. Cardiovasc Pathol 2023; 63:107497. [PMID: 36375720 DOI: 10.1016/j.carpath.2022.107497] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 11/03/2022] [Accepted: 11/04/2022] [Indexed: 11/13/2022] Open
Abstract
Sudden cardiac death is, by definition, an unexpected, untimely death caused by a cardiac condition in a person with known or unknown heart disease. This major international public health problem accounts for approximately 15-20% of all deaths. Typically more common in older adults with acquired heart disease, SCD also can occur in the young where the cause is more likely to be a genetically transmitted process. As these inherited disease processes can affect multiple family members, it is critical that these deaths are appropriately and thoroughly investigated. Across the United States, SCD cases in those less than 40 years of age will often fall under medical examiner/coroner jurisdiction resulting in scene investigation, review of available medical records and a complete autopsy including toxicological and histological studies. To date, there have not been consistent or uniform guidelines for cardiac examination in these cases. In addition, many medical examiner/coroner offices are understaffed and/or underfunded, both of which may hamper specialized examinations or studies (e.g., molecular testing). Use of such guidelines by pathologists in cases of SCD in decedents aged 1-39 years of age could result in life-saving medical intervention for other family members. These recommendations also may provide support for underfunded offices to argue for the significance of this specialized testing. As cardiac examinations in the setting of SCD in the young fall under ME/C jurisdiction, this consensus paper has been developed with members of the Society of Cardiovascular Pathology working with cardiovascular pathology-trained, practicing forensic pathologists.
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Affiliation(s)
| | | | - Cristina Basso
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health - University of Padua, Padua, Italy
| | | | | | | | | | - Emily Duncanson
- Jesse E. Edwards Registry of Cardiovascular Disease, St. Paul, MN, USA
| | | | | | | | | | | | | | | | | | - Katarzyna Michaud
- University Center of Legal Medicine Lausanne - Geneva, Lausanne University Hospital and University of Lausanne, Switzerland
| | | | | | - Sarah Parsons
- Victorian Institute of Forensic Medicine, Melbourne, Australia
| | | | - Stefania Rizzo
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health - University of Padua, Padua, Italy
| | | | | | - Mary N Sheppard
- St. George's Medical School, University of London, London, United Kingdom
| | | | | | - Gaetano Thiene
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health - University of Padua, Padua, Italy
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14
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Specterman MJ, Behr ER. Cardiogenetics: the role of genetic testing for inherited arrhythmia syndromes and sudden death. Heart 2023; 109:434-441. [PMID: 36167638 DOI: 10.1136/heartjnl-2021-320015] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 07/06/2022] [Indexed: 12/07/2022] Open
Abstract
There have been remarkable advances in our knowledge of the underlying heritability of cardiac arrhythmias. Long QT syndrome, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, progressive cardiac conduction disease and the short QT syndrome comprise the inherited arrhythmia syndromes (IASs). Pathogenic variants in cardiac ion channel and calcium handling protein genes lead to these conditions, usually in the absence of overt structural cardiac disease. Diagnosis is contingent on the ECG phenotype but genetic testing may help to confirm the diagnosis and provide information on the mechanism of arrhythmogenesis that may guide treatment and provide prognostic information in relation to the risk of sudden arrhythmic death. Clinical genetic testing uses 'panels' of genes that are the likely culprits for the IASs being investigated. An International Consortium (Clinical Genome Resource) has curated gene panels based on genetic and experimental evidence of causation of inherited conditions and that have a role in clinical genetic testing. A 'single gene' or monogenic basis for IASs exists but in future, missing heritability and incomplete penetrance will be uncovered by association of common variants through genome-wide association studies. Novel rare variants will also be detected through whole-genome sequencing. The formulation of polygenic risk scores will likely help to predict phenotypic expression and response to treatments/risk stratification and move genetic testing very much to the fore of the diagnostic process.
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Affiliation(s)
- Mark J Specterman
- Cardiovascular Clinical Academic Group, Molecular and Clinical Sciences Research Institute, St George's University of London, London, UK
| | - Elijah R Behr
- Cardiovascular Clinical Academic Group, Molecular and Clinical Sciences Research Institute, St George's University of London, London, UK
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15
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Kontorovich AR. Approaches to Genetic Screening in Cardiomyopathies: Practical Guidance for Clinicians. JACC. HEART FAILURE 2023; 11:133-142. [PMID: 36754525 DOI: 10.1016/j.jchf.2022.11.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 11/28/2022] [Accepted: 11/29/2022] [Indexed: 02/08/2023]
Abstract
Patients and families benefit when the genetic etiology of cardiomyopathy is elucidated through a multidisciplinary approach including genetic counseling and judicious use of genetic testing. The yield of genetic testing is optimized when performed on a proband with a clear phenotype, and interrogates genes that are validated in association with that specific form of cardiomyopathy. Variants of uncertain significance are frequently uncovered and should not be overinterpreted. Identifying an impactful genetic variant as the cause of a patient's cardiomyopathy can have important prognostic impact, and enable streamlined cascade testing to highlight at risk relatives. Certain genotypes are associated with unique potential cardiac and noncardiac risk factors and may dictate personalized approaches to treatment.
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Affiliation(s)
- Amy R Kontorovich
- Center for Inherited Cardiovascular Diseases, Icahn School of Medicine at Mount Sinai, New York, New York, USA.
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16
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Singer ES, Bagnall RD. Splicing Functional Assays Into the Genetic Testing Pipeline. CIRCULATION. GENOMIC AND PRECISION MEDICINE 2022; 15:e003949. [PMID: 36350765 DOI: 10.1161/circgen.122.003949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Emma S Singer
- Agnes Ginges Centre for Molecular Cardiology at Centenary Institute (E.S.S., R.D.B.), The University of Sydney, NSW, Australia.,Faculty of Medicine and Health (E.S.S., R.D.B.), The University of Sydney, NSW, Australia
| | - Richard D Bagnall
- Agnes Ginges Centre for Molecular Cardiology at Centenary Institute (E.S.S., R.D.B.), The University of Sydney, NSW, Australia.,Faculty of Medicine and Health (E.S.S., R.D.B.), The University of Sydney, NSW, Australia
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17
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Zhang Y, Grimwood AL, Hancox JC, Harmer SC, Dempsey CE. Evolutionary coupling analysis guides identification of mistrafficking-sensitive variants in cardiac K + channels: Validation with hERG. Front Pharmacol 2022; 13:1010119. [PMID: 36339618 PMCID: PMC9632996 DOI: 10.3389/fphar.2022.1010119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 09/30/2022] [Indexed: 09/27/2023] Open
Abstract
Loss of function (LOF) mutations of voltage sensitive K+ channel proteins hERG (Kv11.1) and KCNQ1 (Kv7.1) account for the majority of instances of congenital Long QT Syndrome (cLQTS) with the dominant molecular phenotype being a mistrafficking one resulting from protein misfolding. We explored the use of Evolutionary Coupling (EC) analysis, which identifies evolutionarily conserved pairwise amino acid interactions that may contribute to protein structural stability, to identify regions of the channels susceptible to misfolding mutations. Comparison with published experimental trafficking data for hERG and KCNQ1 showed that the method strongly predicts "scaffolding" regions of the channel membrane domains and has useful predictive power for trafficking phenotypes of individual variants. We identified a region in and around the cytoplasmic S2-S3 loop of the hERG Voltage Sensor Domain (VSD) as susceptible to destabilising mutation, and this was confirmed using a quantitative LI-COR ® based trafficking assay that showed severely attenuated trafficking in eight out of 10 natural hERG VSD variants selected using EC analysis. Our analysis highlights an equivalence in the scaffolding structures of the hERG and KCNQ1 membrane domains. Pathogenic variants of ion channels with an underlying mistrafficking phenotype are likely to be located within similar scaffolding structures that are identifiable by EC analysis.
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Affiliation(s)
- Yihong Zhang
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University Walk, Bristol, United Kingdom
| | - Amy L. Grimwood
- School of Biological Sciences, Life Sciences Building, Bristol, United Kingdom
| | - Jules C. Hancox
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University Walk, Bristol, United Kingdom
| | - Stephen C. Harmer
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University Walk, Bristol, United Kingdom
| | - Christopher E. Dempsey
- School of Biochemistry, Biomedical Sciences Building, University Walk, Bristol, United Kingdom
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18
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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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19
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Burke W, Parens E, Chung WK, Berger SM, Appelbaum PS. The Challenge of Genetic Variants of Uncertain Clinical Significance : A Narrative Review. Ann Intern Med 2022; 175:994-1000. [PMID: 35436152 PMCID: PMC10555957 DOI: 10.7326/m21-4109] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Genomic tests expand diagnostic and screening opportunities but also identify genetic variants of uncertain clinical significance (VUSs). Only a minority of VUSs are likely to prove pathogenic when later reassessed, but resolution of the uncertainty is rarely timely. That uncertainty adds complexity to clinical decision making and can result in harms and costs to patients and the health care system, including the time-consuming analysis required to interpret a VUS and the potential for unnecessary treatment and adverse psychological effects. Current efforts to improve variant interpretation will help reduce the scope of the problem, but the high prevalence of rare and novel variants in the human genome points to VUSs as an ongoing challenge. Additional strategies can help mitigate the potential harms of VUSs, including testing protocols that limit identification or reporting of VUSs, subclassification of VUSs according to the likelihood of pathogenicity, routine family-based evaluation of variants, and enhanced counseling efforts. All involve tradeoffs, and the appropriate balance of measures is likely to vary for different test uses and clinical settings. Cross-specialty deliberation and public input could contribute to systematic and broadly supported policies for managing VUSs.
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Affiliation(s)
- Wylie Burke
- Department of Bioethics and Humanities, University of Washington, Seattle, WA, USA
| | | | - Wendy K. Chung
- Departments of Pediatrics and Medicine, Columbia University Irving Medical Center, New York, NY, USA
| | - Sara M. Berger
- Department of Pediatrics, Columbia University Irving Medical Center, New York, NY, USA
| | - Paul S. Appelbaum
- Department of Psychiatry, Columbia University Irving Medical Center, New York, NY, USA
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20
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Phul S, Kuenze G, Vanoye CG, Sanders CR, George AL, Meiler J. Predicting the functional impact of KCNQ1 variants with artificial neural networks. PLoS Comput Biol 2022; 18:e1010038. [PMID: 35442947 PMCID: PMC9060377 DOI: 10.1371/journal.pcbi.1010038] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 05/02/2022] [Accepted: 03/18/2022] [Indexed: 12/23/2022] Open
Abstract
Recent advances in experimental and computational protein structure determination have provided access to high-quality structures for most human proteins and mutants thereof. However, linking changes in structure in protein mutants to functional impact remains an active area of method development. If successful, such methods can ultimately assist physicians in taking appropriate treatment decisions. This work presents three artificial neural network (ANN)-based predictive models that classify four key functional parameters of KCNQ1 variants as normal or dysfunctional using PSSM-based evolutionary and/or biophysical descriptors. Recent advances in predicting protein structure and variant properties with artificial intelligence (AI) rely heavily on the availability of evolutionary features and thus fail to directly assess the biophysical underpinnings of a change in structure and/or function. The central goal of this work was to develop an ANN model based on structure and physiochemical properties of KCNQ1 potassium channels that performs comparably or better than algorithms using only on PSSM-based evolutionary features. These biophysical features highlight the structure-function relationships that govern protein stability, function, and regulation. The input sensitivity algorithm incorporates the roles of hydrophobicity, polarizability, and functional densities on key functional parameters of the KCNQ1 channel. Inclusion of the biophysical features outperforms exclusive use of PSSM-based evolutionary features in predicting activation voltage dependence and deactivation time. As AI is increasingly applied to problems in biology, biophysical understanding will be critical with respect to 'explainable AI', i.e., understanding the relation of sequence, structure, and function of proteins. Our model is available at www.kcnq1predict.org.
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Affiliation(s)
- Saksham Phul
- Center for Structural Biology, Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Georg Kuenze
- Center for Structural Biology, Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee, United States of America
- Institute for Drug Discovery, Leipzig University, Leipzig, Germany
| | - Carlos G. Vanoye
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - Charles R. Sanders
- Center for Structural Biology, Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Alfred L. George
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - Jens Meiler
- Center for Structural Biology, Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee, United States of America
- Institute for Drug Discovery, Leipzig University, Leipzig, Germany
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, United States of America
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21
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Zimmermann MT. Molecular Modeling is an Enabling Approach to Complement and Enhance Channelopathy Research. Compr Physiol 2022; 12:3141-3166. [PMID: 35578963 DOI: 10.1002/cphy.c190047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Hundreds of human membrane proteins form channels that transport necessary ions and compounds, including drugs and metabolites, yet details of their normal function or how function is altered by genetic variants to cause diseases are often unknown. Without this knowledge, researchers are less equipped to develop approaches to diagnose and treat channelopathies. High-resolution computational approaches such as molecular modeling enable researchers to investigate channelopathy protein function, facilitate detailed hypothesis generation, and produce data that is difficult to gather experimentally. Molecular modeling can be tailored to each physiologic context that a protein may act within, some of which may currently be difficult or impossible to assay experimentally. Because many genomic variants are observed in channelopathy proteins from high-throughput sequencing studies, methods with mechanistic value are needed to interpret their effects. The eminent field of structural bioinformatics integrates techniques from multiple disciplines including molecular modeling, computational chemistry, biophysics, and biochemistry, to develop mechanistic hypotheses and enhance the information available for understanding function. Molecular modeling and simulation access 3D and time-dependent information, not currently predictable from sequence. Thus, molecular modeling is valuable for increasing the resolution with which the natural function of protein channels can be investigated, and for interpreting how genomic variants alter them to produce physiologic changes that manifest as channelopathies. © 2022 American Physiological Society. Compr Physiol 12:3141-3166, 2022.
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Affiliation(s)
- Michael T Zimmermann
- Bioinformatics Research and Development Laboratory, Genomic Sciences and Precision Medicine Center, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.,Clinical and Translational Sciences Institute, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.,Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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22
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Glazer AM, Davogustto G, Shaffer CM, Vanoye CG, Desai RR, Farber-Eger EH, Dikilitas O, Shang N, Pacheco JA, Yang T, Muhammad A, Mosley JD, Van Driest SL, Wells QS, Shaffer LL, Kalash OR, Wada Y, Bland S, Yoneda ZT, Mitchell DW, Kroncke BM, Kullo IJ, Jarvik GP, Gordon AS, Larson EB, Manolio TA, Mirshahi T, Luo JZ, Schaid D, Namjou B, Alsaied T, Singh R, Singhal A, Liu C, Weng C, Hripcsak G, Ralston JD, McNally EM, Chung WK, Carrell DS, Leppig KA, Hakonarson H, Sleiman P, Sohn S, Glessner J, Denny J, Wei WQ, George AL, Shoemaker MB, Roden DM. Arrhythmia Variant Associations and Reclassifications in the eMERGE-III Sequencing Study. Circulation 2022; 145:877-891. [PMID: 34930020 PMCID: PMC8940719 DOI: 10.1161/circulationaha.121.055562] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
BACKGROUND Sequencing Mendelian arrhythmia genes in individuals without an indication for arrhythmia genetic testing can identify carriers of pathogenic or likely pathogenic (P/LP) variants. However, the extent to which these variants are associated with clinically meaningful phenotypes before or after return of variant results is unclear. In addition, the majority of discovered variants are currently classified as variants of uncertain significance, limiting clinical actionability. METHODS The eMERGE-III study (Electronic Medical Records and Genomics Phase III) is a multicenter prospective cohort that included 21 846 participants without previous indication for cardiac genetic testing. Participants were sequenced for 109 Mendelian disease genes, including 10 linked to arrhythmia syndromes. Variant carriers were assessed with electronic health record-derived phenotypes and follow-up clinical examination. Selected variants of uncertain significance (n=50) were characterized in vitro with automated electrophysiology experiments in HEK293 cells. RESULTS As previously reported, 3.0% of participants had P/LP variants in the 109 genes. Herein, we report 120 participants (0.6%) with P/LP arrhythmia variants. Compared with noncarriers, arrhythmia P/LP carriers had a significantly higher burden of arrhythmia phenotypes in their electronic health records. Fifty-four participants had variant results returned. Nineteen of these 54 participants had inherited arrhythmia syndrome diagnoses (primarily long-QT syndrome), and 12 of these 19 diagnoses were made only after variant results were returned (0.05%). After in vitro functional evaluation of 50 variants of uncertain significance, we reclassified 11 variants: 3 to likely benign and 8 to P/LP. CONCLUSIONS Genome sequencing in a large population without indication for arrhythmia genetic testing identified phenotype-positive carriers of variants in congenital arrhythmia syndrome disease genes. As the genomes of large numbers of people are sequenced, the disease risk from rare variants in arrhythmia genes can be assessed by integrating genomic screening, electronic health record phenotypes, and in vitro functional studies. REGISTRATION URL: https://www. CLINICALTRIALS gov; Unique identifier; NCT03394859.
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Affiliation(s)
| | | | | | | | | | | | | | - Ning Shang
- Columbia University Irving Medical Center, New York NY
| | | | - Tao Yang
- Vanderbilt University Medical Center, Nashville TN
| | | | | | | | | | | | | | - Yuko Wada
- Vanderbilt University Medical Center, Nashville TN
| | - Sarah Bland
- Vanderbilt University Medical Center, Nashville TN
| | | | | | | | | | - Gail P. Jarvik
- Departments of Medicine (Medical Genetics) and Genome Sciences, University of Washington School of Medicine, Seattle, WA
| | | | | | | | | | | | | | - Bahram Namjou
- Cincinnati Children’s Hospital Medical Center, Cincinnati OH
| | - Tarek Alsaied
- Cincinnati Children’s Hospital Medical Center, Cincinnati OH
| | | | | | - Cong Liu
- Columbia University Irving Medical Center, New York NY
| | - Chunhua Weng
- Columbia University Irving Medical Center, New York NY
| | | | - James D. Ralston
- Departments of Medicine (Medical Genetics) and Genome Sciences, University of Washington School of Medicine, Seattle, WA
| | | | | | | | | | | | | | | | | | | | | | - Wei-Qi Wei
- Vanderbilt University Medical Center, Nashville TN
| | | | | | - Dan M. Roden
- Vanderbilt University Medical Center, Nashville TN
- Correspondence should be addressed to Dan M. Roden, MD, Vanderbilt University Medical Center, 2215B Garland Ave, 1285 MRBIV, Nashville, TN 37232,
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23
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Discerning the Ambiguous Role of Missense TTN Variants in Inherited Arrhythmogenic Syndromes. J Pers Med 2022; 12:jpm12020241. [PMID: 35207729 PMCID: PMC8877366 DOI: 10.3390/jpm12020241] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 01/29/2022] [Accepted: 02/05/2022] [Indexed: 11/18/2022] Open
Abstract
The titin gene (TTN) is associated with several diseases, including inherited arrhythmias. Most of these diagnoses are attributed to rare TTN variants encoding truncated forms, but missense variants represent a diagnostic challenge for clinical genetics. The proper interpretation of genetic data is critical for translation into the clinical setting. Notably, many TTN variants were classified before 2015, when the American College of Medical Genetics and Genomics (ACMG) published recommendations to accurately classify genetic variants. Our aim was to perform an exhaustive reanalysis of rare missense TTN variants that were classified before 2015, and that have ambiguous roles in inherited arrhythmogenic syndromes. Rare missense TTN variants classified before 2015 were updated following the ACMG recommendations and according to all the currently available data. Our cohort included 193 individuals definitively diagnosed with an inherited arrhythmogenic syndrome before 2015. Our analysis resulted in the reclassification of 36.8% of the missense variants from unknown to benign/likely benign. Of all the remaining variants, currently classified as of unknown significance, 38.3% showed a potential, but not confirmed, deleterious role. Most of these rare missense TTN variants with a suspected deleterious role were identified in patients diagnosed with hypertrophic cardiomyopathy. More than 35% of the rare missense TTN variants previously classified as ambiguous were reclassified as not deleterious, mainly because of improved population frequencies. Despite being inconclusive, almost 40% of the variants showed a potentially deleterious role in inherited arrhythmogenic syndromes. Our results highlight the importance of the periodical reclassification of rare missense TTN variants to improve genetic diagnoses and help increase the accuracy of personalized medicine.
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24
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Neubauer J, Kissel CK, Bolliger SA, Barbon D, Thali MJ, Kloiber D, Bode PK, Kovacs B, Graf U, Maspoli A, Berger W, Saguner AM, Haas C. Benefits and outcomes of a new multidisciplinary approach for the management and financing of sudden unexplained death cases in a forensic setting in Switzerland. Forensic Sci Int 2022; 334:111240. [DOI: 10.1016/j.forsciint.2022.111240] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/01/2022] [Accepted: 02/22/2022] [Indexed: 12/29/2022]
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25
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Scheiper-Welling S, Tabunscik M, Gross TE, Jenewein T, Beckmann BM, Niess C, Gradhand E, Wunder C, Schneider PM, Rothschild MA, Verhoff MA, Kauferstein S. Variant interpretation in molecular autopsy: a useful dilemma. Int J Legal Med 2022; 136:475-482. [PMID: 35091851 PMCID: PMC8847204 DOI: 10.1007/s00414-021-02764-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 12/15/2021] [Indexed: 11/28/2022]
Abstract
Abstract
Sudden cardiac death (SCD) in adolescents and young adults may be the first manifestation of an inherited arrhythmic syndrome. Thus identification of a genetic origin in sudden death cases deemed inconclusive after a comprehensive autopsy and may help to reduce the risk of lethal episodes in the remaining family. Using next-generation sequencing (NGS), a large number of variants of unknown significance (VUS) are detected. In the majority of cases, there is insufficient evidence of pathogenicity, representing a huge dilemma in current genetic investigations. Misinterpretation of such variants may lead to inaccurate genetic diagnoses and/or the adoption of unnecessary and/or inappropriate therapeutic approaches. In our study, we applied current (ACMG) recommendations for variant classification in post-mortem genetic screening of a cohort of 56 SCD victims. We identified a total 53 rare protein-altering variants (MAF < 0.2%) classified as VUS or worse. Twelve percent of the cases exhibited a clinically actionable variant (pathogenic, likely pathogenic or VUS – potentially pathogenic) that would warrant cascade genetic screening in relatives. Most of the variants detected by means of the post-mortem genetic investigations were VUS. Thus, genetic testing by itself might be fairly meaningless without supporting background data. This data reinforces the need for an experienced multidisciplinary team for obtaining reliable and accountable interpretations of variant significance for elucidating potential causes for SCDs in the young. This enables the early identification of relatives at risk or excludes family members as genetic carriers. Also, development of adequate forensic guidelines to enable appropriate interpretation of rare genetic variants is fundamental.
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Affiliation(s)
| | - Monika Tabunscik
- Institute of Legal Medicine, Goethe University, University Hospital Frankfurt, Frankfurt, Germany
| | - Theresa E Gross
- Institute of Legal Medicine, Faculty of Medicine and University Clinic, University of Cologne, Cologne, Germany
| | - Tina Jenewein
- Institute of Legal Medicine, Goethe University, University Hospital Frankfurt, Frankfurt, Germany
| | - Britt M Beckmann
- Institute of Legal Medicine, Goethe University, University Hospital Frankfurt, Frankfurt, Germany
| | - Constanze Niess
- Institute of Legal Medicine, Goethe University, University Hospital Frankfurt, Frankfurt, Germany
| | - Elise Gradhand
- Institute of Pathology, Goethe University, University Hospital Frankfurt, Kennedyallee 104, 60596, Frankfurt, Germany
| | - Cora Wunder
- Institute of Legal Medicine, Goethe University, University Hospital Frankfurt, Frankfurt, Germany
| | - Peter M Schneider
- Institute of Legal Medicine, Faculty of Medicine and University Clinic, University of Cologne, Cologne, Germany
| | - Markus A Rothschild
- Institute of Legal Medicine, Faculty of Medicine and University Clinic, University of Cologne, Cologne, Germany
| | - Marcel A Verhoff
- Institute of Legal Medicine, Goethe University, University Hospital Frankfurt, Frankfurt, Germany
| | - Silke Kauferstein
- Institute of Legal Medicine, Goethe University, University Hospital Frankfurt, Frankfurt, Germany.
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26
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Bains S, Dotzler SM, Krijger C, Giudicessi JR, Ye D, Bikker H, Rohatgi RK, Tester DJ, Bos JM, Wilde AAM, Ackerman MJ. A phenotype-enhanced variant classification framework to decrease the burden of missense variants of uncertain significance in type 1 long QT syndrome. Heart Rhythm 2021; 19:435-442. [PMID: 34798354 DOI: 10.1016/j.hrthm.2021.11.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 11/10/2021] [Accepted: 11/11/2021] [Indexed: 12/16/2022]
Abstract
BACKGROUND Pathogenic/likely pathogenic (P/LP) variants in the KCNQ1-encoded Kv7.1 potassium channel cause type 1 long QT syndrome (LQT1). Despite the revamped 2015 American College of Medical Genetics (ACMG) variant interpretation guidelines, the burden of KCNQ1 variants of uncertain significance (VUS) in patients with LQTS remains ∼30%. OBJECTIVE The purpose of this study was to determine whether a phenotype-enhanced (PE) variant classification approach could reduce the VUS burden in LQTS genetic testing. METHODS Retrospective analysis was performed on 79 KCNQ1 missense variants in 356 patients from Mayo Clinic and an independent cohort of 42 variants in 225 patients from Amsterdam University Medical Center (UMC). Each variant was classified initially using the ACMG guidelines and then readjudicated using a PE-ACMG framework that incorporated the LQTS clinical diagnostic Schwartz score plus 4 "LQT1-defining features": broad-based/slow upstroke T waves, syncope/seizure during exertion, swimming-associated events, and a maladaptive LQT1 treadmill stress test. RESULTS According to the ACMG guidelines, Mayo Clinic variants were classified as follows: 17 of 79 P variants (22%), 34 of 79 LP variants (43%), and 28 of 79 VUS (35%). Similarly, for Amsterdam UMC, the variant distribution was 9 of 42 P variants (22%), 14 of 42 LP variants (33%), and 19 of 42 variants VUS (45%). After PE-ACMG readjudication, the total VUS burden decreased significantly from 28 (35%) to 13 (16%) (P = .0007) for Mayo Clinic and from 19 (45%) to 12 (29%) (P = .02) for Amsterdam UMC. CONCLUSION Phenotype-guided variant adjudication decreased significantly the VUS burden of LQT1 case-derived KCNQ1 missense variants in 2 independent cohorts. This study demonstrates the value of incorporating LQT1-specific phenotype/clinical data to aid in the interpretation of KCNQ1 missense variants identified during genetic testing for LQTS.
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Affiliation(s)
- Sahej Bains
- Medical Scientist Training Program, Mayo Clinic, Rochester, Minnesota; Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota
| | - Steven M Dotzler
- Medical Scientist Training Program, Mayo Clinic, Rochester, Minnesota; Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota
| | - Christian Krijger
- Department of Experimental Cardiology, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - John R Giudicessi
- Department of Cardiovascular Medicine, Division of Heart Rhythm Services, Windland Smith Rice Genetic Heart Rhythm Clinic, Mayo Clinic, Rochester, Minnesota
| | - Dan Ye
- Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota
| | - Hennie Bikker
- Department of Human Genetics, University of Amsterdam, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Ram K Rohatgi
- Department of Pediatric and Adolescent Medicine (Division of Pediatric Cardiology), Mayo Clinic, Rochester, Minnesota
| | - David J Tester
- Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota; Department of Cardiovascular Medicine, Division of Heart Rhythm Services, Windland Smith Rice Genetic Heart Rhythm Clinic, Mayo Clinic, Rochester, Minnesota; Department of Pediatric and Adolescent Medicine (Division of Pediatric Cardiology), Mayo Clinic, Rochester, Minnesota
| | - J Martijn Bos
- Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota; Department of Cardiovascular Medicine, Division of Heart Rhythm Services, Windland Smith Rice Genetic Heart Rhythm Clinic, Mayo Clinic, Rochester, Minnesota; Department of Pediatric and Adolescent Medicine (Division of Pediatric Cardiology), Mayo Clinic, Rochester, Minnesota
| | - Arthur A M Wilde
- Department of Experimental Cardiology, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Department of Cardiology, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Michael J Ackerman
- Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota; Department of Cardiovascular Medicine, Division of Heart Rhythm Services, Windland Smith Rice Genetic Heart Rhythm Clinic, Mayo Clinic, Rochester, Minnesota; Department of Pediatric and Adolescent Medicine (Division of Pediatric Cardiology), Mayo Clinic, Rochester, Minnesota.
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27
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Sarquella-Brugada G, Fernandez-Falgueras A, Cesar S, Arbelo E, Coll M, Perez-Serra A, Puigmulé M, Iglesias A, Alcalde M, Vallverdú-Prats M, Fiol V, Ferrer-Costa C, Del Olmo B, Picó F, Lopez L, García-Alvarez A, Jordà P, Tiron de Llano C, Toro R, Grassi S, Oliva A, Brugada J, Brugada R, Campuzano O. Clinical impact of rare variants associated with inherited channelopathies: a 5-year update. Hum Genet 2021; 141:1579-1589. [PMID: 34546463 PMCID: PMC9522753 DOI: 10.1007/s00439-021-02370-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 09/13/2021] [Indexed: 12/20/2022]
Abstract
A proper interpretation of the pathogenicity of rare variants is crucial before clinical translation. Ongoing addition of new data may modify previous variant classifications; however, how often a reanalysis is necessary remains undefined. We aimed to extensively reanalyze rare variants associated with inherited channelopathies originally classified 5 years ago and its clinical impact. In 2016, rare variants identified through genetic analysis were classified following the American College of Medical Genetics and Genomics’ recommendations. Five years later, we have reclassified the same variants following the same recommendations but including new available data. Potential clinical implications were discussed. Our cohort included 49 cases of inherited channelopathies diagnosed in 2016. Update show that 18.36% of the variants changed classification mainly due to improved global frequency data. Reclassifications mostly occurred in minority genes associated with channelopathies. Similar percentage of variants remain as deleterious nowadays, located in main known genes (SCN5A, KCNH2 and KCNQ1). In 2016, 69.38% of variants were classified as unknown significance, but now, 53.06% of variants are classified as such, remaining the most common group. No management was modified after translation of genetic data into clinics. After 5 years, nearly 20% of rare variants associated with inherited channelopathies were reclassified. This supports performing periodic reanalyses of no more than 5 years since last classification. Use of newly available data is necessary, especially concerning global frequencies and family segregation. Personalized clinical translation of rare variants can be crucial to management if a significant change in classification is identified.
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Affiliation(s)
- Georgia Sarquella-Brugada
- Medical Science Department, School of Medicine, University of Girona, C/ Emili Grahit 77, 17003, Girona, Catalunya, Spain.,Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
| | - Anna Fernandez-Falgueras
- Cardiovascular Genetics Center, University of Girona-IDIBGI, Girona, Spain.,Centro de Investigación Biomédica en Red. Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain.,Cardiology Service, Hospital Josep Trueta, University of Girona, Girona, Spain
| | - Sergi Cesar
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
| | - Elena Arbelo
- Centro de Investigación Biomédica en Red. Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain.,Arrhythmias Unit, Hospital Clinic, University of Barcelona-IDIBAPS, Barcelona, Spain
| | - Mónica Coll
- Cardiovascular Genetics Center, University of Girona-IDIBGI, Girona, Spain.,Centro de Investigación Biomédica en Red. Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
| | - Alexandra Perez-Serra
- Cardiovascular Genetics Center, University of Girona-IDIBGI, Girona, Spain.,Centro de Investigación Biomédica en Red. Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
| | - Marta Puigmulé
- Cardiovascular Genetics Center, University of Girona-IDIBGI, Girona, Spain.,Centro de Investigación Biomédica en Red. Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
| | - Anna Iglesias
- Cardiovascular Genetics Center, University of Girona-IDIBGI, Girona, Spain.,Centro de Investigación Biomédica en Red. Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
| | - Mireia Alcalde
- Cardiovascular Genetics Center, University of Girona-IDIBGI, Girona, Spain.,Centro de Investigación Biomédica en Red. Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
| | | | - Victoria Fiol
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
| | | | - Bernat Del Olmo
- Cardiovascular Genetics Center, University of Girona-IDIBGI, Girona, Spain.,Centro de Investigación Biomédica en Red. Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
| | - Ferran Picó
- Cardiovascular Genetics Center, University of Girona-IDIBGI, Girona, Spain.,Centro de Investigación Biomédica en Red. Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
| | - Laura Lopez
- Cardiovascular Genetics Center, University of Girona-IDIBGI, Girona, Spain.,Centro de Investigación Biomédica en Red. Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
| | - Ana García-Alvarez
- Centro de Investigación Biomédica en Red. Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain.,Arrhythmias Unit, Hospital Clinic, University of Barcelona-IDIBAPS, Barcelona, Spain
| | - Paloma Jordà
- Centro de Investigación Biomédica en Red. Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain.,Arrhythmias Unit, Hospital Clinic, University of Barcelona-IDIBAPS, Barcelona, Spain
| | | | - Rocío Toro
- Medicine Department, School of Medicine, Cádiz, Spain
| | - Simone Grassi
- Institute of Public Health, Section Legal Medicine, Catholic University, Rome, Italy
| | - Antonio Oliva
- Institute of Public Health, Section Legal Medicine, Catholic University, Rome, Italy
| | - Josep Brugada
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red. Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain.,Arrhythmias Unit, Hospital Clinic, University of Barcelona-IDIBAPS, Barcelona, Spain
| | - Ramon Brugada
- Medical Science Department, School of Medicine, University of Girona, C/ Emili Grahit 77, 17003, Girona, Catalunya, Spain. .,Cardiovascular Genetics Center, University of Girona-IDIBGI, Girona, Spain. .,Centro de Investigación Biomédica en Red. Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain. .,Cardiology Service, Hospital Josep Trueta, University of Girona, Girona, Spain.
| | - Oscar Campuzano
- Medical Science Department, School of Medicine, University of Girona, C/ Emili Grahit 77, 17003, Girona, Catalunya, Spain. .,Cardiovascular Genetics Center, University of Girona-IDIBGI, Girona, Spain. .,Centro de Investigación Biomédica en Red. Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain.
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28
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Fan X, Yang G, Kowitz J, Duru F, Saguner AM, Akin I, Zhou X, El-Battrawy I. Preclinical short QT syndrome models: studying the phenotype and drug-screening. Europace 2021; 24:481-493. [PMID: 34516623 DOI: 10.1093/europace/euab214] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 09/05/2021] [Indexed: 11/14/2022] Open
Abstract
Cardiovascular diseases are the main cause of sudden cardiac death (SCD) in developed and developing countries. Inherited cardiac channelopathies are linked to 5-10% of SCDs, mainly in the young. Short QT syndrome (SQTS) is a rare inherited channelopathy, which leads to both atrial and ventricular tachyarrhythmias, syncope, and even SCD. International European Society of Cardiology guidelines include as diagnostic criteria: (i) QTc ≤ 340 ms on electrocardiogram, (ii) QTc ≤ 360 ms plus one of the follwing, an affected short QT syndrome pathogenic gene mutation, or family history of SQTS, or aborted cardiac arrest, or family history of cardiac arrest in the young. However, further evaluation of the QTc ranges seems to be required, which might be possible by assembling large short QT cohorts and considering genetic screening of the newly described pathogenic mutations. Since the mechanisms underlying the arrhythmogenesis of SQTS is unclear, optimal therapy for SQTS is still lacking. The disease is rare, unclear genotype-phenotype correlations exist in a bevy of cases and the absence of an international short QT registry limit studies on the pathophysiological mechanisms of arrhythmogenesis and therapy of SQTS. This leads to the necessity of experimental models or platforms for studying SQTS. Here, we focus on reviewing preclinical SQTS models and platforms such as animal models, heterologous expression systems, human-induced pluripotent stem cell-derived cardiomyocyte models and computer models as well as three-dimensional engineered heart tissues. We discuss their usefulness for SQTS studies to examine genotype-phenotype associations, uncover disease mechanisms and test drugs. These models might be helpful for providing novel insights into the exact pathophysiological mechanisms of this channelopathy and may offer opportunities to improve the diagnosis and treatment of patients with SQT syndrome.
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Affiliation(s)
- Xuehui Fan
- University of Mannheim, University of Heidelberg, Germany.,Key Laboratory of Medical Electrophysiology, Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Collaborative Innovation Center for Prevention of Cardiovascular Diseases, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan, China
| | - Guoqiang Yang
- Department of Acupuncture and Rehabilitation, Hospital (T.CM.) Affiliated to Southwest Medical University, Luzhou, Sichuan, China.,Research Unit of Molecular Imaging Probes, Department of Radiologic Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
| | | | - Firat Duru
- Department of Cardiology, University Heart Centre, University Hospital Zurich, Zurich, Switzerland.,Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Ardan M Saguner
- Department of Cardiology, University Heart Centre, University Hospital Zurich, Zurich, Switzerland
| | - Ibrahim Akin
- University of Mannheim, University of Heidelberg, Germany.,DZHK (German Center for Cardiovascular Research) Partner Site, Heidelberg-Mannheim, Germany
| | - Xiaobo Zhou
- University of Mannheim, University of Heidelberg, Germany.,Key Laboratory of Medical Electrophysiology, Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Collaborative Innovation Center for Prevention of Cardiovascular Diseases, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan, China.,DZHK (German Center for Cardiovascular Research) Partner Site, Heidelberg-Mannheim, Germany
| | - Ibrahim El-Battrawy
- University of Mannheim, University of Heidelberg, Germany.,Department of Cardiology, University Heart Centre, University Hospital Zurich, Zurich, Switzerland
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29
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An ethical analysis of divergent clinical approaches to the application of genetic testing for autism and schizophrenia. Hum Genet 2021; 141:1069-1084. [PMID: 34453583 DOI: 10.1007/s00439-021-02349-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 08/16/2021] [Indexed: 12/27/2022]
Abstract
Genetic testing to identify genetic syndromes and copy number variants (CNVs) via whole genome platforms such as chromosome microarray (CMA) or exome sequencing (ES) is routinely performed clinically, and is considered by a variety of organizations and societies to be a "first-tier" test for individuals with developmental delay (DD), intellectual disability (ID), or autism spectrum disorder (ASD). However, in the context of schizophrenia, though CNVs can have a large effect on risk, genetic testing is not typically a part of routine clinical care, and no clinical practice guidelines recommend testing. This raises the question of whether CNV testing should be similarly performed for individuals with schizophrenia. Here we consider this proposition in light of the history of genetic testing for ID/DD and ASD, and through the application of an ethical analysis designed to enable robust, accountable and justifiable decision-making. Using a systematic framework and application of relevant bioethical principles (beneficence, non-maleficence, autonomy, and justice), our examination highlights that while CNV testing for the indication of ID has considerable benefits, there is currently insufficient evidence to suggest that overall, the potential harms are outweighed by the potential benefits of CNV testing for the sole indications of schizophrenia or ASD. However, although the application of CNV tests for children with ASD or schizophrenia without ID/DD is, strictly speaking, off-label use, there may be clinical utility and benefits substantive enough to outweigh the harms. Research is needed to clarify the harms and benefits of testing in pediatric and adult contexts. Given that genetic counseling has demonstrated benefits for schizophrenia, and has the potential to mitigate many of the potential harms from genetic testing, any decisions to implement genetic testing for schizophrenia should involve high-quality evidence-based genetic counseling.
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30
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Stiles MK, Wilde AAM, Abrams DJ, Ackerman MJ, Albert CM, Behr ER, Chugh SS, Cornel MC, Gardner K, Ingles J, James CA, Juang JMJ, Kääb S, Kaufman ES, Krahn AD, Lubitz SA, MacLeod H, Morillo CA, Nademanee K, Probst V, Saarel EV, Sacilotto L, Semsarian C, Sheppard MN, Shimizu W, Skinner JR, Tfelt-Hansen J, Wang DW. 2020 APHRS/HRS expert consensus statement on the investigation of decedents with sudden unexplained death and patients with sudden cardiac arrest, and of their families. J Arrhythm 2021; 37:481-534. [PMID: 34141003 PMCID: PMC8207384 DOI: 10.1002/joa3.12449] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 10/14/2020] [Indexed: 12/26/2022] Open
Abstract
This international multidisciplinary document intends to provide clinicians with evidence-based practical patient-centered recommendations for evaluating patients and decedents with (aborted) sudden cardiac arrest and their families. The document includes a framework for the investigation of the family allowing steps to be taken, should an inherited condition be found, to minimize further events in affected relatives. Integral to the process is counseling of the patients and families, not only because of the emotionally charged subject, but because finding (or not finding) the cause of the arrest may influence management of family members. The formation of multidisciplinary teams is essential to provide a complete service to the patients and their families, and the varied expertise of the writing committee was formulated to reflect this need. The document sections were divided up and drafted by the writing committee members according to their expertise. The recommendations represent the consensus opinion of the entire writing committee, graded by Class of Recommendation and Level of Evidence. The recommendations were opened for public comment and reviewed by the relevant scientific and clinical document committees of the Asia Pacific Heart Rhythm Society (APHRS) and the Heart Rhythm Society (HRS); the document underwent external review and endorsement by the partner and collaborating societies. While the recommendations are for optimal care, it is recognized that not all resources will be available to all clinicians. Nevertheless, this document articulates the evaluation that the clinician should aspire to provide for patients with sudden cardiac arrest, decedents with sudden unexplained death, and their families.
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Affiliation(s)
- Martin K Stiles
- Waikato Clinical School Faculty of Medicine and Health Science The University of Auckland Hamilton New Zealand
| | - Arthur A M Wilde
- Heart Center Department of Clinical and Experimental Cardiology Amsterdam University Medical Center University of Amsterdam Amsterdam the Netherlands
| | | | | | | | - Elijah R Behr
- Cardiovascular Clinical Academic Group, Molecular and Clinical Sciences Institute St George's University of London, and St George's University Hospitals NHS Foundation Trust London UK
| | | | - Martina C Cornel
- Amsterdam University Medical Center Vrije Universiteit Amsterdam Clinical Genetics Amsterdam Public Health Research Institute Amsterdam the Netherlands
| | | | - Jodie Ingles
- Agnes Ginges Centre for Molecular Cardiology at Centenary Institute The University of Sydney Sydney Australia
| | | | - Jyh-Ming Jimmy Juang
- Cardiovascular Center and Division of Cardiology Department of Internal Medicine National Taiwan University Hospital and National Taiwan University College of Medicine Taipei Taiwan
| | - Stefan Kääb
- Department of Medicine I University Hospital LMU Munich Munich Germany
| | | | | | | | - Heather MacLeod
- Data Coordinating Center for the Sudden Death in the Young Case Registry Okemos MI USA
| | | | - Koonlawee Nademanee
- Chulalongkorn University Faculty of Medicine, and Pacific Rim Electrophysiology Research Institute at Bumrungrad Hospital Bangkok Thailand
| | | | - Elizabeth V Saarel
- Cleveland Clinic Lerner College of Cardiology at Case Western Reserve University Cleveland OH USA
- St Luke's Medical Center Boise ID USA
| | - Luciana Sacilotto
- Heart Institute University of São Paulo Medical School São Paulo Brazil
| | - Christopher Semsarian
- Agnes Ginges Centre for Molecular Cardiology at Centenary Institute The University of Sydney Sydney Australia
| | - Mary N Sheppard
- Cardiovascular Clinical Academic Group, Molecular and Clinical Sciences Institute St George's University of London, and St George's University Hospitals NHS Foundation Trust London UK
| | - Wataru Shimizu
- Department of Cardiovascular Medicine Nippon Medical School Tokyo Japan
| | | | - Jacob Tfelt-Hansen
- Department of Forensic Medicine Faculty of Medical Sciences Rigshospitalet Copenhagen Denmark
| | - Dao Wu Wang
- The First Affiliated Hospital of Nanjing Medical University Nanjing China
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31
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Fadel S, Walker AE. The Postmortem Interpretation of Cardiac Genetic Variants of Unknown Significance in Sudden Death in the Young: A Case Report and Review of the Literature. Acad Forensic Pathol 2021; 10:166-175. [PMID: 33815637 DOI: 10.1177/1925362120984868] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 10/04/2020] [Indexed: 11/16/2022]
Abstract
Sudden cardiac death (SCD) in adolescents and young adults is a major traumatic event for families and communities. In these cases, it is not uncommon to have a negative autopsy with structurally and histologically normal heart. Such SCD cases are generally attributed to channelopathies, which include long QT syndrome, short QT syndrome, Brugada syndrome, and catecholaminergic polymorphic ventricular tachycardia. Our understanding of the causes for SCDs has changed significantly with the advancements in molecular and genetic studies, where many mutations are now known to be associated with certain channelopathies. Postmortem analysis provides great value in informing decision-making with regard to screening tests and prophylactic measures that should be taken to prevent sudden death in first degree relatives of the decedent. As this is a rapidly advancing field, our ability to identify genetic mutations has surpassed our ability to interpret them. This led to a unique challenge in genetic testing called variants of unknown significance (VUS). VUSs present a diagnostic dilemma and uncertainty for clinicians and patients with regard to next steps. Caution should be exercised when interpreting VUSs since misinterpretation can result in mismanagement of patients and their families. A case of a young adult man with drowning as his proximate cause of death is presented in circumstances where cardiac genetic testing was indicated and undertaken. Eight VUSs in genes implicated in inheritable cardiac dysfunction were identified and the interpretation of VUSs in this scenario is discussed.
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32
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González-Garrido A, Domínguez-Pérez M, Jacobo-Albavera L, López-Ramírez O, Guevara-Chávez JG, Zepeda-García O, Iturralde P, Carnevale A, Villarreal-Molina T. Compound Heterozygous KCNQ1 Mutations Causing Recessive Romano-Ward Syndrome: Functional Characterization by Mutant Co-expression. Front Cardiovasc Med 2021; 8:625449. [PMID: 33693037 PMCID: PMC7937651 DOI: 10.3389/fcvm.2021.625449] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/11/2021] [Indexed: 11/13/2022] Open
Abstract
Next Generation Sequencing has identified many KCNQ1 genetic variants associated with type 1 long QT or Romano-Ward syndrome, most frequently inherited in an autosomal dominant fashion, although recessive forms have been reported. Particularly in the case of missense variants, functional studies of mutants are of aid to establish variant pathogenicity and to understand the mechanistic basis of disease. Two compound heterozygous KCNQ1 mutations (p.A300T and p.P535T) were previously found in a child who suffered sudden death. To provide further insight into the clinical significance and basis for pathogenicity of these variants, different combinations of wildtype, A300T and P535T alleles were co-expressed with the accessory β-subunit minK in HEK293 cells, to analyze colocalization with the plasma membrane and some biophysical phenotypes of homo and heterotetrameric channels using the patch-clamp technique. A300T homotetrameric channels showed left-shifted activation V1/2 as previously observed in Xenopus oocytes, decreased maximum conductance density, slow rise-time300ms, and a characteristic use-dependent response. A300T slow rise-time300ms and use-dependent response behaved as dominant biophysical traits for all allele combinations. The P535T variant significantly decreased maximum conductance density and Kv7.1-minK-plasma membrane colocalization. P535T/A300T heterotetrameric channels showed decreased colocalization with plasma membrane, slow rise-time300ms and the A300T characteristic use-dependent response. While A300T left shifted activation voltage dependence behaved as a recessive trait when co-expressed with WT alleles, it was dominant when co-expressed with P535T alleles. Conclusions: The combination of P535T/A300T channel biophysical properties is compatible with recessive Romano Ward syndrome. Further analysis of other biophysical traits may identify other mechanisms involved in the pathophysiology of this disease.
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Affiliation(s)
- Antonia González-Garrido
- Laboratorio de Genómica de Enfermedades Cardiovasculares, Instituto Nacional de Medicina Genómica, Mexico City, Mexico.,Cátedras CONACyT, Consejo Nacional de Ciencia y Tecnología, Mexico City, Mexico
| | - Mayra Domínguez-Pérez
- Laboratorio de Genómica de Enfermedades Cardiovasculares, Instituto Nacional de Medicina Genómica, Mexico City, Mexico
| | - Leonor Jacobo-Albavera
- Laboratorio de Genómica de Enfermedades Cardiovasculares, Instituto Nacional de Medicina Genómica, Mexico City, Mexico
| | - Omar López-Ramírez
- Department of Neurobiology, University of Chicago, Chicago, IL, United States
| | - José Guadalupe Guevara-Chávez
- Laboratorio de Genómica de Enfermedades Cardiovasculares, Instituto Nacional de Medicina Genómica, Mexico City, Mexico
| | - Oscar Zepeda-García
- Laboratorio de Genómica de Enfermedades Cardiovasculares, Instituto Nacional de Medicina Genómica, Mexico City, Mexico
| | - Pedro Iturralde
- Departamento de Electrofisiología, Instituto Nacional de Cardiología "Ignacio Chávez", Mexico, Mexico
| | - Alessandra Carnevale
- Laboratorio de Enfermedades Mendelianas, Instituto Nacional de Medicina Genómica, Mexico, Mexico
| | - Teresa Villarreal-Molina
- Laboratorio de Genómica de Enfermedades Cardiovasculares, Instituto Nacional de Medicina Genómica, Mexico City, Mexico
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Sarquella-Brugada G, García-Algar O, Zambrano MD, Fernández-Falgueres A, Sailer S, Cesar S, Sebastiani G, Martí-Almor J, Aurensanz E, Cruzalegui JC, Merchan EF, Coll M, Pérez-Serra A, Del Olmo B, Fiol V, Iglesias A, Ferrer-Costa C, Puigmulé M, Lopez L, Pico F, Arbelo E, Jordà P, Brugada J, Brugada R, Campuzano O. Early Identification of Prolonged QT Interval for Prevention of Sudden Infant Death. Front Pediatr 2021; 9:704580. [PMID: 34395343 PMCID: PMC8358435 DOI: 10.3389/fped.2021.704580] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 07/05/2021] [Indexed: 11/26/2022] Open
Abstract
Introduction: Long QT syndrome is the main arrhythmogenic disease responsible for sudden death in infants, especially in the first days of life. Performing an electrocardiogram in newborns could enable early diagnosis and adoption of therapeutic measures focused on preventing lethal arrhythmogenic events. However, the inclusion of an electrocardiogram in neonatal screening protocols still remains a matter of discussion. To comprehensively analyse the potential clinical value of performing an electrocardiogram and subsequent follow-up in a cohort of newborns. Methods: Electrocardiograms were performed in 685 neonates within the first week of life. One year follow-up was performed if QTc > 450 ms identified. Comprehensive genetic analysis using massive sequencing was performed in all cases with QTc > 470 ms. Results: We identified 54 neonates with QTc > 450 ms/ <470 ms; all normalized QTc values within 6 months. Eight cases had QTc > 480 ms at birth and, if persistent, pharmacological treatment was administrated during follow-up. A rare variant was identified as the potential cause of long QT syndrome in five cases. Three cases showed a family history of sudden arrhythmogenic death. Conclusions: Our prospective study identifies 0.14% of cases with a definite long QT, supporting implementation of electrocardiograms in routine pediatric protocols. It is an effective, simple and non-invasive approach that can help prevent sudden death in neonates and their relatives. Genetic analyses help to unravel the cause of arrhythmogenic disease in diagnosing neonates. Further, clinical assessment and genetic analysis of relatives allowed early identification of family members at risk of arrhythmias helping to adopt preventive personalized measures.
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Affiliation(s)
- Georgia Sarquella-Brugada
- Arrhythmias Unit, Institut de Recerca Sant Joan de Déu, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain.,Medical Science Department, School of Medicine, University of Girona, Girona, Spain
| | - Oscar García-Algar
- Department of Neonatology, Hospital Clínic-Maternitat, Institut Clinic de Ginecologia, Obstetricia i Neonatología, BCNatal, Barcelona, Spain
| | - María Dolores Zambrano
- Arrhythmias Unit, Institut de Recerca Sant Joan de Déu, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
| | | | - Sebastian Sailer
- Department of Neonatology, Hospital Clínic-Maternitat, Institut Clinic de Ginecologia, Obstetricia i Neonatología, BCNatal, Barcelona, Spain.,Department of Neonatology, Faculty of Medicine, Kepler University Hospital, Johannes Kepler University, Linz, Austria
| | - Sergi Cesar
- Arrhythmias Unit, Institut de Recerca Sant Joan de Déu, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
| | - Giorgia Sebastiani
- Department of Neonatology, Hospital Clínic-Maternitat, Institut Clinic de Ginecologia, Obstetricia i Neonatología, BCNatal, Barcelona, Spain
| | | | - Esther Aurensanz
- Arrhythmias Unit, Institut de Recerca Sant Joan de Déu, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
| | - Jose Carlos Cruzalegui
- Arrhythmias Unit, Institut de Recerca Sant Joan de Déu, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
| | - Erika Fernanda Merchan
- Arrhythmias Unit, Institut de Recerca Sant Joan de Déu, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
| | - Mónica Coll
- Cardiovascular Genetics Center, University of Girona-Institut d'Investigació Biomèdica de Girona Dr. Josep Trueta, Girona, Spain
| | - Alexandra Pérez-Serra
- Cardiovascular Genetics Center, University of Girona-Institut d'Investigació Biomèdica de Girona Dr. Josep Trueta, Girona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares, Madrid, Spain
| | - Bernat Del Olmo
- Cardiovascular Genetics Center, University of Girona-Institut d'Investigació Biomèdica de Girona Dr. Josep Trueta, Girona, Spain
| | - Victoria Fiol
- Arrhythmias Unit, Institut de Recerca Sant Joan de Déu, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
| | - Anna Iglesias
- Cardiovascular Genetics Center, University of Girona-Institut d'Investigació Biomèdica de Girona Dr. Josep Trueta, Girona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares, Madrid, Spain
| | - Carles Ferrer-Costa
- Cardiovascular Genetics Center, University of Girona-Institut d'Investigació Biomèdica de Girona Dr. Josep Trueta, Girona, Spain
| | - Marta Puigmulé
- Cardiovascular Genetics Center, University of Girona-Institut d'Investigació Biomèdica de Girona Dr. Josep Trueta, Girona, Spain
| | - Laura Lopez
- Cardiovascular Genetics Center, University of Girona-Institut d'Investigació Biomèdica de Girona Dr. Josep Trueta, Girona, Spain
| | - Ferran Pico
- Cardiovascular Genetics Center, University of Girona-Institut d'Investigació Biomèdica de Girona Dr. Josep Trueta, Girona, Spain
| | - Elena Arbelo
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares, Madrid, Spain.,Arrhythmias Unit, Hospital Clinic, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain
| | - Paloma Jordà
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares, Madrid, Spain.,Arrhythmias Unit, Hospital Clinic, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain
| | - Josep Brugada
- Arrhythmias Unit, Institut de Recerca Sant Joan de Déu, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares, Madrid, Spain.,Arrhythmias Unit, Hospital Clinic, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain
| | - Ramon Brugada
- Medical Science Department, School of Medicine, University of Girona, Girona, Spain.,Cardiology Service, Hospital Josep Trueta, University of Girona, Girona, Spain.,Cardiovascular Genetics Center, University of Girona-Institut d'Investigació Biomèdica de Girona Dr. Josep Trueta, Girona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares, Madrid, Spain
| | - Oscar Campuzano
- Medical Science Department, School of Medicine, University of Girona, Girona, Spain.,Cardiovascular Genetics Center, University of Girona-Institut d'Investigació Biomèdica de Girona Dr. Josep Trueta, Girona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares, Madrid, Spain
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Koriath CAM, Kenny J, Ryan NS, Rohrer JD, Schott JM, Houlden H, Fox NC, Tabrizi SJ, Mead S. Genetic testing in dementia - utility and clinical strategies. Nat Rev Neurol 2021; 17:23-36. [PMID: 33168964 DOI: 10.1038/s41582-020-00416-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/11/2020] [Indexed: 02/07/2023]
Abstract
Techniques for clinical genetic testing in dementia disorders have advanced rapidly but remain to be more widely implemented in practice. A positive genetic test offers a precise molecular diagnosis, can help members of an affected family to determine personal risk, provides a basis for reproductive choices and can offer options for clinical trials. The likelihood of identifying a specific genetic cause of dementia depends on the clinical condition, the age at onset and family history. Attempts to match phenotypes to single genes are mostly inadvisable owing to clinical overlap between the dementias, genetic heterogeneity, pleiotropy and concurrent mutations. Currently, the appropriate genetic test in most cases of dementia is a next-generation sequencing gene panel, though some conditions necessitate specific types of test such as repeat expansion testing. Whole-exome and whole-genome sequencing are becoming financially feasible but raise or exacerbate complex issues such as variants of uncertain significance, secondary findings and the potential for re-analysis in light of new information. However, the capacity for data analysis and counselling is already restricting the provision of genetic testing. Patients and their relatives need to be given reliable information to enable them to make informed choices about tests, treatments and data sharing; the ability of patients with dementia to make decisions must be considered when providing this information.
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Affiliation(s)
| | - Joanna Kenny
- South West Thames Regional Genetics Service, London, UK
| | - Natalie S Ryan
- Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
- UK Dementia Research Institute, UCL Queen Square Institute of Neurology, London, UK
| | - Jonathan D Rohrer
- Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | - Jonathan M Schott
- Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | - Henry Houlden
- Neurogenetics Laboratory, National Hospital for Neurology and Neurosurgery, London, UK
| | - Nick C Fox
- Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
- UK Dementia Research Institute, UCL Queen Square Institute of Neurology, London, UK
| | - Sarah J Tabrizi
- Huntington's Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | - Simon Mead
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, London, UK.
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35
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Stiles MK, Wilde AAM, Abrams DJ, Ackerman MJ, Albert CM, Behr ER, Chugh SS, Cornel MC, Gardner K, Ingles J, James CA, Jimmy Juang JM, Kääb S, Kaufman ES, Krahn AD, Lubitz SA, MacLeod H, Morillo CA, Nademanee K, Probst V, Saarel EV, Sacilotto L, Semsarian C, Sheppard MN, Shimizu W, Skinner JR, Tfelt-Hansen J, Wang DW. 2020 APHRS/HRS expert consensus statement on the investigation of decedents with sudden unexplained death and patients with sudden cardiac arrest, and of their families. Heart Rhythm 2021; 18:e1-e50. [PMID: 33091602 PMCID: PMC8194370 DOI: 10.1016/j.hrthm.2020.10.010] [Citation(s) in RCA: 140] [Impact Index Per Article: 46.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 10/09/2020] [Indexed: 12/13/2022]
Abstract
This international multidisciplinary document intends to provide clinicians with evidence-based practical patient-centered recommendations for evaluating patients and decedents with (aborted) sudden cardiac arrest and their families. The document includes a framework for the investigation of the family allowing steps to be taken, should an inherited condition be found, to minimize further events in affected relatives. Integral to the process is counseling of the patients and families, not only because of the emotionally charged subject, but because finding (or not finding) the cause of the arrest may influence management of family members. The formation of multidisciplinary teams is essential to provide a complete service to the patients and their families, and the varied expertise of the writing committee was formulated to reflect this need. The document sections were divided up and drafted by the writing committee members according to their expertise. The recommendations represent the consensus opinion of the entire writing committee, graded by Class of Recommendation and Level of Evidence. The recommendations were opened for public comment and reviewed by the relevant scientific and clinical document committees of the Asia Pacific Heart Rhythm Society (APHRS) and the Heart Rhythm Society (HRS); the document underwent external review and endorsement by the partner and collaborating societies. While the recommendations are for optimal care, it is recognized that not all resources will be available to all clinicians. Nevertheless, this document articulates the evaluation that the clinician should aspire to provide for patients with sudden cardiac arrest, decedents with sudden unexplained death, and their families.
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Affiliation(s)
- Martin K Stiles
- Waikato Clinical School, Faculty of Medicine and Health Science, The University of Auckland, Hamilton, New Zealand
| | - Arthur A M Wilde
- Amsterdam University Medical Center, University of Amsterdam, Heart Center, Department of Clinical and Experimental Cardiology, Amsterdam, the Netherlands
| | | | | | | | - Elijah R Behr
- Cardiovascular Clinical Academic Group, Molecular and Clinical Sciences Institute, St George's, University of London, and St George's University Hospitals NHS Foundation Trust, London, United Kingdom
| | - Sumeet S Chugh
- Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Martina C Cornel
- Amsterdam University Medical Center, Vrije Universiteit Amsterdam, Clinical Genetics, Amsterdam Public Health Research Institute, Amsterdam, the Netherlands
| | | | - Jodie Ingles
- Agnes Ginges Centre for Molecular Cardiology at Centenary Institute, The University of Sydney, Sydney, Australia
| | | | - Jyh-Ming Jimmy Juang
- Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Stefan Kääb
- Department of Medicine I, University Hospital, LMU Munich, Munich, Germany
| | | | - Andrew D Krahn
- The University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Heather MacLeod
- Data Coordinating Center for the Sudden Death in the Young Case Registry, Okemos, Michigan, USA
| | | | - Koonlawee Nademanee
- Chulalongkorn University, Faculty of Medicine, and Pacific Rim Electrophysiology Research Institute at Bumrungrad Hospital, Bangkok, Thailand
| | | | - Elizabeth V Saarel
- Cleveland Clinic Lerner College of Cardiology at Case Western Reserve University, Cleveland, Ohio, and St Luke's Medical Center, Boise, Idaho, USA
| | - Luciana Sacilotto
- Heart Institute, University of São Paulo Medical School, São Paulo, Brazil
| | - Christopher Semsarian
- Agnes Ginges Centre for Molecular Cardiology at Centenary Institute, The University of Sydney, Sydney, Australia
| | - Mary N Sheppard
- Cardiovascular Clinical Academic Group, Molecular and Clinical Sciences Institute, St George's, University of London, and St George's University Hospitals NHS Foundation Trust, London, United Kingdom
| | - Wataru Shimizu
- Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan
| | - Jonathan R Skinner
- Cardiac Inherited Disease Group, Starship Hospital, Auckland, New Zealand
| | - Jacob Tfelt-Hansen
- Department of Forensic Medicine, Faculty of Medical Sciences, Rigshospitalet, Copenhagen, Denmark
| | - Dao Wu Wang
- The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
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36
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Recommendations from the Association for European Paediatric and Congenital Cardiology for training in diagnostic and interventional electrophysiology. Cardiol Young 2021; 31:38-46. [PMID: 33292898 DOI: 10.1017/s1047951120004096] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The field of electrophysiology (EP) in paediatric cardiology patients and adults with congenital heart disease is complex and rapidly growing. The current recommendations for diagnostic and invasive electrophysiology of the working group for Cardiac Dysrhythmias and Electrophysiology of the Association for European Paediatric and Congenital Cardiology acknowledges the diveristy of European countries and centers. These training recommendations can be fulfilled in a manageable period of time, without compromising the quality of training required to become an expert in the field of paediatric and congenital EP and are for trainees undergoing or having completed accredited paediatric cardiologist fellowship. Three levels of expertise, the training for General paediatric cardiology EP, for non-invasive EP and invasive EP have been defined. This Association for European EP curriculum describes the theoretical and practicsal knowledge in clinical EP; catheter ablation, cardiac implantable electronic devices, inherited arrhythmias and arrhythmias in adults with congenital heart defects for the 3 levels of expertise.
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37
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Functional evaluation of gene mutations in Long QT Syndrome: strength of evidence from in vitro assays for deciphering variants of uncertain significance. JOURNAL OF CONGENITAL CARDIOLOGY 2020. [DOI: 10.1186/s40949-020-00037-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Genetic screening is now commonplace for patients suspected of having inherited cardiac conditions. Variants of uncertain significance (VUS) in disease-associated genes pose problems for the diagnostician and reliable methods for evaluating VUS function are required. Although function is difficult to interrogate for some genes, heritable channelopathies have established mechanisms that should be amenable to well-validated evaluation techniques.
The cellular electrophysiology techniques of ‘voltage-’ and ‘patch-’ clamp have a long history of successful use and have been central to identifying both the roles of genes involved in different forms of congenital Long QT Syndrome (LQTS) and the mechanisms by which mutations lead to aberrant ion channel function underlying clinical phenotypes. This is particularly evident for KCNQ1, KCNH2 and SCN5A, mutations in which underlie > 90% of genotyped LQTS cases (the LQT1-LQT3 subtypes). Recent studies utilizing high throughput (HT) planar patch-clamp recording have shown it to discriminate effectively between rare benign and pathological variants, studied through heterologous expression of recombinant channels. In combination with biochemical methods for evaluating channel trafficking and supported by biophysical modelling, patch clamp also provides detailed mechanistic insight into the functional consequences of identified mutations. Whilst potentially powerful, patient-specific stem-cell derived cardiomyocytes and genetically modified animal models are currently not well-suited to high throughput VUS study.
Conclusion
The widely adopted 2015 American College of Medical Genetics (ACMG) and Association for Molecular Pathology (AMP) guidelines for the interpretation of sequence variants include the PS3 criterion for consideration of evidence from well-established in vitro or in vivo assays. The wealth of information on underlying mechanisms of LQT1-LQT3 and recent HT patch clamp data support consideration of patch clamp data together (for LQT1 and LQT2) with information from biochemical trafficking assays as meeting the PS3 criterion of well established assays, able to provide ‘strong’ evidence for functional pathogenicity of identified VUS.
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Fantin SM, Huang H, Sanders CR, Ruotolo BT. Collision-Induced Unfolding Differentiates Functional Variants of the KCNQ1 Voltage Sensor Domain. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:2348-2355. [PMID: 32960579 PMCID: PMC8106873 DOI: 10.1021/jasms.0c00288] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The KCNQ1 voltage-gated potassium channel regulates the repolarization of cardiac cells, and a plurality of point mutations in its voltage-sensing domain (VSD) are associated with toxic gain or loss of pore function, resulting in disease. As is the case with many disease-associated membrane proteins, there are hundreds of human variants of interest identified for KCNQ1; however, a significant portion of these variants have not been characterized in relation to their functional and disease associations. Additionally, as the VSD consists of four transmembrane helices, studies into dynamic structural differences among KCNQ1 VSD variants are hindered by the current limitations and deficits in the high-resolution structure determination of membrane proteins. Here, we use native ion mobility-mass spectrometry and collision-induced unfolding (CIU) to address the need for a high throughput-compatible method for the structural characterization of membrane protein variants of unknown significance using the KCNQ1 VSD as a model system. We perform CIU on wild-type and three mutant KCNQ1 VSD forms associated with the toxic gain or loss of function and show through both automated feature detection and comprehensive difference analysis of the CIU data sets that the variants are clearly grouped by function and disease association. We also construct a classification scheme based on the CIU data sets, which is able to differentiate the variant functional groups and classify a recently characterized variant to its correct grouping. Further, we probe the stability of the KCNQ1 VSD variants when liberated from C12E8 micelles at pH 8.0 and find preliminary evidence that the R231C mutation associated with the gain of the pore function is destabilized relative to the wild-type and loss of function variants.
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Affiliation(s)
- Sarah M. Fantin
- University of Michigan Department of Chemistry, Ann Arbor, Michigan 48109, United States
| | - Hui Huang
- Vanderbilt University, Department of Biochemistry, Nashville, Tennessee 37232, United States
| | - Charles R. Sanders
- Vanderbilt University, Department of Biochemistry, Nashville, Tennessee 37232, United States
| | - Brandon T. Ruotolo
- University of Michigan Department of Chemistry, Ann Arbor, Michigan 48109, United States
- Corresponding Author:
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Disease-associated HCN4 V759I variant is not sufficient to impair cardiac pacemaking. Pflugers Arch 2020; 472:1733-1742. [PMID: 33095298 PMCID: PMC7691308 DOI: 10.1007/s00424-020-02481-3] [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: 06/03/2020] [Revised: 09/11/2020] [Accepted: 10/16/2020] [Indexed: 11/16/2022]
Abstract
The hyperpolarization-activated cation current If is a key determinant for cardiac pacemaker activity. It is conducted by subunits of the hyperpolarization-activated cyclic nucleotide–gated (HCN) channel family, of which HCN4 is predominant in mammalian heart. Both loss-of-function and gain-of-function mutations of the HCN4 gene are associated with sinus node dysfunction in humans; however, their functional impact is not fully understood yet. Here, we sought to characterize a HCN4 V759I variant detected in a patient with a family history of sick sinus syndrome. The genomic analysis yielded a mono-allelic HCN4 V759I variant in a 49-year-old woman presenting with a family history of sick sinus syndrome. This HCN4 variant was previously classified as putatively pathogenic because genetically linked to sudden infant death syndrome and malignant epilepsy. However, detailed electrophysiological and cell biological characterization of HCN4 V759I in Xenopus laevis oocytes and embryonic rat cardiomyocytes, respectively, did not reveal any obvious abnormality. Voltage dependence and kinetics of mutant channel activation, modulation of cAMP-gating by the neuronal HCN channel auxiliary subunit PEX5R, and cell surface expression were indistinguishable from wild-type HCN4. In good agreement, the clinically likewise affected mother of the patient does not exhibit the reported HCN4 variance. HCN4 V759I resembles an innocuous genetic HCN channel variant, which is not sufficient to disturb cardiac pacemaking. Once more, our work emphasizes the importance of careful functional interpretation of genetic findings not only in the context of hereditary cardiac arrhythmias.
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40
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Belbachir N, Portero V, Al Sayed ZR, Gourraud JB, Dilasser F, Jesel L, Guo H, Wu H, Gaborit N, Guilluy C, Girardeau A, Bonnaud S, Simonet F, Karakachoff M, Pattier S, Scott C, Burel S, Marionneau C, Chariau C, Gaignerie A, David L, Genin E, Deleuze JF, Dina C, Sauzeau V, Loirand G, Baró I, Schott JJ, Probst V, Wu JC, Redon R, Charpentier F, Le Scouarnec S. RRAD mutation causes electrical and cytoskeletal defects in cardiomyocytes derived from a familial case of Brugada syndrome. Eur Heart J 2020; 40:3081-3094. [PMID: 31114854 DOI: 10.1093/eurheartj/ehz308] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 04/13/2018] [Accepted: 05/02/2019] [Indexed: 12/19/2022] Open
Abstract
AIMS The Brugada syndrome (BrS) is an inherited cardiac disorder predisposing to ventricular arrhythmias. Despite considerable efforts, its genetic basis and cellular mechanisms remain largely unknown. The objective of this study was to identify a new susceptibility gene for BrS through familial investigation. METHODS AND RESULTS Whole-exome sequencing performed in a three-generation pedigree with five affected members allowed the identification of one rare non-synonymous substitution (p.R211H) in RRAD, the gene encoding the RAD GTPase, carried by all affected members of the family. Three additional rare missense variants were found in 3/186 unrelated index cases. We detected higher levels of RRAD transcripts in subepicardium than in subendocardium in human heart, and in the right ventricle outflow tract compared to the other cardiac compartments in mice. The p.R211H variant was then subjected to electrophysiological and structural investigations in human cardiomyocytes derived from induced pluripotent stem cells (iPSC-CMs). Cardiomyocytes derived from induced pluripotent stem cells from two affected family members exhibited reduced action potential upstroke velocity, prolonged action potentials and increased incidence of early afterdepolarizations, with decreased Na+ peak current amplitude and increased Na+ persistent current amplitude, as well as abnormal distribution of actin and less focal adhesions, compared with intra-familial control iPSC-CMs Insertion of p.R211H-RRAD variant in control iPSCs by genome editing confirmed these results. In addition, iPSC-CMs from affected patients exhibited a decreased L-type Ca2+ current amplitude. CONCLUSION This study identified a potential new BrS-susceptibility gene, RRAD. Cardiomyocytes derived from induced pluripotent stem cells expressing RRAD variant recapitulated single-cell electrophysiological features of BrS, including altered Na+ current, as well as cytoskeleton disturbances.
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Affiliation(s)
- Nadjet Belbachir
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, 8 quai Moncousu, 44007 Nantes cedex 1, France.,Division of Cardiovascular Medicine, Department of Medicine, Stanford Cardiovascular Institute, Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Vincent Portero
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, 8 quai Moncousu, 44007 Nantes cedex 1, France
| | - Zeina R Al Sayed
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, 8 quai Moncousu, 44007 Nantes cedex 1, France
| | - Jean-Baptiste Gourraud
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, 8 quai Moncousu, 44007 Nantes cedex 1, France.,l'institut du thorax, CHU Nantes, Nantes, France
| | - Florian Dilasser
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, 8 quai Moncousu, 44007 Nantes cedex 1, France
| | - Laurence Jesel
- CHU Strasbourg, Service de Cardiologie, Strasbourg, France
| | - Hongchao Guo
- Division of Cardiovascular Medicine, Department of Medicine, Stanford Cardiovascular Institute, Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Haodi Wu
- Division of Cardiovascular Medicine, Department of Medicine, Stanford Cardiovascular Institute, Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Nathalie Gaborit
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, 8 quai Moncousu, 44007 Nantes cedex 1, France
| | | | - Aurore Girardeau
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, 8 quai Moncousu, 44007 Nantes cedex 1, France
| | - Stephanie Bonnaud
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, 8 quai Moncousu, 44007 Nantes cedex 1, France.,l'institut du thorax, CHU Nantes, Nantes, France
| | - Floriane Simonet
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, 8 quai Moncousu, 44007 Nantes cedex 1, France.,l'institut du thorax, CHU Nantes, Nantes, France
| | - Matilde Karakachoff
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, 8 quai Moncousu, 44007 Nantes cedex 1, France.,l'institut du thorax, CHU Nantes, Nantes, France
| | | | - Carol Scott
- The Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK
| | - Sophie Burel
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, 8 quai Moncousu, 44007 Nantes cedex 1, France
| | - Céline Marionneau
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, 8 quai Moncousu, 44007 Nantes cedex 1, France
| | - Caroline Chariau
- INSERM, CNRS, UNIV Nantes, CHU Nantes, SFR François Bonamy, iPSC core facility, Nantes, France
| | - Anne Gaignerie
- INSERM, CNRS, UNIV Nantes, CHU Nantes, SFR François Bonamy, iPSC core facility, Nantes, France
| | - Laurent David
- INSERM, CNRS, UNIV Nantes, CHU Nantes, SFR François Bonamy, iPSC core facility, Nantes, France.,Centre de Recherche en Transplantation et Immunologie UMR 1064, INSERM, UNIV Nantes, Institut de Transplantation Urologie Néphrologie (ITUN), CHU Nantes, Nantes, France
| | | | - Jean-François Deleuze
- Centre National de Recherche en Génomique Humaine, Institut de Génomique, CEA, Evry, France
| | - Christian Dina
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, 8 quai Moncousu, 44007 Nantes cedex 1, France.,l'institut du thorax, CHU Nantes, Nantes, France
| | - Vincent Sauzeau
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, 8 quai Moncousu, 44007 Nantes cedex 1, France
| | - Gervaise Loirand
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, 8 quai Moncousu, 44007 Nantes cedex 1, France
| | - Isabelle Baró
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, 8 quai Moncousu, 44007 Nantes cedex 1, France
| | - Jean-Jacques Schott
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, 8 quai Moncousu, 44007 Nantes cedex 1, France.,l'institut du thorax, CHU Nantes, Nantes, France
| | - Vincent Probst
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, 8 quai Moncousu, 44007 Nantes cedex 1, France.,l'institut du thorax, CHU Nantes, Nantes, France
| | - Joseph C Wu
- Division of Cardiovascular Medicine, Department of Medicine, Stanford Cardiovascular Institute, Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Richard Redon
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, 8 quai Moncousu, 44007 Nantes cedex 1, France.,l'institut du thorax, CHU Nantes, Nantes, France
| | - Flavien Charpentier
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, 8 quai Moncousu, 44007 Nantes cedex 1, France.,l'institut du thorax, CHU Nantes, Nantes, France
| | - Solena Le Scouarnec
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, 8 quai Moncousu, 44007 Nantes cedex 1, France
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VanDyke RE, Hashimoto S, Morales A, Pyatt RE, Sturm AC. Impact of variant reclassification in the clinical setting of cardiovascular genetics. J Genet Couns 2020; 30:503-512. [PMID: 33029862 DOI: 10.1002/jgc4.1336] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 08/25/2020] [Accepted: 08/30/2020] [Indexed: 01/06/2023]
Abstract
Genetic testing for cardiovascular disease (CVD) has advanced over the past ten years, but these advancements have posed new challenges in variant classification. To address these challenges, ACMG/AMP published guidelines for variant interpretation in 2015. This study aimed to determine what impact these guidelines have on variant classification in clinical cardiovascular genetics. A retrospective chart review identified patients who underwent clinical genetic testing and had a variant identified in a gene associated with CVD. For each variant, systematic evidence review was performed and ACMG guidelines were applied for classification. These classifications were compared to those provided on patients' genetic test reports. This study identified 223 unique variants in 237 patients. Seventy-nine (35%) of the variants had classifications that differed from their clinical reports. Twenty-eight (35%) of these reclassifications would have changed medical management recommendations for 38 patients. Application of these guidelines resulted in reclassification for approximately one-third of the variants in this study. Clinicians can have a more active role in the process of variant classification. Variant classifications should be updated over time in the clinical CVD setting due to the impact reclassifications can have on clinical screening recommendations.
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Affiliation(s)
- Rebecca E VanDyke
- Division of Human Genetics, The Ohio State University, Columbus, OH, USA
- Department of Clinical Genetics, Northwestern Medicine Central DuPage Hospital, Winfield, IL, USA
| | - Sayaka Hashimoto
- Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, OH, USA
| | - Ana Morales
- Division of Human Genetics, The Ohio State University, Columbus, OH, USA
| | - Robert E Pyatt
- Division of Human Genetics, The Ohio State University, Columbus, OH, USA
- Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, OH, USA
- New Jersey Center for Science, Technology, and Mathematics, Kean University, Union, NJ, USA
| | - Amy C Sturm
- Division of Human Genetics, The Ohio State University, Columbus, OH, USA
- Genomic Medicine Institute, Geisinger, Danville, PA, USA
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42
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Mattivi CL, Bos JM, Bagnall RD, Nowak N, Giudicessi JR, Ommen SR, Semsarian C, Ackerman MJ. Clinical Utility of a Phenotype-Enhanced
MYH7
-Specific Variant Classification Framework in Hypertrophic Cardiomyopathy Genetic Testing. CIRCULATION-GENOMIC AND PRECISION MEDICINE 2020; 13:453-459. [DOI: 10.1161/circgen.120.003039] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Background:
Missense variants in the
MYH7
-encoded MYH7 (beta myosin heavy chain 7) represent a leading cause of hypertrophic cardiomyopathy (HCM).
MYH7
-specific American College of Medical Genetics and Genomics (ACMG) variant classification guidelines were released recently but have yet to be assessed independently. We set out to assess the performance of the
MYH7
-specific ACMG guidelines and determine if the addition of phenotype-enhanced criteria (PE-ACMG) using the HCM Genotype Predictor Score can further reduce the burden of variants of uncertain significance (VUS).
Methods:
Re-assessment was performed on 70
MYH7
-variants in 121 unique patients from Mayo Clinic, and an independent cohort of 54 variants in 70 patients from Royal Prince Alfred Hospital (Australia). Qualifying variants were re-adjudicated using both standard ACMG and
MYH7
-ACMG guidelines, and HCM Genotype Predictor Score was used to provide a validated measure of strength of clinical phenotype to be incorporated into the
MYH7
-ACMG framework.
Results:
Among Mayo Clinic identified variants, 11/70 (16%) were classified as pathogenic (P), 10/70 (14%) as likely pathogenic, and 49/70 (70%) as a VUS. A similar distribution was seen in the Australian patients (12/54 [22%] P, 12/54 [22%] likely pathogenic, and 30/54 [56%] VUS;
P
=not significant). Application of the
MYH7
-ACMG resulted in a nonsignificant reduction of the VUS burden in both cohorts from 49/70 to 39/70 (56%;
P
=0.1; Mayo Clinic) and from 30/54 to 20/54 (37%;
P
=0.1; Australia). Using the combined PE-MYH7-ACMG framework, the VUS decreased significantly from 49 to 27 (
P
<0.001, Mayo Clinic) and from 30 to 16 (
P
<0.001; Australia).
Conclusions:
Use of the
MYH7
-specific guidelines alone failed to significantly decrease VUS burden in 2 independent cohorts. However, a significant reduction in VUS burden was observed after the addition of phenotypic criteria. Using a patient’s strength of sarcomeric HCM phenotype for variant adjudication can increase significantly the clinical utility of genetic testing for patients with HCM.
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Affiliation(s)
- Connor L. Mattivi
- Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic Graduate School of Biomedical Sciences (C.L.M., J.M.B., M.J.A.), Mayo Clinic, Rochester, MN
| | - J. Martijn Bos
- Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic Graduate School of Biomedical Sciences (C.L.M., J.M.B., M.J.A.), Mayo Clinic, Rochester, MN
- Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine (J.M.B., M.J.A.), Mayo Clinic, Rochester, MN
| | - Richard D. Bagnall
- Molecular Cardiology Program at Centenary Institute (R.D.B., N.N., C.S.), The University of Sydney
- Faculty of Medicine and Health (R.D.B., C.S.), The University of Sydney
| | - Natalie Nowak
- Molecular Cardiology Program at Centenary Institute (R.D.B., N.N., C.S.), The University of Sydney
| | - John R. Giudicessi
- Division of Heart Rhythm Services, Department of Cardiovascular Medicine, (J.R.G., S.R.O., M.J.A.), Mayo Clinic, Rochester, MN
| | - Steve R. Ommen
- Division of Heart Rhythm Services, Department of Cardiovascular Medicine, (J.R.G., S.R.O., M.J.A.), Mayo Clinic, Rochester, MN
| | - Christopher Semsarian
- Molecular Cardiology Program at Centenary Institute (R.D.B., N.N., C.S.), The University of Sydney
- Faculty of Medicine and Health (R.D.B., C.S.), The University of Sydney
- Department of Cardiology, Royal Prince Alfred Hospital, Sydney, Australia (C.S.)
| | - Michael J. Ackerman
- Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic Graduate School of Biomedical Sciences (C.L.M., J.M.B., M.J.A.), Mayo Clinic, Rochester, MN
- Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine (J.M.B., M.J.A.), Mayo Clinic, Rochester, MN
- Division of Heart Rhythm Services, Department of Cardiovascular Medicine, (J.R.G., S.R.O., M.J.A.), Mayo Clinic, Rochester, MN
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43
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Campuzano O, Sarquella-Brugada G, Cesar S, Arbelo E, Brugada J, Brugada R. Update on Genetic Basis of Brugada Syndrome: Monogenic, Polygenic or Oligogenic? Int J Mol Sci 2020; 21:ijms21197155. [PMID: 32998306 PMCID: PMC7582739 DOI: 10.3390/ijms21197155] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 09/23/2020] [Accepted: 09/25/2020] [Indexed: 12/13/2022] Open
Abstract
Brugada syndrome is a rare inherited arrhythmogenic disease leading to ventricular fibrillation and high risk of sudden death. In 1998, this syndrome was linked with a genetic variant with an autosomal dominant pattern of inheritance. To date, rare variants identified in more than 40 genes have been potentially associated with this disease. Variants in regulatory regions, combinations of common variants and other genetic alterations are also proposed as potential origins of Brugada syndrome, suggesting a polygenic or oligogenic inheritance pattern. However, most of these genetic alterations remain of questionable causality; indeed, rare pathogenic variants in the SCN5A gene are the only established cause of Brugada syndrome. Comprehensive analysis of all reported genetic alterations identified the origin of disease in no more than 40% of diagnosed cases. Therefore, identifying the cause of this rare arrhythmogenic disease in the many families without a genetic diagnosis is a major current challenge in Brugada syndrome. Additional challenges are interpretation/classification of variants and translation of genetic data into clinical practice. Further studies focused on unraveling the pathophysiological mechanisms underlying the disease are needed. Here we provide an update on the genetic basis of Brugada syndrome.
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Affiliation(s)
- Oscar Campuzano
- Cardiovascular Genetics Centre, University of Girona-IDIBGI, 17190 Girona, Spain
- Medical Science Department, School of Medicine, University of Girona, 17003 Girona, Spain;
- Centro Investigación Biomédica en Red: Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain; (E.A.); (J.B.)
- Correspondence: (O.C.); (R.B.)
| | - Georgia Sarquella-Brugada
- Medical Science Department, School of Medicine, University of Girona, 17003 Girona, Spain;
- Arrhythmia Unit, Hospital Sant Joan de Déu, University of Barcelona, 08950 Barcelona, Spain;
| | - Sergi Cesar
- Arrhythmia Unit, Hospital Sant Joan de Déu, University of Barcelona, 08950 Barcelona, Spain;
| | - Elena Arbelo
- Centro Investigación Biomédica en Red: Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain; (E.A.); (J.B.)
- Arrhythmia Unit, Hospital Sant Joan de Déu, University of Barcelona, 08950 Barcelona, Spain;
| | - Josep Brugada
- Centro Investigación Biomédica en Red: Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain; (E.A.); (J.B.)
- Arrhythmia Unit, Hospital Sant Joan de Déu, University of Barcelona, 08950 Barcelona, Spain;
- Arrhythmia Section, Cardiovascular Institute, Hospital Clinic, University of Barcelona, 08036 Barcelona, Spain
| | - Ramon Brugada
- Cardiovascular Genetics Centre, University of Girona-IDIBGI, 17190 Girona, Spain
- Medical Science Department, School of Medicine, University of Girona, 17003 Girona, Spain;
- Centro Investigación Biomédica en Red: Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain; (E.A.); (J.B.)
- Familial Cardiomyopathies Unit, Hospital Josep Trueta de Girona, 17007 Girona, Spain
- Correspondence: (O.C.); (R.B.)
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Abstract
The cardiology and clinical genetics subspecialty of cardiogenetics has experienced a tremendous growth in the past 25 years. This review discusses examples of the progress that has been made as well as new challenges that have arisen within this field, with special focus on the Netherlands. A significant number of Dutch founder mutations, i.e. mutations shared by a number of individuals who have a common origin and all share a unique chromosomal background on which the mutation occurred, have been identified and have provided unique insights into genotype-phenotype correlations in inherited arrhythmia syndromes and inherited cardiomyopathies. Cardiological and genetic screening of family members of young victims of sudden cardiac death combined with genetic testing in the deceased individual have turned out to be rewarding. However, the interpretation of the results of genetic testing in this setting and in the setting of living patients with a (suspected) phenotype is now considered more challenging than previously anticipated, because the introduction of high-throughput sequencing technologies has resulted in the identification of a significant number of variants of unknown significance. Interpretation of genetic and clinical findings by experienced multidisciplinary teams are key to ensure a high quality of care to the patient and the family.
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Affiliation(s)
- A A M Wilde
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.
| | - E Nannenberg
- Department of Clinical Genetics, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - C van der Werf
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
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Cherny S, Olson R, Chiodo K, Balmert LC, Webster G. Changes in genetic variant results over time in pediatric cardiomyopathy and electrophysiology. J Genet Couns 2020; 30:229-236. [PMID: 32706166 DOI: 10.1002/jgc4.1313] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 06/10/2020] [Accepted: 06/15/2020] [Indexed: 11/11/2022]
Abstract
Genetic testing for cardiac disorders continues to change. Our objective was to assess trends in variant classification in pediatric arrhythmia and cardiomyopathy. We conducted a retrospective review of patients tested for genetic arrhythmia and cardiomyopathy disorders from 2006-2017. Variants were classified by CLIA laboratories. Trends were assessed by the Spearman correlation. There were 914 variants in 583 patients from 337 families. The total number of tests ordered increased over time, accelerating after 2012. There was a strong positive correlation between the average number of genes tested per panel and year of testing (r = .97, p < .001) and a weak correlation between the year and a decrease in the percentage of clinically actionable variants (r = -.20, p = .005). By 2011, VUS represented >50% of variants reported on panels. Over 12 years, 203 genes were interrogated; one or more variants were reported in 91 of 203 genes (45%). 32% of patients had at least one clinically actionable variant; 28% had at least one VUS. Reclassification is an important long-term issue, with 21.5% variants changing clinical interpretation. We observed an increase over time in three areas: total number of tests ordered, average number of genes/panel, and percentage of VUS. Providers may need to interpret results from 90 + genes, and ongoing education is critical. Due to their specific training in test result interpretation, we recommend the inclusion of a genetic counselor in pediatric electrophysiology and cardiomyopathy teams.
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Affiliation(s)
- Sara Cherny
- Division of Cardiology, Ann and Robert H. Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Rachael Olson
- Division of Cardiology, Ann and Robert H. Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Kathryn Chiodo
- Division of Cardiology, Ann and Robert H. Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Lauren C Balmert
- Department of Preventive Medicine (Biostatistics), Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Gregory Webster
- Division of Cardiology, Ann and Robert H. Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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46
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Abstract
The main inherited cardiac arrhythmias are long QT syndrome, short QT syndrome, catecholaminergic polymorphic ventricular tachycardia and Brugada syndrome. These rare diseases are often the underlying cause of sudden cardiac death in young individuals and result from mutations in several genes encoding ion channels or proteins involved in their regulation. The genetic defects lead to alterations in the ionic currents that determine the morphology and duration of the cardiac action potential, and individuals with these disorders often present with syncope or a life-threatening arrhythmic episode. The diagnosis is based on clinical presentation and history, the characteristics of the electrocardiographic recording at rest and during exercise and genetic analyses. Management relies on pharmacological therapy, mostly β-adrenergic receptor blockers (specifically, propranolol and nadolol) and sodium and transient outward current blockers (such as quinidine), or surgical interventions, including left cardiac sympathetic denervation and implantation of a cardioverter-defibrillator. All these arrhythmias are potentially life-threatening and have substantial negative effects on the quality of life of patients. Future research should focus on the identification of genes associated with the diseases and other risk factors, improved risk stratification and, in particular for Brugada syndrome, effective therapies.
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47
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Giudicessi JR, Lieve KVV, Rohatgi RK, Koca F, Tester DJ, van der Werf C, Martijn Bos J, Wilde AAM, Ackerman MJ. Assessment and Validation of a Phenotype-Enhanced Variant Classification Framework to Promote or Demote RYR2 Missense Variants of Uncertain Significance. CIRCULATION-GENOMIC AND PRECISION MEDICINE 2020; 12:e002510. [PMID: 31112425 DOI: 10.1161/circgen.119.002510] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Background Many rare, potentially pathogenic, RYR2 variants identified in individuals with clinically definite catecholaminergic polymorphic ventricular tachycardia are classified ambiguously as variants of uncertain significance (VUS). We aimed to determine if a phenotype-enhanced variant classification approach could reduce the burden of RYR2 VUS encountered during clinical genetic testing. Methods This retrospective study was conducted in 84 RYR2-positive individuals from the Mayo Clinic (Rochester, MN) and validated in 149 RYR2-positive individuals from Amsterdam University Medical Center (Amsterdam, NL). Using a newly developed diagnostic scorecard, the pretest clinical probability of catecholaminergic polymorphic ventricular tachycardia was determined for all RYR2-positive individuals. Each RYR2 variant was then readjudicated using a phenotype-enhanced American College of Medical Genetics approach that incorporates new criteria that reflect the phenotypic strength associated with each individual RYR2 variant. Results Overall, 72 distinct RYR2 variants were identified among the 84 Mayo Clinic (39 unique) and 149 Amsterdam University Medical Center (30 unique) cases. Three variants were present in both cohorts. American College of Medical Genetics guidelines classified 47% of all RYR2 variants as VUS. In the Mayo Clinic cohort, readjudication using amended phenotype-enhanced American College of Medical Genetics standards dropped the VUS rate significantly (20/42 [48%] versus 3/42 [7%]; P<0.001) with 13/20 (65%) RYR2 VUS promoted to likely pathogenic and 4/20 (20%) demoted to likely benign. A similar drop in VUS rate (14/33 [42%] versus 3/33 [9%]; P=0.001) was observed in the Amsterdam University Medical Center validation cohort with 10/14 (71%) RYR2 VUS promoted to likely pathogenic and 1/14 (7%) demoted to likely benign. Conclusions This multicenter study illustrates the potential utility of phenotype-enhanced variant classification in catecholaminergic polymorphic ventricular tachycardia.
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Affiliation(s)
- John R Giudicessi
- Department of Cardiovascular Medicine (Clinician-Investigator Training Program) (J.R.G.)
| | - Krystien V V Lieve
- Amsterdam UMC, University of Amsterdam, Heart Center and Department of Clinical and Experimental Cardiology, Amsterdam Cardiovascular Sciences, The Netherlands (K.V.V.L., F.K., C.v.d.W., A.A.M.W.)
| | - Ram K Rohatgi
- Department of Pediatric and Adolescent Medicine (Division of Pediatric Cardiology) (R.K.R.)
| | - Faruk Koca
- Amsterdam UMC, University of Amsterdam, Heart Center and Department of Clinical and Experimental Cardiology, Amsterdam Cardiovascular Sciences, The Netherlands (K.V.V.L., F.K., C.v.d.W., A.A.M.W.)
| | - David J Tester
- Departments of Cardiovascular Medicine (Division of Heart Rhythm Services), Pediatrics (Division of Pediatric Cardiology), and Molecular Pharmacology and Experimental Therapeutics (Windland Smith Rice Sudden Death Genomics Laboratory), Mayo Clinic, Rochester, MN (D.J.T., J.M.B., M.J.A.)
| | - Christian van der Werf
- Amsterdam UMC, University of Amsterdam, Heart Center and Department of Clinical and Experimental Cardiology, Amsterdam Cardiovascular Sciences, The Netherlands (K.V.V.L., F.K., C.v.d.W., A.A.M.W.)
| | - J Martijn Bos
- Departments of Cardiovascular Medicine (Division of Heart Rhythm Services), Pediatrics (Division of Pediatric Cardiology), and Molecular Pharmacology and Experimental Therapeutics (Windland Smith Rice Sudden Death Genomics Laboratory), Mayo Clinic, Rochester, MN (D.J.T., J.M.B., M.J.A.)
| | - Arthur A M Wilde
- Amsterdam UMC, University of Amsterdam, Heart Center and Department of Clinical and Experimental Cardiology, Amsterdam Cardiovascular Sciences, The Netherlands (K.V.V.L., F.K., C.v.d.W., A.A.M.W.)
| | - Michael J Ackerman
- Departments of Cardiovascular Medicine (Division of Heart Rhythm Services), Pediatrics (Division of Pediatric Cardiology), and Molecular Pharmacology and Experimental Therapeutics (Windland Smith Rice Sudden Death Genomics Laboratory), Mayo Clinic, Rochester, MN (D.J.T., J.M.B., M.J.A.)
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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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Haïssaguerre M, Duchateau J, Dubois R, Hocini M, Cheniti G, Sacher F, Lavergne T, Probst V, Surget E, Vigmond E, Welte N, Chauvel R, Derval N, Pambrun T, Jais P, Nademanee W, Bernus O. Idiopathic Ventricular Fibrillation: Role of Purkinje System and Microstructural Myocardial Abnormalities. JACC Clin Electrophysiol 2020; 6:591-608. [PMID: 32553208 PMCID: PMC7308805 DOI: 10.1016/j.jacep.2020.03.010] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 03/24/2020] [Accepted: 03/24/2020] [Indexed: 12/18/2022]
Abstract
Idiopathic ventricular fibrillation is diagnosed in patients who survived a ventricular fibrillation episode without any identifiable structural or electrical cause after extensive investigations. It is a common cause of sudden death in young adults. The study reviews the diagnostic value of systematic investigations and the new insights provided by detailed electrophysiological mapping. Recent studies have shown the high incidence of microstructural cardiomyopathic areas, which act as the substrate of ventricular fibrillation re-entries. These subclinical alterations require high-density endo- and epicardial mapping to be identified using electrogram criteria. Small areas are involved and located individually in various sites (mostly epicardial). Their characteristics suggest a variety of genetic or acquired pathological processes affecting cellular connectivity or tissue structure, such as cardiomyopathies, myocarditis, or fatty infiltration. Purkinje abnormalities manifesting as triggering ectopy or providing a substrate for re-entry represent a second important cause. The documentation of ephemeral Purkinje ectopy requires continuous electrocardiography monitoring for diagnosis. A variety of diseases affecting Purkinje cell function or conduction are potentially at play in their pathogenesis. Comprehensive investigations can therefore allow the great majority of idiopathic ventricular fibrillation to ultimately receive diagnoses of a cardiac disease, likely underlain by a mosaic of pathologies. Precise phenotypic characterization has significant implications for interpretation of genetic variants, the risk assessment, and individual therapy. Future improvements in imaging or electrophysiological methods may hopefully allow the identification of the subjects at risk and the development of primary prevention strategies.
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Affiliation(s)
- Michel Haïssaguerre
- Department of Electrophysiology and Cardiac Stimulation, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France; Institut Hospitalo-Universitaire Electrophysiology and Heart Modeling Institute, Centre Hospitalier Universitaire de Bordeaux, France; Cardiothoracic Research Center Bordeaux, Université de Bordeaux, Bordeaux, France.
| | - Josselin Duchateau
- Department of Electrophysiology and Cardiac Stimulation, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France; Institut Hospitalo-Universitaire Electrophysiology and Heart Modeling Institute, Centre Hospitalier Universitaire de Bordeaux, France; Cardiothoracic Research Center Bordeaux, Université de Bordeaux, Bordeaux, France
| | - Remi Dubois
- Department of Electrophysiology and Cardiac Stimulation, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France; Institut Hospitalo-Universitaire Electrophysiology and Heart Modeling Institute, Centre Hospitalier Universitaire de Bordeaux, France; Cardiothoracic Research Center Bordeaux, Université de Bordeaux, Bordeaux, France
| | - Mélèze Hocini
- Department of Electrophysiology and Cardiac Stimulation, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France; Institut Hospitalo-Universitaire Electrophysiology and Heart Modeling Institute, Centre Hospitalier Universitaire de Bordeaux, France; Cardiothoracic Research Center Bordeaux, Université de Bordeaux, Bordeaux, France
| | - Ghassen Cheniti
- Department of Electrophysiology and Cardiac Stimulation, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France; Institut Hospitalo-Universitaire Electrophysiology and Heart Modeling Institute, Centre Hospitalier Universitaire de Bordeaux, France; Cardiothoracic Research Center Bordeaux, Université de Bordeaux, Bordeaux, France
| | - Frederic Sacher
- Department of Electrophysiology and Cardiac Stimulation, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France; Institut Hospitalo-Universitaire Electrophysiology and Heart Modeling Institute, Centre Hospitalier Universitaire de Bordeaux, France; Cardiothoracic Research Center Bordeaux, Université de Bordeaux, Bordeaux, France
| | - Thomas Lavergne
- Department of Electrophysiology and Cardiac Stimulation, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France; Institut Hospitalo-Universitaire Electrophysiology and Heart Modeling Institute, Centre Hospitalier Universitaire de Bordeaux, France; Cardiothoracic Research Center Bordeaux, Université de Bordeaux, Bordeaux, France
| | | | - Elodie Surget
- Department of Electrophysiology and Cardiac Stimulation, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France; Institut Hospitalo-Universitaire Electrophysiology and Heart Modeling Institute, Centre Hospitalier Universitaire de Bordeaux, France; Cardiothoracic Research Center Bordeaux, Université de Bordeaux, Bordeaux, France
| | - Ed Vigmond
- Department of Electrophysiology and Cardiac Stimulation, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France; Institut Hospitalo-Universitaire Electrophysiology and Heart Modeling Institute, Centre Hospitalier Universitaire de Bordeaux, France; Cardiothoracic Research Center Bordeaux, Université de Bordeaux, Bordeaux, France
| | - Nicolas Welte
- Department of Electrophysiology and Cardiac Stimulation, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France; Institut Hospitalo-Universitaire Electrophysiology and Heart Modeling Institute, Centre Hospitalier Universitaire de Bordeaux, France; Cardiothoracic Research Center Bordeaux, Université de Bordeaux, Bordeaux, France
| | - Remi Chauvel
- Department of Electrophysiology and Cardiac Stimulation, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France; Institut Hospitalo-Universitaire Electrophysiology and Heart Modeling Institute, Centre Hospitalier Universitaire de Bordeaux, France; Cardiothoracic Research Center Bordeaux, Université de Bordeaux, Bordeaux, France
| | - Nicolas Derval
- Department of Electrophysiology and Cardiac Stimulation, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France; Institut Hospitalo-Universitaire Electrophysiology and Heart Modeling Institute, Centre Hospitalier Universitaire de Bordeaux, France; Cardiothoracic Research Center Bordeaux, Université de Bordeaux, Bordeaux, France
| | - Thomas Pambrun
- Department of Electrophysiology and Cardiac Stimulation, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France; Institut Hospitalo-Universitaire Electrophysiology and Heart Modeling Institute, Centre Hospitalier Universitaire de Bordeaux, France; Cardiothoracic Research Center Bordeaux, Université de Bordeaux, Bordeaux, France
| | - Pierre Jais
- Department of Electrophysiology and Cardiac Stimulation, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France; Institut Hospitalo-Universitaire Electrophysiology and Heart Modeling Institute, Centre Hospitalier Universitaire de Bordeaux, France; Cardiothoracic Research Center Bordeaux, Université de Bordeaux, Bordeaux, France
| | - Wee Nademanee
- Cardiology Department, Bumrungrad International Hospital, Bangkok, Thailand
| | - Olivier Bernus
- Institut Hospitalo-Universitaire Electrophysiology and Heart Modeling Institute, Centre Hospitalier Universitaire de Bordeaux, France; Cardiothoracic Research Center Bordeaux, Université de Bordeaux, Bordeaux, France
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50
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Ye D, Zhou W, Tester DJ, Ackerman MJ. Discovery and characterization of a monogenetic insult, caveolin-3-V37L, that precipitated oligo-proteomic perturbations governing repolarization reserve. Int J Cardiol 2020; 319:71-77. [PMID: 32387251 DOI: 10.1016/j.ijcard.2020.05.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 04/14/2020] [Accepted: 05/04/2020] [Indexed: 11/16/2022]
Abstract
BACKGROUND Caveolin-3 (Cav-3) is an essential scaffolding protein for caveolae formation in cardiomyocytes and targets multiple long QT syndrome (LQTS)-associated ion channels. Mutations in CAV3 have caused an LQT3-like accentuation in late sodium current, INa (Nav1.5). Here, we characterize a novel CAV3-V37L variant and determine whether it is the substrate for the patient's LQTS. METHODS The proband was a 39-year-old female with drug-induced, sudden cardiac arrest (SCA) with profound QT prolongation (QTc > 600 ms). Genetic testing revealed a rare CAV3-V37L variant of uncertain significance (VUS). Whole-cell patch clamp technique was used to measure IKs, IKr, INa, and ICa, L currents co-expressed with either CAV3-WT or CAV3-V37L in TSA201 cells and to measure the action potential duration (APD) in control human induced pluripotent stem cells-derived cardiomyocytes (hiPSC-CMs) overexpressed with CAV3-WT or CAV3-V37L. RESULTS CAV3-V37L did not affect Nav1.5 late current. Instead, CAV3-V37L resulted in 1) ICa, L with slower inactivation, a 1.5 fold increase in peak ICa, L current density and a 1.1 fold increase in ICa, L persistent current, 2) dramatically reduced IKs peak current density by 74.9%, 3) significantly reduced IKr peak current density by 31.1%, and 4) significantly prolonged the APD in hiPSC-CMs. CONCLUSIONS These functional validation assays enabled the promotion of CAV3-V37L from VUS status to a likely pathogenic variant. Although Nav1.5 was spared, this monogenetic insult precipitated an oligo-proteomic impact with a concomitant gain-of-function of ICa, L and loss-of-function of both IKs and IKr culminating in a marked prolongation of the cardiomyocyte's action potential duration.
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Affiliation(s)
- Dan Ye
- Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN 55905, USA; Department of Cardiovascular Medicine/Division of Heart Rhythm Services, Mayo Clinic, Rochester, MN 55905, USA
| | - Wei Zhou
- Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN 55905, USA; Department of Cardiovascular Medicine/Division of Heart Rhythm Services, Mayo Clinic, Rochester, MN 55905, USA
| | - David J Tester
- Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN 55905, USA; Department of Cardiovascular Medicine/Division of Heart Rhythm Services, Mayo Clinic, Rochester, MN 55905, USA
| | - Michael J Ackerman
- Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN 55905, USA; Department of Cardiovascular Medicine/Division of Heart Rhythm Services, Mayo Clinic, Rochester, MN 55905, USA; Department of Pediatric and Adolescent Medicine/Division of Pediatric Cardiology, Mayo Clinic, Rochester, MN 55905, USA.
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