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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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52
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Dougherty L, Bai T, Brown S, Xu K. Exploring DNA Variant Segregation Types Enables Mapping Loci for Recessive Phenotypic Suppression of Columnar Growth in Apple. FRONTIERS IN PLANT SCIENCE 2020; 11:692. [PMID: 32582242 PMCID: PMC7297030 DOI: 10.3389/fpls.2020.00692] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 05/01/2020] [Indexed: 06/11/2023]
Abstract
Columnar apples trees, originated from a bud mutation 'Wijcik McIntosh,' develop a simple canopy and set fruit on spurs. These characteristics make them an important genetic resource for improvement of tree architecture. Genetic studies have uncovered that columnar growth habit is a dominant trait and is caused by a retroposon insertion that induces the expression of the neighboring gene Co encoding a 2OG-Fe(II) oxygenase. Here we report the genetic mapping of two loci of recessive suppressors (genes) c2 (on Chr10) and c3 (on Chr9) that are linked to repression of the retroposon-induced Co gene expression and associated columnar phenotype in 275 F1 seedlings, which were developed from a reciprocal cross between two columnar selections heterozygous at the Co locus. The mapping was accomplished by sequencing a genomic pool comprising 18 columnar seedlings and another pool of 16 standard seedlings that also carry the retroposon insertion, and by exploring DNA variants of segregation types that are informative for mapping recessive traits in apple. The informative segregation types include <hk × hk>, <lm × ll>, <nn × np>, <lm × mm>, and <pp × np>, where each letter denotes one of the four DNA bases and the letters in bold represent variants in relation to the reference genome. The alleles in each first and third positions are assumed in linkage with the recessive suppressors' allele in the two parents, respectively. Using RNA-seq analysis, we further revealed that the Co gene together with the differentially expressed genes under loci c2 and c3 formed a co-expression gene-network module associated with growth habit, in which 12 MapMan Bins were enriched.
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Affiliation(s)
- Laura Dougherty
- Horticulture Section, School of Integrative Plant Science, Cornell Agritech, Cornell University, Geneva, NY, United States
| | - Tuanhui Bai
- Horticulture Section, School of Integrative Plant Science, Cornell Agritech, Cornell University, Geneva, NY, United States
- College of Horticulture, Henan Agricultural University, Zhengzhou, China
| | - Susan Brown
- Horticulture Section, School of Integrative Plant Science, Cornell Agritech, Cornell University, Geneva, NY, United States
| | - Kenong Xu
- Horticulture Section, School of Integrative Plant Science, Cornell Agritech, Cornell University, Geneva, NY, United States
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53
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Li KHC, Lee S, Yin C, Liu T, Ngarmukos T, Conte G, Yan GX, Sy RW, Letsas KP, Tse G. Brugada syndrome: A comprehensive review of pathophysiological mechanisms and risk stratification strategies. IJC HEART & VASCULATURE 2020; 26:100468. [PMID: 31993492 PMCID: PMC6974766 DOI: 10.1016/j.ijcha.2020.100468] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 01/01/2020] [Accepted: 01/02/2020] [Indexed: 12/17/2022]
Abstract
Brugada syndrome (BrS) is an inherited ion channel channelopathy predisposing to ventricular arrhythmias and sudden cardiac death. Originally believed to be predominantly associated with mutations in SCN5A encoding for the cardiac sodium channel, mutations of 18 genes other than SCN5A have been implicated in the pathogenesis of BrS to date. Diagnosis is based on the presence of a spontaneous or drug-induced coved-type ST segment elevation. The predominant electrophysiological mechanism underlying BrS remains disputed, commonly revolving around the three main hypotheses based on abnormal repolarization, depolarization or current-load match. Evidence from computational modelling, pre-clinical and clinical studies illustrates that molecular abnormalities found in BrS lead to alterations in excitation wavelength (λ), which ultimately elevates arrhythmic risk. A major challenge for clinicians in managing this condition is the difficulty in predicting the subset of patients who will suffer from life-threatening ventricular arrhythmic events. Several repolarization risk markers have been used thus far, but these neglect the contributions of conduction abnormalities in the form of slowing and dispersion. Indices incorporating both repolarization and conduction based on the concept of λ have recently been proposed. These may have better predictive values than the existing markers. Current treatment options include pharmacological therapy to reduce the occurrence of arrhythmic events or to abort these episodes, and interventions such as implantable cardioverter-defibrillator insertion or radiofrequency ablation of abnormal arrhythmic substrate.
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Affiliation(s)
- Ka Hou Christien Li
- Faculty of Medicine, Newcastle University, Newcastle, United Kingdom.,Laboratory of Cardiovascular Physiology, Li Ka Shing Institute of Health Sciences, Hong Kong, SAR, PR China
| | - Sharen Lee
- Laboratory of Cardiovascular Physiology, Li Ka Shing Institute of Health Sciences, Hong Kong, SAR, PR China
| | - Chengye Yin
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
| | - Tong Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, PR China
| | - Tachapong Ngarmukos
- Department of Medicine Faculty of Medicine Ramathibodi Hospital Mahidol University, Bangkok, Thailand
| | - Giulio Conte
- Division of Cardiology, Cardiocentro Ticino, Lugano, Switzerland
| | - Gan-Xin Yan
- Lankenau Institute for Medical Research and Lankenau Medical Center, Wynnewood, PA, USA
| | - Raymond W Sy
- Department of Cardiology, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia.,Sydney Medical School, University of Sydney, Camperdown, New South Wales, Australia
| | - Konstantinos P Letsas
- Second Department of Cardiology, Laboratory of Cardiac Electrophysiology, Evangelismos General Hospital of Athens, Athens, Greece
| | - Gary Tse
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, PR China.,Xiamen Cardiovascular Hospital, Xiamen University, Xiamen, China
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Hammami Bomholtz S, Refaat M, Buur Steffensen A, David J, Espinosa K, Nussbaum R, Wojciak J, Hjorth Bentzen B, Scheinman M, Schmitt N. Functional phenotype variations of two novel K
V
7.1 mutations identified in patients with Long QT syndrome. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2020; 43:210-216. [DOI: 10.1111/pace.13870] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 12/20/2019] [Accepted: 12/29/2019] [Indexed: 11/30/2022]
Affiliation(s)
- Sofia Hammami Bomholtz
- Danish National Research Foundation Centre for Cardiac ArrhythmiaUniversity of Copenhagen Copenhagen Denmark
- Department of Biomedical SciencesUniversity of Copenhagen Copenhagen Denmark
| | - Marwan Refaat
- Department of Internal Medicine, Division of CardiologyAmerican University of Beirut Medical Center Beirut Lebanon
- Department of Biochemistry and Molecular GeneticsAmerican University of Beirut Beirut Lebanon
| | - Annette Buur Steffensen
- Danish National Research Foundation Centre for Cardiac ArrhythmiaUniversity of Copenhagen Copenhagen Denmark
- Department of Biomedical SciencesUniversity of Copenhagen Copenhagen Denmark
| | - Jens‐Peter David
- Danish National Research Foundation Centre for Cardiac ArrhythmiaUniversity of Copenhagen Copenhagen Denmark
- Department of Biomedical SciencesUniversity of Copenhagen Copenhagen Denmark
| | - Karin Espinosa
- Danish National Research Foundation Centre for Cardiac ArrhythmiaUniversity of Copenhagen Copenhagen Denmark
- Department of Biomedical SciencesUniversity of Copenhagen Copenhagen Denmark
| | - Robert Nussbaum
- Department of MedicineUniversity of California, San Francisco San Francisco California
| | - Julianne Wojciak
- Department of MedicineUniversity of California, San Francisco San Francisco California
| | - Bo Hjorth Bentzen
- Danish National Research Foundation Centre for Cardiac ArrhythmiaUniversity of Copenhagen Copenhagen Denmark
- Department of Biomedical SciencesUniversity of Copenhagen Copenhagen Denmark
| | - Melvin Scheinman
- Department of MedicineUniversity of California, San Francisco San Francisco California
| | - Nicole Schmitt
- Danish National Research Foundation Centre for Cardiac ArrhythmiaUniversity of Copenhagen Copenhagen Denmark
- Department of Biomedical SciencesUniversity of Copenhagen Copenhagen Denmark
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55
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Yong-Quan Ng G, Yang-Wei Fann D, Jo DG, Sobey CG, Arumugam TV. Dietary Restriction and Epigenetics: Part I. CONDITIONING MEDICINE 2019; 2:284-299. [PMID: 32039345 PMCID: PMC7007115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/14/2023]
Abstract
Biological aging occurs concomitantly with chronological aging and is commonly burdened by the development of age-related conditions, such as neurodegenerative, cardiovascular, and a myriad of metabolic diseases. With a current global shift in disease epidemiology associated with aging and the resultant social, economic, and healthcare burdens faced by many countries, the need to achieve successful aging has fueled efforts to address this problem. Aging is a complex biological phenomenon that has confounded much of the historical research effort to understand it, with still limited knowledge of the underlying molecular mechanisms. Interestingly, dietary restriction (DR) is one intervention that produces anti-aging effects from simple organisms to mammals. Research into DR has revealed robust systemic effects that can result in attenuation of age-related diseases via a myriad of molecular mechanisms. Given that numerous age-associated diseases are often polygenic and affect individuals differently, it is possible that they are confounded by interactions between environmental influences and the genome, a process termed 'epigenetics'. In part one of the review, we summarize the different variants of DR regimens and their corresponding mechanism(s) and resultant effects, as well as in-depth analysis of current knowledge of the epigenetic landscape.
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Affiliation(s)
- Gavin Yong-Quan Ng
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - David Yang-Wei Fann
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Dong-Gyu Jo
- School of Pharmacy, Sungkyunkwan University, Suwon, Republic of Korea
| | - Christopher G. Sobey
- Department of Physiology, Anatomy & Microbiology, School of Life Sciences, La Trobe University, Bundoora, Victoria, Australia
| | - Thiruma V. Arumugam
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- School of Pharmacy, Sungkyunkwan University, Suwon, Republic of Korea
- Department of Physiology, Anatomy & Microbiology, School of Life Sciences, La Trobe University, Bundoora, Victoria, Australia
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56
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57
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Santori M, Gil R, Blanco-Verea A, Riuró H, Díaz-Castro Ó, López-Abel B, Brugada R, Carracedo Á, Pérez GJ, Scornik FS, Brion M. Sudden infant death as the most severe phenotype caused by genetic modulation in a family with atrial fibrillation. Forensic Sci Int Genet 2019; 43:102159. [PMID: 31522018 DOI: 10.1016/j.fsigen.2019.102159] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 08/26/2019] [Accepted: 08/29/2019] [Indexed: 12/29/2022]
Abstract
AIMS To assess the functional impact of two combined KCNH2 variants involved in atrial fibrillation, syncope and sudden infant death syndrome. METHODS AND RESULTS Genetic testing of a 4-month old SIDS victim identified a rare missense heterozygous in KCNH2 variant (V483I) and a missense homozygous polymorphism (K897T) which is often described as a genetic modifier. Electrophysiological characterisation of heterologous HERG channels representing two different KCNH2 genotypes within the family, showed significant differences in both voltage and time dependence of activation and inactivation with a global gain-of-function effect of mutant versus wild type channels and, also, differences between both types of recombinant channels. CONCLUSIONS The rare variant V483I in combination with K897T produces a gain-of-function effect that represents a pathological substrate for atrial fibrillation, syncope and sudden infant death syndrome events in this family. Ascertaining the genotype-phenotype correlation of genetic variants is imperative for the correct assessment of genetic testing and counselling. TRANSLATIONAL PERSPECTIVE According to the current guidelines for clinical interpretation of sequence variants, functional studies are an essential tool for the ascertainment of variant pathogenicity. They are especially relevant in the context of sudden infant death syndrome and sudden cardiac death, where individuals cannot be clinically evaluated. The patch-clamp technique is a gold-standard for analysis of the biophysical mechanisms of ion channels.
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Affiliation(s)
- Montserrat Santori
- Xenética Cardiovascular, Instituto de Investigación Sanitaria de Santiago de Compostela, Spain; Grupo de Medicina Xenómica, Universidade de Santiago de Compostela, Spain.
| | - Rocío Gil
- Xenética Cardiovascular, Instituto de Investigación Sanitaria de Santiago de Compostela, Spain; Grupo de Medicina Xenómica, Universidade de Santiago de Compostela, Spain
| | - Alejandro Blanco-Verea
- Xenética Cardiovascular, Instituto de Investigación Sanitaria de Santiago de Compostela, Spain; Grupo de Medicina Xenómica, Universidade de Santiago de Compostela, Spain
| | - Helena Riuró
- Cardiovascular Genetics Center, Institut d'Investigació Biomèdica de Girona, Spain; Department of Medical Sciences, Medical School, Universitat de Girona, Spain
| | - Óscar Díaz-Castro
- Servizo de Cardioloxía, Hospital de Pontevedra, Servizo Galego de Saúde, Pontevedra, Spain
| | - Bernardo López-Abel
- Xenética Cardiovascular, Instituto de Investigación Sanitaria de Santiago de Compostela, Spain; Servizo de Pediatría, Hospital Clínico Universitario de Santiago de Compostela, Spain
| | - Ramón Brugada
- Cardiovascular Genetics Center, Institut d'Investigació Biomèdica de Girona, Spain; Department of Medical Sciences, Medical School, Universitat de Girona, Spain; Red de Enfermedades Cardiovasculares (CIBERCV), Spain
| | - Ángel Carracedo
- Grupo de Medicina Xenómica, Universidade de Santiago de Compostela, Spain; Fundación Pública Galega de Medicina Xenómica, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Santiago de Compostela, Spain
| | - Guillermo J Pérez
- Department of Medical Sciences, Medical School, Universitat de Girona, Spain; Red de Enfermedades Cardiovasculares (CIBERCV), Spain
| | - Fabiana S Scornik
- Department of Medical Sciences, Medical School, Universitat de Girona, Spain; Red de Enfermedades Cardiovasculares (CIBERCV), Spain
| | - María Brion
- Xenética Cardiovascular, Instituto de Investigación Sanitaria de Santiago de Compostela, Spain; Grupo de Medicina Xenómica, Universidade de Santiago de Compostela, Spain; Red de Enfermedades Cardiovasculares (CIBERCV), Spain
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58
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Giudicessi JR. Machine Learning and Rare Variant Adjudication in Type 1 Long QT Syndrome. ACTA ACUST UNITED AC 2019; 10:CIRCGENETICS.117.001944. [PMID: 29021308 DOI: 10.1161/circgenetics.117.001944] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- John R Giudicessi
- From the Departments of Cardiovascular Medicine and Internal Medicine (Clinician-Investigator Training Program), Mayo Clinic, Rochester, MN.
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59
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Campuzano O, Fernandez-Falgueras A, Sarquella-Brugada G, Cesar S, Arbelo E, García-Álvarez A, Jordà P, Coll M, Fiol V, Iglesias A, Perez-Serra A, Mates J, Del Olmo B, Ferrer C, Alcalde M, Puigmulé M, Mademont-Soler I, Pico F, Lopez L, Tiron C, Brugada J, Brugada R. Personalized Interpretation and Clinical Translation of Genetic Variants Associated With Cardiomyopathies. Front Genet 2019; 10:450. [PMID: 31156706 PMCID: PMC6529573 DOI: 10.3389/fgene.2019.00450] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Accepted: 04/30/2019] [Indexed: 12/04/2022] Open
Abstract
Cardiomyopathies are a heterogeneous group of inherited cardiac diseases characterized by progressive myocardium abnormalities associated with mechanical and/or electrical dysfunction. Massive genetic sequencing technologies allow a comprehensive genetic analysis to unravel the cause of disease. However, most identified genetic variants remain of unknown clinical significance due to incomplete penetrance and variable expressivity. Therefore, genetic interpretation of variants and translation into clinical practice remain a current challenge. We performed retrospective comprehensive clinical assessment and genetic analysis in six families, four diagnosed with arrhythmogenic cardiomyopathy, and two diagnosed with hypertrophic cardiomyopathy (HCM). Genetic testing identified three rare variants (two non-sense and one small indel inducing a frameshift), each present in two families. Although each variant is currently classified as pathogenic and the cause of the diagnosed cardiomyopathy, the onset and/or clinical course differed in each patient. New genetic technology allows comprehensive yet cost-effective genetic analysis, although genetic interpretation, and clinical translation of identified variants should be carefully done in each family in a personalized manner.
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Affiliation(s)
- Oscar Campuzano
- Cardiovascular Genetics Center, Biomedical Research Institute of Girona, University of Girona, Girona, Spain.,Department of Medical Science, School of Medicine, University of Girona, Girona, Spain.,Centro Investigación Biomédica Red Enfermedades Cardiovasculares, Madrid, Spain.,Department of Biochemistry and Molecular Genetics, Hospital Clinic, Barcelona, Spain
| | - Anna Fernandez-Falgueras
- Cardiovascular Genetics Center, Biomedical Research Institute of Girona, University of Girona, Girona, Spain
| | - Georgia Sarquella-Brugada
- Department of Medical Science, School of Medicine, University of Girona, Girona, Spain.,Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
| | - Sergi Cesar
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
| | - Elena Arbelo
- Centro Investigación Biomédica Red Enfermedades Cardiovasculares, Madrid, Spain.,Arrhythmias Unit, Hospital Clinic, University of Barcelona, Barcelona, Spain
| | - Ana García-Álvarez
- Arrhythmias Unit, Hospital Clinic, University of Barcelona, Barcelona, Spain
| | - Paloma Jordà
- Arrhythmias Unit, Hospital Clinic, University of Barcelona, Barcelona, Spain
| | - Monica Coll
- Cardiovascular Genetics Center, Biomedical Research Institute of Girona, University of Girona, Girona, Spain
| | - Victoria Fiol
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
| | - Anna Iglesias
- Cardiovascular Genetics Center, Biomedical Research Institute of Girona, University of Girona, Girona, Spain.,Centro Investigación Biomédica Red Enfermedades Cardiovasculares, Madrid, Spain
| | - Alexandra Perez-Serra
- Cardiovascular Genetics Center, Biomedical Research Institute of Girona, University of Girona, Girona, Spain.,Centro Investigación Biomédica Red Enfermedades Cardiovasculares, Madrid, Spain
| | - Jesus Mates
- Cardiovascular Genetics Center, Biomedical Research Institute of Girona, University of Girona, Girona, Spain
| | - Bernat Del Olmo
- Cardiovascular Genetics Center, Biomedical Research Institute of Girona, University of Girona, Girona, Spain
| | - Carles Ferrer
- Cardiovascular Genetics Center, Biomedical Research Institute of Girona, University of Girona, Girona, Spain
| | - Mireia Alcalde
- Cardiovascular Genetics Center, Biomedical Research Institute of Girona, University of Girona, Girona, Spain.,Centro Investigación Biomédica Red Enfermedades Cardiovasculares, Madrid, Spain
| | - Marta Puigmulé
- Cardiovascular Genetics Center, Biomedical Research Institute of Girona, University of Girona, Girona, Spain
| | - Irene Mademont-Soler
- Cardiovascular Genetics Center, Biomedical Research Institute of Girona, University of Girona, Girona, Spain
| | - Ferran Pico
- Cardiovascular Genetics Center, Biomedical Research Institute of Girona, University of Girona, Girona, Spain
| | - Laura Lopez
- Cardiovascular Genetics Center, Biomedical Research Institute of Girona, University of Girona, Girona, Spain
| | - Coloma Tiron
- Cardiology Service, Hospital Josep Trueta, University of Girona, Girona, Spain
| | - Josep Brugada
- Centro Investigación Biomédica Red Enfermedades Cardiovasculares, Madrid, Spain.,Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain.,Arrhythmias Unit, Hospital Clinic, University of Barcelona, Barcelona, Spain
| | - Ramon Brugada
- Cardiovascular Genetics Center, Biomedical Research Institute of Girona, University of Girona, Girona, Spain.,Department of Medical Science, School of Medicine, University of Girona, Girona, Spain.,Centro Investigación Biomédica Red Enfermedades Cardiovasculares, Madrid, Spain.,Cardiology Service, Hospital Josep Trueta, University of Girona, Girona, Spain
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Baruscotti M, Bucchi A, Milanesi R, Paina M, Barbuti A, Gnecchi-Ruscone T, Bianco E, Vitali-Serdoz L, Cappato R, DiFrancesco D. A gain-of-function mutation in the cardiac pacemaker HCN4 channel increasing cAMP sensitivity is associated with familial Inappropriate Sinus Tachycardia. Eur Heart J 2019; 38:280-288. [PMID: 28182231 DOI: 10.1093/eurheartj/ehv582] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 10/01/2015] [Accepted: 10/07/2015] [Indexed: 01/09/2023] Open
Affiliation(s)
- Mirko Baruscotti
- Department of Biosciences, The PaceLab and 'Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata', Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
| | - Annalisa Bucchi
- Department of Biosciences, The PaceLab and 'Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata', Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
| | - Raffaella Milanesi
- Department of Biosciences, The PaceLab and 'Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata', Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
| | - Manuel Paina
- Department of Biosciences, The PaceLab and 'Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata', Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
| | - Andrea Barbuti
- Department of Biosciences, The PaceLab and 'Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata', Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
| | | | - Elisabetta Bianco
- Cardiovascular Department, 'Ospedali Riuniti di Trieste', University Hospital, Trieste, Italy
| | | | | | - Dario DiFrancesco
- Department of Biosciences, The PaceLab and 'Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata', Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
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61
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Dhar R, Missarova AM, Lehner B, Carey LB. Single cell functional genomics reveals the importance of mitochondria in cell-to-cell phenotypic variation. eLife 2019; 8:38904. [PMID: 30638445 PMCID: PMC6366901 DOI: 10.7554/elife.38904] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 01/13/2019] [Indexed: 12/12/2022] Open
Abstract
Mutations frequently have outcomes that differ across individuals, even when these individuals are genetically identical and share a common environment. Moreover, individual microbial and mammalian cells can vary substantially in their proliferation rates, stress tolerance, and drug resistance, with important implications for the treatment of infections and cancer. To investigate the causes of cell-to-cell variation in proliferation, we used a high-throughput automated microscopy assay to quantify the impact of deleting >1500 genes in yeast. Mutations affecting mitochondria were particularly variable in their outcome. In both mutant and wild-type cells mitochondrial membrane potential - but not amount - varied substantially across individual cells and predicted cell-to-cell variation in proliferation, mutation outcome, stress tolerance, and resistance to a clinically used anti-fungal drug. These results suggest an important role for cell-to-cell variation in the state of an organelle in single cell phenotypic variation.
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Affiliation(s)
- Riddhiman Dhar
- Systems Biology Program, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain.,Universitat Pompeu Fabra, Barcelona, Spain.,Department of Biotechnology, Indian Institute of Technology, Kharagpur, India
| | - Alsu M Missarova
- Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Ben Lehner
- Systems Biology Program, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain.,Universitat Pompeu Fabra, Barcelona, Spain.,Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Lucas B Carey
- Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
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62
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Hylind RJ, Chandler SF, Skinner JR, Abrams DJ. Genetic Testing for Inherited Cardiac Arrhythmias: Current State-of-the-Art and Future Avenues. J Innov Card Rhythm Manag 2018; 9:3406-3416. [PMID: 32494476 PMCID: PMC7252877 DOI: 10.19102/icrm.2018.091102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 03/14/2018] [Indexed: 12/24/2022] Open
Abstract
The seminal discovery that sequence variation in genes encoding cardiac ion channels was behind the inherited cardiac arrhythmic syndromes has led to major advances in understanding the functional biological mechanisms of cardiomyocyte depolarization and repolarization. The cost and speed with which these genes can now be sequenced have allowed for genetic testing to become a major component of clinical care and have led to important ramifications, yet interpretation of specific variants needs to be performed within the context of the clinical findings in the proband and extended family. As technology continues to advance, the promise of therapeutic manipulation of certain genetic pathways grows ever more real.
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Affiliation(s)
- Robyn J. Hylind
- Inherited Cardiac Arrhythmia Program, Department of Cardiology, Boston Children’s Hospital and Harvard Medical School, Boston, MA, USA
| | - Stephanie F. Chandler
- Inherited Cardiac Arrhythmia Program, Department of Cardiology, Boston Children’s Hospital and Harvard Medical School, Boston, MA, USA
| | - Jonathan R. Skinner
- Green Lane Paediatric and Congenital Cardiac Services, Starship Children’s Hospital, Auckland, New Zealand
- Department of Paediatrics, Child and Youth Health, The University of Auckland, Auckland, New Zealand
| | - Dominic J. Abrams
- Inherited Cardiac Arrhythmia Program, Department of Cardiology, Boston Children’s Hospital and Harvard Medical School, Boston, MA, USA
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63
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Gardner RJM, Crozier IG, Binfield AL, Love DR, Lehnert K, Gibson K, Lintott CJ, Snell RG, Jacobsen JC, Jones PP, Waddell-Smith KE, Kennedy MA, Skinner JR. Penetrance and expressivity of the R858H CACNA1C variant in a five-generation pedigree segregating an arrhythmogenic channelopathy. Mol Genet Genomic Med 2018; 7:e00476. [PMID: 30345660 PMCID: PMC6382452 DOI: 10.1002/mgg3.476] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 08/22/2018] [Accepted: 08/23/2018] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Isolated cardiac arrhythmia due to a variant in CACNA1C is of recent knowledge. Most reports have been of singleton cases or of quite small families, and estimates of penetrance and expressivity have been difficult to obtain. We here describe a large pedigree, from which such estimates have been calculated. METHODS We studied a five-generation family, in which a CACNA1C variant c.2573G>A p.Arg858His co-segregates with syncope and cardiac arrest, documenting electrocardiographic data and cardiac symptomatology. The reported patients/families from the literature with CACNA1C gene variants were reviewed, and genotype-phenotype correlations are drawn. RESULTS The range of phenotype in the studied family is wide, from no apparent effect, through an asymptomatic QT interval prolongation on electrocardiography, to episodes of presyncope and syncope, ventricular fibrillation, and sudden death. QT prolongation showed inconsistent correlation with functional cardiology. Based upon analysis of 28 heterozygous family members, estimates of penetrance and expressivity are derived. CONCLUSIONS These estimates of penetrance and expressivity, for this specific variant, may be useful in clinical practice. Review of the literature indicates that individual CACNA1C variants have their own particular genotype-phenotype correlations. We suggest that, at least in respect of the particular variant reported here, "arrhythmogenic channelopathy" may be a more fitting nomenclature than long QT syndrome.
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Affiliation(s)
- R J McKinlay Gardner
- Cardiac Inherited Disease Group, Auckland, New Zealand.,Genetic Health Service New Zealand (South Island Hub), Christchurch Hospital, Christchurch, New Zealand.,Clinical Genetics Group, Department of Women's and Children's Health, University of Otago, Dunedin, New Zealand
| | - Ian G Crozier
- Cardiac Inherited Disease Group, Auckland, New Zealand.,Department of Cardiology, Christchurch Hospital, Christchurch, New Zealand
| | - Alex L Binfield
- Cardiac Inherited Disease Group, Auckland, New Zealand.,Department of Paediatrics, Christchurch Hospital, Christchurch, New Zealand.,Department of Paediatrics, University of Otago, Christchurch, New Zealand
| | - Donald R Love
- Cardiac Inherited Disease Group, Auckland, New Zealand.,LabPlus, Auckland City Hospital, Auckland, New Zealand
| | - Klaus Lehnert
- Cardiac Inherited Disease Group, Auckland, New Zealand.,School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Kate Gibson
- Cardiac Inherited Disease Group, Auckland, New Zealand.,Genetic Health Service New Zealand (South Island Hub), Christchurch Hospital, Christchurch, New Zealand
| | - Caroline J Lintott
- Cardiac Inherited Disease Group, Auckland, New Zealand.,Genetic Health Service New Zealand (South Island Hub), Christchurch Hospital, Christchurch, New Zealand
| | - Russell G Snell
- Cardiac Inherited Disease Group, Auckland, New Zealand.,School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Jessie C Jacobsen
- Cardiac Inherited Disease Group, Auckland, New Zealand.,School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Peter P Jones
- Cardiac Inherited Disease Group, Auckland, New Zealand.,Department of Physiology and HeartOtago, University of Otago, Dunedin, New Zealand
| | - Kathryn E Waddell-Smith
- Cardiac Inherited Disease Group, Auckland, New Zealand.,Department of Cardiology, Auckland City Hospital, Auckland, New Zealand
| | - Martin A Kennedy
- Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Jonathan R Skinner
- Cardiac Inherited Disease Group, Auckland, New Zealand.,Department of Cardiology, Auckland City Hospital, Auckland, New Zealand
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64
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Elston S, Kaski J, Starling L. Long QT syndrome with a functional 2:1 block and multilevel conduction disease. PROGRESS IN PEDIATRIC CARDIOLOGY 2018. [DOI: 10.1016/j.ppedcard.2018.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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65
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Gibbs C, Thalamus J, Tveten K, Busk ØL, Hysing J, Haugaa KH, Holla ØL. Genetic and Phenotypic Characterization of Community Hospital Patients With QT Prolongation. J Am Heart Assoc 2018; 7:e009706. [PMID: 30369311 PMCID: PMC6201409 DOI: 10.1161/jaha.118.009706] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 07/09/2018] [Indexed: 12/19/2022]
Abstract
Background Congenital long- QT syndrome ( LQTS ) is a genetic disorder characterized by prolongation of the corrected QT interval ( QT c) on an ECG . The aim of the present study was to estimate the prevalence of pathogenic and likely pathogenic sequence variants in patients who had at least 1 ECG with a QT c ≥500 ms. Methods and Results Telemark Hospital Trust is a community hospital within the Norwegian national health system, serving ≈173 000 inhabitants. We searched the ECG database at Telemark Hospital Trust, Norway, from January 2004 to December 2014, and identified 1531 patients with at least 1 ECG with a QT c ≥500 ms. At the time of inclusion in this study (2015), 766 patients were alive. A total of 733 patients were invited to participate, and 475 accepted. The 17 genes that have been reported to cause monogenic LQTS were sequenced among the patients. Pro- QT c score was calculated for each patient. A molecular genetic cause of LQTS was detected in 31 (6.5%) of 475 patients. These patients had a lower pro- QT c score than those without pathogenic or likely pathogenic variants (1.7±1.0 versus 2.8±1.6; P<0.001). Conclusions Compared with the general population, hospitalized patients with a QT c ≥500 ms in at least 1 ECG recording had an increased likelihood for pathogenic and likely pathogenic variants in LQTS genes. We recommend increased awareness of the possibility of LQTS in patients with at least 1 ECG with a QT c ≥500 ms.
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Affiliation(s)
- Charlotte Gibbs
- Department of Internal MedicineTelemark Hospital TrustSkienNorway
- Institute of Clinical MedicineFaculty of MedicineUniversity of OsloNorway
| | - Jacob Thalamus
- Department of Internal MedicineTelemark Hospital TrustSkienNorway
| | - Kristian Tveten
- Department of Medical GeneticsTelemark Hospital TrustSkienNorway
| | - Øyvind L. Busk
- Department of Medical GeneticsTelemark Hospital TrustSkienNorway
| | - Jan Hysing
- Department of Internal MedicineTelemark Hospital TrustSkienNorway
| | - Kristina H. Haugaa
- Institute of Clinical MedicineFaculty of MedicineUniversity of OsloNorway
- Center for Cardiological InnovationDepartment of CardiologyOslo University HospitalRikshospitalet and University of OsloNorway
| | - Øystein L. Holla
- Department of Medical GeneticsTelemark Hospital TrustSkienNorway
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66
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Helm BM, Ayers MD, Kean AC. All Along the Watchtower: a Case of Long QT Syndrome Misdiagnosis Secondary to Genetic Testing Misinterpretation. J Genet Couns 2018; 27:1515-1522. [DOI: 10.1007/s10897-018-0287-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 08/02/2018] [Indexed: 11/29/2022]
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Giudicessi JR, Ackerman MJ. Calcium Revisited: New Insights Into the Molecular Basis of Long-QT Syndrome. Circ Arrhythm Electrophysiol 2018; 9:CIRCEP.116.002480. [PMID: 27390209 DOI: 10.1161/circep.116.002480] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 05/27/2016] [Indexed: 12/12/2022]
Affiliation(s)
- John R Giudicessi
- From the Internal Medicine Residency and Clinician-Investigator Programs, Department of Medicine (J.R.G.) and Departments of Cardiovascular Diseases, Pediatrics (Division of Pediatric Cardiology), and Molecular Pharmacology & Experimental Therapeutics (M.J.A.), Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN
| | - Michael J Ackerman
- From the Internal Medicine Residency and Clinician-Investigator Programs, Department of Medicine (J.R.G.) and Departments of Cardiovascular Diseases, Pediatrics (Division of Pediatric Cardiology), and Molecular Pharmacology & Experimental Therapeutics (M.J.A.), Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN.
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68
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van Deventer BS, du Toit-Prinsloo L, van Niekerk C. Feasibility of analysis of the SCN5A gene in paraffin embedded samples in sudden infant death cases at the Pretoria Medico-Legal Laboratory, South Africa. Forensic Sci Med Pathol 2018; 14:276-284. [PMID: 29907895 DOI: 10.1007/s12024-018-9995-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/23/2018] [Indexed: 12/19/2022]
Abstract
To determine variations in the SCN5A gene linked to inherited cardiac arrhythmogenic disorders in sudden, unexplained infant death (SUID) cases examined at the Pretoria Medico-Legal Laboratory, South Africa. A retrospective study was conducted on SUID cases and controls, analyzing DNA extracted from archived formalin-fixed, paraffin-embedded (FFPE) myocardial tissue samples as well as blood samples. A total of 48 FFPE tissue samples (cases), 10 control FFPE tissue samples and nine control blood samples were included. DNA extracted from all samples was used to test for variations in the SCN5A gene by using high resolution melt (HRM) real-time PCR and sequencing. Genetic analysis showed 31 different single nucleotide variants in the entire study population (n = 67). Five previously reported variants of known pathogenic significance, and 14 variants of benign clinical significance, were identified. The study found 12 different variants in the cases that were not published in any database or literature and were considered novel. Of these novel variants, two were predicted as "probably damaging" with a high level of certainty (found in four case samples), one (identified in another case sample) was predicted to be "possibly damaging" with a 50% chance of being disease-causing, and nine were predicted to be benign. This study shows the significant added value of using genetic testing in determining the cause of death in South African SUID cases. Considering the high heritability of these arrhythmic disorders, post mortem genetic testing could play an important role in the understanding of the pathogenesis thereof and could also aid in the diagnosis and treatment of family members at risk, ultimately preventing similar future cases.
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Affiliation(s)
| | - Lorraine du Toit-Prinsloo
- Department of Forensic Medicine, University of Pretoria, Pretoria, South Africa.,Department of Forensic Medicine, Sydney, Forensic & Analytical Science Services (FASS), NSW Health Pathology, Sydney, New South Wales, Australia
| | - Chantal van Niekerk
- Department of Chemical Pathology, University of Pretoria, R3-43 Pathology Building, Prinshof Campus, Pretoria, 0002, Republic of South Africa. .,Department of Chemical Pathology, National Health Laboratory Services (NHLS), Tshwane Academic Division, Pretoria, South Africa.
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69
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Reuter CM, Brimble E, DeFilippo C, Dries AM, Enns GM, Ashley EA, Bernstein JA, Fisher PG, Wheeler MT. A New Approach to Rare Diseases of Children: The Undiagnosed Diseases Network. J Pediatr 2018; 196:291-297.e2. [PMID: 29331327 PMCID: PMC5924635 DOI: 10.1016/j.jpeds.2017.12.029] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 11/09/2017] [Accepted: 12/14/2017] [Indexed: 10/18/2022]
Affiliation(s)
- Chloe M. Reuter
- Stanford Center for Undiagnosed Diseases, Stanford University School of Medicine, Stanford, CA, 94305, USA,Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Elise Brimble
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Colette DeFilippo
- Department of Pediatrics, Division of Medical Genetics, Stanford University School of Medicine, Stanford, CA, 94305, USA,Stanford Children’s Health, Palo Alto, CA, 94304, USA
| | - Annika M. Dries
- Stanford Center for Undiagnosed Diseases, Stanford University School of Medicine, Stanford, CA, 94305, USA,Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | | | - Gregory M. Enns
- Department of Pediatrics, Division of Medical Genetics, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Euan A. Ashley
- Stanford Center for Undiagnosed Diseases, Stanford University School of Medicine, Stanford, CA, 94305, USA,Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA,Department of Genetics, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Jonathan A. Bernstein
- Stanford Center for Undiagnosed Diseases, Stanford University School of Medicine, Stanford, CA, 94305, USA,Department of Pediatrics, Division of Medical Genetics, Stanford University School of Medicine, Stanford, CA, 94305, USA,Stanford Children’s Health, Palo Alto, CA, 94304, USA
| | - Paul Graham Fisher
- Stanford Center for Undiagnosed Diseases, Stanford University School of Medicine, Stanford, CA, 94305, USA,Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, 94305, USA,Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Matthew T. Wheeler
- Stanford Center for Undiagnosed Diseases, Stanford University School of Medicine, Stanford, CA, 94305, USA,Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
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Long QT syndrome type 5-Lite: Defining the clinical phenotype associated with the potentially proarrhythmic p.Asp85Asn-KCNE1 common genetic variant. Heart Rhythm 2018; 15:1223-1230. [PMID: 29625280 DOI: 10.1016/j.hrthm.2018.03.038] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Indexed: 01/27/2023]
Abstract
BACKGROUND Long QT syndrome (LQTS) genetic test reports commonly exclude potentially proarrhythmic common variants such as p.Asp85Asn-KCNE1. OBJECTIVE The purpose of this study was to determine whether a discernible phenotype is associated with p.Asp85Asn-KCNE1 and whether relatively common KCNE1 variants underlie transient QT prolongation pedigrees with negative commercial LQTS genetic tests. METHODS Retrospective review was used to compare demographics, symptomatology, and QT parameters of individuals with p.Asp85Asn-KCNE1 in the absence of other rare/ultra-rare variants in LQTS-susceptibility genes and those who underwent comprehensive LQTS genetic testing. RESULTS Compared to the Genome Aggregation Database, p.Asp85Asn-KCNE1 was more prevalent in individuals undergoing LQTS genetic testing (33/1248 [2.6%] vs 1552/126,652 [1.2%]; P = .0001). In 19 of 33 patients (58%), only p.Asp85Asn-KCNE1 was observed. These patients were predominantly female (90% vs 62%; P = .01) and were less likely to experience syncope (0% vs 34%; P = .0007), receive β-blockers (53% vs 85%; P = .001), or require an implantable cardioverter-defibrillator (5.3% vs 33%; P = .01). However, they exhibited a similar degree of QT prolongation (QTc 460 ms vs 467 ms; P = NS). Whole exome sequencing of 2 commercially genotype-negative pedigrees revealed that p.Asp85Asn-KCNE1 and p.Arg36His-KCNE1 traced with a transient QT prolongation phenotype. Functional characterization of p.Arg36His-KCNE1 demonstrated loss of function, with a 47% reduction in peak IKs current density in the heterozygous state. CONCLUSION We provide further evidence that relatively common variants in KCNE1 may result in a mild QT phenotype designated as "LQT5-Lite" to distinguish such potentially proarrhythmic common variants (ie, functional risk alleles) from rare pathogenic variants that truly confer monogenic disease susceptibility, albeit with incomplete penetrance.
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71
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Giudicessi JR, Wilde AAM, Ackerman MJ. The genetic architecture of long QT syndrome: A critical reappraisal. Trends Cardiovasc Med 2018; 28:453-464. [PMID: 29661707 DOI: 10.1016/j.tcm.2018.03.003] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 03/19/2018] [Accepted: 03/21/2018] [Indexed: 12/19/2022]
Abstract
Collectively, the completion of the Human Genome Project and subsequent development of high-throughput next-generation sequencing methodologies have revolutionized genomic research. However, the rapid sequencing and analysis of thousands upon thousands of human exomes and genomes has taught us that most genes, including those known to cause heritable cardiovascular disorders such as long QT syndrome, harbor an unexpected background rate of rare, and presumably innocuous, non-synonymous genetic variation. In this Review, we aim to reappraise the genetic architecture underlying both the acquired and congenital forms of long QT syndrome by examining how the clinical phenotype associated with and background genetic variation in long QT syndrome-susceptibility genes impacts the clinical validity of existing gene-disease associations and the variant classification and reporting strategies that serve as the foundation for diagnostic long QT syndrome genetic testing.
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Affiliation(s)
- John R Giudicessi
- Department of Cardiovascular Medicine (Cardiovascular Diseases Fellowship and Clinician-Investigator Training Programs), Mayo Clinic, Rochester, MN, United States
| | - Arthur A M Wilde
- Department of Medicine (Division of Cardiology), Columbia University Irving Medical Center, New York, NY, United States; Department of Clinical & Experimental Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Michael J Ackerman
- Departments of Cardiovascular Medicine (Division of Heart Rhythm Services), Pediatrics (Division of Pediatric Cardiology), and Molecular Pharmacology & Experimental Therapeutics (Windland Smith Rice Sudden Death Genomics Laboratory), Mayo Clinic, Rochester, MN, United States.
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72
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Zhu YB, Luo JW, Jiang F, Liu G. Genetic analysis of sick sinus syndrome in a family harboring compound CACNA1C and TTN mutations. Mol Med Rep 2018; 17:7073-7080. [PMID: 29568937 PMCID: PMC5928663 DOI: 10.3892/mmr.2018.8773] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Accepted: 03/06/2018] [Indexed: 12/23/2022] Open
Abstract
Sick sinus syndrome (SSS) is a sinus node dysfunction characterized by severe sinus bradycardia. SSS results in insufficient blood supply to the brain, heart, kidneys, and other organs and is associated with the increased risk of sudden cardiac death. Bradyarrhythmia appears in the absence of any associated cardiac pathology and displays a genetic legacy. The present study identified a family with primary manifestation of sinus bradycardia (five individuals) along with early repolarization (four individuals) and atrial fibrillation (one individual). Targeted exome sequencing was used to screen exons and adjacent splice sites of 61 inherited arrhythmia‑associated genes, to detect pathogenic genes and variant sites in the proband. Family members were sequenced by Sanger sequencing and protein functions predicted by Polyphen‑2 software. A total of three rare variants were identified in the family, including two missense variants in calcium voltage‑gated channel subunit alpha1 C (CACNA1C) (gi:193788541, NM_001129843), c.1786G>A (p.V596M) and c.5344G>A (p.A1782T), and one missense variant in titin (TTN) c.49415G>A (p.R16472H) (gi:291045222, NM_003319). The variants p.V596M and p.R16472H were predicted to be deleterious and resulted in alterations in the amino acid type and sequence of the polypeptide chain, which may partially or completely inactivate the encoded protein. The comparison of literature, gene database, and pedigree phenotype analysis suggests that p.V596M or p.R16472H variants are pathogenic. The complex overlapping variants at three loci lead to a more severe phenotype in the proband, and may increase the susceptibility of individuals to atrial fibrillation. The simultaneous occurrence of V596M and R16472H may increase the severity of early repolarization. Various family members may have carried heterozygous mutants of p.A1782T and p.R16472H due to genetic heterogeneity, however did not exhibit clinical signs of cardiac electrophysiological alterations, potentially attributable to the low vagal tone. To the best of the author's knowledge, this is the first study to suggest the involvement of the novel missense CACNA1C c.1786G>A and TTN c.49415G>A variants in the inheritance of symptomatic bradycardia and development of SSS.
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Affiliation(s)
- Yao-Bin Zhu
- Department of Traditional Chinese Medicine, The First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350005, P.R. China
| | - Jie-Wei Luo
- Provincial Clinical Medical College, Fujian Medical University, Fuzhou, Fujian 350001, P.R. China
| | - Fen Jiang
- Pharmacogenomics Research Center, Inje University College of Medicine, Busan 614‑715, Republic of Korea
| | - Gui Liu
- Department of Traditional Chinese Medicine, Fujian Provincial Hospital, Fuzhou, Fujian 350001, P.R. China
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73
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Coll M, Pérez-Serra A, Mates J, Del Olmo B, Puigmulé M, Fernandez-Falgueras A, Iglesias A, Picó F, Lopez L, Brugada R, Campuzano O. Incomplete Penetrance and Variable Expressivity: Hallmarks in Channelopathies Associated with Sudden Cardiac Death. BIOLOGY 2017; 7:biology7010003. [PMID: 29278359 PMCID: PMC5872029 DOI: 10.3390/biology7010003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 12/19/2017] [Accepted: 12/22/2017] [Indexed: 12/19/2022]
Abstract
Sudden cardiac death is defined as an unexpected decease of cardiac origin. In individuals under 35 years old, most of these deaths are due to familial arrhythmogenic syndromes of genetic origin, also known as channelopathies. These familial cardiac syndromes commonly follow an autosomal dominant pattern of inheritance. Diagnosis, however, can be difficult, mainly due to incomplete penetrance and variable expressivity, which are hallmarks in these syndromes. The clinical manifestation of these diseases can range from asymptomatic to syncope but sudden death can sometimes be the first symptom of disease. Early identification of at-risk individuals is crucial to prevent a lethal episode. In this review, we will focus on the genetic basis of channelopathies and the effect of genetic and non-genetic modifiers on their phenotypes.
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Affiliation(s)
- Monica Coll
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Salt, Spain.
| | - Alexandra Pérez-Serra
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Salt, Spain.
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain.
| | - Jesus Mates
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Salt, Spain.
| | - Bernat Del Olmo
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Salt, Spain.
| | - Marta Puigmulé
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Salt, Spain.
- Medical Science Department, School of Medicine, University of Girona, 17003 Girona, Spain.
| | | | - Anna Iglesias
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Salt, Spain.
| | - Ferran Picó
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Salt, Spain.
| | - Laura Lopez
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Salt, Spain.
| | - Ramon Brugada
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Salt, Spain.
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain.
- Medical Science Department, School of Medicine, University of Girona, 17003 Girona, Spain.
- Cardiology Service, Hospital Josep Trueta, 17003 Girona, Spain.
| | - Oscar Campuzano
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Salt, Spain.
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain.
- Medical Science Department, School of Medicine, University of Girona, 17003 Girona, Spain.
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74
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Influence of genetic modifiers on sudden cardiac death cases. Int J Legal Med 2017; 132:379-385. [DOI: 10.1007/s00414-017-1739-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 11/13/2017] [Indexed: 12/20/2022]
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75
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Paludan-Müller C, Ahlberg G, Ghouse J, Svendsen JH, Haunsø S, Olesen MS. Analysis of 60 706 Exomes Questions the Role of De Novo Variants Previously Implicated in Cardiac Disease. ACTA ACUST UNITED AC 2017; 10:CIRCGENETICS.117.001878. [DOI: 10.1161/circgenetics.117.001878] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 10/20/2017] [Indexed: 11/16/2022]
Affiliation(s)
- Christian Paludan-Müller
- From the Laboratory for Molecular Cardiology, Institute for Biomedical Sciences, University of Copenhagen, Denmark (C.P.-M., G.A., J.G., J.H.S., S.H., M.S.O.); Laboratory for Molecular Cardiology, Department of Cardiology, Heart Centre at Rigshospitalet, Copenhagen University Hospital, Denmark (C.P.-M., G.A., J.G., J.H.S., S.H., M.S.O.); Danish National Research Foundation Centre for Cardiac Arrhythmia, Copenhagen, Denmark (C.P.-M., G.A., J.G., J.H.S., S.H., M.S.O.); and Department of Clinical
| | - Gustav Ahlberg
- From the Laboratory for Molecular Cardiology, Institute for Biomedical Sciences, University of Copenhagen, Denmark (C.P.-M., G.A., J.G., J.H.S., S.H., M.S.O.); Laboratory for Molecular Cardiology, Department of Cardiology, Heart Centre at Rigshospitalet, Copenhagen University Hospital, Denmark (C.P.-M., G.A., J.G., J.H.S., S.H., M.S.O.); Danish National Research Foundation Centre for Cardiac Arrhythmia, Copenhagen, Denmark (C.P.-M., G.A., J.G., J.H.S., S.H., M.S.O.); and Department of Clinical
| | - Jonas Ghouse
- From the Laboratory for Molecular Cardiology, Institute for Biomedical Sciences, University of Copenhagen, Denmark (C.P.-M., G.A., J.G., J.H.S., S.H., M.S.O.); Laboratory for Molecular Cardiology, Department of Cardiology, Heart Centre at Rigshospitalet, Copenhagen University Hospital, Denmark (C.P.-M., G.A., J.G., J.H.S., S.H., M.S.O.); Danish National Research Foundation Centre for Cardiac Arrhythmia, Copenhagen, Denmark (C.P.-M., G.A., J.G., J.H.S., S.H., M.S.O.); and Department of Clinical
| | - Jesper H. Svendsen
- From the Laboratory for Molecular Cardiology, Institute for Biomedical Sciences, University of Copenhagen, Denmark (C.P.-M., G.A., J.G., J.H.S., S.H., M.S.O.); Laboratory for Molecular Cardiology, Department of Cardiology, Heart Centre at Rigshospitalet, Copenhagen University Hospital, Denmark (C.P.-M., G.A., J.G., J.H.S., S.H., M.S.O.); Danish National Research Foundation Centre for Cardiac Arrhythmia, Copenhagen, Denmark (C.P.-M., G.A., J.G., J.H.S., S.H., M.S.O.); and Department of Clinical
| | - Stig Haunsø
- From the Laboratory for Molecular Cardiology, Institute for Biomedical Sciences, University of Copenhagen, Denmark (C.P.-M., G.A., J.G., J.H.S., S.H., M.S.O.); Laboratory for Molecular Cardiology, Department of Cardiology, Heart Centre at Rigshospitalet, Copenhagen University Hospital, Denmark (C.P.-M., G.A., J.G., J.H.S., S.H., M.S.O.); Danish National Research Foundation Centre for Cardiac Arrhythmia, Copenhagen, Denmark (C.P.-M., G.A., J.G., J.H.S., S.H., M.S.O.); and Department of Clinical
| | - Morten S. Olesen
- From the Laboratory for Molecular Cardiology, Institute for Biomedical Sciences, University of Copenhagen, Denmark (C.P.-M., G.A., J.G., J.H.S., S.H., M.S.O.); Laboratory for Molecular Cardiology, Department of Cardiology, Heart Centre at Rigshospitalet, Copenhagen University Hospital, Denmark (C.P.-M., G.A., J.G., J.H.S., S.H., M.S.O.); Danish National Research Foundation Centre for Cardiac Arrhythmia, Copenhagen, Denmark (C.P.-M., G.A., J.G., J.H.S., S.H., M.S.O.); and Department of Clinical
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76
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Tommiska J, Känsäkoski J, Skibsbye L, Vaaralahti K, Liu X, Lodge EJ, Tang C, Yuan L, Fagerholm R, Kanters JK, Lahermo P, Kaunisto M, Keski-Filppula R, Vuoristo S, Pulli K, Ebeling T, Valanne L, Sankila EM, Kivirikko S, Lääperi M, Casoni F, Giacobini P, Phan-Hug F, Buki T, Tena-Sempere M, Pitteloud N, Veijola R, Lipsanen-Nyman M, Kaunisto K, Mollard P, Andoniadou CL, Hirsch JA, Varjosalo M, Jespersen T, Raivio T. Two missense mutations in KCNQ1 cause pituitary hormone deficiency and maternally inherited gingival fibromatosis. Nat Commun 2017; 8:1289. [PMID: 29097701 PMCID: PMC5668380 DOI: 10.1038/s41467-017-01429-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Accepted: 09/14/2017] [Indexed: 01/05/2023] Open
Abstract
Familial growth hormone deficiency provides an opportunity to identify new genetic causes of short stature. Here we combine linkage analysis with whole-genome resequencing in patients with growth hormone deficiency and maternally inherited gingival fibromatosis. We report that patients from three unrelated families harbor either of two missense mutations, c.347G>T p.(Arg116Leu) or c.1106C>T p.(Pro369Leu), in KCNQ1, a gene previously implicated in the long QT interval syndrome. Kcnq1 is expressed in hypothalamic GHRH neurons and pituitary somatotropes. Co-expressing KCNQ1 with the KCNE2 β-subunit shows that both KCNQ1 mutants increase current levels in patch clamp analyses and are associated with reduced pituitary hormone secretion from AtT-20 cells. In conclusion, our results reveal a role for the KCNQ1 potassium channel in the regulation of human growth, and show that growth hormone deficiency associated with maternally inherited gingival fibromatosis is an allelic disorder with cardiac arrhythmia syndromes caused by KCNQ1 mutations.
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Affiliation(s)
- Johanna Tommiska
- Faculty of Medicine, Department of Physiology, University of Helsinki, 00014, Helsinki, Finland.,Children's Hospital, Pediatric Research Center, Helsinki University Central Hospital (HUCH), 00029, Helsinki, Finland
| | - Johanna Känsäkoski
- Faculty of Medicine, Department of Physiology, University of Helsinki, 00014, Helsinki, Finland
| | - Lasse Skibsbye
- Department of Biomedical Sciences, University of Copenhagen, 2200, Copenhagen N, Denmark
| | - Kirsi Vaaralahti
- Faculty of Medicine, Department of Physiology, University of Helsinki, 00014, Helsinki, Finland
| | - Xiaonan Liu
- Institute of Biotechnology, Biocenter 3, University of Helsinki, 00014, Helsinki, Finland
| | - Emily J Lodge
- Centre for Craniofacial and Regenerative Biology, King's College London, Floor 27 Tower Wing, Guy's Campus, London, SE1 9RT, UK
| | - Chuyi Tang
- Department of Biomedical Sciences, University of Copenhagen, 2200, Copenhagen N, Denmark
| | - Lei Yuan
- Department of Biomedical Sciences, University of Copenhagen, 2200, Copenhagen N, Denmark
| | - Rainer Fagerholm
- Faculty of Medicine, Department of Physiology, University of Helsinki, 00014, Helsinki, Finland.,Department of Obstetrics and Gynecology, HUCH, 00029, Helsinki, Finland
| | - Jørgen K Kanters
- Laboratory of Experimental Cardiology, Department of Biomedical Sciences, University of Copenhagen, 22000, Copenhagen, Denmark.,Department of Cardiology, Herlev & Gentofte University Hospitals, University of Copenhagen, 22000, Copenhagen, Denmark
| | - Päivi Lahermo
- Institute for Molecular Medicine Finland (FIMM), Helsinki Institute of Life Science HiLIFE, University of Helsinki, 00014, Helsinki, Finland
| | - Mari Kaunisto
- Institute for Molecular Medicine Finland (FIMM), Helsinki Institute of Life Science HiLIFE, University of Helsinki, 00014, Helsinki, Finland
| | | | - Sanna Vuoristo
- Faculty of Medicine, Department of Physiology, University of Helsinki, 00014, Helsinki, Finland
| | - Kristiina Pulli
- Faculty of Medicine, Department of Physiology, University of Helsinki, 00014, Helsinki, Finland
| | - Tapani Ebeling
- Department of Medicine, Oulu University Hospital, Finland and Research Unit of Internal Medicine, University of Oulu, 90014, Oulu, Finland
| | - Leena Valanne
- Helsinki Medical Imaging Center, HUCH, 00029, Helsinki, Finland
| | | | - Sirpa Kivirikko
- Department of Clinical Genetics, HUCH, 00029, Helsinki, Finland
| | - Mitja Lääperi
- Faculty of Medicine, Department of Physiology, University of Helsinki, 00014, Helsinki, Finland
| | - Filippo Casoni
- Inserm U1172, Jean-Pierre Aubert Research Center, Development and Plasticity of the Neuroendocrine Brain, 59045, Lille, France.,University of Lille, School of Medicine, 59045, Lille, France
| | - Paolo Giacobini
- Inserm U1172, Jean-Pierre Aubert Research Center, Development and Plasticity of the Neuroendocrine Brain, 59045, Lille, France.,University of Lille, School of Medicine, 59045, Lille, France
| | - Franziska Phan-Hug
- Pediatrics, Division of Pediatric Endocrinology, Diabetology and Obesity, University Hospital Lausanne (CHUV), 1011, Lausanne, Switzerland
| | - Tal Buki
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, Institute of Structural Biology, 69978, Ramat Aviv, Israel
| | - Manuel Tena-Sempere
- Department of Cell Biology, Physiology and Immunology, University of Córdoba, 14071, Cordoba, Spain.,Instituto Maimonides de Investigacion Biomedica (IMIBIC/HURS), 14004, Cordoba, Spain.,CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, 28029, Madrid, Spain
| | - Nelly Pitteloud
- Pediatrics, Division of Pediatric Endocrinology, Diabetology and Obesity, University Hospital Lausanne (CHUV), 1011, Lausanne, Switzerland
| | - Riitta Veijola
- Department of Children and Adolescents, Oulu University Hospital, 90029, Oulu, Finland.,Department of Pediatrics, PEDEGO Research Center, Medical Research Center, University of Oulu, 90014, Oulu, Finland
| | - Marita Lipsanen-Nyman
- Children's Hospital, Pediatric Research Center, Helsinki University Central Hospital (HUCH), 00029, Helsinki, Finland
| | - Kari Kaunisto
- Department of Children and Adolescents, Oulu University Hospital, 90029, Oulu, Finland
| | - Patrice Mollard
- IGF, CNRS, INSERM, Univ. Montpellier, F-34094, Montpellier, France
| | - Cynthia L Andoniadou
- Centre for Craniofacial and Regenerative Biology, King's College London, Floor 27 Tower Wing, Guy's Campus, London, SE1 9RT, UK.,Department of Internal Medicine III, Technische Universität Dresden, Fetscherstraße 74, 01307, Dresden, Germany
| | - Joel A Hirsch
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, Institute of Structural Biology, 69978, Ramat Aviv, Israel
| | - Markku Varjosalo
- Institute of Biotechnology, Biocenter 3, University of Helsinki, 00014, Helsinki, Finland
| | - Thomas Jespersen
- Department of Biomedical Sciences, University of Copenhagen, 2200, Copenhagen N, Denmark
| | - Taneli Raivio
- Faculty of Medicine, Department of Physiology, University of Helsinki, 00014, Helsinki, Finland. .,Children's Hospital, Pediatric Research Center, Helsinki University Central Hospital (HUCH), 00029, Helsinki, Finland.
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77
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Golden A. From phenologs to silent suppressors: Identifying potential therapeutic targets for human disease. Mol Reprod Dev 2017; 84:1118-1132. [PMID: 28834577 DOI: 10.1002/mrd.22880] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 08/04/2017] [Indexed: 12/16/2022]
Abstract
Orthologous phenotypes, or phenologs, are seemingly unrelated phenotypes generated by mutations in a conserved set of genes. Phenologs have been widely observed and accepted by those who study model organisms, and allow one to study a set of genes in a model organism to learn more about the function of those genes in other organisms, including humans. At the cellular and molecular level, these conserved genes likely function in a very similar mode, but are doing so in different tissues or cell types and can result in different phenotypic effects. For example, the RAS-RAF-MEK-MAPK pathway in animals is a highly conserved signaling pathway that animals adopted for numerous biological processes, such as vulval induction in Caenorhabditis elegans and cell proliferation in mammalian cells; but this same gene set has been co-opted to function in a variety of cellular contexts. In this review, I give a few examples of how suppressor screens in model organisms (with a emphasis on C. elegans) can identify new genes that function in a conserved pathway in many other organisms. I also demonstrate how the identification of such genes can lead to important insights into mammalian biology. From such screens, an occasional silent suppressor that does not cause a phenotype on its own is found; such suppressors thus make for good candidates as therapeutic targets.
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Affiliation(s)
- Andy Golden
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
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78
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Sacilotto L, Epifanio HB, Darrieux FCDC, Wulkan F, Oliveira TGM, Hachul DT, Pereira ADC, Scanavacca MI. Compound Heterozygous SCN5A Mutations in a Toddler - Are they Associated with a More Severe Phenotype? Arq Bras Cardiol 2017; 108:70-73. [PMID: 28146213 PMCID: PMC5245850 DOI: 10.5935/abc.20170006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 10/10/2016] [Indexed: 12/02/2022] Open
Abstract
Compound heterozygosity has been described in inherited arrhythmias, and usually
associated with a more severe phenotype. Reports of this occurrence in Brugada
syndrome patients are still rare. We report a study of genotype-phenotype
correlation after the identification of new variants by genetic testing. We
describe the case of an affected child with a combination of two different
likely pathogenic SCN5A variants, presenting sinus node
dysfunction, flutter and atrial fibrillation, prolonged HV interval, spontaneous
type 1 Brugada pattern in the prepubescent age and familiar history of sudden
death.
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Affiliation(s)
- Luciana Sacilotto
- Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil
| | | | | | - Fanny Wulkan
- Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil
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79
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Allelic Complexity in Long QT Syndrome: A Family-Case Study. Int J Mol Sci 2017; 18:ijms18081633. [PMID: 28749435 PMCID: PMC5578023 DOI: 10.3390/ijms18081633] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 07/13/2017] [Accepted: 07/21/2017] [Indexed: 12/17/2022] Open
Abstract
Congenital long QT syndrome (LQTS) is associated with high genetic and allelic heterogeneity. In some cases, more than one genetic variant is identified in the same (compound heterozygosity) or different (digenic heterozygosity) genes, and subjects with multiple pathogenic mutations may have a more severe disease. Standard-of-care clinical genetic testing for this and other arrhythmia susceptibility syndromes improves the identification of complex genotypes. Therefore, it is important to distinguish between pathogenic mutations and benign rare variants. We identified four genetic variants (KCNQ1-p.R583H, KCNH2-p.C108Y, KCNH2-p.K897T, and KCNE1-p.G38S) in an LQTS family. On the basis of in silico analysis, clinical data from our family, and the evidence from previous studies, we analyzed two mutated channels, KCNQ1-p.R583H and KCNH2-p.C108Y, using the whole-cell patch clamp technique. We found that KCNQ1-p.R583H was not associated with a severe functional impairment, whereas KCNH2-p.C108Y, a novel variant, encoded a non-functional channel that exerts dominant-negative effects on the wild-type. Notably, the common variants KCNH2-p.K897T and KCNE1-p.G38S were previously reported to produce more severe phenotypes when combined with disease-causing alleles. Our results indicate that the novel KCNH2-C108Y variant can be a pathogenic LQTS mutation, whereas KCNQ1-p.R583H, KCNH2-p.K897T, and KCNE1-p.G38S could be LQTS modifiers.
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80
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Parent L. A helical segment makes potassium channels go-go. J Biol Chem 2017; 292:7706-7707. [PMID: 28476926 DOI: 10.1074/jbc.h117.779298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
More than 500 variants in the KCNH2 gene, which encodes the cardiac human ether-a-go-go (hERG) ion channel, have been associated with sudden cardiac death, but only a subset of these variants have been investigated. Matthew D. Perry and colleagues now combine NMR spectroscopy and electrophysiological experiments to explore the functional properties of mutations within an overlooked hERG helix, finding important contributions to channel function.
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Affiliation(s)
- Lucie Parent
- From the Département de Pharmacologie et Physiologie, Faculté de Médecine, Centre de recherche de l'Institut de Cardiologie de Montréal, Université de Montréal, Montréal, Québec H3C 3J7, Canada
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81
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Giudicessi JR, Kullo IJ, Ackerman MJ. Precision Cardiovascular Medicine: State of Genetic Testing. Mayo Clin Proc 2017; 92:642-662. [PMID: 28385198 PMCID: PMC6364981 DOI: 10.1016/j.mayocp.2017.01.015] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 12/23/2016] [Accepted: 01/30/2017] [Indexed: 01/11/2023]
Abstract
In the 15 years following the release of the first complete human genome sequences, our understanding of rare and common genetic variation as determinants of cardiovascular disease susceptibility, prognosis, and therapeutic response has grown exponentially. As such, the use of genomics to enhance the care of patients with cardiovascular diseases has garnered increased attention from clinicians, researchers, and regulatory agencies eager to realize the promise of precision genomic medicine. However, owing to a large burden of "complex" common diseases, emphasis on evidence-based practice, and a degree of unfamiliarity/discomfort with the language of genomic medicine, the development and implementation of genomics-guided approaches designed to further individualize the clinical management of a variety of cardiovascular disorders remains a challenge. In this review, we detail a practical approach to genetic testing initiation and interpretation as well as review the current state of cardiovascular genetic and pharmacogenomic testing in the context of relevant society and regulatory agency recommendations/guidelines.
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Affiliation(s)
- John R Giudicessi
- Department of Internal Medicine, Internal Medicine Residency Program, Clinician-Investigator Training Program, Mayo Clinic, Rochester, MN
| | - Iftikhar J Kullo
- Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN; Gonda Vascular Center, Mayo Clinic, Rochester, MN.
| | - Michael J Ackerman
- Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN; Division of Heart Rhythm Services, Mayo Clinic, Rochester, MN; Department of Pediatric and Adolescent Medicine, Division of Pediatric Cardiology, Mayo Clinic, Rochester, MN; Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN.
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82
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Meurs KM, Weidman JA, Rosenthal SL, Lahmers KK, Friedenberg SG. Ventricular arrhythmias in Rhodesian Ridgebacks with a family history of sudden death and results of a pedigree analysis for potential inheritance patterns. J Am Vet Med Assoc 2017; 248:1135-8. [PMID: 27135669 DOI: 10.2460/javma.248.10.1135] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate a group of related Rhodesian Ridgebacks with a family history of sudden death for the presence of arrhythmia and to identify possible patterns of disease inheritance among these dogs. DESIGN Prospective case series and pedigree investigation. ANIMALS 25 Rhodesian Ridgebacks with shared bloodlines. PROCEDURES Pedigrees of 4 young dogs (1 female and 3 males; age, 7 to 12 months) that died suddenly were evaluated, and owners of closely related dogs were asked to participate in the study. Dogs were evaluated by 24-hour Holter monitoring, standard ECG, echocardiography, or some combination of these to assess cardiac status. Necropsy reports, if available, were reviewed. RESULTS 31 close relatives of the 4 deceased dogs were identified. Of 21 dogs available for examination, 8 (2 males and 6 females) had ventricular tachyarrhythmias (90 to 8,700 ventricular premature complexes [VPCs]/24 h). No dogs had clinical signs of cardiac disease reported. Echocardiographic or necropsy evaluation for 7 of 12 dogs deemed affected (ie, with frequent or complex VPCs or sudden death) did not identify structural lesions. Five of 6 screened parents of affected dogs had 0 to 5 VPCs/24 h (all singlets), consistent with a normal reading. Pedigree evaluation suggested an autosomal recessive pattern of inheritance, but autosomal dominant inheritance with incomplete penetrance could not be ruled out. CONCLUSIONS AND CLINICAL RELEVANCE Holter monitoring of Rhodesian Ridgebacks with a family history of an arrhythmia or sudden death is recommended for early diagnosis of disease. An autosomal recessive pattern of inheritance in the studied dogs was likely, and inbreeding should be strongly discouraged.
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83
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Abstract
Cardiac arrhythmias can follow disruption of the normal cellular electrophysiological processes underlying excitable activity and their tissue propagation as coherent wavefronts from the primary sinoatrial node pacemaker, through the atria, conducting structures and ventricular myocardium. These physiological events are driven by interacting, voltage-dependent, processes of activation, inactivation, and recovery in the ion channels present in cardiomyocyte membranes. Generation and conduction of these events are further modulated by intracellular Ca2+ homeostasis, and metabolic and structural change. This review describes experimental studies on murine models for known clinical arrhythmic conditions in which these mechanisms were modified by genetic, physiological, or pharmacological manipulation. These exemplars yielded molecular, physiological, and structural phenotypes often directly translatable to their corresponding clinical conditions, which could be investigated at the molecular, cellular, tissue, organ, and whole animal levels. Arrhythmogenesis could be explored during normal pacing activity, regular stimulation, following imposed extra-stimuli, or during progressively incremented steady pacing frequencies. Arrhythmic substrate was identified with temporal and spatial functional heterogeneities predisposing to reentrant excitation phenomena. These could arise from abnormalities in cardiac pacing function, tissue electrical connectivity, and cellular excitation and recovery. Triggering events during or following recovery from action potential excitation could thereby lead to sustained arrhythmia. These surface membrane processes were modified by alterations in cellular Ca2+ homeostasis and energetics, as well as cellular and tissue structural change. Study of murine systems thus offers major insights into both our understanding of normal cardiac activity and its propagation, and their relationship to mechanisms generating clinical arrhythmias.
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Affiliation(s)
- Christopher L-H Huang
- Physiological Laboratory and the Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
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84
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Sanchez O, Campuzano O, Fernández-Falgueras A, Sarquella-Brugada G, Cesar S, Mademont I, Mates J, Pérez-Serra A, Coll M, Pico F, Iglesias A, Tirón C, Allegue C, Carro E, Gallego MÁ, Ferrer-Costa C, Hospital A, Bardalet N, Borondo JC, Vingut A, Arbelo E, Brugada J, Castellà J, Medallo J, Brugada R. Natural and Undetermined Sudden Death: Value of Post-Mortem Genetic Investigation. PLoS One 2016; 11:e0167358. [PMID: 27930701 PMCID: PMC5145162 DOI: 10.1371/journal.pone.0167358] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 11/11/2016] [Indexed: 12/15/2022] Open
Abstract
Background Sudden unexplained death may be the first manifestation of an unknown inherited cardiac disease. Current genetic technologies may enable the unraveling of an etiology and the identification of relatives at risk. The aim of our study was to define the etiology of natural deaths, younger than 50 years of age, and to investigate whether genetic defects associated with cardiac diseases could provide a potential etiology for the unexplained cases. Methods and Findings Our cohort included a total of 789 consecutive cases (77.19% males) <50 years old (average 38.6±12.2 years old) who died suddenly from non-violent causes. A comprehensive autopsy was performed according to current forensic guidelines. During autopsy a cause of death was identified in most cases (81.1%), mainly due to cardiac alterations (56.87%). In unexplained cases, genetic analysis of the main genes associated with sudden cardiac death was performed using Next Generation Sequencing technology. Genetic analysis was performed in suspected inherited diseases (cardiomyopathy) and in unexplained death, with identification of potentially pathogenic variants in nearly 50% and 40% of samples, respectively. Conclusions Cardiac disease is the most important cause of sudden death, especially after the age of 40. Close to 10% of cases may remain unexplained after a complete autopsy investigation. Molecular autopsy may provide an explanation for a significant part of these unexplained cases. Identification of genetic variations enables genetic counseling and undertaking of preventive measures in relatives at risk.
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Affiliation(s)
- Olallo Sanchez
- Cardiovascular Genetics Center, University of Girona-IDIBGI, Girona (Spain)
| | - Oscar Campuzano
- Cardiovascular Genetics Center, University of Girona-IDIBGI, Girona (Spain)
- Department of Medical Sciences, School of Medicine, University of Girona, Girona (Spain)
| | - Anna Fernández-Falgueras
- Cardiovascular Genetics Center, University of Girona-IDIBGI, Girona (Spain)
- Cardiovascular Genetics Unit, Hospital Josep Trueta, Girona (Spain)
| | | | - Sergi Cesar
- Arrhythmia Unit, Hospital Sant Joan de Déu, University of Barcelona, Barcelona (Spain)
| | - Irene Mademont
- Cardiovascular Genetics Center, University of Girona-IDIBGI, Girona (Spain)
| | - Jesus Mates
- Cardiovascular Genetics Center, University of Girona-IDIBGI, Girona (Spain)
| | | | - Monica Coll
- Cardiovascular Genetics Center, University of Girona-IDIBGI, Girona (Spain)
| | - Ferran Pico
- Cardiovascular Genetics Center, University of Girona-IDIBGI, Girona (Spain)
| | - Anna Iglesias
- Cardiovascular Genetics Center, University of Girona-IDIBGI, Girona (Spain)
| | - Coloma Tirón
- Cardiovascular Genetics Unit, Hospital Josep Trueta, Girona (Spain)
| | - Catarina Allegue
- Cardiovascular Genetics Center, University of Girona-IDIBGI, Girona (Spain)
| | - Esther Carro
- Arrhythmia Unit, Hospital Sant Joan de Déu, University of Barcelona, Barcelona (Spain)
| | - María Ángeles Gallego
- Forensic Pathology Service, Institut Medicina Legal Ciències Mèdiques Catalunya, Barcelona (Spain)
| | | | - Anna Hospital
- Forensic Pathology Service, Institut Medicina Legal i Ciències Forenses de Catalunya, Girona (Spain)
| | - Narcís Bardalet
- Forensic Pathology Service, Institut Medicina Legal i Ciències Forenses de Catalunya, Girona (Spain)
| | - Juan Carlos Borondo
- Histopathology Unit, Instituto Nacional de Toxicología y Ciencias Forenses, Barcelona (Spain)
| | - Albert Vingut
- Histopathology Unit, Instituto Nacional de Toxicología y Ciencias Forenses, Barcelona (Spain)
| | - Elena Arbelo
- Arrhythmia Unit, Hospital Clinic de Barcelona, University of Barcelona, Barcelona (Spain)
| | - Josep Brugada
- Arrhythmia Unit, Hospital Sant Joan de Déu, University of Barcelona, Barcelona (Spain)
- Arrhythmia Unit, Hospital Clinic de Barcelona, University of Barcelona, Barcelona (Spain)
| | - Josep Castellà
- Forensic Pathology Service, Institut Medicina Legal Ciències Mèdiques Catalunya, Barcelona (Spain)
| | - Jordi Medallo
- Forensic Pathology Service, Institut Medicina Legal Ciències Mèdiques Catalunya, Barcelona (Spain)
| | - Ramon Brugada
- Cardiovascular Genetics Center, University of Girona-IDIBGI, Girona (Spain)
- Department of Medical Sciences, School of Medicine, University of Girona, Girona (Spain)
- Cardiovascular Genetics Unit, Hospital Josep Trueta, Girona (Spain)
- * E-mail:
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Bezzerides VJ, Zhang D, Pu WT. Modeling Inherited Arrhythmia Disorders Using Induced Pluripotent Stem Cell-Derived Cardiomyocytes. Circ J 2016; 81:12-21. [PMID: 27916777 DOI: 10.1253/circj.cj-16-1113] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Inherited arrhythmia disorders (IADs) are a group of potentially lethal diseases that remain diagnostic and management challenges. Although the genetic basis for many of these disorders is well known, the pathogenicity of individual mutations and the resulting clinical outcomes are difficult to predict. Treatment options remain imperfect, and optimizing therapy for individual patients can be difficult. Recent advances in the derivation of induced pluripotent stem cells (iPSCs) from patients and creation of genetically engineered human models using CRISPR/Cas9 has the potential to dramatically advance translational arrhythmia research. In this review, we discuss the current state of modeling IADs using human iPSC-derived cardiomyocytes. We also discuss current limitations and areas for further study.
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86
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Omar A, Zhou M, Berman A, Sorrentino RA, Yar N, Weintraub NL, Kim IM, Lei W, Tang Y. Genomic-based diagnosis of arrhythmia disease in a personalized medicine era. EXPERT REVIEW OF PRECISION MEDICINE AND DRUG DEVELOPMENT 2016; 1:497-504. [PMID: 28944294 PMCID: PMC5606339 DOI: 10.1080/23808993.2016.1264258] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
INTRODUCTION Although thousands of potentially disease-causing mutations have been identified in a handful of genes, the genetic heterogeneity has led to diagnostic confusions, stemming directly from the limitations in our arsenal of genetic tools. AREAS COVERED We discuss the genetic basis of cardiac ion channelopathies, the gaps in our knowledge and how Next-generation sequencing technology (NGS) and can be used to bridge them, and how induced pluripotent stem cell (iPSC) derived-cardiomyocytes can be used for drug discovery. EXPERT COMMENTARY Univariate, arrhythmogenic arrhythmias can explain some congenital arrhythmias, however, it is far from a comprehensive understanding of the complexity of many arrhythmias. Mutational screening is a critical step in personalized medicine and is critical to the management of patients with arrhythmias. The success of personalized medicine requires a more efficient way to identify a high number of genetic variants potentially implicated in cardiac arrhythmogenic diseases than traditional sequencing methods (eg, Sanger sequencing). Next-generation sequencing technology provides us with unprecedented opportunities to achieve high-throughput, rapid, and cost-effective detection of congenital arrhythmias in patients. Moreover, in personalized medicine era, IPSC derived-cardiomyocytes can be used as 'cardiac arrhythmia in a dish' model for drug discovery, and help us improve management of arrhythmias in patients by developing patient-specific drug therapies with target specificity.
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Affiliation(s)
- Abdullah Omar
- Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Mi Zhou
- Cardiac Surgery department, Ruijin Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Adam Berman
- Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Robert A. Sorrentino
- Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Neela Yar
- Purdue University, West Lafayette, IN, USA
| | - Neal L. Weintraub
- Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Il-man Kim
- Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Wei Lei
- Cardiovascular Medicine Center, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Yaoliang Tang
- Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, USA
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87
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Ghouse J, Have CT, Skov MW, Andreasen L, Ahlberg G, Nielsen JB, Skaaby T, Olesen SP, Grarup N, Linneberg A, Pedersen O, Vestergaard H, Haunsø S, Svendsen JH, Hansen T, Kanters JK, Olesen MS. Numerous Brugada syndrome-associated genetic variants have no effect on J-point elevation, syncope susceptibility, malignant cardiac arrhythmia, and all-cause mortality. Genet Med 2016; 19:521-528. [PMID: 27711072 DOI: 10.1038/gim.2016.151] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 08/15/2016] [Indexed: 12/19/2022] Open
Abstract
PURPOSE We investigated whether Brugada syndrome (BrS)-associated variants identified in the general population have an effect on J-point elevation as well as whether carriers of BrS variants were more prone to experience syncope and malignant ventricular arrhythmia and had increased mortality compared with noncarriers. METHODS All BrS-associated variants were identified using the Human Gene Mutation Database (HGMD). Individuals were randomly selected from a general population study using whole-exome sequencing data (n = 870) and genotype array data (n = 6,161) and screened for BrS-associated variants. Electrocardiograms (ECG) were analyzed electronically, and data on syncope, ventricular arrhythmias, and mortality were obtained from administrative health-care registries. RESULTS In HGMD, 382 BrS-associated genetic variants were identified. Of these, 28 variants were identified in the study cohort. None of the carriers presented with type 1 BrS ECG pattern. Mean J-point elevation in V1 and V2 were within normal guideline limits for carriers and noncarriers. There was no difference in syncope susceptibility (carriers 8/624; noncarriers 98/5,562; P = 0.51), ventricular arrhythmia (carriers 4/620; noncarriers 9/5,524; P = 0.24), or overall mortality (hazard ratio 0.93, 95% CI 0.63-1.4). CONCLUSIONS Our data indicate that a significant number of BrS-associated variants are not the monogenic cause of BrS.Genet Med advance online publication 06 October 2016.
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Affiliation(s)
- Jonas Ghouse
- The Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark.,Laboratory of Molecular Cardiology, Department of Cardiology, The Heart Centre, University Hospital of Copenhagen, Rigshospitalet, Denmark
| | - Christian T Have
- The Novo Nordisk Foundation Centre for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Morten W Skov
- The Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark.,Laboratory of Molecular Cardiology, Department of Cardiology, The Heart Centre, University Hospital of Copenhagen, Rigshospitalet, Denmark
| | - Laura Andreasen
- The Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark.,Laboratory of Molecular Cardiology, Department of Cardiology, The Heart Centre, University Hospital of Copenhagen, Rigshospitalet, Denmark
| | - Gustav Ahlberg
- The Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark.,Laboratory of Molecular Cardiology, Department of Cardiology, The Heart Centre, University Hospital of Copenhagen, Rigshospitalet, Denmark
| | - Jonas B Nielsen
- The Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark.,Laboratory of Molecular Cardiology, Department of Cardiology, The Heart Centre, University Hospital of Copenhagen, Rigshospitalet, Denmark.,Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, USA
| | - Tea Skaaby
- Research Centre for Prevention and Health, The Capital Region, Copenhagen, Denmark
| | - Søren-Peter Olesen
- The Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark
| | - Niels Grarup
- The Novo Nordisk Foundation Centre for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Allan Linneberg
- Research Centre for Prevention and Health, The Capital Region, Copenhagen, Denmark.,Department of Clinical Experimental Research, Rigshospitalet, Copenhagen, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Oluf Pedersen
- The Novo Nordisk Foundation Centre for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Henrik Vestergaard
- The Novo Nordisk Foundation Centre for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Stig Haunsø
- The Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark.,Laboratory of Molecular Cardiology, Department of Cardiology, The Heart Centre, University Hospital of Copenhagen, Rigshospitalet, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jesper H Svendsen
- The Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark.,Laboratory of Molecular Cardiology, Department of Cardiology, The Heart Centre, University Hospital of Copenhagen, Rigshospitalet, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Torben Hansen
- The Novo Nordisk Foundation Centre for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Jørgen K Kanters
- Laboratory of Experimental Cardiology, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Morten S Olesen
- The Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark.,Laboratory of Molecular Cardiology, Department of Cardiology, The Heart Centre, University Hospital of Copenhagen, Rigshospitalet, Denmark
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88
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Juang JMJ, Horie M. Genetics of Brugada syndrome. J Arrhythm 2016; 32:418-425. [PMID: 27761167 PMCID: PMC5063259 DOI: 10.1016/j.joa.2016.07.012] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 05/03/2016] [Accepted: 07/06/2016] [Indexed: 12/19/2022] Open
Abstract
In 1992, the Brugada syndrome (BrS) was recognized as a disease responsible for sudden cardiac death, characterized by a right bundle-branch block with ST segment elevation in the leads V1 and V2. This syndrome is highly associated with sudden cardiac death, especially in young males. BrS is currently diagnosed in patients with ST-segment elevation showing type 1 morphology ≥ 2 mm in ≥1 leads among the right precordial leads V1 or V2 positioned in the 2nd, 3rd, or 4th intercostal space, and occurring either spontaneously or after a provocative drug test by the intravenous administration of Class I antiarrhythmic drugs. With accumulated findings, the BrS inheritance model is believed to be an autosomal dominant inheritable model with incomplete penetrance, although most patients with BrS were sporadic cases. SCN5A, which was identified as the first BrS-associated gene in 1998, has emerged as the most common gene associated with BrS, and more than 10 BrS-associated genes have been identified thereafter. Mutation-specific genetic testing is recommended for the family members and appropriate relatives following the identification of BrS-causative mutations in an index patient. In addition, comprehensive or BrS1 (SCN5A) targeted genetic testing could be useful for patients in whom a cardiologist has established a clinical index of suspicion for BrS based on the patient׳s clinical history, family history, and the expressed electrocardiographic (resting 12-lead ECGs and/or provocative drug challenge testing) phenotype. Over the past 20 years, extensive research in this field has allowed better understanding of the pathophysiology, genetic background, and management of BrS even though controversies still exist. In this review article, a background of genetics, the genetic background of BrS, the genotype and phenotype relationship, the role of genetic screening in clinical practice, and the interpretation of the identified genetic variants have been addressed based on this understanding.
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Affiliation(s)
- 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
| | - Minoru Horie
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Japan
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89
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Is Symptomatic Long QT Syndrome Associated with Depression in Women and Men? J Genet Couns 2016; 26:491-500. [PMID: 27553078 DOI: 10.1007/s10897-016-0004-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 08/02/2016] [Indexed: 01/01/2023]
Abstract
We examined whether long QT syndrome (LQTS) mutation carrier status or symptomatic LQTS are associated with depression, and whether there are sex differences in these potential relationships. The sample comprised 782 participants (252 men). Of the 369 genetically defined LQTS mutation carriers, 169 were symptomatic and 200 were asymptomatic. The control group consisted of 413 unaffected relatives. Depression was assessed using the Beck Depression Inventory-II (BDI-II). No association was found for LQTS mutation carrier status with depression. The multinomial logistic regression showed that LQTS mutation carrier men with arrhythmic events scored higher on depression compared with the control group, even when adjusting for age, β-blockers, antidepressants, and social support (OR = 1.09, 95 % CI [1.02, 1.15], p = .007). The binary logistic regression comparing symptomatic and asymptomatic LQTS mutation carriers showed that symptomatic LQTS was associated with depression in men (OR = 1.10, 95 % CI [1.03, 1.19], p = .009). The results were unchanged when additionally adjusted for education. These findings suggest that symptomatic LQTS is associated with depression in men but not in women. Overall, however, depression is more frequent in women than men. Thus, regular screening for depression in LQTS mutation carriers and their unaffected family members can be important.
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90
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Musa H, Murphy NP, Curran J, Higgins JD, Webb TR, Makara MA, Wright P, Lancione PJ, Lubbers ER, Healy JA, Smith SA, Bennett V, Hund TJ, Kline CF, Mohler PJ. Common human ANK2 variant confers in vivo arrhythmia phenotypes. Heart Rhythm 2016; 13:1932-40. [PMID: 27298202 DOI: 10.1016/j.hrthm.2016.06.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Indexed: 12/17/2022]
Abstract
BACKGROUND Human ANK2 (ankyrin-B) loss-of-function variants are directly linked with arrhythmia phenotypes. However, in atypical non-ion channel arrhythmia genes such as ANK2 that lack the same degree of robust structure/function and clinical data, it may be more difficult to assign variant disease risk based simply on variant location, minor allele frequency, and/or predictive structural algorithms. The human ankyrin-B p.L1622I variant found in arrhythmia probands displays significant diversity in minor allele frequency across populations. OBJECTIVE The objective of this study was to directly test the in vivo impact of ankyrin-B p.L1622I on cardiac electrical phenotypes and arrhythmia risk using a new animal model. METHODS We tested arrhythmia phenotypes in a new "knock-in" animal model harboring the human ankyrin-B p.L1622I variant. RESULTS Ankyrin-B p.L1622I displays reduced posttranslational expression in vivo, resulting in reduced cardiac ankyrin-B expression and reduced association with binding-partner Na/Ca exchanger. Ankyrin-B(L1622I/L1622I) mice display changes in heart rate, atrioventricular and intraventricular conduction, and alterations in repolarization. Furthermore, ankyrin-B(L1622I/L1622I) mice display catecholamine-dependent arrhythmias. At the cellular level, ankyrin-B(L1622I/L1622I) myocytes display increased action potential duration and severe arrhythmogenic afterdepolarizations that provide a mechanistic rationale for the arrhythmias. CONCLUSION Our findings support in vivo arrhythmogenic phenotypes of an ANK2 variant with unusual frequency in select populations. On the basis of our findings and current clinical data, we support classification of p.L1622I as a "mild" loss-of-function variant that may confer arrhythmia susceptibility in the context of secondary risk factors including environment, medication, and/or additional genetic variation.
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Affiliation(s)
- Hassan Musa
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH; Department of Physiology & Cell Biology College of Medicine, The Ohio State University, Columbus, OH
| | - Nathaniel P Murphy
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH; Department of Physiology & Cell Biology College of Medicine, The Ohio State University, Columbus, OH
| | - Jerry Curran
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH; Department of Physiology & Cell Biology College of Medicine, The Ohio State University, Columbus, OH
| | - John D Higgins
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH; Department of Physiology & Cell Biology College of Medicine, The Ohio State University, Columbus, OH
| | - Tyler R Webb
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH; Department of Physiology & Cell Biology College of Medicine, The Ohio State University, Columbus, OH
| | - Michael A Makara
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH; Department of Physiology & Cell Biology College of Medicine, The Ohio State University, Columbus, OH
| | - Patrick Wright
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Peter J Lancione
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH; Department of Physiology & Cell Biology College of Medicine, The Ohio State University, Columbus, OH
| | - Ellen R Lubbers
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH; Department of Physiology & Cell Biology College of Medicine, The Ohio State University, Columbus, OH
| | - Jane A Healy
- Department of Biochemistry and Howard Hughes Medical Institute, Duke University Medical Center, Durham, NC
| | - Sakima A Smith
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH; Department of Internal Medicine, Division of Cardiovascular Medicine
| | - Vann Bennett
- Department of Biochemistry and Howard Hughes Medical Institute, Duke University Medical Center, Durham, NC
| | - Thomas J Hund
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH; Department of Internal Medicine, Division of Cardiovascular Medicine,; Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, OH
| | - Crystal F Kline
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH; Department of Physiology & Cell Biology College of Medicine, The Ohio State University, Columbus, OH
| | - Peter J Mohler
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH; Department of Physiology & Cell Biology College of Medicine, The Ohio State University, Columbus, OH; Department of Internal Medicine, Division of Cardiovascular Medicine,.
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91
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Szepesváry E, Kaski JP. Genetic testing for inheritable cardiac channelopathies. Br J Hosp Med (Lond) 2016; 77:294-302. [DOI: 10.12968/hmed.2016.77.5.294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cardiac channelopathies are linked to an increased risk of ventricular arrhythmia and sudden death. This article reviews the clinical characteristics and genetic basis of common cardiac ion-channel diseases, highlights some genotype–phenotype correlations, and summarizes genetic testing for inheritable cardiac channelopathies.
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Affiliation(s)
- Eszter Szepesváry
- Clinical Fellow in the Inherited Cardiovascular Diseases Unit, Great Ormond Street Hospital, London
| | - Juan Pablo Kaski
- Consultant Paediatric Cardiologist in the Inherited Cardiovascular Diseases Unit, Great Ormond Street Hospital, London WC1N 3JH
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92
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Genotype-based clinical manifestation and treatment of Chinese long QT syndrome patients with KCNQ1 mutations - R380S and W305L. Cardiol Young 2016; 26:754-63. [PMID: 26344792 DOI: 10.1017/s1047951115001304] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
UNLABELLED Aim Most long QT syndrome patients are associated with genetic mutations. We aimed to investigate the clinical and biochemical characteristics and look for genotype-based preventive implications in Chinese long QT syndrome patients. Methods and results We identified two missense mutations of the KCNQ1 gene in two independent Chinese families, including a previously reported mutation R380S in the C-terminus and a novel mutation W305L in the P-loop domain of the Kv7.1 channel, respectively. The proband with R380S was an 11-year-old girl who suffered a prolonged corrected QT interval of 660 ms, recurrent syncope, and sudden cardiac death, whose father was an asymptomatic carrier. The mutation W305L was detected in a 36-year-old woman with long QT syndrome and her immediate family members including the proband's younger sister with an unexplained syncope, her son, and her elder daughter without symptoms. Metoprolol appeared to be effective in preventing arrhythmias and syncope in long QT syndrome patients with mutation W305L. Both R380S and W305L mutations led to "loss-of-function" of the Kv7.1 channel accounting for the clinical phenotypes. CONCLUSIONS We first show two missense KCNQ1 mutations - R380S and W305L - in Chinese long QT syndrome patients, resulting in the loss of protein function. Mutation W305L in the P-loop domain of the Kv7.1 may derive a pronounced benefit from β-blocker therapy in symptomatic long QT syndrome patients, whereas mutation R380S located in the C-terminus may be associated with a high risk of sudden cardiac death.
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93
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Broendberg AK, Pedersen LN, Nielsen JC, Jensen HK. Repeated molecular genetic analysis in Brugada syndrome revealed a novel disease-associated large deletion in the SCN5A gene. HeartRhythm Case Rep 2016; 2:261-264. [PMID: 28491684 PMCID: PMC5419769 DOI: 10.1016/j.hrcr.2016.02.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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Mizusawa Y. Recent advances in genetic testing and counseling for inherited arrhythmias. J Arrhythm 2016; 32:389-397. [PMID: 27761163 PMCID: PMC5063262 DOI: 10.1016/j.joa.2015.12.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 12/01/2015] [Accepted: 12/17/2015] [Indexed: 12/19/2022] Open
Abstract
Inherited arrhythmias, such as cardiomyopathies and cardiac ion channelopathies, along with coronary heart disease (CHD) are three most common disorders that predispose adults to sudden cardiac death. In the last three decades, causal genes in inherited arrhythmias have been successfully identified. At the same time, it has become evident that the genetic architectures are more complex than previously known. Recent advancements in DNA sequencing technology (next generation sequencing) have enabled us to study such complex genetic traits. This article discusses indications for genetic testing of patients with inherited arrhythmias. Further, it describes the benefits and challenges that we face in the era of next generation sequencing. Finally, it briefly discusses genetic counseling, in which a multidisciplinary approach is required due to the increased complexity of the genetic information related to inherited arrhythmias.
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Key Words
- ARVD/C, arrhythmogenic right ventricular dysplasia/cardiomyopathy
- BrS, Brugada syndrome
- CHD, coronary heart disease
- CPVT, catecholaminergic polymorphic ventricular tachycardia
- Cardiac ion channelopathies
- Cardiomyopathies
- DCM, dilated cardiomyopathy
- GWAS, genome wide association study
- Genetic counseling
- Genetic testing
- HCM, hypertrophic cardiomyopathy
- HF, heart failure
- ICD, implantable cardioverter defibrillator
- Inherited arrhythmias
- LQTS, long QT syndrome
- NGS, next generation sequencing
- SCD, sudden cardiac death
- VA, ventricular arrhythmia
- VF, ventricular fibrillation
- WES, whole exome sequencing
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Affiliation(s)
- Yuka Mizusawa
- Department of Clinical and Experimental Cardiology, Academic Medical Center, University of Amsterdam, Room K2-115, Meibergdreef 9, 1105AZ Amsterdam, The Netherlands
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Campuzano O, Sarquella-Brugada G, Brugada R, Brugada J. Genetics of channelopathies associated with sudden cardiac death. Glob Cardiol Sci Pract 2015; 2015:39. [PMID: 26566530 PMCID: PMC4625210 DOI: 10.5339/gcsp.2015.39] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 06/30/2015] [Indexed: 12/19/2022] Open
Abstract
Recent technological advances in cardiology have resulted in new guidelines for the diagnosis, treatment and prevention of diseases. Despite these improvements, sudden death remains one of the main challenges to clinicians because the majority of diseases associated with sudden cardiac death are characterized by incomplete penetrance and variable expressivity. Hence, patients may be unaware of their illness, and physical activity can be the trigger for syncope as first symptom of the disease. Most common causes of sudden cardiac death are congenital alterations and structural heart diseases, although a significant number remain unexplained after comprehensive autopsy. In these unresolved cases, channelopathies are considered the first potential cause of death. Since all these diseases are of genetic origin, family members could be at risk, despite being asymptomatic. Genetics has also benefited from technological advances, and genetic testing has been incorporated into the sudden death field, identifying the cause in clinically affected patients, asymptomatic family members and post-mortem cases without conclusive diagnosis. This review focuses on recent advances in the genetics of channelopathies associated with sudden cardiac death.
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Affiliation(s)
- Oscar Campuzano
- Cardiovascular Genetics Center, University of Girona - IDIBGI, Spain ; Department of Medical Sciences, School of Medicine, University of Girona, Spain
| | | | - Ramon Brugada
- Cardiovascular Genetics Center, University of Girona - IDIBGI, Spain ; Department of Medical Sciences, School of Medicine, University of Girona, Spain
| | - Josep Brugada
- Unit of Arrhythmias, Hospital Sant Joan de Deu, University of Barcelona, Spain ; Unit of Arrhythmias, Hospital Clinic de Barcelona, University of Barcelona, Spain
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Castro-Torres Y, Carmona-Puerta R, Katholi RE. Ventricular repolarization markers for predicting malignant arrhythmias in clinical practice. World J Clin Cases 2015; 3:705-720. [PMID: 26301231 PMCID: PMC4539410 DOI: 10.12998/wjcc.v3.i8.705] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 02/22/2015] [Accepted: 06/08/2015] [Indexed: 02/05/2023] Open
Abstract
Malignant cardiac arrhythmias which result in sudden cardiac death may be present in individuals apparently healthy or be associated with other medical conditions. The way to predict their appearance represents a challenge for the medical community due to the tragic outcomes in most cases. In the last two decades some ventricular repolarization (VR) markers have been found to be useful to predict malignant cardiac arrhythmias in several clinical conditions. The corrected QT, QT dispersion, Tpeak-Tend, Tpeak-Tend dispersion and Tp-e/QT have been studied and implemented in clinical practice for this purpose. These markers are obtained from 12 lead surface electrocardiogram. In this review we discuss how these markers have demonstrated to be effective to predict malignant arrhythmias in medical conditions such as long and short QT syndromes, Brugada syndrome, early repolarization syndrome, acute myocardial ischemia, heart failure, hypertension, diabetes mellitus, obesity and highly trained athletes. Also the main pathophysiological mechanisms that explain the arrhythmogenic predisposition in these diseases and the basis for the VR markers are discussed. However, the same results have not been found in all conditions. Further studies are needed to reach a global consensus in order to incorporate these VR parameters in risk stratification of these patients.
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97
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Selga E, Campuzano O, Pinsach-Abuin M, Pérez-Serra A, Mademont-Soler I, Riuró H, Picó F, Coll M, Iglesias A, Pagans S, Sarquella-Brugada G, Berne P, Benito B, Brugada J, Porres JM, López Zea M, Castro-Urda V, Fernández-Lozano I, Brugada R. Comprehensive Genetic Characterization of a Spanish Brugada Syndrome Cohort. PLoS One 2015; 10:e0132888. [PMID: 26173111 PMCID: PMC4501715 DOI: 10.1371/journal.pone.0132888] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 06/22/2015] [Indexed: 12/12/2022] Open
Abstract
Background Brugada syndrome (BrS) is a rare genetic cardiac arrhythmia that can lead to sudden cardiac death in patients with a structurally normal heart. Genetic variations in SCN5A can be identified in approximately 20-25% of BrS cases. The aim of our work was to determine the spectrum and prevalence of genetic variations in a Spanish cohort diagnosed with BrS. Methodology/Principal Findings We directly sequenced fourteen genes reported to be associated with BrS in 55 unrelated patients clinically diagnosed. Our genetic screening allowed the identification of 61 genetic variants. Of them, 20 potentially pathogenic variations were found in 18 of the 55 patients (32.7% of the patients, 83.3% males). Nineteen of them were located in SCN5A, and had either been previously reported as pathogenic variations or had a potentially pathogenic effect. Regarding the sequencing of the minority genes, we discovered a potentially pathogenic variation in SCN2B that was described to alter sodium current, and one nonsense variant of unknown significance in RANGRF. In addition, we also identified 40 single nucleotide variations which were either synonymous variants (four of them had not been reported yet) or common genetic variants. We next performed MLPA analysis of SCN5A for the 37 patients without an identified genetic variation, and no major rearrangements were detected. Additionally, we show that being at the 30-50 years range or exhibiting symptoms are factors for an increased potentially pathogenic variation discovery yield. Conclusions In summary, the present study is the first comprehensive genetic evaluation of 14 BrS-susceptibility genes and MLPA of SCN5A in a Spanish BrS cohort. The mean pathogenic variation discovery yield is higher than that described for other European BrS cohorts (32.7% vs 20-25%, respectively), and is even higher for patients in the 30-50 years age range.
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Affiliation(s)
- Elisabet Selga
- Cardiovascular Genetics Centre, Institut d’Investigació Biomèdica de Girona (IDIBGi), Girona, Spain and Medical School, Universitat de Girona (UdG), Girona, Spain
| | - Oscar Campuzano
- Cardiovascular Genetics Centre, Institut d’Investigació Biomèdica de Girona (IDIBGi), Girona, Spain and Medical School, Universitat de Girona (UdG), Girona, Spain
| | - Mel·lina Pinsach-Abuin
- Cardiovascular Genetics Centre, Institut d’Investigació Biomèdica de Girona (IDIBGi), Girona, Spain and Medical School, Universitat de Girona (UdG), Girona, Spain
| | - Alexandra Pérez-Serra
- Cardiovascular Genetics Centre, Institut d’Investigació Biomèdica de Girona (IDIBGi), Girona, Spain and Medical School, Universitat de Girona (UdG), Girona, Spain
| | - Irene Mademont-Soler
- Cardiovascular Genetics Centre, Institut d’Investigació Biomèdica de Girona (IDIBGi), Girona, Spain and Medical School, Universitat de Girona (UdG), Girona, Spain
| | - Helena Riuró
- Cardiovascular Genetics Centre, Institut d’Investigació Biomèdica de Girona (IDIBGi), Girona, Spain and Medical School, Universitat de Girona (UdG), Girona, Spain
| | - Ferran Picó
- Cardiovascular Genetics Centre, Institut d’Investigació Biomèdica de Girona (IDIBGi), Girona, Spain and Medical School, Universitat de Girona (UdG), Girona, Spain
| | - Mònica Coll
- Cardiovascular Genetics Centre, Institut d’Investigació Biomèdica de Girona (IDIBGi), Girona, Spain and Medical School, Universitat de Girona (UdG), Girona, Spain
| | - Anna Iglesias
- Cardiovascular Genetics Centre, Institut d’Investigació Biomèdica de Girona (IDIBGi), Girona, Spain and Medical School, Universitat de Girona (UdG), Girona, Spain
| | - Sara Pagans
- Cardiovascular Genetics Centre, Institut d’Investigació Biomèdica de Girona (IDIBGi), Girona, Spain and Medical School, Universitat de Girona (UdG), Girona, Spain
| | - Georgia Sarquella-Brugada
- Paediatric Arrhythmia Unit, Cardiology Department, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
| | - Paola Berne
- Arrhythmia Unit, Hospital Clínic of Barcelona, University of Barcelona, Barcelona, Spain
| | - Begoña Benito
- Arrhythmia Unit, Hospital Clínic of Barcelona, University of Barcelona, Barcelona, Spain
| | - Josep Brugada
- Arrhythmia Unit, Hospital Clínic of Barcelona, University of Barcelona, Barcelona, Spain
| | - José M. Porres
- Arrhythmia Unit, Hospital Universitario Donostia, San Sebastian, Spain
| | | | | | | | - Ramon Brugada
- Cardiovascular Genetics Centre, Institut d’Investigació Biomèdica de Girona (IDIBGi), Girona, Spain and Medical School, Universitat de Girona (UdG), Girona, Spain
- Hospital Josep Trueta, Girona, Spain
- * E-mail:
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Viales RR, Eichstaedt CA, Ehlken N, Fischer C, Lichtblau M, Grünig E, Hinderhofer K. Mutation in BMPR2 Promoter: A 'Second Hit' for Manifestation of Pulmonary Arterial Hypertension? PLoS One 2015; 10:e0133042. [PMID: 26167679 PMCID: PMC4500409 DOI: 10.1371/journal.pone.0133042] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 06/22/2015] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Hereditary pulmonary arterial hypertension (HPAH) can be caused by autosomal dominant inherited mutations of TGF-β genes, such as the bone morphogenetic protein receptor 2 (BMPR2) and Endoglin (ENG) gene. Additional modifier genes may play a role in disease manifestation and severity. In this study we prospectively assessed two families with known BMPR2 or ENG mutations clinically and genetically and screened for a second mutation in the BMPR2 promoter region. METHODS We investigated the BMPR2 promoter region by direct sequencing in two index-patients with invasively confirmed diagnosis of HPAH, carrying a mutation in the BMPR2 and ENG gene, respectively. Sixteen family members have been assessed clinically by non-invasive methods and genetically by direct sequencing. RESULTS In both index patients with a primary BMPR2 deletion (exon 2 and 3) and Endoglin missense variant (c.1633G>A, p.(G545S)), respectively, we detected a second mutation (c.-669G>A) in the promoter region of the BMPR2 gene. The index patients with 2 mutations/variants were clinically severely affected at early age, whereas further family members with only one mutation had no manifest HPAH. CONCLUSION The finding of this study supports the hypothesis that additional mutations may lead to an early and severe manifestation of HPAH. This study shows for the first time that in the regulatory region of the BMPR2 gene the promoter may be important for disease penetrance. Further studies are needed to assess the incidence and clinical relevance of mutations of the BMPR2 promoter region in a larger patient cohort.
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Affiliation(s)
- Rebecca Rodríguez Viales
- University Hospital Heidelberg, Centre for pulmonary hypertension of the Thoraxclinic Heidelberg, Heidelberg, Germany; Heidelberg University, Institute of Human Genetics, Heidelberg, Germany
| | - Christina A Eichstaedt
- University Hospital Heidelberg, Centre for pulmonary hypertension of the Thoraxclinic Heidelberg, Heidelberg, Germany
| | - Nicola Ehlken
- University Hospital Heidelberg, Centre for pulmonary hypertension of the Thoraxclinic Heidelberg, Heidelberg, Germany
| | - Christine Fischer
- Heidelberg University, Institute of Human Genetics, Heidelberg, Germany
| | - Mona Lichtblau
- University Hospital Heidelberg, Centre for pulmonary hypertension of the Thoraxclinic Heidelberg, Heidelberg, Germany
| | - Ekkehard Grünig
- University Hospital Heidelberg, Centre for pulmonary hypertension of the Thoraxclinic Heidelberg, Heidelberg, Germany
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Identification of cis-suppression of human disease mutations by comparative genomics. Nature 2015; 524:225-9. [PMID: 26123021 DOI: 10.1038/nature14497] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2014] [Accepted: 04/23/2015] [Indexed: 11/08/2022]
Abstract
Patterns of amino acid conservation have served as a tool for understanding protein evolution. The same principles have also found broad application in human genomics, driven by the need to interpret the pathogenic potential of variants in patients. Here we performed a systematic comparative genomics analysis of human disease-causing missense variants. We found that an appreciable fraction of disease-causing alleles are fixed in the genomes of other species, suggesting a role for genomic context. We developed a model of genetic interactions that predicts most of these to be simple pairwise compensations. Functional testing of this model on two known human disease genes revealed discrete cis amino acid residues that, although benign on their own, could rescue the human mutations in vivo. This approach was also applied to ab initio gene discovery to support the identification of a de novo disease driver in BTG2 that is subject to protective cis-modification in more than 50 species. Finally, on the basis of our data and models, we developed a computational tool to predict candidate residues subject to compensation. Taken together, our data highlight the importance of cis-genomic context as a contributor to protein evolution; they provide an insight into the complexity of allele effect on phenotype; and they are likely to assist methods for predicting allele pathogenicity.
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Baroni D, Moran O. On the multiple roles of the voltage gated sodium channel β1 subunit in genetic diseases. Front Pharmacol 2015; 6:108. [PMID: 26042039 PMCID: PMC4434899 DOI: 10.3389/fphar.2015.00108] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 05/06/2015] [Indexed: 11/13/2022] Open
Abstract
Voltage-gated sodium channels are intrinsic plasma membrane proteins that initiate the action potential in electrically excitable cells. They are composed of a pore-forming α-subunit and associated β-subunits. The β1-subunit was the first accessory subunit to be cloned. It can be important for controlling cell excitability and modulating multiple aspects of sodium channel physiology. Mutations of β1 are implicated in a wide variety of inherited pathologies, including epilepsy and cardiac conduction diseases. This review summarizes β1-subunit related channelopathies pointing out the current knowledge concerning their genetic background and their underlying molecular mechanisms.
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Affiliation(s)
- Debora Baroni
- Istituto di Biofisica - Consiglio Nazionale delle Ricerche, Genova Italy
| | - Oscar Moran
- Istituto di Biofisica - Consiglio Nazionale delle Ricerche, Genova Italy
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