1
|
McDonald K, Larkin K, Dickinson DJ, Golden A, Bai X, Doonan R. Using CRISPR knock-in of fluorescent tags to examine isoform-specific expression of EGL-19 in C. elegans. MICROPUBLICATION BIOLOGY 2023; 2023:10.17912/micropub.biology.000858. [PMID: 37746064 PMCID: PMC10514701 DOI: 10.17912/micropub.biology.000858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 06/12/2023] [Accepted: 09/06/2023] [Indexed: 09/26/2023]
Abstract
L-type voltage-gated calcium channels (VGCCs) regulate calcium influx and excitation-contraction coupling in many types of muscle cells. Thus, VGCC mutations can cause skeletal and cardiac muscle diseases in humans, such as Duchenne muscular dystrophy and Timothy syndrome. To better understand the genetics and native expression of VGCCs, we have chosen to use the microscopic roundworm, C. elegans . The egl-19 locus is the sole L-type VGCC gene and it encodes three distinct isoforms (a, b, and c). Isoform c is curious because the protein is truncated, lacking the transmembrane domains that form the physical calcium channel. In this study, we have characterized egl-19 expression using CRISPR/Cas9 genome editing to 'knock-in' fluorescent tags of differing colors, allowing us to distinguish the expression pattern of each isoform. Not surprisingly, we found that EGL-19 is expressed in all types of muscle. In addition, we provide evidence that the truncated c isoform is expressed. Finally, although we find evidence that specific isoforms can have unique subcellular distributions, we also observed some expression patterns that appear to be artifacts. Overall, our results show interesting patterns of egl-19 expression, but also highlight the need for caution when interpreting expression of reporter genes even when they represent endogenous tags.
Collapse
Affiliation(s)
- Kara McDonald
- Glow Worms Stream, Freshman Research Initiative, College of Natural Sciences, The University of Texas at Austin, Austin, Texas, United States
| | - Kerry Larkin
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States
- Department of Cell Biology, Yale University, New Haven, Connecticut, United States
| | - Daniel J Dickinson
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, United States
| | - Andy Golden
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States
| | - Xiaofei Bai
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States
- Department of Biology, University of Florida, Gainesville, Florida, United States
| | - Ryan Doonan
- Glow Worms Stream, Freshman Research Initiative, College of Natural Sciences, The University of Texas at Austin, Austin, Texas, United States
| |
Collapse
|
2
|
Yan Z, Zhong L, Zhu W, Chung SK, Hou P. Chinese herbal medicine for the treatment of cardiovascular diseases ─ targeting cardiac ion channels. Pharmacol Res 2023; 192:106765. [PMID: 37075871 DOI: 10.1016/j.phrs.2023.106765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 04/04/2023] [Accepted: 04/12/2023] [Indexed: 04/21/2023]
Abstract
Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality, imposing an increasing global health burden. Cardiac ion channels (voltage-gated NaV, CaV, KVs, and others) synergistically shape the cardiac action potential (AP) and control the heartbeat. Dysfunction of these channels, due to genetic mutations, transcriptional or post-translational modifications, may disturb the AP and lead to arrhythmia, a major risk for CVD patients. Although there are five classes of anti-arrhythmic drugs available, they can have varying levels of efficacies and side effects on patients, possibly due to the complex pathogenesis of arrhythmias. As an alternative treatment option, Chinese herbal remedies have shown promise in regulating cardiac ion channels and providing anti-arrhythmic effects. In this review, we first discuss the role of cardiac ion channels in maintaining normal heart function and the pathogenesis of CVD, then summarize the classification of Chinese herbal compounds, and elaborate detailed mechanisms of their efficacy in regulating cardiac ion channels and in alleviating arrhythmia and CVD. We also address current limitations and opportunities for developing new anti-CVD drugs based on Chinese herbal medicines.
Collapse
Affiliation(s)
- Zhenzhen Yan
- Dr. Neher's Biophysics Laboratory for Innovative Drug Discovery, State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macao SAR, China
| | - Ling Zhong
- Dr. Neher's Biophysics Laboratory for Innovative Drug Discovery, State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macao SAR, China
| | - Wandi Zhu
- Cardiovascular Medicine Division and Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Sookja Kim Chung
- Dr. Neher's Biophysics Laboratory for Innovative Drug Discovery, State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macao SAR, China; Faculty of Medicine & Faculty of Innovation Engineering at Macau University of Science and Technology, Taipa, Macao SAR, China; State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong, China
| | - Panpan Hou
- Dr. Neher's Biophysics Laboratory for Innovative Drug Discovery, State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macao SAR, China; Macau University of Science and Technology Zhuhai MUST Science and Technology Research Institute. Zhuhai, Guangdong, China.
| |
Collapse
|
3
|
RBM24 controls cardiac QT interval through CaMKIIδ splicing. Cell Mol Life Sci 2022; 79:613. [PMID: 36454480 DOI: 10.1007/s00018-022-04624-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 10/26/2022] [Accepted: 11/05/2022] [Indexed: 12/02/2022]
Abstract
Calcium/calmodulin-dependent kinase II delta (CaMKIIδ) is the predominant cardiac isoform and it is alternatively spliced to generate multiple variants. Variable variants allow for distinct localization and potentially different functions in the heart. Dysregulation of CaMKIIδ splicing has been demonstrated to be involved in the pathogenesis of heart diseases, such as cardiac hypertrophy, arrhythmia, and diastolic dysfunction. However, the mechanisms that regulate CaMKIIδ are incompletely understood. Here, we show that RNA binding motif protein 24 (RBM24) is a key splicing regulator of CaMKIIδ. RBM24 ablation leads to the aberrant shift of CaMKIIδ towards the δ-C isoform, which is known to activate the L-type Ca current. In line with this, we found marked alteration in Ca2+ handling followed by prolongation of the ventricular cardiac action potential and QT interval in RBM24 knockout mice, and these changes could be attenuated by treatment with an inhibitor of CaMKIIδ. Importantly, knockdown of RBM24 in human embryonic stem cell-derived cardiomyocytes showed similar electrophysiological abnormalities, suggesting the important role of RBM24 in the human heart. Thus, our data suggest that RBM24 is a critical regulator of CaMKIIδ to control the cardiac QT interval, highlighting the key role of splicing regulation in cardiac rhythm.
Collapse
|
4
|
Novelli V, Memmi M, Malovini A, Mazzanti A, Liu N, Yanfei R, Bongianino R, Denegri M, Monteforte N, Bloise R, Morini M, Napolitano C. The role of CACNA1C in Brugada syndrome: prevalence and phenotype of probands referred for genetic testing. Heart Rhythm 2022; 19:798-806. [PMID: 34999275 DOI: 10.1016/j.hrthm.2021.12.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 12/07/2021] [Accepted: 12/27/2021] [Indexed: 11/18/2022]
Abstract
BACKGROUND Contradictory evidence is available on the role of the CACNA1C gene, encoding for the α-subunit of the cardiac L-type calcium channel (CaV1.2), as a cause of the BrS3 variant of Brugada syndrome (BrS). OBJECTIVE We aimed at tackling this issue in a large BrS cohort to define the yield of molecular screening and to address the hypothesis if an appropriate patient selection could improve the clinical utility. METHODS A total of 709 patients entered this study. BrS probands (n= 563, consecutively referred) underwent CACNA1C sequencing. Two matched cohorts where defined: discovery cohort (n = 200 patients) and confirmation cohort (n = 363 patients). Furthermore, the clinical phenotypes of a matched SCN5A positive BrS cohort (n= 146) were included for comparative genotype-phenotype correlation. RESULTS In the discovery cohort, we identified 11 different rare variants in 9 patients of whom 10 (5%) were considered potentially causative based on their frequency in the general population. However, ACMG criteria were unable to classify the majority (80%) of them eventually labeled as variants of unknown significance (VUS). Functional studies revealed a loss of function for 9 variants pointing to a prevalence of CACNA1C causative variants in 4% in the discovery cohort. Genotype-phenotype correlation showed that pathogenic variants are significantly more frequent in patients with a shorter QTc (12.9 % vs 2.2 % in patients with QTc < 390 ms). CONCLUSION CACNA1C is an infrequent but definitive cause of BrS typically associated with short QT. Functional studies are highly relevant to improve variant interpretation.
Collapse
Affiliation(s)
- Valeria Novelli
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy; Istituto di Medicina Genomica, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Mirella Memmi
- Molecular Cardiology, Istituti Clinici Scientifici Maugeri, IRCCS, Pavia, Italy
| | - Alberto Malovini
- Laboratory of Informatics and Systems Engineering for Clinical Research, Istituti Clinici Scientifici Maugeri IRCCS, Pavia, Italy
| | - Andrea Mazzanti
- Molecular Cardiology, Istituti Clinici Scientifici Maugeri, IRCCS, Pavia, Italy; Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Nian Liu
- Molecular Cardiology, Istituti Clinici Scientifici Maugeri, IRCCS, Pavia, Italy
| | - Ruan Yanfei
- Molecular Cardiology, Istituti Clinici Scientifici Maugeri, IRCCS, Pavia, Italy
| | - Rossana Bongianino
- Molecular Cardiology, Istituti Clinici Scientifici Maugeri, IRCCS, Pavia, Italy
| | - Marco Denegri
- Molecular Cardiology, Istituti Clinici Scientifici Maugeri, IRCCS, Pavia, Italy
| | - Nicola Monteforte
- Molecular Cardiology, Istituti Clinici Scientifici Maugeri, IRCCS, Pavia, Italy
| | - Raffaella Bloise
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy; Molecular Cardiology, Istituti Clinici Scientifici Maugeri, IRCCS, Pavia, Italy
| | - Massimo Morini
- Molecular Cardiology, Istituti Clinici Scientifici Maugeri, IRCCS, Pavia, Italy
| | - Carlo Napolitano
- Molecular Cardiology, Istituti Clinici Scientifici Maugeri, IRCCS, Pavia, Italy; Department of Molecular Medicine, University of Pavia, Pavia, Italy.
| |
Collapse
|
5
|
Monasky MM, Rutigliani C, Micaglio E, Pappone C. Commentary: Peptide-Based Targeting of the L-Type Calcium Channel Corrects the Loss-of-Function Phenotype of Two Novel Mutations of the CACNA1 Gene Associated With Brugada Syndrome. Front Physiol 2021; 12:682567. [PMID: 34177625 PMCID: PMC8220137 DOI: 10.3389/fphys.2021.682567] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 05/10/2021] [Indexed: 01/27/2023] Open
Affiliation(s)
- Michelle M Monasky
- Arrhythmology Department, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy
| | | | - Emanuele Micaglio
- Arrhythmology Department, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy
| | - Carlo Pappone
- Arrhythmology Department, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy.,Vita-Salute San Raffaele University, Milan, Italy
| |
Collapse
|
6
|
Gezalian MM, Mangiacotti L, Rajput P, Sparrow N, Schlick K, Lahiri S. Cerebrovascular and neurological perspectives on adrenoceptor and calcium channel modulating pharmacotherapies. J Cereb Blood Flow Metab 2021; 41:693-706. [PMID: 33210576 PMCID: PMC7983505 DOI: 10.1177/0271678x20972869] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 10/12/2020] [Accepted: 10/13/2020] [Indexed: 02/02/2023]
Abstract
Adrenoceptor and calcium channel modulating medications are widely used in clinical practice for acute neurological and systemic conditions. It is generally assumed that the cerebrovascular effects of these drugs mirror that of their systemic effects - and this is reflected in how these medications are currently used in clinical practice. However, recent research suggests that there are distinct cerebrovascular-specific effects of these medications that are related to the unique characteristics of the cerebrovascular anatomy including the regional heterogeneity in density and distribution of adrenoceptor subtypes and calcium channels along the cerebrovasculature. In this review, we critically evaluate existing basic science and clinical research to discuss known and putative interactions between adrenoceptor and calcium channel modulating pharmacotherapies, the neurovascular unit, and cerebrovascular anatomy. In doing so, we provide a rationale for selecting vasoactive medications based on lesion location and lay a foundation for future investigations that will define neuroprotective paradigms of adrenoceptor and calcium channel modulating therapies to improve neurological outcomes in acute neurological and systemic disorders.
Collapse
Affiliation(s)
- Michael M Gezalian
- Departments of Neurology and Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Luigi Mangiacotti
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Padmesh Rajput
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Nicklaus Sparrow
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Konrad Schlick
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Shouri Lahiri
- Departments of Neurology, Neurosurgery, and Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| |
Collapse
|
7
|
Striessnig J. Voltage-Gated Ca 2+-Channel α1-Subunit de novo Missense Mutations: Gain or Loss of Function - Implications for Potential Therapies. Front Synaptic Neurosci 2021; 13:634760. [PMID: 33746731 PMCID: PMC7966529 DOI: 10.3389/fnsyn.2021.634760] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 02/02/2021] [Indexed: 12/12/2022] Open
Abstract
This review summarizes our current knowledge of human disease-relevant genetic variants within the family of voltage gated Ca2+ channels. Ca2+ channelopathies cover a wide spectrum of diseases including epilepsies, autism spectrum disorders, intellectual disabilities, developmental delay, cerebellar ataxias and degeneration, severe cardiac arrhythmias, sudden cardiac death, eye disease and endocrine disorders such as congential hyperinsulinism and hyperaldosteronism. A special focus will be on the rapidly increasing number of de novo missense mutations identified in the pore-forming α1-subunits with next generation sequencing studies of well-defined patient cohorts. In contrast to likely gene disrupting mutations these can not only cause a channel loss-of-function but can also induce typical functional changes permitting enhanced channel activity and Ca2+ signaling. Such gain-of-function mutations could represent therapeutic targets for mutation-specific therapy of Ca2+-channelopathies with existing or novel Ca2+-channel inhibitors. Moreover, many pathogenic mutations affect positive charges in the voltage sensors with the potential to form gating-pore currents through voltage sensors. If confirmed in functional studies, specific blockers of gating-pore currents could also be of therapeutic interest.
Collapse
Affiliation(s)
- Jörg Striessnig
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria
| |
Collapse
|
8
|
Kato K, Ohno S, Sonoda K, Fukuyama M, Makiyama T, Ozawa T, Horie M. LMNA Missense Mutation Causes Nonsense-Mediated mRNA Decay and Severe Dilated Cardiomyopathy. CIRCULATION-GENOMIC AND PRECISION MEDICINE 2020; 13:435-443. [PMID: 32818388 DOI: 10.1161/circgen.119.002853] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND LMNA is a known causative gene of dilated cardiomyopathy and familial conduction disturbance. Nonsense-mediated mRNA decay, normally caused by nonsense mutations, is a safeguard process to protect cells from deleterious effects of inappropriate proteins from mutated genes. Nonsense-mediated mRNA decay induced by nonstop codon mutations is rare. We investigated the effect of an LMNA missense mutation identified in 2 families affected by cardiac laminopathy. METHODS Genomic DNA and total RNA were isolated from patients' peripheral blood lymphocytes or cardiac tissue. LMNA-coding exons were screened by direct sequencing. Complementary DNAs were generated by a reverse transcription-polymerase chain reaction from total RNA. Quantitative polymerase chain reaction was performed to quantify the LMNA complementary DNA amount by using specific primers for lamins A and C. A minigene splicing reporter experiment was performed to assess the effect of detected variants on RNA splicing. The protein expressions of both isoforms were analyzed by Western blotting. RESULTS We detected a missense variant c.936 G>C (p. Q312H) at the end of exon 5 of LMNA by genomic DNA sequencing in 2 unrelated families affected by dilated cardiomyopathy and cardiac conduction disturbance. This variant was previously reported in a French family suffering from muscular dystrophy and cardiac conduction disturbance. Sequencing of complementary DNA demonstrated that the mutated allele was absent. By quantitative polymerase chain reaction assay, we confirmed a 90% reduction in LMNA complementary DNA. The minigene splicing reporter assay demonstrated a splicing error by the variant. Western blot analysis revealed that lamin A and C expressions were reduced far >50%. CONCLUSIONS We report an LMNA missense mutation found in 2 families, which disrupted a normal splicing site, led to nonsense-mediated mRNA decay, and resulted in severe cardiac laminopathy.
Collapse
Affiliation(s)
- Koichi Kato
- Department of Cardiovascular Medicine (K.K., S.O., M.F., T.O., M.H.), Shiga University of Medical Science, Otsu
| | - Seiko Ohno
- Department of Cardiovascular Medicine (K.K., S.O., M.F., T.O., M.H.), Shiga University of Medical Science, Otsu
- Center for Epidemiologic Research in Asia (S.O., M.H.), Shiga University of Medical Science, Otsu
- Department of Bioscience and Genetics, National Cerebral and Cardiovascular Center, Suita (S.O., K.S.)
| | - Keiko Sonoda
- Department of Bioscience and Genetics, National Cerebral and Cardiovascular Center, Suita (S.O., K.S.)
| | - Megumi Fukuyama
- Department of Cardiovascular Medicine (K.K., S.O., M.F., T.O., M.H.), Shiga University of Medical Science, Otsu
| | - Takeru Makiyama
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Japan (T.M.)
| | - Tomoya Ozawa
- Department of Cardiovascular Medicine (K.K., S.O., M.F., T.O., M.H.), Shiga University of Medical Science, Otsu
| | - Minoru Horie
- Department of Cardiovascular Medicine (K.K., S.O., M.F., T.O., M.H.), Shiga University of Medical Science, Otsu
- Center for Epidemiologic Research in Asia (S.O., M.H.), Shiga University of Medical Science, Otsu
| |
Collapse
|
9
|
Monasky MM, Micaglio E, Ciconte G, Pappone C. Brugada Syndrome: Oligogenic or Mendelian Disease? Int J Mol Sci 2020; 21:ijms21051687. [PMID: 32121523 PMCID: PMC7084676 DOI: 10.3390/ijms21051687] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 02/27/2020] [Accepted: 02/28/2020] [Indexed: 02/06/2023] Open
Abstract
Brugada syndrome (BrS) is diagnosed by a coved-type ST-segment elevation in the right precordial leads on the electrocardiogram (ECG), and it is associated with an increased risk of sudden cardiac death (SCD) compared to the general population. Although BrS is considered a genetic disease, its molecular mechanism remains elusive in about 70-85% of clinically-confirmed cases. Variants occurring in at least 26 different genes have been previously considered causative, although the causative effect of all but the SCN5A gene has been recently challenged, due to the lack of systematic, evidence-based evaluations, such as a variant's frequency among the general population, family segregation analyses, and functional studies. Also, variants within a particular gene can be associated with an array of different phenotypes, even within the same family, preventing a clear genotype-phenotype correlation. Moreover, an emerging concept is that a single mutation may not be enough to cause the BrS phenotype, due to the increasing number of common variants now thought to be clinically relevant. Thus, not only the complete list of genes causative of the BrS phenotype remains to be determined, but also the interplay between rare and common multiple variants. This is particularly true for some common polymorphisms whose roles have been recently re-evaluated by outstanding works, including considering for the first time ever a polygenic risk score derived from the heterozygous state for both common and rare variants. The more common a certain variant is, the less impact this variant might have on heart function. We are aware that further studies are warranted to validate a polygenic risk score, because there is no mutated gene that connects all, or even a majority, of BrS cases. For the same reason, it is currently impossible to create animal and cell line genetic models that represent all BrS cases, which would enable the expansion of studies of this syndrome. Thus, the best model at this point is the human patient population. Further studies should first aim to uncover genetic variants within individuals, as well as to collect family segregation data to identify potential genetic causes of BrS.
Collapse
Affiliation(s)
| | | | | | - Carlo Pappone
- Correspondence: ; Tel.: +39-0252-774260; Fax: +39-0252-774306
| |
Collapse
|
10
|
Campuzano O, Fernandez-Falgueras A, Lemus X, Sarquella-Brugada G, Cesar S, Coll M, Mates J, Arbelo E, Jordà P, Perez-Serra A, Del Olmo B, Ferrer-Costa C, Iglesias A, Fiol V, Puigmulé M, Lopez L, Pico F, Brugada J, Brugada R. Short QT Syndrome: A Comprehensive Genetic Interpretation and Clinical Translation of Rare Variants. J Clin Med 2019; 8:jcm8071035. [PMID: 31315195 PMCID: PMC6678338 DOI: 10.3390/jcm8071035] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Revised: 07/08/2019] [Accepted: 07/11/2019] [Indexed: 12/14/2022] Open
Abstract
Short QT syndrome, one of the most lethal entities associated with sudden cardiac death, is a rare genetic disease characterized by short QT intervals detected by electrocardiogram. Several genetic variants are causally linked to the disease, but there has yet to be a comprehensive analysis of variants among patients with short QT syndrome. To fill this gap, we performed an exhaustive study of variants currently catalogued as deleterious in short QT syndrome according to the American College of Medical Genetics and Genomics and the Association for Molecular Pathology. Analysis of the 32 variants described in the literature determined that only nine (28.12%) have a conclusive pathogenic role. All definitively pathogenic variants are located in KCNQ1, KCNH2, or KCNJ2; three genes encoding potassium channels. Other variants located in genes encoding calcium or sodium channels are associated with electrical alterations concomitant with shortened QT intervals but do not guarantee a diagnosis of short QT syndrome. We recommend caution regarding previously reported variants classified as pathogenic. An exhaustive re-analysis is necessary to clarify the role of each variant before routinely translating genetic findings to the clinical setting.
Collapse
Affiliation(s)
- Oscar Campuzano
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain.
- Centro Investigación Biomédica en Red Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain.
- Medical Science Department, School of Medicine, University of Girona, 17071 Girona, Spain.
- Biochemistry and Molecular Genetics Department, Hospital Clinic, IDIBAPS, 08036 Barcelona, Spain.
| | | | - Ximena Lemus
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Georgia Sarquella-Brugada
- Medical Science Department, School of Medicine, University of Girona, 17071 Girona, Spain
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, 08950 Barcelona, Spain
| | - Sergi Cesar
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, 08950 Barcelona, Spain
| | - Monica Coll
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Jesus Mates
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Elena Arbelo
- Centro Investigación Biomédica en Red Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain
- Arrhythmias Unit, Hospital Clinic, University of Barcelona, 08036 Barcelona, Spain
| | - Paloma Jordà
- Centro Investigación Biomédica en Red Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain
- Arrhythmias Unit, Hospital Clinic, University of Barcelona, 08036 Barcelona, Spain
| | | | - Bernat Del Olmo
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Carles Ferrer-Costa
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Anna Iglesias
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Victoria Fiol
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, 08950 Barcelona, Spain
| | - Marta Puigmulé
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Laura Lopez
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Ferran Pico
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Josep Brugada
- Centro Investigación Biomédica en Red Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, 08950 Barcelona, Spain
- Arrhythmias Unit, Hospital Clinic, University of Barcelona, 08036 Barcelona, Spain
| | - Ramon Brugada
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain.
- Centro Investigación Biomédica en Red Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain.
- Medical Science Department, School of Medicine, University of Girona, 17071 Girona, Spain.
- Cardiology Service, Hospital Josep Trueta, University of Girona, 17007 Girona, Spain.
| |
Collapse
|
11
|
Bozarth X, Dines JN, Cong Q, Mirzaa GM, Foss K, Merritt JL, Thies J, Mefford HC, Novotny E. Expanding clinical phenotype in CACNA1C related disorders: From neonatal onset severe epileptic encephalopathy to late-onset epilepsy. Am J Med Genet A 2018; 176:2733-2739. [PMID: 30513141 PMCID: PMC6312477 DOI: 10.1002/ajmg.a.40657] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 09/17/2018] [Accepted: 09/18/2018] [Indexed: 02/01/2023]
Abstract
CACNA1C (NM_000719.6) encodes an L-type calcium voltage-gated calcium channel (Cav 1.2), and pathogenic variants have been associated with two distinct clinical entities: Timothy syndrome and Brugada syndrome. Thus far, CACNA1C has not been reported as a gene associated with epileptic encephalopathy and is less commonly associated with epilepsy. We report three individuals from two families with variants in CACNA1C. Patient 1 presented with neonatal onset epileptic encephalopathy (NOEE) and was found to have a de novo missense variant in CACNA1C (c.4087G>A (p.V1363M)) on exome sequencing. In Family 2, Patient 2 presented with congenital cardiac anomalies and cardiomyopathy and was found to have a paternally inherited splice site variant, c.3717+1_3717+2insA, on a cardiomyopathy panel. Her father, Patient 3, presented with learning difficulties, late-onset epilepsy, and congenital cardiac anomalies. Family 2 highlights variable expressivity seen within a family. This case series expands the clinical and molecular phenotype of CACNA1C-related disorders and highlights the need to include CACNA1C on epilepsy gene panels.
Collapse
Affiliation(s)
- Xiuhua Bozarth
- Division of Pediatric Neurology, Department of Neurology, University of Washington, Seattle, WA
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA
| | - Jennifer N. Dines
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA
- Division of Medical Genetics, Department of Internal Medicine, University of Washington, Seattle, WA
| | - Qian Cong
- Department of Biochemistry and Institution for Protein Design, University of Washington, Seattle, WA
| | - Ghayda M. Mirzaa
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA
| | - Kimberly Foss
- Division of Genetic Medicine, Seattle Children’s Hospital, Seattle, WA
| | - J. Lawrence Merritt
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA
| | - Jenny Thies
- Division of Genetic Medicine, Seattle Children’s Hospital, Seattle, WA
| | - Heather C. Mefford
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA
| | - Edward Novotny
- Division of Pediatric Neurology, Department of Neurology, University of Washington, Seattle, WA
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA
| |
Collapse
|
12
|
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.
Collapse
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
| |
Collapse
|
13
|
Monasky MM, Pappone C, Piccoli M, Ghiroldi A, Micaglio E, Anastasia L. Calcium in Brugada Syndrome: Questions for Future Research. Front Physiol 2018; 9:1088. [PMID: 30147658 PMCID: PMC6095984 DOI: 10.3389/fphys.2018.01088] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 07/23/2018] [Indexed: 12/11/2022] Open
Abstract
The Brugada syndrome (BrS) is characterized by coved-type ST-segment elevation in the right precordial leads on the electrocardiogram (ECG) and increased risk of sudden cardiac death (SCD). While it is an inheritable disease, determining the true prevalence is a challenge, since patients may report no known family history of the syndrome, present with a normal spontaneous ECG pattern at the time of examination, and test negative for all known BrS-causative genes. In fact, SCD is often the first indication that a person is affected by the syndrome. Men are more likely to be symptomatic than women. Abnormal, low-voltage, fractionated electrograms have been found in the epicardium of the right ventricular outflow tract (RVOT). Ablation of this area abolishes the abnormal electrograms and helps to prevent arrhythmic recurrences. BrS patients are more likely to experience ventricular tachycardia/fibrillation (VT/VF) during fever or during an increase in vagal tone. Isoproterenol helps to reverse the ECG BrS phenotype. In this review, we discuss roles of calcium in various conditions that are relevant to BrS, such as changes in temperature, heart rate, and vagal tone, and the effects of gender and isoproterenol on calcium handling. Studies are warranted to further investigate these mechanisms in models of BrS.
Collapse
Affiliation(s)
| | - Carlo Pappone
- Arrhythmology Department, IRCCS Policlinico San Donato, Milan, Italy
| | - Marco Piccoli
- Stem Cells for Tissue Engineering Lab, IRCCS Policlinico San Donato, Milan, Italy
| | - Andrea Ghiroldi
- Stem Cells for Tissue Engineering Lab, IRCCS Policlinico San Donato, Milan, Italy
| | - Emanuele Micaglio
- Arrhythmology Department, IRCCS Policlinico San Donato, Milan, Italy
| | - Luigi Anastasia
- Stem Cells for Tissue Engineering Lab, IRCCS Policlinico San Donato, Milan, Italy.,Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
| |
Collapse
|
14
|
Abstract
Background: Several studies have shown that the Single Nucleotide Polymorphism (SNP) in the CACAN1C gene, rs1006737, is related to different mood disorder illnesses, such as bipolar disorder and schizophrenia. Current day molecular procedures for allele detection of this gene can be very expensive and time consuming. Hence, a sensitive and specific molecular procedure for detecting these mutations in a large number of subjects is desirable, especially for research groups who have no complex laboratory equipment. Objective: The possibility of using a Fluorescence Resonance Energy Transfer (FRET) probe was evaluated by means of bioinformatic tools, designed for forecasting the molecular behavior of DNA probes used in the research field or for laboratory analysis methods. Method: In this study we used the DINAMelt Web Server to predict the Tms of FRET oligo in the presence of the A and/or G allele in rs1006737. The PCR primers were designed by using oligo 4 and oligo 6 primer analysis software, Results: The molecular probe described in this study detected a Tm difference of 5-6°C between alleles A and G in rs1006737, which also showed good discrimination for a heterozygous profile for this genomic region. Conclusion: Although in silico studies represent a relatively new avenue of inquiry, they have now started to be used to predict how a molecular probe interacts with its biological target, reducing the time and costs of molecular test tuning. The results of this study seem promising for further laboratory tests on allele detection in rs1006737 region.
Collapse
Affiliation(s)
- Germano Orrù
- Department of Surgical Sciences, Molecular Biology Service (MBS), University of Cagliari, Cagliari, Italy.,National Research Council of Italy, ISPA, Sassari, Italy
| | - Mauro Giovanni Carta
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Alessia Bramanti
- Istituto di Scienze Applicate e Sistemi Intelligenti, ISASI, Messina, Italy
| |
Collapse
|
15
|
Ion Channel Disorders and Sudden Cardiac Death. Int J Mol Sci 2018; 19:ijms19030692. [PMID: 29495624 PMCID: PMC5877553 DOI: 10.3390/ijms19030692] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 02/22/2018] [Accepted: 02/23/2018] [Indexed: 12/19/2022] Open
Abstract
Long QT syndrome, short QT syndrome, Brugada syndrome and catecholaminergic polymorphic ventricular tachycardia are inherited primary electrical disorders that predispose to sudden cardiac death in the absence of structural heart disease. Also known as cardiac channelopathies, primary electrical disorders respond to mutations in genes encoding cardiac ion channels and/or their regulatory proteins, which result in modifications in the cardiac action potential or in the intracellular calcium handling that lead to electrical instability and life-threatening ventricular arrhythmias. These disorders may have low penetrance and expressivity, making clinical diagnosis often challenging. However, because sudden cardiac death might be the first presenting symptom of the disease, early diagnosis becomes essential. Genetic testing might be helpful in this regard, providing a definite diagnosis in some patients. Yet important limitations still exist, with a significant proportion of patients remaining with no causative mutation identifiable after genetic testing. This review aims to provide the latest knowledge on the genetic basis of cardiac channelopathies and discuss the role of the affected proteins in the pathophysiology of each one of these diseases.
Collapse
|
16
|
Huang L, Wu KH, Zhang L, Wang Q, Tang S, Wu Q, Jiang PH, Lin JJC, Guo J, Wang L, Loh SH, Cheng J. Critical Roles of Xirp Proteins in Cardiac Conduction and Their Rare Variants Identified in Sudden Unexplained Nocturnal Death Syndrome and Brugada Syndrome in Chinese Han Population. J Am Heart Assoc 2018; 7:e006320. [PMID: 29306897 PMCID: PMC5778954 DOI: 10.1161/jaha.117.006320] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Accepted: 11/16/2017] [Indexed: 12/24/2022]
Abstract
BACKGROUND Sudden unexplained nocturnal death syndrome (SUNDS) remains an autopsy negative entity with unclear etiology. Arrhythmia has been implicated in SUNDS. Mutations/deficiencies in intercalated disc components have been shown to cause arrhythmias. Human cardiomyopathy-associated 1 (XIRP1) and 3 (XIRP2) are intercalated disc-associated, Xin repeats-containing proteins. Mouse Xirp1 is necessary for the integrity of intercalated disc and for the surface expression of transient outward and delayed rectifier K+ channels, whereas mouse Xirp2 is required for Xirp1 intercalated disc localization. Thus, XIRP1 and XIRP2 may be potentially causal genes for SUNDS. METHODS AND RESULTS We genetically screened XIRP genes in 134 sporadic SUNDS victims and 22 Brugada syndrome (BrS) cases in a Chinese Han population. We identified 16 rare variants (6 were in silico predicted as deleterious) in SUNDS victims, including a novel variant, XIRP2-E215K. There were also four rare variants (2 were in silico predicted as deleterious) detected in BrS cases, including a novel variant, XIRP2-L2718P. Interestingly, among these 20 variants, we detected 2 likely pathogenic variants: a nonsense variant (XIRP2-Q2875*) and a frameshift variant (XIRP2-T2238QfsX7). Analyzing available Xirp2 knockout mice, we further found that mouse hearts without Xirp2 exhibited prolonged PR and QT intervals, slow conduction velocity, atrioventricular conduction block, and an abnormal infranodal ventricular conduction system. Whole-cell patch-clamp detected altered ionic currents in Xirp2-/- cardiomyocytes, consistent with the observed association between Xirp2 and Nav1.5/Kv1.5 in co-immunoprecipitation. CONCLUSIONS This is the first report identifying likely pathogenic XIRP rare variants in arrhythmogenic disorders such as SUNDS and Brugada syndrome, and showing critical roles of Xirp2 in cardiac conduction.
Collapse
Affiliation(s)
- Lei Huang
- Department of Forensic Pathology, Zhongshan School of Medicine Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Kuo-Ho Wu
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
- Institute of Physiology, National Defense Medical Center, Taipei, Taiwan
- Institute of Pharmacology, National Defense Medical Center, Taipei, Taiwan
| | - Liyong Zhang
- Department of Forensic Pathology, Zhongshan School of Medicine Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Qinchuan Wang
- Department of Biology, University of Iowa, Iowa City, IA
| | - Shuangbo Tang
- Department of Forensic Pathology, Zhongshan School of Medicine Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Qiuping Wu
- Department of Forensic Pathology, Zhongshan School of Medicine Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Pei-Hsiu Jiang
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
- Institute of Physiology, National Defense Medical Center, Taipei, Taiwan
| | | | - Jian Guo
- BGI-Shenzhen, Shenzhen, Guangdong, China
- China National GeneBank BGI-Shenzhen, Shenzhen, Guangdong, China
| | - Lin Wang
- BGI-Shenzhen, Shenzhen, Guangdong, China
- China National GeneBank BGI-Shenzhen, Shenzhen, Guangdong, China
| | - Shih-Hurng Loh
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
- Institute of Pharmacology, National Defense Medical Center, Taipei, Taiwan
| | - Jianding Cheng
- Department of Forensic Pathology, Zhongshan School of Medicine Sun Yat-sen University, Guangzhou, Guangdong, China
| |
Collapse
|
17
|
Zhang Q, Chen J, Qin Y, Wang J, Zhou L. Mutations in voltage-gated L-type calcium channel: implications in cardiac arrhythmia. Channels (Austin) 2018; 12:201-218. [PMID: 30027834 PMCID: PMC6104696 DOI: 10.1080/19336950.2018.1499368] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 06/08/2018] [Accepted: 07/05/2018] [Indexed: 02/06/2023] Open
Abstract
The voltage-gated L-type calcium channel (LTCC) is essential for multiple cellular processes. In the heart, calcium influx through LTCC plays an important role in cardiac electrical excitation. Mutations in LTCC genes, including CACNA1C, CACNA1D, CACNB2 and CACNA2D, will induce the dysfunctions of calcium channels, which result in the abnormal excitations of cardiomyocytes, and finally lead to cardiac arrhythmias. Nevertheless, the newly found mutations in LTCC and their functions are continuously being elucidated. This review summarizes recent findings on the mutations of LTCC, which are associated with long QT syndromes, Timothy syndromes, Brugada syndromes, short QT syndromes, and some other cardiac arrhythmias. Indeed, we describe the gain/loss-of-functions of these mutations in LTCC, which can give an explanation for the phenotypes of cardiac arrhythmias. Moreover, we present several challenges in the field at present, and propose some diagnostic or therapeutic approaches to these mutation-associated cardiac diseases in the future.
Collapse
Affiliation(s)
- Qing Zhang
- Department of Cardiology, the Second Affiliated Hospital of Nantong University, Nantong First Hospital, Nantong, Jiangsu, China
- Department of Cardiology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Junjie Chen
- Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yao Qin
- Department of Cardiology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Juejin Wang
- Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Lei Zhou
- Department of Cardiology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| |
Collapse
|
18
|
Wu Y, Ai M, Bardeesi ASA, Xu L, Zheng J, Zheng D, Yin K, Wu Q, Zhang L, Huang L, Cheng J. Brugada syndrome: a fatal disease with complex genetic etiologies - still a long way to go. Forensic Sci Res 2017; 2:115-125. [PMID: 30483629 PMCID: PMC6197104 DOI: 10.1080/20961790.2017.1333203] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Accepted: 05/04/2017] [Indexed: 12/19/2022] Open
Abstract
Brugada syndrome (BrS) is an arrhythmogenic disorder which was first described in 1992. This disease is a channelopathy characterized by ST-segment elevations in the right precordial leads and is susceptible to sudden death. BrS is a fatal disease with gender and age preferences. It occurs mainly in young male subjects with a structurally normal heart and silently progresses to sudden death with no significant symptoms. The prevalence of BrS has been reported in the ranges of 5–20 per 10 000 people. The disease is more prevalent in Asia. Nowadays, numerous variations in 23 genes have been linked to BrS since the first gene SCN5A has been associated with BrS in 1998. Not only can clinical specialists apply these discoveries in risk assessment, diagnosis and personal medicine, but also forensic pathologists can make full use of these variations to conduct death cause identification. However, despite the progress in genetics, these associated genes can only account for approximately 35% of the BrS cases while the etiology of the remaining BrS cases is still unexplained. In this review, we discussed the prevalence, the genes associated with BrS and the application of molecular autopsy in forensic pathology. We also summarized the present obstacles, and provided a new insight into the genetic basis of BrS.
Collapse
Affiliation(s)
- Yeda Wu
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
| | - Mei Ai
- Forensic Science Center of WASTON Guangdong Province, Guangzhou, China
| | - Adham Sameer A Bardeesi
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
| | - Lunwu Xu
- The Branch Office of Yanping, Public Security Bureau of Nanping, Nanping, China
| | - Jingjing Zheng
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
| | - Da Zheng
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
| | - Kun Yin
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
| | - Qiuping Wu
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
| | - Liyong Zhang
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
| | - Lei Huang
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
| | - Jianding Cheng
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
| |
Collapse
|
19
|
Fernández-Falgueras A, Sarquella-Brugada G, Brugada J, Brugada R, Campuzano O. Cardiac Channelopathies and Sudden Death: Recent Clinical and Genetic Advances. BIOLOGY 2017; 6:biology6010007. [PMID: 28146053 PMCID: PMC5372000 DOI: 10.3390/biology6010007] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 01/17/2017] [Accepted: 01/20/2017] [Indexed: 12/19/2022]
Abstract
Sudden cardiac death poses a unique challenge to clinicians because it may be the only symptom of an inherited heart condition. Indeed, inherited heart diseases can cause sudden cardiac death in older and younger individuals. Two groups of familial diseases are responsible for sudden cardiac death: cardiomyopathies (mainly hypertrophic cardiomyopathy, dilated cardiomyopathy, and arrhythmogenic cardiomyopathy) and channelopathies (mainly long QT syndrome, Brugada syndrome, short QT syndrome, and catecholaminergic polymorphic ventricular tachycardia). This review focuses on cardiac channelopathies, which are characterized by lethal arrhythmias in the structurally normal heart, incomplete penetrance, and variable expressivity. Arrhythmias in these diseases result from pathogenic variants in genes encoding cardiac ion channels or associated proteins. Due to a lack of gross structural changes in the heart, channelopathies are often considered as potential causes of death in otherwise unexplained forensic autopsies. The asymptomatic nature of channelopathies is cause for concern in family members who may be carrying genetic risk factors, making the identification of these genetic factors of significant clinical importance.
Collapse
Affiliation(s)
| | | | - Josep Brugada
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, Barcelona 08950, Spain.
| | - Ramon Brugada
- Cardiovascular Genetics Center, IDIBGI, Girona 17190, Spain.
- Medical Sciences Department, School of Medicine, University of Girona, Girona 17071, Spain.
- Familial Cardiomyopathies Unit, Hospital Josep Trueta, Girona 17007, Spain.
| | - Oscar Campuzano
- Cardiovascular Genetics Center, IDIBGI, Girona 17190, Spain.
- Medical Sciences Department, School of Medicine, University of Girona, Girona 17071, Spain.
| |
Collapse
|
20
|
Huang L, Tang S, Chen Y, Zhang L, Yin K, Wu Y, Zheng J, Wu Q, Makielski JC, Cheng J. Molecular pathological study on LRRC10 in sudden unexplained nocturnal death syndrome in the Chinese Han population. Int J Legal Med 2016; 131:621-628. [PMID: 28032242 DOI: 10.1007/s00414-016-1516-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 12/07/2016] [Indexed: 11/28/2022]
Abstract
Sudden unexplained nocturnal death syndrome (SUNDS) is a perplexing disorder to both forensic pathologists and clinic physicians. Clinical features of SUNDS survivors suggested that SUNDS is similar to Brugada syndrome (BrS). Leucine-rich repeat containing 10 (LRRC10) gene was a newly identified gene linked to dilated cardiomyopathy, a disease associated with sudden cardiac death. To investigate the prevalence and spectrum of genetic variants of LRRC10 gene in SUNDS and BrS, the coding regions of LRRC10 were genetically screened in 113 sporadic SUNDS victims (from January 2005 to December 2015, 30.7 ± 7.5 years) and ten BrS patients (during January 2010 to December 2014, 38.7 ± 10.3 years) using direct Sanger sequencing. Afterwards, LRRC10 missense variant carriers were screened for a panel of 80 genes known to be associated with inherited cardiac arrhythmia/cardiomyopathy using target-captured next-generation sequencing. In this study, an in silico-predicted malignant LRRC10 mutation p.E129K was detected in one SUNDS victim without pathogenic rare variant in a panel of 80 arrhythmia/cardiomyopathy-related genes. We also provided evidence to show that rare variant p.P69L might contribute to the genetic cause for one SUNDS victim and two BrS family members. This is the first report of genetic screening of LRRC10 in Chinese SUNDS victims and BrS patients. LRRC10 may be a new susceptible gene for SUNDS, and LRRC10 variant was initially and genetically linked to BrS-associated arrhythmia.
Collapse
Affiliation(s)
- Lei Huang
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Shuangbo Tang
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Yili Chen
- Department of Cardiology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Liyong Zhang
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Kun Yin
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Yeda Wu
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Jinxiang Zheng
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Qiuping Wu
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Jonathan C Makielski
- Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin, Madison, WI, USA
| | - Jianding Cheng
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China.
| |
Collapse
|
21
|
Association of common and rare variants of SCN10A gene with sudden unexplained nocturnal death syndrome in Chinese Han population. Int J Legal Med 2016; 131:53-60. [DOI: 10.1007/s00414-016-1397-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2016] [Accepted: 05/31/2016] [Indexed: 12/19/2022]
|
22
|
Abstract
The Brugada syndrome is characterized by unique 'coved-type' ST-segment elevation in the right precordial leads of electrocardiogram and ventricular fibrillation, and is responsible for 4 to 12% of sudden cardiac death in the general population. The frequency is higher in Southeast Asia including Japan compared with Western countries. Brugada syndrome is an inherited disease usually transmitted in an autosomal-dominant manner, and incomplete penetrance is frequently seen within affected families. To date, 20 genes have been associated with Brugada syndrome, but pathogenic mutations in the genes are identified in only about 30% of patients. The genetic background includes mutations in genes encoding sodium channel, calcium channels and potassium channels, as well as proteins affecting ion channels. Mutations in SCN5A, encoding the cardiac predominant sodium channel α-subunit, account for 20 to 30% of patients with Brugada syndrome and mutations in other genes only account for about 5% of patients. Furthermore, a recent genome-wide association study has identified new loci associated with the susceptibility of Brugada syndrome.
Collapse
Affiliation(s)
- Hiroshi Watanabe
- Department of Cardiovascular Biology and Medicine, Division of Cardiology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Tohru Minamino
- Department of Cardiovascular Biology and Medicine, Division of Cardiology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| |
Collapse
|
23
|
Schneider MAE. Cellular quality control: a two-edged sword in Brugada syndrome. Heart Rhythm 2013; 11:635-6. [PMID: 24389230 DOI: 10.1016/j.hrthm.2013.12.036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Indexed: 12/21/2022]
|