RESUMO
BACKGROUND: Arrhythmogenic cardiomyopathy (ACM) is characterized by progressive loss of cardiomyocytes with fibrofatty tissue replacement, systolic dysfunction, and life-threatening arrhythmias. A substantial proportion of ACM is caused by mutations in genes of the desmosomal cell-cell adhesion complex, but the underlying mechanisms are not well understood. In the current study, we investigated the relevance of defective desmosomal adhesion for ACM development and progression. METHODS: We mutated the binding site of DSG2 (desmoglein-2), a crucial desmosomal adhesion molecule in cardiomyocytes. This DSG2-W2A mutation abrogates the tryptophan swap, a central interaction mechanism of DSG2 on the basis of structural data. Impaired adhesive function of DSG2-W2A was confirmed by cell-cell dissociation assays and force spectroscopy measurements by atomic force microscopy. The DSG2-W2A knock-in mouse model was analyzed by echocardiography, ECG, and histologic and biomolecular techniques including RNA sequencing and transmission electron and superresolution microscopy. The results were compared with ACM patient samples, and their relevance was confirmed in vivo and in cardiac slice cultures by inhibitor studies applying the small molecule EMD527040 or an inhibitory integrin-αVß6 antibody. RESULTS: The DSG2-W2A mutation impaired binding on molecular level and compromised intercellular adhesive function. Mice bearing this mutation develop a severe cardiac phenotype recalling the characteristics of ACM, including cardiac fibrosis, impaired systolic function, and arrhythmia. A comparison of the transcriptome of mutant mice with ACM patient data suggested deregulated integrin-αVß6 and subsequent transforming growth factor-ß signaling as driver of cardiac fibrosis. Blocking integrin-αVß6 led to reduced expression of profibrotic markers and reduced fibrosis formation in mutant animals in vivo. CONCLUSIONS: We show that disruption of desmosomal adhesion is sufficient to induce a phenotype that fulfils the clinical criteria to establish the diagnosis of ACM, confirming the dysfunctional adhesion hypothesis. Deregulation of integrin-αVß6 and transforming growth factor-ß signaling was identified as a central step toward fibrosis. A pilot in vivo drug test revealed this pathway as a promising target to ameliorate fibrosis. This highlights the value of this model to discern mechanisms of cardiac fibrosis and to identify and test novel treatment options for ACM.
Assuntos
Displasia Arritmogênica Ventricular Direita , Cardiomiopatias , Camundongos , Animais , Cardiomiopatias/genética , Arritmias Cardíacas/genética , Arritmias Cardíacas/metabolismo , Integrinas/metabolismo , Miócitos Cardíacos/metabolismo , Fibrose , Fator de Crescimento Transformador beta/metabolismo , Fatores de Crescimento Transformadores/metabolismo , Displasia Arritmogênica Ventricular Direita/patologiaRESUMO
Sudden cardiac death (SCD) in adolescents and young adults may be the first manifestation of an inherited arrhythmic syndrome. Thus identification of a genetic origin in sudden death cases deemed inconclusive after a comprehensive autopsy and may help to reduce the risk of lethal episodes in the remaining family. Using next-generation sequencing (NGS), a large number of variants of unknown significance (VUS) are detected. In the majority of cases, there is insufficient evidence of pathogenicity, representing a huge dilemma in current genetic investigations. Misinterpretation of such variants may lead to inaccurate genetic diagnoses and/or the adoption of unnecessary and/or inappropriate therapeutic approaches. In our study, we applied current (ACMG) recommendations for variant classification in post-mortem genetic screening of a cohort of 56 SCD victims. We identified a total 53 rare protein-altering variants (MAF < 0.2%) classified as VUS or worse. Twelve percent of the cases exhibited a clinically actionable variant (pathogenic, likely pathogenic or VUS - potentially pathogenic) that would warrant cascade genetic screening in relatives. Most of the variants detected by means of the post-mortem genetic investigations were VUS. Thus, genetic testing by itself might be fairly meaningless without supporting background data. This data reinforces the need for an experienced multidisciplinary team for obtaining reliable and accountable interpretations of variant significance for elucidating potential causes for SCDs in the young. This enables the early identification of relatives at risk or excludes family members as genetic carriers. Also, development of adequate forensic guidelines to enable appropriate interpretation of rare genetic variants is fundamental.
Assuntos
Morte Súbita Cardíaca , Testes Genéticos , Adolescente , Autopsia , Estudos de Coortes , Morte Súbita Cardíaca/etiologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Adulto JovemRESUMO
BACKGROUND: Long QT syndrome (LQTS) is a rare genetic disorder and a major preventable cause of sudden cardiac death in the young. A causal rare genetic variant with large effect size is identified in up to 80% of probands (genotype positive) and cascade family screening shows incomplete penetrance of genetic variants. Furthermore, a proportion of cases meeting diagnostic criteria for LQTS remain genetically elusive despite genetic testing of established genes (genotype negative). These observations raise the possibility that common genetic variants with small effect size contribute to the clinical picture of LQTS. This study aimed to characterize and quantify the contribution of common genetic variation to LQTS disease susceptibility. METHODS: We conducted genome-wide association studies followed by transethnic meta-analysis in 1656 unrelated patients with LQTS of European or Japanese ancestry and 9890 controls to identify susceptibility single nucleotide polymorphisms. We estimated the common variant heritability of LQTS and tested the genetic correlation between LQTS susceptibility and other cardiac traits. Furthermore, we tested the aggregate effect of the 68 single nucleotide polymorphisms previously associated with the QT-interval in the general population using a polygenic risk score. RESULTS: Genome-wide association analysis identified 3 loci associated with LQTS at genome-wide statistical significance (P<5×10-8) near NOS1AP, KCNQ1, and KLF12, and 1 missense variant in KCNE1(p.Asp85Asn) at the suggestive threshold (P<10-6). Heritability analyses showed that ≈15% of variance in overall LQTS susceptibility was attributable to common genetic variation (h2SNP 0.148; standard error 0.019). LQTS susceptibility showed a strong genome-wide genetic correlation with the QT-interval in the general population (rg=0.40; P=3.2×10-3). The polygenic risk score comprising common variants previously associated with the QT-interval in the general population was greater in LQTS cases compared with controls (P<10-13), and it is notable that, among patients with LQTS, this polygenic risk score was greater in patients who were genotype negative compared with those who were genotype positive (P<0.005). CONCLUSIONS: This work establishes an important role for common genetic variation in susceptibility to LQTS. We demonstrate overlap between genetic control of the QT-interval in the general population and genetic factors contributing to LQTS susceptibility. Using polygenic risk score analyses aggregating common genetic variants that modulate the QT-interval in the general population, we provide evidence for a polygenic architecture in genotype negative LQTS.
Assuntos
Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Síndrome do QT Longo/genética , Adolescente , Adulto , Idade de Início , Alelos , Estudos de Casos e Controles , Eletrocardiografia , Estudos de Associação Genética , Estudo de Associação Genômica Ampla/métodos , Genótipo , Humanos , Síndrome do QT Longo/diagnóstico , Síndrome do QT Longo/mortalidade , Síndrome do QT Longo/terapia , Herança Multifatorial , Fenótipo , Polimorfismo de Nucleotídeo Único , Prognóstico , Índice de Gravidade de Doença , Adulto JovemRESUMO
PURPOSE: Stringent variant interpretation guidelines can lead to high rates of variants of uncertain significance (VUS) for genetically heterogeneous disease like long QT syndrome (LQTS) and Brugada syndrome (BrS). Quantitative and disease-specific customization of American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) guidelines can address this false negative rate. METHODS: We compared rare variant frequencies from 1847 LQTS (KCNQ1/KCNH2/SCN5A) and 3335 BrS (SCN5A) cases from the International LQTS/BrS Genetics Consortia to population-specific gnomAD data and developed disease-specific criteria for ACMG/AMP evidence classes-rarity (PM2/BS1 rules) and case enrichment of individual (PS4) and domain-specific (PM1) variants. RESULTS: Rare SCN5A variant prevalence differed between European (20.8%) and Japanese (8.9%) BrS patients (p = 5.7 × 10-18) and diagnosis with spontaneous (28.7%) versus induced (15.8%) Brugada type 1 electrocardiogram (ECG) (p = 1.3 × 10-13). Ion channel transmembrane regions and specific N-terminus (KCNH2) and C-terminus (KCNQ1/KCNH2) domains were characterized by high enrichment of case variants and >95% probability of pathogenicity. Applying the customized rules, 17.4% of European BrS and 74.8% of European LQTS cases had (likely) pathogenic variants, compared with estimated diagnostic yields (case excess over gnomAD) of 19.2%/82.1%, reducing VUS prevalence to close to background rare variant frequency. CONCLUSION: Large case-control data sets enable quantitative implementation of ACMG/AMP guidelines and increased sensitivity for inherited arrhythmia genetic testing.
Assuntos
Síndrome de Brugada , Síndrome do QT Longo , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/epidemiologia , Arritmias Cardíacas/genética , Síndrome de Brugada/genética , Testes Genéticos , Humanos , Síndrome do QT Longo/diagnóstico , Síndrome do QT Longo/epidemiologia , Síndrome do QT Longo/genética , Mutação , Controle da PopulaçãoRESUMO
AIMS: Sudden cardiac death (SCD) is among the most common causes of death in western countries including Germany. Whereas risk stratification and primary prevention is still insufficient, we also lack accurate incidence estimates. Current estimates vary widely (18.6-128/100,000/year), but data on SCD incidence in Germany are missing. Depending on SCD definitions, death needs to occur between 1 and 24 h after the onset of symptoms. METHODS AND RESULTS: In the district of Aurich (190,000 inhabitants, Lower Saxony, Germany), emergency medical service (EMS) is provided by a district government operated single carrier and two hospitals. To evaluate all EMS calls in this district from 2002 to 2009, we obtained EMS protocols, medical records, and death certificates for data analysis and adjudication of SCD. We defined SCD according to the definition of the World Health Organization, considering patients with cardiac arrest within ≤1 h after the onset of symptoms. We also required cardiopulmonary resuscitation being performed by EMS personnel. The overall mortality rate in the district of Aurich (1060/100,000/year) corresponded well with the average mortality rate in Germany (1030/100,000/year). During the observation period, we adjudicated 1212 SCD cases, equivalent to an annual rate of 151 SCD cases (81 cases/100,000/year). Rates remained remarkably stable over time, and affected a considerable number of individuals of working age (32/100,000/year). CONCLUSION: Consistent with prior reports, the SCD incidence in a district of Germany is substantial. Despite an elaborate EMS system and advanced medical care, SCD rates remain stable and necessitate improved, individualized risk stratification.
Assuntos
Reanimação Cardiopulmonar/mortalidade , Morte Súbita Cardíaca/epidemiologia , Morte Súbita Cardíaca/prevenção & controle , Serviços Médicos de Emergência/estatística & dados numéricos , Sistema de Registros , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Reanimação Cardiopulmonar/estatística & dados numéricos , Criança , Pré-Escolar , Feminino , Alemanha/epidemiologia , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Distribuição por Sexo , Adulto JovemRESUMO
AIMS: A recent genome-wide association study identified a haplotype block on chromosome 4q25 associated with atrial fibrillation (AF). We sought to replicate this association in four independent cohorts. METHODS AND RESULTS: The Framingham Heart Study and Rotterdam Study are community-based longitudinal studies. The Vanderbilt AF Registry and German AF Network (AFNet) are case-control studies. Participants with AF (n = 3508) were more likely to be male and were older than referent participants (n = 12 173; Framingham 82 +/- 10 vs. 71 +/- 13 years; Rotterdam 73 +/- 8 vs. 69 +/- 9 years; Vanderbilt 54 +/- 14 vs. 57 +/- 14 years; AFNet 62 +/- 12 vs. 49 +/- 14 years). Single nucleotide polymorphism (SNP) rs2200733 was associated with AF in all four cohorts, with odds ratios (ORs) ranging from 1.37 in Rotterdam [95% confidence interval (CI) 1.18-1.59; P = 3.1 x 10(-5)] to 2.52 in AFNet (95% CI 2.22-2.8; P = 1.8 x 10(-49)). There also was a significant association between AF and rs10033464 in Framingham (OR 1.34; 95% CI 1.03-1.75; P = 0.031) and AFNet (OR 1.30; 95% CI 1.13-1.51; P = 0.0002), but not Vanderbilt (OR 1.16; 95% CI 0.86-1.56; P = 0.33). A meta-analysis of the current and prior AF studies revealed an OR of 1.90 (95% CI 1.60-2.26; P = 3.3 x 10(-13)) for rs2200733 and of 1.36 (95% CI 1.26-1.47; P = 6.7 x 10(-15)) for rs10033464. CONCLUSION: The non-coding SNPs rs2200733 and rs10033464 are strongly associated with AF in four cohorts of European descent. These results confirm the significant relations between AF and intergenic variants on chromosome 4.
Assuntos
Fibrilação Atrial/genética , Cromossomos Humanos Par 4/genética , Polimorfismo de Nucleotídeo Único/genética , Idoso , Fibrilação Atrial/complicações , Estudos de Casos e Controles , Feminino , Predisposição Genética para Doença , Variação Genética/genética , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de RiscoRESUMO
The authors investigated whether computerized parameters quantifying ventricular repolarization delay, heterogeneity, and instability characterize individuals who developed drug-induced Torsades de Pointes. Assessing an individual's propensity to Torsades de Pointes when exposed to a QT-prolonging drug is challenging because baseline QT prolongation has limited predictive value. Five-minute digital 12-lead electrocardiograms were acquired at baseline and after a sotalol challenge in 16 patients who had a history of Torsades de Pointes in the context of a QT-prolonging drug and 17 patients who did not have such history. Computerized measurements of QTc, T peak to T end intervals (TpTe), TpTe/QTc, and QT variability were implemented, and novel quantifiers of ventricular repolarization heterogeneity from the early (ERD) and late (LRD) part of the T wave were investigated. Compared with electrocardiograms of patients without a history of Torsades de Pointes, the baseline electrocardiograms of patients with a history of Torsades de Pointes had a longer QTc and an increased repolarization heterogeneity of the early part of the T wave (ERD30%: 44 +/- 13 vs 35 +/- 8 ms, P = .02). On sotalol, the electrocardiograms from individuals with Torsades de Pointes revealed a delay of the terminal part of the T wave that was not present in patients without Torsades de Pointes (TpTe: 27 +/- 40 vs -2 +/- 21 ms, P = .02; LRD70%: 20 +/- 29 vs 2 +/- 4 ms, P = .04). Results suggest that the electrocardiogram abnormalities characterizing patients with a history of Torsades de Pointes are (1) an increased repolarization heterogeneity at baseline and (2) a sotalol-induced prolongation of the terminal part of the T wave.
Assuntos
Antiarrítmicos/efeitos adversos , Sotalol/efeitos adversos , Torsades de Pointes/fisiopatologia , Disfunção Ventricular/fisiopatologia , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Torsades de Pointes/induzido quimicamente , Disfunção Ventricular/induzido quimicamenteRESUMO
Pheochromocytoma is an infrequent secondary cause of arterial hypertension, often associated with paroxysmal headache, sweating, weight loss, and palpitations. Cardiovascular complications of pheochromocytoma include sudden death, heart failure due to toxic cardiomyopathy, and hypertensive encephalopathy. Here we report the case of a female with an acquired long-QT-syndrome as a rare complication of an extra-adrenal pheochromocytoma. Diagnosis was made after sotalol-induced Torsades de Pointes.
Assuntos
Neoplasias das Glândulas Suprarrenais/complicações , Feocromocitoma/complicações , Torsades de Pointes/diagnóstico , Torsades de Pointes/etiologia , Adulto , Antiarrítmicos/efeitos adversos , Eletrocardiografia , Feminino , Humanos , Fatores de Risco , Sotalol/efeitos adversos , Torsades de Pointes/induzido quimicamenteAssuntos
Canal de Potássio KCNQ1/genética , Síndrome do QT Longo/genética , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Taquicardia Ventricular/genética , Adolescente , Morte Súbita Cardíaca/etiologia , Feminino , Genes Dominantes , Heterozigoto , Humanos , Síndrome do QT Longo/complicações , Masculino , Linhagem , Taquicardia Ventricular/complicaçõesRESUMO
BACKGROUND: Considerable interest exists in the identification of genetic modifiers of disease severity in the long-QT syndrome (LQTS) as their identification may contribute to refinement of risk stratification. METHODS AND RESULTS: We searched for single-nucleotide polymorphisms (SNPs) that modulate the corrected QT (QTc)-interval and the occurrence of cardiac events in 639 patients harboring different mutations in KCNH2. We analyzed 1201 SNPs in and around 18 candidate genes, and in another approach investigated 22 independent SNPs previously identified as modulators of QTc-interval in genome-wide association studies in the general population. In an analysis for quantitative effects on the QTc-interval, 3 independent SNPs at NOS1AP (rs10494366, P=9.5×10(-8); rs12143842, P=4.8×10(-7); and rs2880058, P=8.6×10(-7)) were strongly associated with the QTc-interval with marked effects (>12 ms/allele). Analysis of patients versus general population controls uncovered enrichment of QTc-prolonging alleles in patients for 2 SNPs, located respectively at NOS1AP (rs12029454; odds ratio, 1.85; 95% confidence interval, 1.32-2.59; P=3×10(-4)) and KCNQ1 (rs12576239; odds ratio, 1.84; 95% confidence interval, 1.31-2.60; P=5×10(-4)). An analysis of the cumulative effect of the 6 NOS1AP SNPs by means of a multilocus genetic risk score (GRS(NOS1AP)) uncovered a strong linear relationship between GRS(NOS1AP) and the QTc-interval (P=4.2×10(-7)). Furthermore, patients with a GRS(NOS1AP) in the lowest quartile had a lower relative risk of cardiac events compared with patients in the other quartiles combined (P=0.039). CONCLUSIONS: We uncovered unexpectedly large effects of NOS1AP SNPs on the QTc-interval and a trend for effects on risk of cardiac events. For the first time, we linked common genetic variation at KCNQ1 with risk of long-QT syndrome.
Assuntos
Síndrome do QT Longo/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Antagonistas Adrenérgicos beta/uso terapêutico , Alelos , Estudos de Casos e Controles , Eletrocardiografia , Feminino , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Canal de Potássio KCNQ1/genética , Síndrome do QT Longo/tratamento farmacológico , Síndrome do QT Longo/patologia , Masculino , Razão de Chances , Polimorfismo de Nucleotídeo Único , Fatores de Risco , Índice de Gravidade de DoençaRESUMO
Brugada syndrome is a rare cardiac arrhythmia disorder, causally related to SCN5A mutations in around 20% of cases. Through a genome-wide association study of 312 individuals with Brugada syndrome and 1,115 controls, we detected 2 significant association signals at the SCN10A locus (rs10428132) and near the HEY2 gene (rs9388451). Independent replication confirmed both signals (meta-analyses: rs10428132, P = 1.0 × 10(-68); rs9388451, P = 5.1 × 10(-17)) and identified one additional signal in SCN5A (at 3p21; rs11708996, P = 1.0 × 10(-14)). The cumulative effect of the three loci on disease susceptibility was unexpectedly large (Ptrend = 6.1 × 10(-81)). The association signals at SCN5A-SCN10A demonstrate that genetic polymorphisms modulating cardiac conduction can also influence susceptibility to cardiac arrhythmia. The implication of association with HEY2, supported by new evidence that Hey2 regulates cardiac electrical activity, shows that Brugada syndrome may originate from altered transcriptional programming during cardiac development. Altogether, our findings indicate that common genetic variation can have a strong impact on the predisposition to rare diseases.
Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Síndrome de Brugada/complicações , Síndrome de Brugada/genética , Morte Súbita Cardíaca/etiologia , Variação Genética , Canal de Sódio Disparado por Voltagem NAV1.5/genética , Canal de Sódio Disparado por Voltagem NAV1.8/genética , Proteínas Repressoras/genética , Alelos , Animais , Estudos de Casos e Controles , Cromossomos Humanos Par 3 , Cromossomos Humanos Par 6 , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Masculino , Camundongos , Camundongos Knockout , Razão de Chances , Polimorfismo de Nucleotídeo Único , Canais de Sódio/genética , Canais de Sódio/metabolismoRESUMO
OBJECTIVES: The purpose of this study was to compare the efficacy of beta-blockers in congenital long QT syndrome (LQTS). BACKGROUND: Beta-blockers are the mainstay in managing LQTS. Studies comparing the efficacy of commonly used beta-blockers are lacking, and clinicians generally assume they are equally effective. METHODS: Electrocardiographic and clinical parameters of 382 LQT1/LQT2 patients initiated on propranolol (n = 134), metoprolol (n = 147), and nadolol (n = 101) were analyzed, excluding patients <1 year of age at beta-blocker initiation. Symptoms before therapy and the first breakthrough cardiac events (BCEs) were documented. RESULTS: Patients (56% female, 27% symptomatic, heart rate 76 ± 16 beats/min, QTc 472 ± 46 ms) were started on beta-blocker therapy at a median age of 14 years (interquartile range: 8 to 32 years). The QTc shortening with propranolol was significantly greater than with other beta-blockers in the total cohort and in the subset with QTc >480 ms. None of the asymptomatic patients had BCEs. Among symptomatic patients (n = 101), 15 had BCEs (all syncopes). The QTc shortening was significantly less pronounced among patients with BCEs. There was a greater risk of BCEs for symptomatic patients initiated on metoprolol compared to users of the other 2 beta-blockers combined, after adjustment for genotype (odds ratio: 3.95, 95% confidence interval: 1.2 to 13.1, p = 0.025). Kaplan-Meier analysis showed a significantly lower event-free survival for symptomatic patients receiving metoprolol compared to propranolol/nadolol. CONCLUSIONS: Propranolol has a significantly better QTc shortening effect compared to metoprolol and nadolol, especially in patients with prolonged QTc. Propranolol and nadolol are equally effective, whereas symptomatic patients started on metoprolol are at a significantly higher risk for BCEs. Metoprolol should not be used for symptomatic LQT1 and LQT2 patients.
Assuntos
Antagonistas Adrenérgicos beta/uso terapêutico , Síndrome do QT Longo/tratamento farmacológico , Metoprolol/uso terapêutico , Nadolol/uso terapêutico , Propranolol/uso terapêutico , Adolescente , Antagonistas Adrenérgicos beta/farmacologia , Adulto , Criança , Intervalo Livre de Doença , Eletrocardiografia/efeitos dos fármacos , Feminino , Humanos , Síndrome do QT Longo/mortalidade , Masculino , Metoprolol/farmacologia , Nadolol/farmacologia , Prognóstico , Propranolol/farmacologia , Prevenção Secundária , Análise de Sobrevida , Resultado do Tratamento , Adulto JovemRESUMO
The electrocardiographic PR interval (or PQ interval) reflects atrial and atrioventricular nodal conduction, disturbances of which increase risk of atrial fibrillation. We report a meta-analysis of genome-wide association studies for PR interval from seven population-based European studies in the CHARGE Consortium: AGES, ARIC, CHS, FHS, KORA, Rotterdam Study, and SardiNIA (N = 28,517). We identified nine loci associated with PR interval at P < 5 x 10(-8). At the 3p22.2 locus, we observed two independent associations in voltage-gated sodium channel genes, SCN10A and SCN5A. Six of the loci were near cardiac developmental genes, including CAV1-CAV2, NKX2-5 (CSX1), SOX5, WNT11, MEIS1, and TBX5-TBX3, providing pathophysiologically interesting candidate genes. Five of the loci, SCN5A, SCN10A, NKX2-5, CAV1-CAV2, and SOX5, were also associated with atrial fibrillation (N = 5,741 cases, P < 0.0056). This suggests a role for common variation in ion channel and developmental genes in atrial and atrioventricular conduction as well as in susceptibility to atrial fibrillation.
Assuntos
Eletrocardiografia , Estudo de Associação Genômica Ampla , Sistema de Condução Cardíaco/fisiologia , Idoso , Fibrilação Atrial/genética , Fibrilação Atrial/fisiopatologia , Estudos de Coortes , Feminino , Loci Gênicos/genética , Predisposição Genética para Doença , Humanos , Masculino , Metanálise como AssuntoRESUMO
Atrial fibrillation (AF) is the most common sustained arrhythmia. Previous studies have identified several genetic loci associated with typical AF. We sought to identify common genetic variants underlying lone AF. This condition affects a subset of individuals without overt heart disease and with an increased heritability of AF. We report a meta-analysis of genome-wide association studies conducted using 1,335 individuals with lone AF (cases) and 12,844 unaffected individuals (referents). Cases were obtained from the German AF Network, Heart and Vascular Health Study, the Atherosclerosis Risk in Communities Study, the Cleveland Clinic and Massachusetts General Hospital. We identified an association on chromosome 1q21 to lone AF (rs13376333, adjusted odds ratio = 1.56; P = 6.3 x 10(-12)), and we replicated this association in two independent cohorts with lone AF (overall combined odds ratio = 1.52, 95% CI 1.40-1.64; P = 1.83 x 10(-21)). rs13376333 is intronic to KCNN3, which encodes a potassium channel protein involved in atrial repolarization.
Assuntos
Fibrilação Atrial/genética , Polimorfismo de Nucleotídeo Único , Canais de Potássio Ativados por Cálcio de Condutância Baixa/genética , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Estudo de Associação Genômica Ampla , Humanos , Íntrons/genética , Masculino , Metanálise como Assunto , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único/fisiologia , Adulto JovemRESUMO
AIMS: The QT interval in the general population is a complex trait with 30-50% heritability. QT prolongation is associated with an increased risk of sudden death. A recent family-based study found an association between QT interval and the common non-synonymous Glycin 38 Serine variant (G38S, rs1805127) of the KCNE1 gene coding for the minK-potassium channel subunit. We intended to replicate this finding in a large population sample of central European Caucasian ancestry as part of our ongoing search for genetic variants predisposing to arrhythmias. METHODS AND RESULTS: We studied 3966 unrelated individuals from the KORA S4 population-based study without atrial fibrillation, pacemaker implant, or pregnancy. Individuals were genotyped by MALDI-TOF mass spectrometry. We did not detect any significant association between the genotypes of the G38S variant and the QT interval in the entire population or in any gender. CONCLUSION: Unlike the common Lysine 897 Threonine variant of KCNH2 (K897T, rs1805123) the G38S variant of KCNE1 does not appear to have a strong modifying effect on QT interval. However, we cannot rule out an effect of G38S on QT in other ethnic groups, under exercise or medications or on the risk for arrhythmias and sudden death.