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2.
Nat Genet ; 53(8): 1135-1142, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34282336

RESUMO

Birth weight is a common measure of fetal growth that is associated with a range of health outcomes. It is directly affected by the fetal genome and indirectly by the maternal genome. We performed genome-wide association studies on birth weight in the genomes of the child and parents and further analyzed birth length and ponderal index, yielding a total of 243 fetal growth variants. We clustered those variants based on the effects of transmitted and nontransmitted alleles on birth weight. Out of 141 clustered variants, 22 were consistent with parent-of-origin-specific effects. We further used haplotype-specific polygenic risk scores to directly test the relationship between adult traits and birth weight. Our results indicate that the maternal genome contributes to increased birth weight through blood-glucose-raising alleles while blood-pressure-raising alleles reduce birth weight largely through the fetal genome.


Assuntos
Peso ao Nascer/genética , Desenvolvimento Fetal/genética , Adulto , Glicemia/genética , Pressão Sanguínea/genética , Estatura/genética , Doenças Cardiovasculares/genética , Feminino , Estudo de Associação Genômica Ampla , Haplótipos , Humanos , Islândia , Recém-Nascido , Masculino , Modelos Genéticos , Polimorfismo de Nucleotídeo Único
4.
Eur Heart J ; 42(20): 1959-1971, 2021 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-33580673

RESUMO

AIMS: The aim of this study was to use human genetics to investigate the pathogenesis of sick sinus syndrome (SSS) and the role of risk factors in its development. METHODS AND RESULTS: We performed a genome-wide association study of 6469 SSS cases and 1 000 187 controls from deCODE genetics, the Copenhagen Hospital Biobank, UK Biobank, and the HUNT study. Variants at six loci associated with SSS, a reported missense variant in MYH6, known atrial fibrillation (AF)/electrocardiogram variants at PITX2, ZFHX3, TTN/CCDC141, and SCN10A and a low-frequency (MAF = 1.1-1.8%) missense variant, p.Gly62Cys in KRT8 encoding the intermediate filament protein keratin 8. A full genotypic model best described the p.Gly62Cys association (P = 1.6 × 10-20), with an odds ratio (OR) of 1.44 for heterozygotes and a disproportionally large OR of 13.99 for homozygotes. All the SSS variants increased the risk of pacemaker implantation. Their association with AF varied and p.Gly62Cys was the only variant not associating with any other arrhythmia or cardiovascular disease. We tested 17 exposure phenotypes in polygenic score (PGS) and Mendelian randomization analyses. Only two associated with the risk of SSS in Mendelian randomization, AF, and lower heart rate, suggesting causality. Powerful PGS analyses provided convincing evidence against causal associations for body mass index, cholesterol, triglycerides, and type 2 diabetes (P > 0.05). CONCLUSION: We report the associations of variants at six loci with SSS, including a missense variant in KRT8 that confers high risk in homozygotes and points to a mechanism specific to SSS development. Mendelian randomization supports a causal role for AF in the development of SSS.


Assuntos
Fibrilação Atrial , Diabetes Mellitus Tipo 2 , Marca-Passo Artificial , Fibrilação Atrial/genética , Estudo de Associação Genômica Ampla , Humanos , Canal de Sódio Disparado por Voltagem NAV1.8 , Síndrome do Nó Sinusal/genética
5.
Eur Heart J ; 41(28): 2618-2628, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32702746

RESUMO

AIMS: To explore whether variability in dietary cholesterol and phytosterol absorption impacts the risk of coronary artery disease (CAD) using as instruments sequence variants in the ABCG5/8 genes, key regulators of intestinal absorption of dietary sterols. METHODS AND RESULTS: We examined the effects of ABCG5/8 variants on non-high-density lipoprotein (non-HDL) cholesterol (N up to 610 532) and phytosterol levels (N = 3039) and the risk of CAD in Iceland, Denmark, and the UK Biobank (105 490 cases and 844 025 controls). We used genetic scores for non-HDL cholesterol to determine whether ABCG5/8 variants confer greater risk of CAD than predicted by their effect on non-HDL cholesterol. We identified nine rare ABCG5/8 coding variants with substantial impact on non-HDL cholesterol. Carriers have elevated phytosterol levels and are at increased risk of CAD. Consistent with impact on ABCG5/8 transporter function in hepatocytes, eight rare ABCG5/8 variants associate with gallstones. A genetic score of ABCG5/8 variants predicting 1 mmol/L increase in non-HDL cholesterol associates with two-fold increase in CAD risk [odds ratio (OR) = 2.01, 95% confidence interval (CI) 1.75-2.31, P = 9.8 × 10-23] compared with a 54% increase in CAD risk (OR = 1.54, 95% CI 1.49-1.59, P = 1.1 × 10-154) associated with a score of other non-HDL cholesterol variants predicting the same increase in non-HDL cholesterol (P for difference in effects = 2.4 × 10-4). CONCLUSIONS: Genetic variation in cholesterol absorption affects levels of circulating non-HDL cholesterol and risk of CAD. Our results indicate that both dietary cholesterol and phytosterols contribute directly to atherogenesis.


Assuntos
Doença da Artéria Coronariana , Fitosteróis , Membro 5 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Doença da Artéria Coronariana/epidemiologia , Doença da Artéria Coronariana/genética , Humanos , Islândia , Esteróis
7.
Europace ; 22(4): 530-537, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-31860069

RESUMO

AIMS: Atrial fibrillation (AF) has been associated with reduced brain volume, cognitive impairment, and reduced cerebral blood flow. The causes of reduced cerebral blood flow in AF are unknown, but no reduction was seen in individuals without the arrhythmia in a previous study. The aim of this study was to test the hypothesis that brain perfusion, measured with magnetic resonance imaging (MRI), improves after cardioversion of AF to sinus rhythm (SR). METHODS AND RESULTS: All patients undergoing elective cardioversion at our institution were invited to participate. A total of 44 individuals were included. Magnetic resonance imaging studies were done before and after cardioversion with both brain perfusion and cerebral blood flow measurements. However, 17 did not complete the second MRI as they had a recurrence of AF during the observation period (recurrent AF group), leaving 17 in the SR group and 10 in the AF group to complete both measurements. Brain perfusion increased after cardioversion to SR by 4.9 mL/100 g/min in the whole brain (P < 0.001) and by 5.6 mL/100 g/min in grey matter (P < 0.001). Cerebral blood flow increased by 58.6 mL/min (P < 0.05). Both brain perfusion and cerebral blood flow remained unchanged when cardioversion was unsuccessful. CONCLUSION: In this study of individuals undergoing elective cardioversion for AF, restoration, and maintenance of SR for at least 10 weeks after was associated with an improvement of brain perfusion and cerebral blood flow measured by both arterial spin labelling and phase contrast MRI. In those individuals where cardioversion was unsuccessful, there was no change in perfusion or blood flow.


Assuntos
Fibrilação Atrial , Cardioversão Elétrica , Fibrilação Atrial/diagnóstico por imagem , Fibrilação Atrial/terapia , Encéfalo/diagnóstico por imagem , Humanos , Perfusão , Resultado do Tratamento
9.
Scand Cardiovasc J ; 54(3): 186-191, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31809597

RESUMO

Introduction: Atrioventricular (AV) node conduction disturbances are common following surgical aortic valve replacement (SAVR), and in some cases the patient needs a permanent pacemaker (PPM) implantation before discharge from hospital. Little is known about the long-term need for PPM and the PPM dependency of these individuals. We determined the incidence of PPM implantation before and after discharge in SAVR patients. Methods: We studied 557 consecutive patients who underwent SAVR for aortic stenosis in Iceland between 2002 and 2016. Timing and indication for PPM were registered, with a new concept, ventricular pacing proportion (VPP), defined as ventricular pacing ≥90% of the time, being used to approximate pacemaker dependency. The median follow-up time was 73 months. We plotted the cumulative incidence of pacemaker implantation, treating death as a competing risk. Results: Of the 557 patients, 22 (3.9%) received PPM in the first 30 days after surgery, most commonly for complete AV block (n = 14) or symptomatic bradycardia (n = 8); Thirty-eight other patients (6.8%) had a PPM implanted >30 days postoperatively, at a median of 43 months after surgery (range 0‒181), most often for AV block (n = 13) or sick-sinus syndrome (n = 10). The cumulative incidence of PPM implantation at 1, 5, and 10 years postoperatively was 5.0%, 9.2%, and 12.3%, respectively. During follow-up, 45.0% of the 60 patients had VPP ≥90%. Conclusion: The cumulative incidence of permanent pacemaker implantation following SAVR was about 12% at 10 years, with every other patient having VPP ≥90% during follow-up. This suggests that AV node conduction disturbances extend significantly beyond the perioperative period.


Assuntos
Estenose da Valva Aórtica/cirurgia , Valva Aórtica/cirurgia , Bloqueio Atrioventricular/terapia , Estimulação Cardíaca Artificial , Implante de Prótese de Valva Cardíaca/efeitos adversos , Marca-Passo Artificial , Síndrome do Nó Sinusal/terapia , Idoso , Idoso de 80 Anos ou mais , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/fisiopatologia , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/epidemiologia , Estenose da Valva Aórtica/fisiopatologia , Bloqueio Atrioventricular/diagnóstico , Bloqueio Atrioventricular/epidemiologia , Bloqueio Atrioventricular/fisiopatologia , Feminino , Humanos , Islândia/epidemiologia , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Síndrome do Nó Sinusal/diagnóstico , Síndrome do Nó Sinusal/epidemiologia , Síndrome do Nó Sinusal/fisiopatologia , Fatores de Tempo , Resultado do Tratamento
10.
Nat Commun ; 10(1): 4803, 2019 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-31641117

RESUMO

Features of the QRS complex of the electrocardiogram, reflecting ventricular depolarisation, associate with various physiologic functions and several pathologic conditions. We test 32.5 million variants for association with ten measures of the QRS complex in 12 leads, using 405,732 electrocardiograms from 81,192 Icelanders. We identify 190 associations at 130 loci, the majority of which have not been reported before, including associations with 21 rare or low-frequency coding variants. Assessment of genes expressed in the heart yields an additional 13 rare QRS coding variants at 12 loci. We find 51 unreported associations between the QRS variants and echocardiographic traits and cardiovascular diseases, including atrial fibrillation, complete AV block, heart failure and supraventricular tachycardia. We demonstrate the advantage of in-depth analysis of the QRS complex in conjunction with other cardiovascular phenotypes to enhance our understanding of the genetic basis of myocardial mass, cardiac conduction and disease.


Assuntos
Eletrocardiografia , Coração/fisiologia , Proteínas/genética , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/genética , Feminino , Regulação da Expressão Gênica , Variação Genética , Estudo de Associação Genômica Ampla , Coração/fisiopatologia , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/genética , Humanos , Islândia , Masculino , Taquicardia Supraventricular/diagnóstico , Taquicardia Supraventricular/genética
12.
Europace ; 2019 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-30882141

RESUMO

Asymptomatic arrhythmias are frequently encountered in clinical practice. Although studies specifically dedicated to these asymptomatic arrhythmias are lacking, many arrhythmias still require proper diagnostic and prognostic evaluation and treatment to avoid severe consequences, such as stroke or systemic emboli, heart failure, or sudden cardiac death. The present document reviews the evidence, where available, and attempts to reach a consensus, where evidence is insufficient or conflicting.

14.
Circ Genom Precis Med ; 11(8): e002151, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30354339

RESUMO

BACKGROUND: Dilated cardiomyopathy (DCM) is an important cause of heart failure. Variants in >50 genes have been reported to cause DCM, but causative variants have been found in less than half of familial cases. Variants causing DCM in Iceland have not been reported before. METHODS: We performed a genome-wide association study on DCM based on whole genome sequencing. We tested the association of 32.5 million sequence variants in 424 cases and 337 689 population controls in Iceland. RESULTS: We identified 2 DCM variants in established cardiomyopathy genes, a missense variant p.Phe145Leu in NKX2-5 carried by 1 in 7100 Icelanders ( P=7.0×10-12) and a frameshift variant p.Phe1626Serfs*40 in FLNC carried by 1 in 3600 Icelanders ( P=2.1×10-10). Both variants associate with heart failure and sudden cardiac death. Additionally, p.Phe145Leu in NKX2-5 associates with high degree atrioventricular block and atrial septal defect ( P<1.4×10-4). The penetrance of serious heart disease among carriers of the NKX2-5 variant is high and higher than that of the FLNC variant. CONCLUSIONS: Two rare variants in NKX2-5 and FLNC, carried by 1 in 2400 Icelanders, cause familial DCM in Iceland. These genes have recently been associated with DCM. Given the serious consequences of these variants, we suggest screening for them in individuals with DCM and their family members, with subsequent monitoring of carriers, offering early intervention.


Assuntos
Cardiomiopatia Dilatada/complicações , Cardiomiopatia Dilatada/genética , Morte Súbita Cardíaca/etiologia , Filaminas/genética , Proteína Homeobox Nkx-2.5/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Cardiomiopatia Dilatada/epidemiologia , Estudos de Casos e Controles , Morte Súbita Cardíaca/epidemiologia , Feminino , Mutação da Fase de Leitura , Estudo de Associação Genômica Ampla , Humanos , Islândia/epidemiologia , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto , Penetrância , Adulto Jovem
15.
Commun Biol ; 1: 68, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30271950

RESUMO

Most sequence variants identified hitherto in genome-wide association studies (GWAS) of atrial fibrillation are common, non-coding variants associated with risk through unknown mechanisms. We performed a meta-analysis of GWAS of atrial fibrillation among 29,502 cases and 767,760 controls from Iceland and the UK Biobank with follow-up in samples from Norway and the US, focusing on low-frequency coding and splice variants aiming to identify causal genes. We observe associations with one missense (OR = 1.20) and one splice-donor variant (OR = 1.50) in RPL3L, the first ribosomal gene implicated in atrial fibrillation to our knowledge. Analysis of 167 RNA samples from the right atrium reveals that the splice-donor variant in RPL3L results in exon skipping. We also observe an association with a missense variant in MYZAP (OR = 1.38), encoding a component of the intercalated discs of cardiomyocytes. Both discoveries emphasize the close relationship between the mechanical and electrical function of the heart.

16.
Nat Genet ; 50(9): 1234-1239, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30061737

RESUMO

To identify genetic variation underlying atrial fibrillation, the most common cardiac arrhythmia, we performed a genome-wide association study of >1,000,000 people, including 60,620 atrial fibrillation cases and 970,216 controls. We identified 142 independent risk variants at 111 loci and prioritized 151 functional candidate genes likely to be involved in atrial fibrillation. Many of the identified risk variants fall near genes where more deleterious mutations have been reported to cause serious heart defects in humans (GATA4, MYH6, NKX2-5, PITX2, TBX5)1, or near genes important for striated muscle function and integrity (for example, CFL2, MYH7, PKP2, RBM20, SGCG, SSPN). Pathway and functional enrichment analyses also suggested that many of the putative atrial fibrillation genes act via cardiac structural remodeling, potentially in the form of an 'atrial cardiomyopathy'2, either during fetal heart development or as a response to stress in the adult heart.


Assuntos
Fibrilação Atrial/genética , Mutação/genética , Bancos de Espécimes Biológicos , Predisposição Genética para Doença/genética , Estudo de Associação Genômica Ampla/métodos , Genômica/métodos , Cardiopatias Congênitas/genética , Humanos , Risco
17.
Genome Biol ; 19(1): 87, 2018 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-30012220

RESUMO

BACKGROUND: Genome-wide association studies conducted on QRS duration, an electrocardiographic measurement associated with heart failure and sudden cardiac death, have led to novel biological insights into cardiac function. However, the variants identified fall predominantly in non-coding regions and their underlying mechanisms remain unclear. RESULTS: Here, we identify putative functional coding variation associated with changes in the QRS interval duration by combining Illumina HumanExome BeadChip genotype data from 77,898 participants of European ancestry and 7695 of African descent in our discovery cohort, followed by replication in 111,874 individuals of European ancestry from the UK Biobank and deCODE cohorts. We identify ten novel loci, seven within coding regions, including ADAMTS6, significantly associated with QRS duration in gene-based analyses. ADAMTS6 encodes a secreted metalloprotease of currently unknown function. In vitro validation analysis shows that the QRS-associated variants lead to impaired ADAMTS6 secretion and loss-of function analysis in mice demonstrates a previously unappreciated role for ADAMTS6 in connexin 43 gap junction expression, which is essential for myocardial conduction. CONCLUSIONS: Our approach identifies novel coding and non-coding variants underlying ventricular depolarization and provides a possible mechanism for the ADAMTS6-associated conduction changes.


Assuntos
Proteínas ADAMTS/genética , Conexina 43/genética , Exoma , Loci Gênicos , Sistema de Condução Cardíaco/metabolismo , Miocárdio/metabolismo , Grupo com Ancestrais do Continente Africano , Animais , Eletrocardiografia , Grupo com Ancestrais do Continente Europeu , Feminino , Expressão Gênica , Perfilação da Expressão Gênica , Estudo de Associação Genômica Ampla , Sistema de Condução Cardíaco/fisiopatologia , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Miocárdio/patologia , Fases de Leitura Aberta , Polimorfismo de Nucleotídeo Único , Sequenciamento Completo do Exoma
18.
Nat Commun ; 9(1): 2904, 2018 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-30046033

RESUMO

Electrocardiographic PR interval measures atrio-ventricular depolarization and conduction, and abnormal PR interval is a risk factor for atrial fibrillation and heart block. Our genome-wide association study of over 92,000 European-descent individuals identifies 44 PR interval loci (34 novel). Examination of these loci reveals known and previously not-yet-reported biological processes involved in cardiac atrial electrical activity. Genes in these loci are over-represented in cardiac disease processes including heart block and atrial fibrillation. Variants in over half of the 44 loci were associated with atrial or blood transcript expression levels, or were in high linkage disequilibrium with missense variants. Six additional loci were identified either by meta-analysis of ~105,000 African and European-descent individuals and/or by pleiotropic analyses combining PR interval with heart rate, QRS interval, and atrial fibrillation. These findings implicate developmental pathways, and identify transcription factors, ion-channel genes, and cell-junction/cell-signaling proteins in atrio-ventricular conduction, identifying potential targets for drug development.


Assuntos
Função Atrial/fisiologia , Nó Atrioventricular/fisiologia , Fenômenos Eletrofisiológicos/genética , Estudo de Associação Genômica Ampla , Eletrocardiografia , Feminino , Humanos , Desequilíbrio de Ligação/genética , Masculino , Mutação de Sentido Incorreto/genética , Fatores de Risco
19.
Eur Heart J ; 39(34): 3243-3249, 2018 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-29590334

RESUMO

Aims: Coarctation of the aorta (CoA) accounts for 4-8% of congenital heart defects (CHDs) and confers substantial morbidity despite treatment. It is increasingly recognized as a highly heritable condition. The aim of the study was to search for sequence variants that affect the risk of CoA. Methods and results: We performed a genome-wide association study of CoA among Icelanders (120 cases and 355 166 controls) based on imputed variants identified through whole-genome sequencing. We found association with a rare (frequency = 0.34%) missense mutation p.Arg721Trp in MYH6 (odds ratio = 44.2, P = 5.0 × 10-22), encoding the alpha-heavy chain subunit of cardiac myosin, an essential sarcomere protein. Approximately 20% of individuals with CoA in Iceland carry this mutation. We show that p.Arg721Trp also associates with other CHDs, in particular bicuspid aortic valve. We have previously reported broad effects of p.Arg721Trp on cardiac electrical function and strong association with sick sinus syndrome and atrial fibrillation. Conclusion: Through a population approach, we found that a rare missense mutation p.Arg721Trp in the sarcomere gene MYH6 has a strong effect on the risk of CoA and explains a substantial fraction of the Icelanders with CoA. This is the first mutation associated with non-familial or sporadic form of CoA at a population level. The p.Arg721Trp in MYH6 causes a cardiac syndrome with highly variable expressivity and emphasizes the importance of sarcomere integrity for cardiac development and function.


Assuntos
Coartação Aórtica/genética , Miosinas Cardíacas/genética , DNA/genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Mutação de Sentido Incorreto , Cadeias Pesadas de Miosina/genética , Adolescente , Adulto , Coartação Aórtica/metabolismo , Doenças Assintomáticas , Miosinas Cardíacas/metabolismo , Criança , Pré-Escolar , Análise Mutacional de DNA , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Cadeias Pesadas de Miosina/metabolismo , Linhagem , Estudos Retrospectivos , Adulto Jovem
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