Publications by authors named "Rosa B Thorolfsdottir"

Obesity is associated with adverse effects on health and quality of life. Improved understanding of its underlying pathophysiology is essential for developing counteractive measures. To search for sequence variants with large effects on BMI, we perform a multi-ancestry meta-analysis of 13 genome-wide association studies on BMI, including data derived from 1,534,555 individuals of European ancestry, 339,657 of Asian ancestry, and 130,968 of African ancestry.

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Atrial fibrillation (AF) is the most common heart rhythm abnormality and is a leading cause of heart failure and stroke. This large-scale meta-analysis of genome-wide association studies increased the power to detect single-nucleotide variant associations and found more than 350 AF-associated genetic loci. We identified candidate genes related to muscle contractility, cardiac muscle development and cell-cell communication at 139 loci.

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Article Synopsis
  • The study aims to investigate the genetic factors associated with accessory atrioventricular pathways (APs) and related heart rhythm disorders using a genome-wide association study (GWAS).
  • It involved analyzing genetic data from over 1,200,000 control individuals and 2,310 individuals with APs from multiple countries and various health databases.
  • Key findings revealed three significant genetic variants linked to APs, particularly in specific genes (CCDC141 and SCN10A), with implications for understanding conditions like paroxysmal supraventricular tachycardia (PSVT).
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Importance: Recurrent pericarditis is a treatment challenge and often a debilitating condition. Drugs inhibiting interleukin 1 cytokines are a promising new treatment option, but their use is based on scarce biological evidence and clinical trials of modest sizes, and the contributions of innate and adaptive immune processes to the pathophysiology are incompletely understood.

Objective: To use human genomics, transcriptomics, and proteomics to shed light on the pathogenesis of pericarditis.

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Article Synopsis
  • Long-QT syndrome (LQTS) is a heart condition that can cause sudden cardiac death and is mainly linked to rare genetic variants in specific genes.
  • A study in Iceland identified 12 genetic variants associated with prolonged QTc intervals, revealing a higher carrier frequency than previously thought.
  • The study concluded that certain variants, particularly p.Tyr315Cys and p.Leu273Phe, lead to more severe outcomes, which can inform better risk assessment and treatment strategies for patients with QTc prolongation.
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  • This study investigates the genetics of syncope, a common medical condition, to improve understanding of its causes and potential outcomes.
  • A large-scale analysis of genetic data from over half a million people identified 18 genetic variants linked to syncope, most of which were newly discovered, highlighting the condition's unique genetic traits.
  • The findings suggest a relationship between syncope and cardiovascular health, indicating that genetic factors related to heart rate and blood pressure regulation could be involved, reinforcing the need for careful evaluation of patients experiencing syncope.
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Nonalcoholic fatty liver (NAFL) and its sequelae are growing health problems. We performed a genome-wide association study of NAFL, cirrhosis and hepatocellular carcinoma, and integrated the findings with expression and proteomic data. For NAFL, we utilized 9,491 clinical cases and proton density fat fraction extracted from 36,116 liver magnetic resonance images.

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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.

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Article Synopsis
  • The study aimed to explore the genetic basis and risk factors associated with sick sinus syndrome (SSS) using a large dataset of SSS cases and controls.
  • Researchers identified six genetic variants linked to SSS, highlighting a specific missense variant in the KRT8 gene that significantly increases risk, particularly in homozygotes.
  • The findings suggest a causal relationship between atrial fibrillation (AF) and SSS, while other common factors like body mass index and type 2 diabetes did not show a direct link to SSS risk.
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Article Synopsis
  • The study aimed to explore the genetic causes of sick sinus syndrome (SSS) and understand risk factors contributing to its development.
  • A genome-wide association study involving over 6,000 SSS cases and nearly 1 million controls identified six genetic variants linked to SSS, with a notable missense variant in the KRT8 gene showing a particularly high risk for homozygotes.
  • Conclusions suggest that certain genetic factors are associated with SSS, and findings support that atrial fibrillation (AF) may play a causal role in its development, while other common health issues like obesity and diabetes seem unrelated.
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The electrocardiographic PR interval reflects atrioventricular conduction, and is associated with conduction abnormalities, pacemaker implantation, atrial fibrillation (AF), and cardiovascular mortality. Here we report a multi-ancestry (N = 293,051) genome-wide association meta-analysis for the PR interval, discovering 202 loci of which 141 have not previously been reported. Variants at identified loci increase the percentage of heritability explained, from 33.

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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.

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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.

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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.

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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), or near genes important for striated muscle function and integrity (for example, CFL2, MYH7, PKP2, RBM20, SGCG, SSPN).

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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.

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Aortic valve stenosis (AS) is the most common valvular heart disease, and valve replacement is the only definitive treatment. Here we report a large genome-wide association (GWA) study of 2,457 Icelandic AS cases and 349,342 controls with a follow-up in up to 4,850 cases and 451,731 controls of European ancestry. We identify two new AS loci, on chromosome 1p21 near PALMD (rs7543130; odds ratio (OR) = 1.

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Background: Genome-wide association studies (GWAS) have yielded variants at >30 loci that associate with atrial fibrillation (AF), including rare coding mutations in the sarcomere genes MYH6 and MYL4.

Objectives: The aim of this study was to search for novel AF associations and in doing so gain insights into the mechanisms whereby variants affect AF risk, using electrocardiogram (ECG) measurements.

Methods: The authors performed a GWAS of 14,255 AF cases and 374,939 controls, using whole-genome sequence data from the Icelandic population, and tested novel signals in 2,002 non-Icelandic cases and 12,324 controls.

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Coronary artery disease has been the leading cause of death and disability in Iceland during the past decades although in recent years, malignancy has taken over that position. A steady improvement in the level of major risk factors has been evident since 1980. This trend explains 72% of the decrease in premature mortality from coronary artery disease during the past three decades.

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Background: Coronary heart disease (CHD) mortality rates have been decreasing in Iceland since the 1980s, largely reflecting improvements in cardiovascular risk factors. The purpose of this study was to predict future CHD mortality in Iceland based on potential risk factor trends.

Methods And Findings: The previously validated IMPACT model was used to predict changes in CHD mortality between 2010 and 2040 among the projected population of Iceland aged 25-74.

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