Publications by authors named "Gardar Sveinbjornsson"

Background & Aims: The genetic underpinnings of hepatocellular carcinoma (HCC) remain largely unknown. Thus, we aimed to identify new genetic risk loci for HCC.

Methods: We performed a genome-wide association study (GWAS) meta-analysis of 11 cohorts with validation in two independent cohorts.

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POPDC2 encodes the Popeye domain-containing protein 2, which has an important role in cardiac pacemaking and conduction, due in part to its cyclic AMP (cAMP)-dependent binding and regulation of TREK-1 potassium channels. Loss of Popdc2 in mice results in sinus pauses and bradycardia, and morpholino-mediated knockdown of popdc2 in zebrafish results in atrioventricular (AV) block. We identified bi-allelic variants in POPDC2 in four families with a phenotypic spectrum consisting of sinus node dysfunction, AV conduction defects, and hypertrophic cardiomyopathy.

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Bipolar disorder is a highly heritable psychiatric disorder; genome-wide association studies of bipolar disorder have yielded over 60 risk loci harboring common variants. To harness the information contained in rare loss-of-function (LOF) variants, holding promise for informing on the underlying biology, we performed a variant burden analysis for bipolar disorder using gene-based aggregation of LOF variants in whole-genome sequencing data from Iceland (4,197 cases, more than 200,000 controls) and the UK Biobank (1,881 cases, 426,622 controls). We found that HECTD2 was associated with bipolar disorder and confirmed it using the Bipolar Exome dataset.

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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 a prevalent and morbid abnormality of the heart rhythm with a strong genetic component. Here, we meta-analyzed genome and exome sequencing data from 36 studies that included 52,416 AF cases and 277,762 controls. In burden tests of rare coding variation, we identified novel associations between AF and the genes MYBPC3, LMNA, PKP2, FAM189A2 and KDM5B.

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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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Heart failure (HF) is a major contributor to global morbidity and mortality. While distinct clinical subtypes, defined by etiology and left ventricular ejection fraction, are well recognized, their genetic determinants remain inadequately understood. In this study, we report a genome-wide association study of HF and its subtypes in a sample of 1.

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Article Synopsis
  • Dilated cardiomyopathy (DCM) is a major cause of heart failure, and this study analyzes genetic factors by examining 14,256 DCM cases and 36,203 participants from the UK Biobank for related traits.
  • Researchers discovered 80 genomic risk loci and pinpointed 62 potential effector genes tied to DCM, including some linked to rare variants.
  • The study uses advanced transcriptomics to explore how cellular functions contribute to DCM, showing that polygenic scores can help predict the disease in the general population and emphasize the importance of genetic testing and development of precise treatments.
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Mendelian Randomization studies indicate that BMI contributes to various diseases, but it's unclear if this is entirely mediated by BMI itself. This study examines whether disease risk from BMI-associated sequence variants is mediated through BMI or other mechanisms, using data from Iceland and the UK Biobank. The associations of BMI genetic risk score with diseases like fatty liver disease, knee replacement, and glucose intolerance were fully attenuated when conditioned on BMI, and largely for type 2 diabetes, heart failure, myocardial infarction, atrial fibrillation, and hip replacement.

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  • Researchers analyzed genetic data from nearly 130,000 cancer patients and over 730,000 healthy controls to identify variants linked to cancer risk across 22 cancer types.
  • Four high-risk genes were found: BIK (prostate cancer), ATG12 (colorectal cancer), TG (thyroid cancer), and CMTR2 (lung cancer and melanoma).
  • Additionally, two genes, AURKB (general cancer risk) and PPP1R15A (breast cancer), were associated with decreased cancer risk, indicating potential pathways for cancer prevention strategies.
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Background: Signal transducer and activator of transcription 6 (STAT6) is central to type 2 (T2) inflammation, and common noncoding variants at the STAT6 locus associate with various T2 inflammatory traits, including diseases, and its pathway is widely targeted in asthma treatment.

Objective: We sought to test the association of a rare missense variant in STAT6, p.L406P, with T2 inflammatory traits, including the risk of asthma and allergic diseases, and to characterize its functional consequences in cell culture.

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  • Human genetic studies reveal new insights into the biological processes of ovarian aging through rare protein-coding variants in a large study of women.
  • The genes identified (e.g., SAMHD1 and ZNF518A) show stronger effects on reproductive lifespan and cancer risk compared to common variants, with some variants linked to earlier menopause.
  • The research suggests a connection between genetic factors influencing ovarian aging and an increased incidence of de novo mutations, highlighting the importance of DNA damage response in fertility.
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  • 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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Age at menopause (AOM) has a substantial impact on fertility and disease risk. While many loci with variants that associate with AOM have been identified through genome-wide association studies (GWAS) under an additive model, other genetic models are rarely considered. Here through GWAS meta-analysis under the recessive model of 174,329 postmenopausal women from Iceland, Denmark, the United Kingdom (UK; UK Biobank) and Norway, we study low-frequency variants with a large effect on AOM.

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  • - Parkinson's disease (PD) is a serious neurodegenerative disorder, and rising cases emphasize the need to identify factors that can be changed to reduce risk.
  • - A study involving 8,647 PD patients and 777,693 controls identified a new link between rare ITSN1 gene variants and PD, supported by other research databases.
  • - The research suggests that issues with Rho GTPases and synaptic vesicle transport might play a role in PD development, indicating potential new treatment strategies.
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Gene promoter and enhancer sequences are bound by transcription factors and are depleted of methylated CpG sites (cytosines preceding guanines in DNA). The absence of methylated CpGs in these sequences typically correlates with increased gene expression, indicating a regulatory role for methylation. We used nanopore sequencing to determine haplotype-specific methylation rates of 15.

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  • Early pregnancy bleeding and postpartum hemorrhage (PPH) present significant risks to maternal health, with PPH being the leading cause of maternal death and early bleeding often linked to pregnancy loss.
  • A meta-analysis identified five genetic loci associated with PPH, highlighting candidate genes (HAND2, TBX3, RAP2C/FRMD7) that interact with progesterone receptors, suggesting a connection between PPH and progesterone signaling issues.
  • While bleeding in early pregnancy didn't show specific genetic signals, it was strongly correlated with other human traits, indicating it may be influenced by multiple genetic and possibly socio-economic factors not yet fully understood.
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encodes for the Popeye domain-containing protein 2 which has an important role in cardiac pacemaking and conduction, due in part to its cAMP-dependent binding and regulation of TREK-1 potassium channels. Loss of in mice results in sinus pauses and bradycardia and morpholino knockdown of zebrafish results in atrioventricular (AV) block. We identified bi-allelic variants in in 4 families that presented with a phenotypic spectrum consisting of sinus node dysfunction, AV conduction defects and hypertrophic cardiomyopathy.

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Autoimmune thyroid disease (AITD) is a common autoimmune disease. In a GWAS meta-analysis of 110,945 cases and 1,084,290 controls, 290 sequence variants at 225 loci are associated with AITD. Of these variants, 115 are previously unreported.

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We report a multi-ancestry genome-wide association study on liver cirrhosis and its associated endophenotypes, alanine aminotransferase (ALT) and γ-glutamyl transferase. Using data from 12 cohorts, including 18,265 cases with cirrhosis, 1,782,047 controls, up to 1 million individuals with liver function tests and a validation cohort of 21,689 cases and 617,729 controls, we identify and validate 14 risk associations for cirrhosis. Many variants are located near genes involved in hepatic lipid metabolism.

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  • X-chromosomal genetic variants can provide important information about differences in human traits and diseases between sexes.
  • A large-scale study analyzed kidney-related traits in nearly 909,000 individuals, finding 23 genetic loci linked to uric acid levels and estimated glomerular filtration rate (eGFR), including four new genes that may play a role in kidney function.
  • The research also discovered five novel sex-specific interactions, with variations showing different effects in males and females, and highlighted genes that are responsive to androgens (male hormones), indicating a complex relationship between sex and kidney-related genetics.
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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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Background: In 2021, the American College of Medical Genetics and Genomics (ACMG) recommended reporting actionable genotypes in 73 genes associated with diseases for which preventive or therapeutic measures are available. Evaluations of the association of actionable genotypes in these genes with life span are currently lacking.

Methods: We assessed the prevalence of coding and splice variants in genes on the ACMG Secondary Findings, version 3.

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