European Ancestry Research Articles

Risk of Parkinson's disease and depression severity in different populations: A two-sample Mendelian randomization analysis.

Depression is widely recognized as a common non-motor symptom of Parkinson's disease (PD). Across different studies, the reported prevalence of depression in PD varies widely, ranging from 2.7% to 90%, but it is unclear whether this association is due to genetic or acquired factors. Whether there is a causal relationship remains unknown. The aim of this study was to use a two-sample Mendelian randomization (MR) approach to investigate the causal effect of PD on depression. Analyses were conducted separately for individuals of European and East Asian ancestry using publicly available summary data from genome-wide association studies. Depression was divided into two categories: ever depressed for a whole week and major depressive disorder (MDD). PD data were used as the exposure and were obtained from the International Parkinson's Disease Genomics Consortium and the BioBank Japan PheWeb, while depression data were used as the outcome and were obtained from the ntegrative Epidemiology Unit (IEU) Open GWAS Project(A public GWAS database）and the Psychiatric Genomics Consortium. The influence of PD on depression was assessed using inverse variance weighted (IVW), weighted median, MR-Egger, and weighted mode methods. Heterogeneity and pleiotropy were tested, and the results were validated using FinnGen GWAS data from version R9. In individuals of European ancestry, there was a causal relationship between PD and ever depressed for a whole week (IVW method, odds ratio [OR]=0.990; 95% CI, 0.984-0.996; p=.002), but no causal relationship was observed between PD and MDD (IVW method, OR=0.974; 95% CI, 0.942-1.009; p=.141). In individuals of East Asian ancestry, no causal relationship was observed between PD and ever depressed for a whole week (IVW method, OR=1.001; 95% CI, 0.829-1.209; p=.990) and between PD and MDD (IVW method, OR=1.017; 95% CI, 0.982-1.052; p=.342). The results of the three additional analysis methods were similar to those of the IVW method, and there was no heterogeneity according to Cochran's Q-test. There was no evidence of pleiotropy based on MR-Egger intercept test and MR-PRESSO. The FinnGen validation dataset supported these findings. The results are stable and reliable. The observed increase in depression among PD patients could potentially be attributed to modifiable acquired factors. Consequently, there is an urgent need to strengthen the management of PD patients in order to prevent the development of depression in the future.

The NOS1AP gene rs10494366 common genetic variant does not modify the risk of sudden cardiac death in users of digoxin.

Common genetic variations in the nitric oxide synthase-1 adaptor protein (NOS1AP) gene are associated with QT-interval prolongation. In a previous study, we observed an association between the rs10494366 variant of this gene and an increased QT-interval shortening in digoxin users. As QT-interval shortening is a risk factor for sudden cardiac death (SCD), in this study, we investigated whether the association between digoxin use and risk of SCD differs in participants with different NOS1AP rs10494366 genotypes. We included 11 377 individuals from the prospective population-based cohort of the Rotterdam Study. We used Cox proportional hazard regression analysis with digoxin as time-dependent exposure to estimate the associations between current digoxin use and the risk of SCD among different rs10494366 genotype groups in the adjusted models. We also studied whether such an association was dose-dependent, comparing high dosage (≥ 0.250 mg), moderate dosage (0.125 mg ≤ dose< 0.250 mg) and low dosage (< 0.125 mg) digoxin users with non-users. The median baseline age of the total study population was 62 (interquartile range [IQR] 58-71) years. The cumulative incidence of SCD was 4.1% (469 cases), and among them, 74 (15.7%) individuals were current digoxin users at the time of death, during a median follow-up of 11.5 (IQR 6.5-17) years. Current digoxin users had an increased risk of SCD (multivariable adjusted model hazard ratio [HR]: 3.07; 95% confidence interval [CI]: 2.38-3.98), with no significant differences between the three genotype groups. The adjusted HRs were 4.03 [95% CI: 1.98-8.21] in the minor homozygous GG, 3.46 [95% CI: 2.37-5.04] in the heterozygous TG and 2.56 [95%CI: 1.70-3.86] in the homozygous TT genotype groups. Compared to low- and moderate-dose, high-dose digoxin users with GG genotype had the highest risk of SCD (HR: 5.61 [95% CI: 1.34-23.47]). Current use of digoxin is associated with a significantly increased risk of SCD. The NOS1AP gene rs10494366 variant did not modify the digoxin-associated risk of SCD in a population of European ancestry.

Bivariate genome-wide association study of circulating fibrinogen and C-reactive protein levels

BackgroundFibrinogen and C-reactive protein (CRP) play an important role in inflammatory pathways and share multiple genetic loci reported in previously published genome-wide association studies (GWAS), highlighting their common genetic background. Leveraging the shared biology may identify further loci pleiotropically associated with both fibrinogen and CRP. ObjectivesTo identify novel genetic variants that are pleiotropic and associated with both fibrinogen and CRP, by integrating both phenotypes in a bivariate GWAS by using a multitrait GWAS. MethodsWe performed a bivariate GWAS to identify further pleiotropic genetic loci, using summary statistics of previously published GWAS on fibrinogen (n = 120 246) from the Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium, consisting of European ancestry samples and CRP (n = 363 228) from UK Biobank, including 5 different population groups. The main analysis was performed using metaUSAT and N-GWAMA. We conducted replication for novel CRP associations to test the robustness of the findings using an independent GWAS for CRP (n = 148 164). We also performed colocalization analysis to compare the associations in identified loci for the 2 traits and Genotype-Tissue Expression data. ResultsWe identified 87 pleiotropic loci that overlapped between metaUSAT and N-GWAMA, including 23 previously known for either fibrinogen or CRP, 58 novel loci for fibrinogen, and 6 novel loci for both fibrinogen and CRP. Overall, there were 30 pleiotropic and novel loci for both traits, and 7 of these showed evidence of colocalization, located in or near ZZZ3, NR1I2, RP11-72L22.1, MICU1, ARL14EP, SOCS2, and PGM5. Among these 30 loci, 13 replicated for CRP in an independent CRP GWAS. ConclusionBivariate GWAS identified additional associated loci for fibrinogen and CRP. This analysis suggests fibrinogen and CRP share a common genetic architecture with many pleiotropic loci.

C9orf72 repeat expansions in Wakayama: One potential cause of amyotrophic lateral sclerosis in the Kii Peninsula, Japan

A cluster of cases of amyotrophic lateral sclerosis (ALS) exists in the southern part of the Kii Peninsula in Japan. Although both genetic and environmental factors are thought to be causative, the critical cause of this cluster has not been identified. C9orf72 is the most common genetic factor in both familial and sporadic C9orf72-related ALS in people of European ancestry, but it is rare among Japanese populations. However, a previous report revealed that the frequency of C9orf72-related ALS was significantly higher in the cluster area. We evaluated the proportion of C9orf72 hexanucleotide repeat expansions in 99 cases of ALS diagnosed in Wakayama Prefecture, including the cluster area, by using repeat-primed polymerase chain reaction and fluorescence fragment length analysis. We found that 2 of the 99 patients (0 % of those with familial ALS and 2.4 % of those with sporadic ALS) had hexanucleotide repeat expansions in C9orf72, and long-read sequencing revealed that these expansions were causative. No expansions were observed among 90 patients with Parkinson's disease or among 90 healthy controls. Haplotype analysis with long-read sequencing data revealed that the two patients with repeat expansions shared the common haplotype with that previously reported in Finnish patients with C9orf72-related ALS, which suggests a founder effect. C9orf72 was thought to be a rare causative gene in Japan, but this study revealed that it may be relatively common in Wakayama Prefecture.

Association between psychiatric disorders and irritable bowel syndrome: A bidirectional Mendelian randomization study

ObjectivePrevious studies have suggested that irritable bowel syndrome (IBS) is strongly associated with psychiatric disorders. However, it is unclear whether this association is causal, concomitant, or accidental. Thus, we performed Mendelian randomization (MR) analysis to evaluate the causal effects of several psychiatric disorders on IBS. MethodsSummary data of genome-wide association studies (GWASs) were obtained mainly from the Psychiatric Genomics Consortium (PGC) on individuals of European ancestry and from a recent GWAS on IBS. We used three MR methods, the inverse-variance weighting (IVW), weighted median (WM), and MR-Egger regression (MR-Egger). In addition, two other indicators, namely, the MR-IVW Cochran's Q statistic and MR-Egger intercept, were used to assess heterogeneity and detect directional horizontal pleiotropy, respectively. ResultsHeritability was high for bipolar disorder (81.18 %, 95 % CI = 73.18–148.18 %), schizophrenia (33.88 %, 95 % CI = 33.57–38.19 %), and panic disorder (30.66 %, 95 % CI = 20.74–40.58 %). For other disorders, there was a low liability-scale SNP heritability for major depressive disorder (MDD) (0.67 %, 95 % CI = 0.61–0.73 %), anxiety disorder (7.63 %, 95 % CI = 1.67–13.59 %), PTSD (0.96 %, 95 % CI = 0.12–1.8 %), and IBS (2.44 %, 95 % CI = 2.13–2.75 %). We also observed that schizophrenia had a significant causal effect on IBS according to MR-IVW. Notably, the individual causal estimates of genetic instruments for MDD and schizophrenia were heterogeneous, but no pleiotropic effects were observed. ConclusionsOur analyses revealed the causal effects of MDD and schizophrenia on IBS, a matter that has been subject to debate for decades, and also showed that IBS had causal effects on MDD.

Disparities in outcomes by race and ethnicity in the Canadian cystic fibrosis population

BackgroundCystic Fibrosis has historically been described as a disease that affects people of European ancestry. Consequently, much of what we know about CF is based on evidence generated from data collected in white individuals. This may lead to systematic bias in how non-white people with CF are diagnosed and treated. In this study we compared clinical outcomes between the white and non-white people with CF in Canada. MethodsCanadian CF Registry data collected between 2000 and 2019 were used in this population-based cohort study. Demographic characteristics and clinical outcomes of people with CF identified as white and those identified as non-white were compared. Analyses were adjusted for cohort effects but not socioeconomic status. ResultsBetween 2000 and 2019, 5516 people with CF in the Registry were identified as white and 323 were identified as non-white. At diagnosis, the white and non-white groups were similar with respect to sex at birth, age at diagnosis, prevalence of pancreatic insufficiency, and meconium ileus. The non-white group had similar rates of CF-related complications and bacterial infections compared to the white, but worse lung function, worse nutritional status, lower treatment rates, and higher rate of hospitalizations. During the 20-year study period, the non-white group had a 1.85 higher risk of death compared to the white group (HR 95 %CI 1.39; 2.47). InterpretationThere is an urgent need understand why outcomes for Canadians with CF differ between white and non-white individuals, including the role of socioeconomic circumstances.

A Phenome-Wide Association Study (PheWAS) of Genetic Risk for C-Reactive Protein in Children of European Ancestry: Results From the ABCD Study.

C-reactive protein (CRP) is a moderately heritable marker of systemic inflammation that is associated with adverse physical and mental health outcomes. Identifying factors associated with genetic liability to elevated CRP in childhood may inform our understanding of variability in CRP that could be targeted to prevent and/or delay the onset of related health outcomes. We conducted a phenome-wide association study (PheWAS) of genetic risk for elevated CRP (i.e. CRP polygenic risk score [PRS]) among children genetically similar to European ancestry reference populations (median analytic n = 5,509) from the Adolescent Brain and Cognitive Development℠ (ABCD) Study. Associations between CRP PRS and 2,377 psychosocial and neuroimaging phenotypes were estimated using independent mixed effects models. Post hoc analyses examined whether: (1) covarying for measured body mass index (BMI) or removing the shared genetic architecture between CRP and BMI altered phenotypic associations, (2) sex moderated CRP PRS associations, and (3) associations are unconfounded by assortative mating or passive gene-environment correlations (using a within-family analyses). Multiple testing was adjusted for using Bonferroni and false discovery rate (FDR) correction. Nine phenotypes were positively associated with CRP PRS after multiple testing correction: five weight- and eating-related phenotypes (e.g. BMI, overeating), three phenotypes related to caregiver somatic problems (e.g. caregiver somatic complaints), as well as weekday video watching (all ps = 1.2 × 10-7 - 2.5 × 10-4, all p FDR s = 0.0002 - 0.05). No neuroimaging phenotypes were associated with CRP PRS (all ps = 0.0003 - 0.998; all p FDR s = 0.08 - 0.998) after correction for multiple testing. Eating and weight-related phenotypes remained associated with CRP PRS in within-family analyses. Covarying for BMI resulted in largely consistent results, and sex did not moderate any CRP PRS associations. Removing the shared genetic variance between CRP and BMI attenuated all relationships; associations with weekday video watching, caregiver somatic problems and caregiver report that the child is overweight remained significant while associations with waist circumference, weight, and caregiver report that child overeats did not. Genetic liability to elevated CRP is associated with higher weight, eating, and weekday video watching during childhood as well as caregiver somatic problems. These associations were consistent with direct genetic effects (i.e., not solely due to confounding factors like passive gene-environment correlations) and were independent of measured BMI. The majority of associations with weight and eating phenotypes were attributable to shared genetic architecture between BMI and inflammation. The relationship between genetics and heightened inflammation in later life may be partially attributable to modifiable behaviors (e.g. weight and activity levels) that are expressed as early as childhood.

Fine-mapping the CYP2A6 regional association with nicotine metabolism among African American smokers.

The nicotine metabolite ratio (NMR; 3'hydroxycotinine/cotinine) is a stable biomarker for CYP2A6 enzyme activity and nicotine clearance, with demonstrated clinical utility in personalizing smoking cessation treatment. Common genetic variation in the CYP2A6 region is strongly associated with NMR in smokers. Here, we investigated this regional association in more detail. We evaluated the association of CYP2A6 single-nucleotide polymorphisms (SNPs) and * alleles with NMR among African American smokers (N = 953) from two clinical trials of smoking cessation. Stepwise conditional analysis and Bayesian fine-mapping were undertaken. Putative causal variants were incorporated into an existing African ancestry-specific genetic risk score (GRS) for NMR, and the performance of the updated GRS was evaluated in both African American (n = 953) and European ancestry smokers (n = 933) from these clinical trials. Five independent associations with NMR in the CYP2A6 region were identified using stepwise conditional analysis, including the deletion variant CYP2A6*4 (beta = -0.90, p = 1.55 × 10-11). Six putative causal variants were identified using Bayesian fine-mapping (posterior probability, PP = 0.67), with the top causal configuration including CYP2A6*4, rs116670633, CYP2A6*9, rs28399451, rs8192720, and rs10853742 (PP = 0.09). Incorporating these putative causal variants into an existing ancestry-specific GRS resulted in comparable prediction of NMR within African American smokers, and improved trans-ancestry portability of the GRS to European smokers. Our findings suggest that both * alleles and SNPs underlie the association of the CYP2A6 region with NMR among African American smokers, identify a shortlist of variants that may causally influence nicotine clearance, and suggest that portability of GRSs across populations can be improved through inclusion of putative causal variants.

Genetic ancestry proportion influences risk of adverse events from tuberculosis treatment in Brazil.

Tuberculosis (TB) treatment is highly effective, but response to therapy can vary by geography, race, and ethnicity. We assessed for differences in TB treatment response in a representative and heterogeneous Brazilian population. We estimated genetic ancestry proportion according to major ancestry groups (African, European, and Amerindian ancestry) in the Regional Prospective Observational Research in Tuberculosis (RePORT)-Brazil cohort. RePORT-Brazil is an observational prospective cohort study of individuals with newly-diagnosed, culture-confirmed, pulmonary TB. TB treatment outcomes that were attributed to TB treatment included Grade 2 or higher adverse drug reaction (ADR), Grade 3 or higher ADR, hepatic ADR, and failure/recurrence. Ancestry proportion was the main predictor in logistic regression for each outcome, with adjustments for candidate confounders. There were 941 pulmonary TB patients included in this study. We observed a decreased risk of Grade 2+ ADR when African ancestry proportion increased by 10% (Odds Ratio [OR] 0.41, 95% Confidence Interval [CI] 0.20 -0.85) and an increased risk for Grade 2+ ADR with increasing European ancestry (OR 2.84, 95% CI 1.47 - 5.48). We then performed the same analysis adding HIV status as an interaction term. The decreased risk for Grade 2+ ADR seen for African ancestry proportion did not hold for persons living with HIV; we observed increased risk for Grade 2+ ADR with increasing African ancestry proportion. There were no associations with Amerindian ancestry or for other treatment outcomes. In this Brazilian TB cohort, toxicity risk was associated with African and European ancestry, divergent, and affected by HIV. #RePORT-Brazil Consortium members include: Aline Benjamin and Flavia M. Sant'Anna Instituto Nacional de Infectologia Evandro Chagas, Fiocruz, Rio de Janeiro, Brazil Jamile Garcia de Oliveira and João Marine Clínica de Saúde Rinaldo Delmare, Rio de Janeiro, Brazil Adriana Rezende and Anna Cristina Carvalho Secretaria de Saúde de Duque de Caxias, Rio de Janeiro, Brazil Michael Rocha and Betânia Nogueira Instituto Brasileiro para Investigação da Tuberculose, Fundação José Silveira, Salvador, Brazil Alexandra Brito and Renata Spener Fundação Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil Megan Turner Vanderbilt University Medical Center, Nashville, USA.

Genome-wide analyses of neonatal jaundice reveal a marked departure from adult bilirubin metabolism

Jaundice affects almost all neonates in their first days of life and is caused by the accumulation of bilirubin. Although the core biochemistry of bilirubin metabolism is well understood, it is not clear why some neonates experience more severe jaundice and require treatment with phototherapy. Here, we present the first genome-wide association study of neonatal jaundice to date in nearly 30,000 parent-offspring trios from Norway (cases ≈ 2000). The alternate allele of a common missense variant affecting the sequence of UGT1A4 reduces the susceptibility to jaundice five-fold, which replicated in separate cohorts of neonates of African American and European ancestries. eQTL colocalization analyses indicate that the association may be driven by regulation of UGT1A1 in the intestines, but not in the liver. Our results reveal marked differences in the genetic variants involved in neonatal jaundice compared to those regulating bilirubin levels in adults, suggesting distinct genetic mechanisms for the same biological pathways.

Periodontitis and Chronic Obstructive Pulmonary Disease: A bidirectional Mendelian randomization study.

Observational studies have suggested an association between chronic periodontitis (CP) and chronic obstructive pulmonary disease (COPD). This study aimed to determine whether there is a causal relationship between CP and COPD incidence. Two‑sample Mendelian Randomization (MR) analysis using summary statistics from two genome‑wide association studies (GWASs) of European ancestry. Single nucleotide polymorphisms (SNPs) associated with COPD were obtained from the FinnGen database, which included 16,380,382 SNPs. The diagnosis of COPD was based on the Global Initiative for Chronic Obstructive Lung Disease (GOLD 2023). We also obtained SNPs associated with CP from the FinnGen database, which included 16,380,378 SNPs. Sixteen eligible SNPs were extracted to analyze the causal effect of CP on COPD incidence. There was no causal correlation between CP and COPD using the inverse variance-weighted method (IVW) (OR=0.97, 95%CI= 0.91-1.05; p=0.482). Seven eligible SNPs were extracted to analyze the causal effect of COPD on CP incidence. Again, there was also no causal correlation between using IVW (OR=1.09, 95%CI=0.93-1.28; p=0.279). We did not demonstrate a causal relationship between genetically predicted CP and COPD, or between genetically predicted COPD and CP.

Causal associations between insulin and Lp(a) levels in Caucasian population: a Mendelian randomization study

BackgroundNumerous observational studies have demonstrated that circulating lipoprotein(a) [Lp(a)] might be inversely related to the risk of type 2 diabetes (T2D). However, recent Mendelian randomization (MR) studies do not consistently support this association. The results of in vitro research suggest that high insulin concentrations can suppress Lp(a) levels by affecting apolipoprotein(a) [apo(a)] synthesis. This study aimed to identify the relationship between genetically predicted insulin concentrations and Lp(a) levels, which may partly explain the associations between low Lp(a) levels and increased risk of T2D.MethodsIndependent genetic variants strongly associated with fasting insulin levels were identified from meta-analyses of genome-wide association studies in European populations (GWASs) (N = 151,013). Summary level data for Lp(a) in the population of European ancestry were acquired from a GWAS in the UK Biobank (N = 361,194). The inverse-variance weighted (IVW) method approach was applied to perform two-sample summary-level MR. Robust methods for sensitivity analysis were utilized, such as MR‒Egger, the weighted median (WME) method, MR pleiotropy residual sum and outlier (MR-PRESSO), leave-one-out analysis, and MR Steiger.ResultsGenetically predicted fasting insulin levels were negatively associated with Lp(a) levels (β = − 0.15, SE = 0.05, P = 0.003). The sensitivity analysis revealed that WME (β = − 0.26, SE = 0.07, P = 0.0002), but not MR‒Egger (β = − 0.22, SE = 0.13, P = 0.11), supported a causal relationship between genetically predisposed insulin levels and Lp(a).ConclusionOur MR study provides robust evidence supporting the association between genetically predicted increased insulin concentrations and decreased concentrations of Lp(a). These findings suggest that hyperinsulinaemia, which typically accompanies T2D, can partially explain the inverse relationship between low Lp(a) concentrations and an increased risk of T2D.

Association of metabolites on ischemic stroke subtypes: a 2-sample Mendelian randomization study.

Metabolomics is increasingly being utilized in IS research to elucidate the intricate metabolic alterations that occur during ischemic stroke (IS). However, establishing causality in these associations remains unclear between metabolites and IS subtypes. In this study, we employ Mendelian randomization (MR) to identify specific metabolites and investigate potential causal relationships between metabolites and IS subtypes. MR analysis was conducted using genome-wide association study (GWAS) summary data. We obtained 1,091 blood metabolites and 309 metabolite ratios from the GWAS Catalog (GCST90199621-90201020), which gene sequencing data from 8,299 individuals from the Canadian Longitudinal Study. We obtained GWAS summary statistics for IS subtypes which include large artery stroke (LAS), cardioembolic stroke (CES), and small vessel stroke (SVS) from the MEGASTROKE consortium that included 446,696 cases of European ancestry and 406,111 controls of European ancestry. The primary analysis utilized inverse-variance weighted (IVW) method. To validate our results, we performed supplementary analyses employing the MR-Egger, weighted median, simple mode, and weighted mode methods. Heterogeneity and pleiotropy were assessed through Cochran's Q test, MR-Egger intercept test, and leave-one-out analysis. The study assessed the possible causality of serum metabolites in the risk of IS subtypes. The discovery of significant causal links between 33 metabolites and 3 distinct IS subtypes. Metabolites show significant potential as circulating metabolic biomarkers and offer promise for clinical applications in the prevention and screening of IS subtypes. These discoveries notably advance our comprehension of the molecular processes specific to IS subtypes and create avenues for investigating targeted treatment approaches in the future.

Causal relationships between GLP1 receptor agonists, blood lipids, and heart failure: a drug-target mendelian randomization and mediation analysis

BackgroundGlucagon-like peptide-1 receptor (GLP1R) agonists have been shown to reduce major cardiovascular events in diabetic patients, but their role in heart failure (HF) remains controversial. Recent evidence implies their potential benefits on cardiometabolism such as lipid metabolism, which may contribute to lowering the risk of HF. Consequently, we designed a Mendelian randomization (MR) study to investigate the causal relationships of circulating lipids mediating GLP1R agonists in HF.MethodsThe available cis-eQTLs for GLP1R target gene were selected as instrumental variables (IVs) of GLP1R agonism. Positive control analyses of type 2 diabetes mellitus (T2DM) and body mass index (BMI) were conducted to validate the enrolled IVs. Two-sample MR was performed to evaluate the associations between GLP1R agonism and HF as well as left ventricular ejection fraction (LVEF). Summary data for HF and LVEF were obtained from two genome-wide association studies (GWASs), which included 977,323 and 40,000 individuals of European ancestry, respectively. The primary method employed was the random-effects inverse variance weighted, with several other methods used for sensitivity analyses, including MR-Egger, MR PRESSO, and weighted median. Additionally, multivariable MR and mediation MR were applied to identify potentially causal lipid as mediator.ResultsA total of 18 independent IVs were included. The positive control analyses showed that GLP1R agonism significantly reduced the risk of T2DM (OR = 0.79, 95% CI = 0.75–0.85, p < 0.0001) and decreased BMI (OR = 0.95, 95% CI = 0.93–0.96, p < 0.0001), ensuring the effectiveness of selected IVs. We found favorable evidence to support the protective effect of GLP1R agonism on HF (OR = 0.75, 95% CI = 0.71–0.79, p < 0.0001), but there was no obvious correlation with increased LVEF (OR = 1.01, 95% CI = 0.95–1.06, p = 0.8332). Among the six blood lipids, only low-density lipoprotein cholesterol (LDL-C) was both associated with GLP1R agonism and HF. The causal effect of GLP1R agonism on HF was partially mediated through LDL-C by 4.23% of the total effect (95% CI = 1.04–7.42%, p = 0.0093).ConclusionsThis study supported the causal relationships of GLP1R agonists with a reduced risk of HF. LDL-C might be the mediator in this association, highlighting the cardiometabolic benefit of GLP1R agonists on HF.Graphical

Rare coding variant analysis for human diseases across biobanks and ancestries.

Large-scale sequencing has enabled unparalleled opportunities to investigate the role of rare coding variation in human phenotypic variability. Here, we present a pan-ancestry analysis of sequencing data from three large biobanks, including the All of Us research program. Using mixed-effects models, we performed gene-based rare variant testing for 601 diseases across 748,879 individuals, including 155,236 with ancestry dissimilar to European. We identified 363 significant associations, which highlighted core genes for the human disease phenome and identified potential novel associations, including UBR3 for cardiometabolic disease and YLPM1 for psychiatric disease. Pan-ancestry burden testing represented an inclusive and useful approach for discovery in diverse datasets, although we also highlight the importance of ancestry-specific sensitivity analyses in this setting. Finally, we found that effect sizes for rare protein-disrupting variants were concordant between samples similar to European ancestry and other genetic ancestries (βDeming = 0.7-1.0). Our results have implications for multi-ancestry and cross-biobank approaches in sequencing association studies for human disease.

Prevalence, Cardiac Phenotype, and Outcomes of Transthyretin Variants in the UK Biobank Population

The population prevalence of cardiac transthyretin amyloidosis (ATTR) caused by pathogenic variation in the TTR gene (vATTR) is unknown. To estimate the population prevalence of disease-causing TTR variants and evaluate associated phenotypes and outcomes. This population-based cohort study analyzed UK Biobank (UKB) participants with whole-exome sequencing, electrocardiogram, and cardiovascular magnetic resonance data. Participants were enrolled from 2006 to 2010, with a median follow-up of 12 (IQR, 11-13) years (cutoff date for the analysis, March 12, 2024). Sixty-two candidate TTR variants were extracted based on rarity (minor allele frequency ≤0.0001) and/or previously described associations with amyloidosis if more frequent. Carrier status for TTR variants. Associations of TTR carrier status with vATTR prevalence and cardiovascular imaging and electrocardiogram traits were explored using descriptive statistics. Associations between TTR carrier status and atrial fibrillation, conduction disease, heart failure, and all-cause mortality were evaluated using adjusted Cox proportional hazards models. Genotypic and diagnostic concordance was examined using International Statistical Classification of Diseases, Tenth Revision codes from the hospital record. The overall cohort included 469 789 UKB participants (mean [SD] age, 56.5 [8.1] years; 54.2% female and 45.8% male). A likely pathogenic/pathogenic (LP/P) TTR variant was detected in 473 (0.1%) participants, with Val142Ile being the most prevalent (367 [77.6%]); 91 individuals (0.02%) were carriers of a variant of unknown significance . The overall prevalence of LP/P variants was 0.02% (105 of 444 243) in participants with European ancestry and 4.3% (321 of 7533) in participants with African ancestry. The LP/P variants were associated with higher left ventricular mass indexed to body surface area (β = 4.66; 95% CI, 1.87-7.44), and Val142Ile was associated with a longer PR interval (β = 18.34; 95% CI, 5.41-31.27). The LP/P carrier status was associated with a higher risk of heart failure (hazard ratio [HR], 2.68; 95% CI, 1.75-4.12) and conduction disease (HR, 1.88; 95% CI, 1.25-2.83). Higher all-cause mortality risk was observed for non-Val142Ile LP/P variants (HR, 1.98; 95% CI, 1.06-3.67). Thirteen participants (2.8%) with LP/P variants had diagnostic codes compatible with cardiac or neurologic amyloidosis. Variants of unknown significance were not associated with outcomes. This study found that approximately 1 in 1000 UKB participants were LP/P TTR variant carriers, exceeding previously reported prevalence. The findings emphasize the need for clinical vigilance in identifying individuals at risk of developing vATTR and associated poor outcomes.

Biological Insights from Schizophrenia-associated Loci in Ancestral Populations.

Large-scale genome-wide association studies of schizophrenia have uncovered hundreds of associated loci but with extremely limited representation of African diaspora populations. We surveyed electronic health records of 200,000 individuals of African ancestry in the Million Veteran and All of Us Research Programs, and, coupled with genotype-level data from four case-control studies, realized a combined sample size of 13,012 affected and 54,266 unaffected persons. Three genome-wide significant signals - near PLXNA4, PMAIP1, and TRPA1 - are the first to be independently identified in populations of predominantly African ancestry. Joint analyses of African, European, and East Asian ancestries across 86,981 cases and 303,771 controls, yielded 376 distinct autosomal loci, which were refined to 708 putatively causal variants via multi-ancestry fine-mapping. Utilizing single-cell functional genomic data from human brain tissue and two complementary approaches, transcriptome-wide association studies and enhancer-promoter contact mapping, we identified a consensus set of 94 genes across ancestries and pinpointed the specific cell types in which they act. We identified reproducible associations of schizophrenia polygenic risk scores with schizophrenia diagnoses and a range of other mental and physical health problems. Our study addresses a longstanding gap in the generalizability of research findings for schizophrenia across ancestral populations, underlining shared biological underpinnings of schizophrenia across global populations in the presence of broadly divergent risk allele frequencies.

Causal association between 731 immunocyte phenotypes and liver cirrhosis: A bidirectional two-sample mendelian randomization analysis.

Liver cirrhosis is a progressive hepatic disease whose immunological basis has attracted increasing attention. However, it remains unclear whether a concrete causal association exists between immunocyte phenotypes and liver cirrhosis. To explore the concrete causal relationships between immunocyte phenotypes and liver cirrhosis through a mendelian randomization (MR) study. Data on 731 immunocyte phenotypes were obtained from genome-wide association studies. Liver cirrhosis data were derived from the Finn Gen dataset, which included 214403 individuals of European ancestry. We used inverse variable weighting as the primary analysis method to assess the causal relationship. Sensitivity analyses were conducted to evaluate heterogeneity and horizontal pleiotropy. The MR analysis demonstrated that 11 immune cell phenotypes have a positive association with liver cirrhosis [P < 0.05, odds ratio (OR) > 1] and that 9 immunocyte phenotypes were negatively correlated with liver cirrhosis (P < 0.05, OR < 1). Liver cirrhosis was positively linked to 9 immune cell phenotypes (P < 0.05, OR > 1) and negatively linked to 10 immune cell phenotypes (P < 0.05; OR < 1). None of these associations showed heterogeneity or horizontally pleiotropy (P > 0.05). This bidirectional two-sample MR study demonstrated a concrete causal association between immunocyte phenotypes and liver cirrhosis. These findings offer new directions for the treatment of liver cirrhosis.

Characterizing features affecting local ancestry inference performance in admixed populations.

In recent years, significant efforts have been made to improve methods for genomic studies of admixed populations using Local Ancestry Inference (LAI). Accurate LAI is crucial to ensure downstream analyses reflect the genetic ancestry of research participants accurately. Here, we test analytic strategies for LAI to provide guidelines for optimal accuracy, focusing on admixed populations reflective of Latin America's primary continental ancestries - African (AFR), Amerindigenous (AMR), and European (EUR). Simulating LD-informed admixed haplotypes under a variety of 2 and 3-way admixture models, we implemented a standard LAI pipeline, testing three reference panel compositions to quantify their overall and ancestry-specific accuracy. We examined LAI miscall frequencies and true positive rates (TPR) across simulation models and continental ancestries. AMR tracts have notably reduced LAI accuracy as compared to EUR and AFR tracts in all comparisons, with TPR means for AMR ranging from 88-94%, EUR from 96-99% and AFR 98-99%. When LAI miscalls occurred, they most frequently erroneously called European ancestry in true Amerindigenous sites. Using a reference panel well-matched to the target population, even with a lower sample size, LAI produced true-positive estimates that were not statistically different from a high sample size but mismatched reference, while being more computationally efficient. While directly responsive to admixed Latin American cohort compositions, these trends are broadly useful for informing best practices for LAI across other admixed populations. Our findings reinforce the need for inclusion of more underrepresented populations in sequencing efforts to improve reference panels.

Fine-mapping across diverse ancestries drives the discovery of putative causal variants underlying human complex traits and diseases.

Genome-wide association studies (GWAS) of human complex traits or diseases often implicate genetic loci that span hundreds or thousands of genetic variants, many of which have similar statistical significance. While statistical fine-mapping in individuals of European ancestry has made important discoveries, cross-population fine-mapping has the potential to improve power and resolution by capitalizing on the genomic diversity across ancestries. Here we present SuSiEx, an accurate and computationally efficient method for cross-population fine-mapping. SuSiEx integrates data from an arbitrary number of ancestries, explicitly models population-specific allele frequencies and linkage disequilibrium patterns, accounts for multiple causal variants in a genomic region and can be applied to GWAS summary statistics. We comprehensively assessed the performance of SuSiEx using simulations. We further showed that SuSiEx improves the fine-mapping of a range of quantitative traits available in both the UK Biobank and Taiwan Biobank, and improves the fine-mapping of schizophrenia-associated loci by integrating GWAS across East Asian and European ancestries.