Genome-wide Significance Threshold Research Articles

Potential use of pharmacogenetics in cardiology: genome-wide association studies of amiodarone-induced thyroid disorders

Abstract Background Amiodarone is a commonly prescribed antiarrhythmic drug used to manage supraventricular and ventricular arrhythmias. The use of amiodarone is associated with a broad range of adverse effects, including amiodarone-induced hypothyroidism (AIH) or amiodarone-induced thyrotoxicosis (AIT) (1). Both conditions are linked with increased mortality and have no known reliable risk predictors (2). Purpose We investigated the genetic underpinnings of amiodarone-induced thyroid disorders, and the clinical validity and utility of screening for genetic variants. Methods We conducted the first genome-wide association studies (GWAS) of AIH and AIT using data from three large biobanks. We compared the AUCs for SNPs identified through the above GWAS with polygenic risk scores for both hypo- and hyperthyroidism. Finally, we tested the clinical validity and utility of screening for risk variants. Results We found two risk loci for AIH. The lead variant at the first locus, rs1443438, was intronic to FOXE1 (OR 0.39, MAF = 35%, P = 1.59 × 10-42). The other lead variant, rs2209796, was located 93 kb upstream to FOXA2 (OR 0.56, MAF = 29%, P = 2.64 × 10-15: Figure 1). For AIT, we found one risk locus. The lead variant, rs2268803, was intronic to CAPZB (OR 1.81, MAF = 42%, P = 2.43 × 10-8: Figure 1). Next, we added GWAS SNPs or polygenic risk scores to risk prediction models consisting of age, sex and 4 principal components (PCs), and compared AUC estimates between risk models. Using GWAS SNPs, we found that the AIT variant increased the AUC with 6% (95%CI 1.1 – 10.3, AUC: 0.72) and 9% (95%CI 6.2 – 11.2, AUC: 0.75) for AIH, compared to the benchmark model. Both GWAS SNP models were superior to polygenic risk scores in terms of AUC (P for difference <0.05). The positive and negative predictive value (PPV and NPV) for the AIT-variant was 14.6% and 95.7%, respectively. For the AIH-variants combined, we found a PPV of 17% and a NPV of 95%. Conclusions Common genetic variants are associated with both amiodarone-induced hypo- and hyperthyroidism and are at this point, superior to polygenic risk scores in predicting amiodarone-induced thyroid disorders. These findings add to the potentials of pharmacogenetics in cardiology. Figure 1. Double Manhattan plot of amiodarone induced thyroid disorders. The Y-axis is the negative log10 of the P-value for each single nucleotide polymorphism. The X-axis is the chromosome, with positions on each chromosome ranging from lower to higher (left to right). The dotted line marks the threshold for genome-wide significance. Amiodoarone-induced hypothyroidism at the top, and amiodarone-induced thyrotoxicosis at the bottom.Figure 1

Genetic Variants Associated with Sensitive Skin: A Genome-Wide Association Study in Korean Women

Sensitive skin (SS) is associated with discomfort, including burning, stinging, and itching. These symptoms are often exacerbated by environmental factors and personal care products. In this genome-wide association study (GWAS), we aimed to identify the genetic variants associated with SS in 1690 Korean female participants; 389 and 1301 participants exhibited sensitive and non-sensitive skin, respectively. Using a combination of self-reported questionnaires, patch tests, and sting tests, we selected 115 sensitive and 181 non-sensitive participants for genetic analysis. A GWAS was performed to identify the loci associated with SS. Although none of the single-nucleotide polymorphisms (SNPs) met the genome-wide significance threshold, we identified several SNPs with suggestive associations. SNP rs11689992 in the 2q11.3 region increased SS risk by approximately 3.67 times. SNP rs7614738 in the USP4 locus elevated SS risk by 2.34 times and was found to be an expression quantitative trait locus for GPX1, a gene involved in oxidative stress and inflammation. Additionally, SNPs rs12306124 in the RASSF8 locus and rs10483893 in the NRXN3 region were identified. These results suggest that the genetic variations affecting oxidative stress, cell growth regulation, and neurobiology potentially influence skin sensitivity, providing a basis for further investigation and the development of personalized approaches to manage sensitive skin.

Analyses of GWAS signal using GRIN identify additional genes contributing to suicidal behavior

Genome-wide association studies (GWAS) identify genetic variants underlying complex traits but are limited by stringent genome-wide significance thresholds. We present GRIN (Gene set Refinement through Interacting Networks), which increases confidence in the expanded gene set by retaining genes strongly connected by biological networks when GWAS thresholds are relaxed. GRIN was validated on both simulated interrelated gene sets as well as multiple GWAS traits. From multiple GWAS summary statistics of suicide attempt, a complex phenotype, GRIN identified additional genes that replicated across independent cohorts and retained biologically interrelated genes despite a relaxed significance threshold. We present a conceptual model of how these retained genes interact through neurobiological pathways that may influence suicidal behavior, and identify existing drugs associated with these pathways that would not have been identified under traditional GWAS thresholds. We demonstrate GRIN’s utility in boosting GWAS results by increasing the number of true positive genes identified from GWAS results.

Germline Polymorphisms Associated with Overall Survival in Lung Adenocarcinoma: Genome-Wide Analysis.

Lung cancer remains a global health concern, with substantial variation in patient survival. Despite advances in detection and treatment, the genetic basis for the divergent outcomes is not understood. We investigated germline polymorphisms that modulate overall survival in 1464 surgically resected lung adenocarcinoma patients. A multivariable Cox proportional hazard model was used to assess the association of more than seven million polymorphisms with overall survival at the 60-month follow-up, considering age, sex, pathological stage, decade of surgery and principal components as covariates. Genes in which variants were identified were studied in silico to investigate functional roles. Six germline variants passed the genome-wide significance threshold. These single nucleotide polymorphisms were mapped to non-coding (intronic) regions on chromosomes 2, 3, and 5. The minor alleles of rs13000315, rs151212827, and rs190923216 (chr. 2, 3 and 5, respectively) were found to be independent negative prognostic factors. All six variants have been reported to regulate the expression of nine genes, seven of which are protein-coding, in different tissues. Survival-associated variants on chromosomes 2 and 3 were already reported to regulate the expression of NT5DC2 and NAGK, with high expression associated with the minor alleles. High NT5DC2 and NAGK expression in lung adenocarcinoma tissue was already shown to correlate with poor overall survival. This study highlights a potential regulatory role of the identified polymorphisms in influencing outcome and suggests a mechanistic link between these variants, gene expression regulation, and lung adenocarcinoma prognosis. Validation and functional studies are warranted to elucidate the mechanisms underlying these associations.

Testing the causal relationship of fat and sugar intake with depression and cortisol: a Mendelian Randomisation study

Unhealthy diets high in fat and sugar content may have an impact on psychological health and increase the risk of Major Depressive Disorder (MDD) and stress levels. On the other hand, MDD and stress might be related to food choices and intake. However, it is not clear whether diet, and specifically fat and sugar intake, is causally related to stress and MDD, and whether this relationship may be bi-directional. This study utilised Mendelian Randomisation (MR) to investigate the causal nature of the relationship of fat and sugar intake with MDD and cortisol (as a proxy of stress), and to shed light on the direction of this relationship. Summary-level data for all exposure and outcome variables were obtained from large-scale, non-overlapping GWASs in individuals of European ancestry. Bidirectional analyses were performed: one with macronutrients as exposures and one with MDD/cortisol as exposures. Random-effects inverse-variance weighted regression was used as the primary analytic method for genetic instruments with at least two single nucleotide polymorphisms (SNPs) available (and individual Wald ratio was used when only one SNP was available). Higher levels of genetically predicted relative sugar intake were causally associated with lower MDD risk, for both genome-wide significant p-value threshold of p < 1 × 10−8, (OR = 0.553, 95% CI: 0.395-0.775) and relaxed p-value threshold of p < 1 × 10−6 (OR = 0.786, 95% CI: 0.630–0.981). No reverse causality was detected in the opposite direction as MDD was not associated with sugar consumption. The associations observed for all the other pairs of variables were weak and imprecise. A number of limitations was present in the study, such as low-SNP based heritability for some exposures, inability to prove whether variants were correlated with unmeasured confounders and self-reporting of MDD data. Lifestyle and/or pharmacological interventions targeting sugar-related physiological mechanisms may help to reduce depressive symptoms. However, more research is necessary on short- and long-term effects of sugar on the risk of MDD. Additionally, future studies should investigate whether the amount and type of sugar consumed may underlie the impact of sugar on mood and stress levels.

Meta-analysis of genome-wide association studies of stable warfarin dose in patients of African ancestry

AbstractWarfarin dose requirements are highly variable because of clinical and genetic factors. Although genetic variants influencing warfarin dose have been identified in European and East Asian populations, more work is needed to identify African-specific genetic variants to help optimize warfarin dosing. We performed genome-wide association studies (GWASs) in 4 African cohorts from Uganda, South Africa, and Zimbabwe, totaling 989 warfarin-treated participants who reached stable dose and had international normalized ratios within therapeutic ranges. We also included 2 African American cohorts recruited by the International Warfarin Pharmacogenetics Consortium (n = 316) and the University of Alabama at Birmingham (n = 199). After the GWAS, we performed standard error-weighted meta-analyses and then conducted stepwise conditional analyses to account for known loci in chromosomes 10 and 16. The genome-wide significance threshold was set at P < 5 × 10−8. The meta-analysis, comprising 1504 participants, identified 242 significant SNPs across 3 genomic loci, with 99.6% of these located within known loci on chromosomes 10 (top SNP: rs58800757, P = 4.27 × 10−13) and 16 (top SNP: rs9925964, P = 9.97 × 10−16). Adjustment for the VKORC1 SNP -1639G>A revealed an additional locus on chromosome 2 (top SNPs rs116057875/rs115254730/rs115240773, P = 3.64 × 10−8), implicating the MALL gene, that could indirectly influence warfarin response through interactions with caveolin-1. In conclusion, we reaffirmed the importance of CYP2C9 and VKORC1 in influencing warfarin dose requirements, and identified a new locus (MALL), that still requires direct evidence of biological plausibility.

Haplotype-based association mapping of genomic regions associated with Zymoseptoria tritici resistance using 217 diverse wheat genotypes

BackgroundSeptoria tritici blotch (STB) is considered to be one of the most destructive foliar wheat diseases and is caused by Zymoseptoria tritici. The yield losses are severe and in Northwestern Europe can reach up to 50%. The efficacy of fungicides is diminishing due to changes in the genetic structure of the pathogen. Therefore, resistance breeding is the most effective strategy of disease management. Recently, genome-wide association studies (GWAS) have become more popular due to their robustness in dissecting complex traits, including STB resistance in wheat. This was made possible by the use of large mapping populations and new sequencing technologies. High-resolution mapping benefits from historical recombination and greater allele numbers in GWAS.ResultsIn our study, 217 wheat genotypes of diverse origin were phenotyped against five Z. tritici isolates (IPO323, IPO88004, IPO92004, IPO86036 and St1-03) and genotyped on the DArTseq platform. In polytunnel tests two disease parameters were evaluated: the percentage of leaf area covered by necrotic lesions (NEC) and the percentage of leaf area covered by lesions bearing pycnidia (PYC). The disease escape parameters heading date (Hd) and plant height (Ht) were also measured. Pearson’s correlation showed a positive effect between disease parameters, providing additional information. The Structure analysis indicated four subpopulations which included from 28 (subpopulation 2) to 79 genotypes (subpopulation 3). All of the subpopulations showed a relatively high degree of admixture, which ranged from 60% of genotypes with less than 80% of proportions of the genome attributed to assigned subpopulation for group 2 to 85% for group 4. Haplotype-based GWAS analysis allowed us to identify 27 haploblocks (HBs) significantly associated with analysed traits with a p-value above the genome-wide significance threshold (5%, which was –log10(p) > 3.64) and spread across the wheat genome. The explained phenotypic variation of identified significant HBs ranged from 0.2% to 21.5%. The results of the analysis showed that four haplotypes (HTs) associated with disease parameters cause a reduction in the level of leaf coverage by necrosis and pycnidia, namely: Chr3A_HB98_HT2, Chr5B_HB47_HT1, Chr7B_HB36_HT1 and Chr5D_HB10_HT3.ConclusionsGWAS analysis enabled us to identify four significant chromosomal regions associated with a reduction in STB disease parameters. The list of valuable HBs and wheat varieties possessing them provides promising material for further molecular analysis of resistance loci and development of breeding programmes.

The role of Immune cells in Alzheimer's disease: a bidirectional Mendelian randomization study.

Alzheimer's disease (AD) is a leading cause of dementia, characterized by the accumulation of amyloid-beta (Aβ) and hyperphosphorylated tau proteins, leading to neuroinflammation and neuronal damage. The role of the immune system in AD pathogenesis is increasingly recognized, prompting an exploration of the causal relationship between immune cells and AD by using Mendelian randomization (MR) approaches. Utilizing genome-wide association study (GWAS) data from European cohorts, we conducted an MR study to investigate the causal links between immune cell phenotypes and AD. We selected single nucleotide polymorphisms (SNPs) associated with immune cell traits at a genome-wide significance threshold and applied various MR methods, including MR Egger, Weighted median, and inverse variance weighted analysis, to assess the causality between 731 immune phenotypes and AD. Our MR analysis identified 15 immune cell types with significant causal relationships to AD pathogenesis. Notably, the absolute count of CD28-CD4-CD8- T cells and the expression of HLA DR on B cells were linked to a protective effect against AD, while 13 other immune phenotypes were identified as contributing to the risk factors for the disease. The causal effects of AD on immunophenotypic traits are predominantly negative, implying that AD may impair the functionality of immune cells. Validation through independent datasets, such as FinnGen and GCST90027158, confirmed the causal association between six specific immune cells and AD. This comprehensive MR study elucidates the intricate network of causal relationships between diverse immunophenotypic traits and AD, providing novel insights into the immunopathogenesis of AD. The findings suggest potential immunological targets that could be leveraged for early diagnosis, disease monitoring, and therapeutic intervention.

Family-based genome-wide association analysis of novelty seeking in a Korean schizophrenic population: A pilot study.

Schizophrenia (SPR) is the most devastating mental illness that causes severe deterioration in social and occupational functioning, but, the etiology remains unknown. The objective of this study is to explore the genetic underpinnings of novelty seeking behavior in schizophrenic family within the Korean population. By conducting a family-based genome-wide association study, we aim to identify potential genetic markers and variations associated with novelty seeking traits in the context of SPR. We have recruited 27 probands (with SPR) with their parents and siblings whenever possible. DNA was extracted from blood sampling of 58 individuals in 27 families and analyzed in an Illumina core exome single nucleotide polymorphism (SNP) array. A family-based association test (qFAM) was used to derive SNP association values across all chromosomes. Although none of the final 800,000 SNPs reached the genome-wide significant threshold of 8.45 × 10-7, the most significant 4 SNPs were within the 10-5 to 10-7. This study identifies genetic associations between novelty seeking behavior and SPR within families. RAPGEF5 emerges as a significant gene, along with other neuropsychiatric-related genes. Noteworthy genes like DRD4 and COMT did not show associations, possibly due to the focus on schizophrenic family. While shedding light on this complex relationship, larger studies are needed for robust conclusions and deeper mechanistic insights.

Predicting the potential deterioration of Barrett's esophagus based on gut microbiota: a Mendelian randomization analysis.

Esophageal adenocarcinoma (EAC) is one of the most malignant tumors in the digestive system. To make thing worse, the scarcity of treatment options is disheartening. However, if detected early, there is a possibility of reversing the condition. Unfortunately, there is still a lack of relevant early screening methods. Considering that Barrett's esophagus (BE), a precursor lesion of EAC, has been confirmed as the only known precursor of EAC. Analyzing which BE cases will progress to EAC and understanding the processes and mechanisms involved is of great significance for early screening of such patients. Considering the significant alterations in the gut microbiota of patients with BE and its potential role in the progression to EAC, this study aims to analyze the relationship between BE, EAC, and GM to identify potential diagnostic biomarkers and therapeutic targets. This study utilized comprehensive statistical data on gut microbiota from a large-scale genome-wide association meta-analysis conducted by the MiBioGen consortium (n = 18,340). Subsequently, we selected a set of single nucleotide polymorphisms (SNPs) that fell below the genome-wide significance threshold (1 × 10-5) as instrumental variables. To investigate the causal relationship between gut microbiota and BE and EAC, we employed various MR analysis methods, including Inverse Variance Weighting (IVW), MR-Egger regression, weighted median (WM), and weighted mean. Additionally, we assessed the level of pleiotropy, heterogeneity, and stability of genetic variations through MR-Egger intercept test, MR-PRESSO, Cochran's Q test, and "leave-one-out" sensitivity analysis. Furthermore, we conducted reverse MR analysis to identify the causal relationships between gut microbiota and BE and EAC. The results from the Inverse Variance-Weighted (IVW) analysis indicate that Alistipes (P = 4.86 × 10-2), Lactobacillus (P = 2.11 × 10-2), Prevotella 7 (P = 4.28 × 10-2), and RuminococcaceaeUCG004 (P = 4.34 × 10-2) are risk factors for Barrett's esophagus (BE), while Flavonifractor (P = 8.81 × 10-3) and RuminococcaceaeUCG004 (P = 4.99 × 10-2) are risk factors for esophageal adenocarcinoma (EAC). On the other hand, certain gut microbiota genera appear to have a protective effect against both BE and EAC. These include Eubacterium (nodatum group) (P = 4.51 × 10-2), Holdemania (P = 1.22 × 10-2), and Lactococcus (P = 3.39 × 10-2) in the BE cohort, as well as Eubacterium (hallii group) (P = 4.07 × 10-2) and Actinomyces (P = 3.62 × 10-3) in the EAC cohort. According to the results of reverse MR analysis, no significant causal effects of BE and EAC on gut microbiota were observed. Furthermore, no significant heterogeneity or pleiotropy was detected in the instrumental variables. We have established a causal relationship between the gut microbiota and BE and EAC. This study holds profound significance for screening BE patients who may be at risk of deterioration, as it can provide them with timely medical interventions to reverse the condition.

AXIN1 mutations in nonsyndromic craniosynostosis.

Occurring once in every 2000 live births, craniosynostosis (CS) is the most frequent cranial birth defect. Although the genetic etiologies of syndromic CS cases are well defined, the genetic cause of most nonsyndromic cases remains unknown. The authors analyzed exome or RNA sequencing data from 876 children with nonsyndromic CS, including 291 case-parent trios and 585 additional probands. The authors also utilized the GeneMatcher platform and the Gabriella Miller Kids First genome sequencing project to identify additional CS patients with AXIN1 mutations. The authors describe 11 patients with nonsyndromic CS harboring rare, damaging mutations in AXIN1, an inhibitor of Wnt signaling. AXIN1 regulates signaling upstream of key mediators of osteoblast differentiation. Three of the 6 mutations identified in trios occurred de novo in the proband, while 3 were transmitted from unaffected parents. Patients with nonsyndromic CS were highly enriched for mutations in AXIN1 compared to both expectation (p = 0.0008) and exome sequencing data from > 76,000 healthy controls (p = 2.3 × 10-6), surpassing the thresholds for genome-wide significance. These findings describe the first phenotype associated with mutations in AXIN1, with mutations identified in approximately 1% of nonsyndromic CS cases. The results strengthen the existing link between Wnt signaling and maintenance of cranial suture patency and have implications for genetic testing in families with CS.

Discussion on the relationship between gut microbiota and glioma through Mendelian randomization test based on the brain gut axis.

In the realm of Gut-Brain axis research, existing evidence points to a complex bidirectional regulatory mechanism between gut microbiota and the brain. However, the question of whether a causal relationship exists between gut microbiota and specific types of brain tumors, such as gliomas, remains unresolved. To address this gap, we employed publicly available Genome-Wide Association Study (GWAS) and MIOBEN databases, conducting an in-depth analysis using Two-Sample Mendelian Randomization (MR). We carried out two sets of MR analyses. The preliminary analysis included fewer instrumental variables due to a high genome-wide statistical significance threshold (5×10-8). To enable a more comprehensive and detailed analysis, we adjusted the significance threshold to 1×10-5. We performed linkage disequilibrium analysis (R2 <0.001, clumping distance = 10,000kb) and detailed screening of palindromic SNPs, followed by MR analysis and validation through sensitivity analysis. Our findings reveal a causal relationship between gut microbiota and gliomas. Further confirmation via Inverse Variance Weighting (IVW) identified eight specific microbial communities related to gliomas. Notably, the Peptostreptococcaceae and Olsenella communities appear to have a protective effect, reducing glioma risk. This study not only confirms the causal link between gut microbiota and gliomas but also suggests a new avenue for future glioma treatment.

Integrated proteomic and genomic analysis to identify predictive biomarkers for valproate response in bipolar disorder: a 6-month follow-up study

BackgroundSeveral genetic studies have been undertaken to elucidate the intricate interplay between genetics and drug responses in bipolar disorder (BD). However, there has been notably limited research on biomarkers specifically linked to valproate, with only a few studies investigating integrated proteomic and genomic factors in response to valproate treatment. Therefore, this study aimed to identify biological markers for the therapeutic response to valproate treatment in BD. Patients with BD in remission were assessed only at baseline, whereas those experiencing acute mood episodes were evaluated at three points (baseline, 8 ± 2 weeks, and 6 ± 1 months). The response to valproate treatment was measured using the Alda scale, with individuals scoring an Alda A score ≥ 5 categorized into the acute-valproate responder (acute-VPAR) group. We analyzed 158 peptides (92 proteins) from peripheral blood samples using multiple reaction monitoring mass spectrometry, and proteomic result-guided candidate gene association analyses, with 1,627 single nucleotide variants (SNVs), were performed using the Korean chip.ResultsThe markers of 37 peptides (27 protein) showed temporal upregulation, indicating possible association with response to valproate treatment. A total of 58 SNVs in 22 genes and 37 SNVs in 16 genes showed nominally significant associations with the Alda A continuous score and the acute-VPAR group, respectively. No SNVs reached the genome-wide significance threshold; however, three SNVs (rs115788299, rs11563197, and rs117669164) in the secreted phosphoprotein 2 gene reached a gene-based false discovery rate-corrected significance threshold with response to valproate treatment. Significant markers were associated with the pathophysiological processes of bipolar disorders, including the immune response, acute phase reaction, and coagulation cascade. These results suggest that valproate effectively suppresses mechanisms associated with disease progression.ConclusionsThe markers identified in this study could be valuable indicators of the underlying mechanisms associated with response to valproate treatment.

No bidirectional relationship between sleep phenotypes and risk of proliferative diabetic retinopathy: a two-sample Mendelian randomization study

This study aimed to investigate the probable existence of a causal relationship between sleep phenotypes and proliferative diabetic retinopathy (PDR). Single nucleotide polymorphisms associated with sleep phenotypes were selected as instrumental variables at the genome-wide significance threshold (P < 5 × 10−8). Inverse‐variance weighted was applied as the primary Mendelian randomization (MR) analysis method, and MR Egger regression, weighted median, simple mode, and weighted mode methods were used as complementary analysis methods to estimate the causal association between sleep phenotypes and PDR. Results indicated that genetically predicted sleep phenotypes had no causal effects on PDR risk after Bonferroni correction (P = 0.05/10) [Chronotype: P = 0.143; Daytime napping: P = 0.691; Daytime sleepiness: P = 0.473; Insomnia: P = 0.181; Long sleep duration: P = 0.671; Morning person:P = 0.113; Short sleep duration: P = 0.517; Obstructive sleep apnea: P = 0.091; Sleep duration: P = 0.216; and snoring: P = 0.014]. Meanwhile, there are no reverse causality for genetically predicted PDR on sleep phenotypes [Chronotype: P = 0.100; Daytime napping: P = 0.146; Daytime sleepiness: P = 0.469; Insomnia: P = 0.571; Long sleep duration: P = 0.779; Morning person: P = 0.040; Short sleep duration: P = 0.875; Obstructive sleep apnea: P = 0.628; Sleep duration: P = 0.896; and snoring: P = 0.047]. This study’s findings did not support the causal effect of between sleep phenotypes and PDR. Whereas, longitudinal studies can further verify results validation.

Germline genetic regulation of the colorectal tumor immune microenvironment

ObjectiveTo evaluate the contribution of germline genetics to regulating the briskness and diversity of T cell responses in CRC, we conducted a genome-wide association study to examine the associations between germline genetic variation and quantitative measures of T cell landscapes in 2,876 colorectal tumors from participants in the Molecular Epidemiology of Colorectal Cancer Study (MECC).MethodsGermline DNA samples were genotyped and imputed using genome-wide arrays. Tumor DNA samples were extracted from paraffin blocks, and T cell receptor clonality and abundance were quantified by immunoSEQ (Adaptive Biotechnologies, Seattle, WA). Tumor infiltrating lymphocytes per high powered field (TILs/hpf) were scored by a gastrointestinal pathologist. Regression models were used to evaluate the associations between each variant and the three T-cell features, adjusting for sex, age, genotyping platform, and global ancestry. Three independent datasets were used for replication.ResultsWe identified a SNP (rs4918567) near RBM20 associated with clonality at a genome-wide significant threshold of 5 × 10− 8, with a consistent direction of association in both discovery and replication datasets. Expression quantitative trait (eQTL) analyses and in silico functional annotation for these loci provided insights into potential functional roles, including a statistically significant eQTL between the T allele at rs4918567 and higher expression of ADRA2A (P = 0.012) in healthy colon mucosa.ConclusionsOur study suggests that germline genetic variation is associated with the quantity and diversity of adaptive immune responses in CRC. Further studies are warranted to replicate these findings in additional samples and to investigate functional genomic mechanisms.

Genetic associations of cardiovascular risk genes in European patients with coronary artery spasm.

Coronary artery spasm (CAS) is a frequent finding in patients presenting with angina pectoris. Although the pathogenesis of CAS is incompletely understood, previous studies suggested a genetic contribution. Our study aimed to elucidate genetic variants in a cohort of European patients with angina and unobstructed coronary arteries who underwent acetylcholine (ACh) provocation testing. A candidate association analysis of 208 genes previously associated with cardiovascular conditions was performed using genotyped and imputed variants in patients grouped in epicardial (focal, diffuse) CAS (n = 119) and microvascular CAS (n = 87). Patients with a negative ACh test result (n = 45) served as controls. We found no association below the genome-wide significance threshold of p < 5 × 10-8, thus not confirming variants in ALDH2, NOS3, and ROCK2 previously reported in CAS patients of Asian ancestry. However, the analysis identified suggestive associations (p < 10-05) for the groups of focal epicardial CAS (CDH13) and diffuse epicardial CAS (HDAC9, EDN1). Downstream analysis of the potential EDN1 risk locus showed that CAS patients have significantly increased plasma endothelin-1 levels (ET-1) compared to controls. An EDN1 haplotype comprising rs9349379 and rs2070698 was significantly associated to ET-1 levels (p = 0.01). In summary, we suggest EDN1 as potential genetic risk loci for patients with diffuse epicardial CAS, and European ancestry. Plasma ET-1 levels may serve as a potential cardiac marker.

Abstract 6148: Multiple new Ewing sarcoma susceptibility loci expand knowledge of germline genetic etiology and nominate mechanisms of risk

Abstract Ewing sarcoma (EwS) is a rare and aggressive pediatric cancer with peak incidence in the second decade of life. EwS occurs primarily in children of European ancestry suggesting a genetic component to susceptibility. Prior investigations identified six susceptibility loci associated with EwS, with evidence for additional signals not reaching the commonly accepted threshold for genome-wide significance (i.e., p&amp;lt;5×10−8). At least two of these loci demonstrate evidence of tagging variation in length of nearby GGAA microsatellites, which alter binding of the pathognomonic EWSR1::FLI1 fusion resulting in downstream dysregulation of target genes promoting sarcomagenesis. To identify additional susceptibility loci, we performed the largest genome-wide association study (GWAS) to date consisting of 1,640 EwS cases and 8,457 cancer-free individuals of European ancestry from 8 studies and matched by principal components. Genotype imputation was carried out by study/array using TOPMed data as the reference and each set was analyzed using PLINK 1.9 adjusting for significant principal components. Variants were included in each study if minor allele count was greater than five in each set of cases. Individual study results were combined using fixed effects meta-analysis in Metasoft with variants demonstrating evidence for heterogeneity excluded.For previously reported EwS loci (i.e., 1p36.22, 6p25.1, 10q21.3, 15q15.1, 20p11.22 and 20p11.23), odds ratios (OR) remained high for GWAS (OR=1.5-2.4) and the -log10 p-values grew by several orders of magnitude, providing strong evidence for replication in the additional 907 EwS cases and 7,111 cancer-free controls. Our analysis identified five novel loci reaching genome-wide significance (P-valuemeta&amp;lt; 5×10−8) at 5q32, 7q32.3, 8q24.2, 13q32.3, and 17q23.2. Risk allele frequency of newly identified loci ranged from 0.001 to 0.75with estimated ORs ranging from 1.31-4.30. eQTL analyses nominated nearby biologically plausible candidate genes for future functional investigation including LARS1, a gene implicated in osteosarcoma and skeletal muscle dysgenesis, at the 5q32 locus and COX5BP6, a gene implicated in age at menarche and testosterone levels, at 13q32.3.Our results add to evidence supporting a strong inherited genetic component to EwS risk and particularly a genetic architecture harboring a substantial number of common variants with moderate effect. Ongoing work is focusing on enrichment analyses of GGAA microsatellite repeat sequences in identified risk loci to search for evidence for germline-somatic interactions with EWSR1::FLI1. Citation Format: Aubrey K. Hubbard, Weiyin Zhou, Carrie Boyce, Javed Khan, Melissa M. Hudson, Kirsten K. Ness, Zhaoming Wang, Katherine A. Janeway, Philip J. Lupo, Lindsay M. Morton, Stephen J. Chanock, Thomas G. Grünewald, Olivier Delattre, Mitchell J. Machiela, Ewing Sarcoma Germline Genetics Group. Multiple new Ewing sarcoma susceptibility loci expand knowledge of germline genetic etiology and nominate mechanisms of risk [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6148.

Abstract 6139: Genetic modifiers of KRAS-mutant colorectal cancer

Abstract Somatic driver mutations in KRAS are found in ~40% of colorectal cancers (CRCs) and are associated with worse outcomes. In the US, individuals of African ancestry with CRC are more likely to have tumors with KRAS mutations than individuals of European ancestry, even after considering differences in socioeconomic status and other risk factors. Germline variants can influence somatic mutation events and may provide a selective advantage such that a mutated cell is more likely to progress to a cancer. Germline variants have been found to associate with somatic mutations in a variety of tumors. Based on ancestry differences in KRAS tumor mutation frequency, we hypothesized that germline variants altering molecular pathways that support KRAS tumorigenesis will associate with KRAS-mutant status. To test this, we performed a two-step association study using KRAS mutation status as our phenotype in individuals with microsatellite stable CRC. First, we conducted a discovery analysis using genome-wide germline genotypes and somatic mutation data from 6,386 non-Hispanic White CRC patients from the Cancer Genome Atlas and the GECCO consortium, considering sex and tumor location as covariates. To select variants for additional study, we used in-silico tools, such as expression quantitative trait loci (eQTL), to predict how associated variants may alter gene expression and chromatin. After reviewing relevant genomic features, excluding SNVs with minor allele frequency &amp;lt;10% and pruning SNVs in linkage disequilibrium (r2&amp;gt;0.75), we identified candidate loci for a multi-ancestry independent validation analysis. In the discovery analysis, no variants met genome-wide significance thresholds (p-value &amp;lt;5x10-8), though 3 SNVs associated with KRAS mutation status with p-values &amp;lt;1x10-6 and 50 with p-values &amp;lt;1x10-5. Of these 50 SNVs, 21 met criteria for validation. We chose 80 additional SNVs (p-value &amp;lt;1x10-4) with predicted functional effect, for a total of 101 SNVs for analyses. In our preliminary validation analysis of 1,487 individuals grouped by self-reported race, no variants had a significant association in all populations. The rs726800 variant showed nominal association with KRAS mutation status (p-value=0.028) in self-reported non-Hispanic White individuals. This variant is within potential cis-regulatory distance of HS3ST3A1 and COX10-DT, both of which have been reported as cancer biomarkers. Nominal associations were identified in self-reported Black (n=7 SNVs) and Hispanic or Latino (n=3 SNVs) individuals, though both groups had limited sample sizes. Additional validation samples are being analyzed, as well as analysis with adjustment for genetic ancestry. Future functional studies of top candidate variants will add mechanistic insight. In summary, we identified germline SNVs that associate with KRAS somatic mutations in CRC and may inform the cellular context that supports development of colorectal tumors with KRAS mutations. Citation Format: Nijole P. Tjader, Johnny Ramroop, Tanish Gandhi, Peter T. Campbell, Andrew T. Chan, Steven Gallinger, Graham G. Giles, Marc J. Gunter, Tabitha A. Harrison, Michael Hoffmeister, Polly A. Newcomb, Shuji Ogino, Amanda I. Phipps, Conghui Qu, Robert E. Schoen, Andrew Pellatt, Michael O. Woods, Bethany Van Guelpen, Patrick Stevens, Heather Hampel, Ulrike Peters, Joseph P. McElroy, Amanda E. Toland. Genetic modifiers of KRAS-mutant colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6139.

Genome-wide association study of osteoporosis identifies genetic risk and interactions with Dietary Approaches to Stop Hypertension diet and sugar-sweetened beverages in a Hispanic cohort of older adults.

Osteoporosis (OP) and low bone mass can be debilitating and costly conditions if not acted on quickly. This disease is also difficult to diagnose as the symptoms develop unnoticed until fracture occurs. Therefore, gaining understanding of the genetic risk associated with these conditions could be beneficial for health-care professionals in early detection and prevention. The Boston Puerto Rican Osteoporosis (BPROS) study, an ancillary study to the Boston Puerto Rican Health Study (BPRHS), collected information regarding bone and bone health. All bone measurements were taken during regular BPROS visits using dual-energy X-ray absorptiometry. The OP was defined as T-score ≤ -2.5 (≥2.5 SDs below peak bone mass). Dietary variables were collected at the second wave of the BPRHS via a food frequency questionnaire. We conducted genome-wide associations with bone outcomes, including BMD and OP for 978 participants. We also examined the interactions with dietary quality on the relationships between genotype and bone outcomes. We further tested if candidate genetic variants described in previous GWAS on OP and BMD contribute to OP risk in this population. Four variants were associated with OP: rs114829316 (IQ motif containing J gene), rs76603051, rs12214684 (melanin-concentrating hormone receptor 2 gene), and rs77303493 (Ras and Rab interactor 2 gene), and 2 variants were associated with BMD of lumbar spine (rs11855618, cingulin-like 1 gene) and hip (rs73480593, NTRK2), reaching the genome-wide significance threshold of P≤ 5E-08. In a gene-diet interaction analysis, we found that 1 SNP showed a significant interaction with the overall Dietary Approaches to Stop Hypertension (DASH) score, and 7 SNPs with sugar-sweetened beverages (SSBs), a major contributor to the DASH score. This study identifies new genetic markers related to OP and BMD in older Hispanic adults. Additionally, we uncovered unique genetic markers that interact with dietary quality, specifically SSBs, in relation to bone health. These findings may be useful to guide early detection and preventative care.

Phenome-wide Mendelian randomization analysis reveals multiple health comorbidities of coeliac disease

Coeliac disease (CeD) has been associated with a broad range of diseases in observational data; however, whether these associations are causal remains undetermined. We conducted a phenome-wide Mendelian randomization analysis (MR-PheWAS) to investigate the comorbidities of CeD. Single nucleotide polymorphisms (SNPs) associated with CeD at the genome-wide significance threshold and without linkage disequilibrium (R2 <0.001) were selected from a genome-wide association study including 12,041 CeD cases as the instrumental variables. We first constructed a polygenic risk score for CeD and estimated its associations with 1060 unique clinical outcomes in the UK Biobank study (N=385,917). We then used two-sample MR analysis to replicate the identified associations using data from the FinnGen study (N=377,277). We performed a secondary analysis using a genetic instrument without extended MHC gene SNPs. Genetic liability to CeD was associated with 68 clinical outcomes in the UK Biobank, and 38 of the associations were replicated in the FinnGen study. Genetic liability to CeD was associated with a higher risk of several autoimmune diseases (type 1 diabetes and its complications, Graves' disease, Sjögren syndrome, chronic hepatitis, systemic and cutaneous lupus erythematosus, and sarcoidosis), non-Hodgkin's lymphoma, and osteoporosis and a lower risk of prostate diseases. The associations for type 1 diabetes and non-Hodgkin's lymphoma attenuated when excluding SNPs in the MHC region, indicating shared genetic aetiology. This study uncovers multiple clinical outcomes associated with genetic liability to CeD, which suggests the necessity of comorbidity monitoring among this population. This project was funded by Karolinska Institutet and the Swedish Research Council.