scholarly journals Integrated Genetics and Micronutrient Data to Inform the Causal Association Between Serum Calcium Levels and Ischemic Stroke

2020 ◽  
Vol 8 ◽  
Author(s):  
Qiang Meng ◽  
Lu Huang ◽  
Kai Tao ◽  
Yong Liu ◽  
Jiangpeng Jing ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Serum Calcium ◽  
Calcium Intake ◽  
Genetic Variants ◽  
Large Scale ◽  
Genome Wide Association Study ◽  
Mr Studies ◽  
Causal Association ◽  
Gwas Dataset ◽  
The Impact

There has been an increased interest for observational studies or randomized controlled trials exploring the impact of calcium intake on cardiovascular diseases (CVD) including coronary artery disease (CAD) and ischemic stroke (IS). However, a direct relationship between total calcium intake and CVD has not been well established and remains controversial. Mendelian randomization (MR) studies have been performed to evaluate the causal association between serum calcium levels and CAD risk and found that increased serum calcium levels could increase the risk of CAD. However, MR analysis found no significant association between genetically higher serum calcium levels and IS as well as its subtypes. Hence, three MR studies reported inconsistent effects of serum calcium levels on CAD and IS. Here, we performed an updated MR study to investigate the association of serum calcium levels with the risk of IS using large-scale genome-wide association study (GWAS) datasets. We selected 14 independent genetic variants as the potential instrumental variables from a large-scale serum calcium GWAS dataset and extracted summary statistics corresponding to the 14 serum calcium genetic variants from the MEGASTROKE Consortium IS GWAS dataset. Interestingly, we found a significant association between serum calcium levels and IS risk using the robust inverse-variance weighted (IVW) and penalized robust IVW methods, with β = 0.243 and P = 0.002. Importantly, the MR results from the robust MR-Egger and penalized robust MR-Egger methods further supported the causal association between serum calcium levels and IS risk, with β = 0.256 and P = 0.005. Meanwhile, the estimates from other MR methods are also consistent with the above findings.

scholarly journals Genetically increased serum calcium levels reduce Alzheimer’s disease risk

2018 ◽  
Author(s):  
Qinghua Jiang ◽  
Yang Hu ◽  
Shuilin Jin ◽  
Guiyou Liu
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Genetic Association ◽  
Serum Calcium ◽  
Genetic Variants ◽  
Large Scale ◽  
Mendelian Randomization ◽  
European Descent ◽  
Gwas Dataset ◽  
Weighted Median

AbstractIMPORTANCE Alzheimer’s disease (AD) is the leading cause of disability in the elderly. It has been a long time about the calcium hypothesis of AD on the basis of emerging evidence since 1994. However, most studies focused on the association between calcium homeostasis and AD, and concerned the intracellular calcium concentration. Only few studies reported reduced serum calcium levels in AD. Until now, it remains unclear whether serum calcium levels are genetically associated with AD risk.OBJECTIVE To evaluate the genetic association between increased serum calcium levels and AD riskDESIGN, SETTING, AND PARTICIPANTS We performed a Mendelian randomization study to investigate the association of increased serum calcium with AD risk using the genetic variants from the large-scale serum calcium genome-wide association study (GWAS) dataset (N=61,079 individuals of European descent) and the large-scale AD GWAS dataset (N=54,162 individuals including 17,008 AD cases and 37,154 controls of European descent). Inverse-variance weighted meta-analysis (IVW) was used to provide a combined estimate of the genetic association. Meanwhile, we selected the weighted median regression and MR-Egger regression as the complementary analysis methods to examine the robustness of the IVW estimate.EXPOSURES Genetic predisposition to increased serum calcium levelsMAIN OUTCOMES AND MEASURES The risk of AD.RESULTS We selected 6 independent genetic variants influencing serum calcium levels as the instrumental variables. IVW analysis showed that a genetically increased serum calcium level (per 1 standard deviation (SD) increase 0.5-mg/dL) was significantly associated with a reduced AD risk (OR=0.56, 95% CI: 0.34-0.94, P=5.00E-03). Meanwhile, both the weighted median estimate (OR=0.60, 95% CI: 0.34-1.06, P=0.08) and MR-Egger estimate (OR=0.66, 95% CI: 0.26-1.67, P=0.381) were consistent with the IVW estimate in terms of direction and magnitude.CONCLUSIONS AND RELEVANCE We provided evidence that genetically increased serum calcium levels could reduce the risk of AD. Meanwhile, randomized controlled study should be further conducted to assess the effect of serum calcium levels on AD risk, and further clarify whether diet calcium intake or calcium supplement, or both could reduce the risk of AD.Key PointsQuestion Is there a genetic relationship between elevated serum calcium levels and the risk of Alzheimer’s disease?Findings This Mendelian randomization study showed that the genetically increased serum calcium levels were associated with the reduced risk of Alzheimer’s disease.Meaning These findings provide evidence that genetically increased serum calcium levels could reduce the risk of Alzheimer’s disease.

scholarly journals An Updated Mendelian Randomization Analysis of the Association Between Serum Calcium Levels and the Risk of Alzheimer’s Disease

2021 ◽  
Vol 12 ◽  
Author(s):  
Yuchen Shi ◽  
Ruifei Liu ◽  
Ying Guo ◽  
Qiwei Li ◽  
Haichun Zhou ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Serum Calcium ◽  
Large Scale ◽  
Mendelian Randomization ◽  
Causal Association ◽  
Cognitively Normal ◽  
Gwas Dataset ◽  
Weighted Median ◽  
Normal Controls

It has been a long time that the relationship between serum calcium levels and Alzheimer’s disease (AD) remains unclear. Until recently, observational studies have evaluated the association between serum calcium levels and the risk of AD, however, reported inconsistent findings. Meanwhile, a Mendelian randomization (MR) study had been conducted to test the causal association between serum calcium levels and AD risk, however, only selected 6 serum calcium SNPs as the instrumental variables. Hence, these findings should be further verified using additional more genetic variants and large-scale genome-wide association study (GWAS) dataset to increase the statistical power. Here, we conduct an updated MR analysis of the causal association between serum calcium levels and the risk of AD using a two-stage design. In discovery stage, we conducted a MR analysis using 14 SNPs from serum calcium GWAS dataset (N = 61,079), and AD GWAS dataset (N = 63,926, 21,982 cases, 41,944 cognitively normal controls). All four MR methods including IVW, weighted median, MR-Egger, and MR-PRESSO showed a reduced trend of AD risk with the increased serum calcium levels. In the replication stage, we performed a MR analysis using 166 SNPs from serum calcium GWAS dataset (N = 305,349), and AD GWAS dataset (N = 63,926, 21,982 cases, 41,944 cognitively normal controls). Only the weighted median indicated that genetically increased serum calcium level was associated with the reduced risk of AD. Hence, additional studies are required to investigate these findings.

scholarly journals Calcium Intake and Serum Calcium Level in Relation to the Risk of Ischemic Stroke: Findings from the REGARDS Study

2019 ◽  
Vol 21 (3) ◽  
pp. 312-323 ◽  
Author(s):  
Daniel T. Dibaba ◽  
Pengcheng Xun ◽  
Alyce D. Fly ◽  
Aurelian Bidulescu ◽  
Cari L. Tsinovoi ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Serum Calcium ◽  
Calcium Intake ◽  
Calcium Level ◽  
Serum Calcium Level ◽  
Regards Study

scholarly journals Mendelian randomization to evaluate the effect of plasma vitamin C levels on the risk of Alzheimer’s disease

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Haijie Liu ◽  
Yan Zhang ◽  
Yang Hu ◽  
Haihua Zhang ◽  
Tao Wang ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Vitamin C ◽  
Cognitive Performance ◽  
Large Scale ◽  
Mendelian Randomization ◽  
Plasma Vitamin ◽  
Causal Association ◽  
Uk Biobank ◽  
Gwas Dataset

Abstract Objective Until now, observational studies have explored the impact of vitamin C intake on Alzheimer’s disease (AD) risk, however, reported ambiguous findings. To develop effective therapies or prevention, the causal link between vitamin C levels and AD should be established. Methods Here, we selected 11 plasma vitamin C genetic variants from a large-scale plasma vitamin C GWAS dataset (N = 52,018) as the potential instrumental variables. We extracted their corresponding summary statistics from large-scale IGAP clinically diagnosed AD GWAS dataset (N = 63,926) and UK Biobank AD proxy phenotype GWAS dataset (N = 314,278), as well as two UK Biobank subgroups including the maternal AD group (27,696 cases of maternal AD and 260,980 controls) and paternal AD group (14,338 cases of paternal AD and 245,941 controls). We then performed a Mendelian randomization (MR) study to evaluate the causal association between plasma vitamin C levels and the risk of AD and AD proxy phenotype. Meanwhile, we further verified these findings using a large-scale cognitive performance GWAS dataset (N = 257,841). Results In IGAP, we found no significant causal association between plasma vitamin C levels and the risk of AD. In UK Biobank, we found that per 1 SD increase in plasma vitamin C levels (about 20.2 μmol/l) was significantly associated with the reduced risk of AD proxy phenotype (OR = 0.93, 95% CI 0.88–0.98, P = 7.00E−03). A subgroup MR analysis in UK Biobank indicated that per 1 SD increase in plasma vitamin C levels could significantly reduce the risk of AD proxy phenotype in the maternal AD group (OR = 0.89, 95% CI 0.84–0.94, P = 7.29E−05), but not in the paternal AD group (OR = 1.02, 95% CI 0.92–1.12, P = 7.59E−01). The leave-one-out permutation further showed that the SLC23A1 rs33972313 variant largely changed the precision of the overall MR estimates in all these four GWAS datasets. Meanwhile, we did not observe any significant causal effect of plasma vitamin C levels on the cognitive performance. Conclusion We demonstrated that there may be no causal association between plasma vitamin C levels and the risk of AD in people of European descent. The insistent findings in clinically diagnosed AD and AD proxy phenotype may be caused by the phenotypic heterogeneity.

scholarly journals Within-patient genetic diversity of SARS-CoV-2

2020 ◽  
Author(s):  
Jack Kuipers ◽  
Aashil A Batavia ◽  
Kim Philipp Jablonski ◽  
Fritz Bayer ◽  
Nico Borgsmüller ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variants ◽  
Large Scale ◽  
Virus Genome ◽  
Spike Gene ◽  
Medical Interventions ◽  
Consensus Sequences ◽  
The Public ◽  
Number Of Patients ◽  
The Impact

AbstractSARS-CoV-2, the virus responsible for the current COVID-19 pandemic, is evolving into different genetic variants by accumulating mutations as it spreads globally. In addition to this diversity of consensus genomes across patients, RNA viruses can also display genetic diversity within individual hosts, and co-existing viral variants may affect disease progression and the success of medical interventions. To systematically examine the intra-patient genetic diversity of SARS-CoV-2, we processed a large cohort of 3939 publicly-available deeply sequenced genomes with specialised bioinformatics software, along with 749 recently sequenced samples from Switzerland. We found that the distribution of diversity across patients and across genomic loci is very unbalanced with a minority of hosts and positions accounting for much of the diversity. For example, the D614G variant in the Spike gene, which is present in the consensus sequences of 67.4% of patients, is also highly diverse within hosts, with 29.7% of the public cohort being affected by this coexistence and exhibiting different variants. We also investigated the impact of several technical and epidemiological parameters on genetic heterogeneity and found that age, which is known to be correlated with poor disease outcomes, is a significant predictor of viral genetic diversity.Author SummarySince it arose in late 2019, the new coronavirus (SARS-CoV-2) behind the COVID-19 pandemic has mutated and evolved during its global spread. Individual patients may host different versions, or variants, of the virus, hallmarked by different mutations. We examine the diversity of genetic variants coexisting within patients across a cohort of 3939 publicly accessible samples and 749 recently sequenced samples from Switzerland. We find that a small number of patients carry most of the diversity, and that patients with more diversity tend to be older. We also find that most of the diversity is concentrated in certain regions and positions of the virus genome. In particular, we find that a variant reported to increase infectivity is among the most diverse positions. Our study provides a large-scale survey of within-patient diversity of the SARS-CoV-2 genome.

scholarly journals ANGI — Anorexia Nervosa Genetics Initiative

2020 ◽  
Vol 23 (2) ◽  
pp. 135-136
Author(s):  
Cynthia Bulik ◽  
Martin Kennedy ◽  
Tracey Wade
Keyword(s):  
Anorexia Nervosa ◽  
Genetic Variants ◽  
Large Scale ◽  
Genome Wide Association Study ◽  
Genetic Correlations ◽  
Genome Wide Association ◽  
Life Threatening Illness ◽  
Genome Wide ◽  
Life Threatening

AbstractIdentification of genetic variants associated with eating disorders is underway. The Anorexia Nervosa Genetics Initiative, an initiative of the Klarman Family Foundation, has contributed to advancing the field, yielding a large-scale genome-wide association study published in Nature Genetics. Eight genetic variants significantly associated with anorexia nervosa were identified, along with patterns of genetic correlations that suggest both psychiatric and metabolic origins of this serious and life-threatening illness. This article details the role of Professor Nick Martin in contributing to this important collaboration.

scholarly journals Exome Array Analysis of Early-Onset Ischemic Stroke

Stroke ◽  
2020 ◽  
Vol 51 (11) ◽  
pp. 3356-3360
Author(s):  
Thomas Jaworek ◽  
Kathleen A. Ryan ◽  
Brady J. Gaynor ◽  
Patrick F. McArdle ◽  
Oscar C. Stine ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Early Onset ◽  
Large Scale ◽  
Genome Wide Association Study ◽  
Meta Analysis ◽  
Population Level ◽  
Small Vessel ◽  
Stroke Treatment ◽  
Functional Variants ◽  
Individual Snps

Background and Purpose: The genetic contribution to ischemic stroke may include rare- or low-frequency variants of high-penetrance and large-effect sizes. Analyses focusing on early-onset disease, an extreme-phenotype, and on the exome, the protein-coding portion of genes, may increase the likelihood of identifying such rare functional variants. To evaluate this hypothesis, we implemented a 2-stage discovery and replication design, and then addressed whether the identified variants also associated with older-onset disease. Methods: Discovery was performed in UMD-GEOS Study (University of Maryland-Genetics of Early-Onset Stroke), a biracial population-based study of first-ever ischemic stroke cases 15 to 49 years of age (n=723) and nonstroke controls (n=726). All participants had prior GWAS (Genome Wide Association Study) and underwent Illumina exome-chip genotyping. Logistic-regression was performed to test single-variant associations with all-ischemic stroke and TOAST (Trial of ORG 10172 in Acute Stroke Treatment) subtypes in Whites and Blacks. Population level results were combined using meta-analysis. Gene-based aggregation testing and meta-analysis were performed using seqMeta. Covariates included age and gender, and principal-components for population structure. Pathway analyses were performed across all nominally associated genes for each stroke outcome. Replication was attempted through lookups in a previously reported meta-analysis of early-onset stroke and a large-scale stroke genetics study consisting of primarily older-onset cases. Results: Gene burden tests identified a significant association with NAT10 in small-vessel stroke ( P =3.79×10 − 6 ). Pathway analysis of the top 517 genes ( P <0.05) from the gene-based analysis of small-vessel stroke identified several signaling and metabolism-related pathways related to neurotransmitter, neurodevelopmental notch-signaling, and lipid/glucose metabolism. While no individual SNPs reached chip-wide significance ( P <2.05×10 −7 ), several were near, including an intronic variant in LEXM (rs7549251; P =4.08×10 − 7 ) and an exonic variant in TRAPPC11 (rs67383011; P =5.19×10 − 6 ). Conclusions: Exome-based analysis in the setting of early-onset stroke is a promising strategy for identifying novel genetic risk variants, loci, and pathways.

Abstract 28: Genetic Variants From Lysine-Specific Demethylase 4C (KDM4C) Associated With White Matter Hyperintensity Burden in Ischemic Stroke Patients

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Jiang Li ◽  
Vida Abedi ◽  
Anne-Karin Giese ◽  
Markus D Schirmer ◽  
Kathleen Donahue ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
White Matter ◽  
Genetic Variants ◽  
Genome Wide Association Study ◽  
European Ancestry ◽  
White Matter Hyperintensity ◽  
Significance Level ◽  
Brain Extraction ◽  
Lysine Specific Demethylase ◽  
A Genome

Introduction: Although white matter hyperintensities (WMH) have been linked to cerebrovascular disease, the exact pathogenesis is not known. The purpose of this study was to identify common variants associated with WMH burden among patients with an acute ischemic stroke (AIS) through a genome-wide association study (GWAS). Methods: A total of 946 AIS patients with validated European ancestry and MRI data were included in this study. WMH volume (WMHv), as a quantitative trait, was calculated by a fully-automated quantification process, which integrates the automated brain extraction, intensity normalization, and WMH segmentation using spatial priors. The GWAS was carried out by a linear mixed regression model (GEMMA), adjusted for covariates, to account for the potential population structure and relatedness. The WMHv ranked in top and bottom quantile were converted to a binary trait which represent high and low WMHv subgroups. Results: The rs10815506 (MAF = 0.043; β=3.89; p=6.66E-09), at an intronic region of KDM4C , which encodes Lysine-specific demethylase 4C , was the top signal associated with WMHv. This SNP is in high linkage disequilibrium (LD) (R 2 = 0.79; D’ = 0.93) with rs35389625, a nonsynonymous variant (Asn>Ser), predicted to be pathogenic by SIFT and Polyphen. The rs35389625 was also associated with WMHv but at a lower significance level (MAF=0.040; β=3.19; p=3.21E-06). Patients with homozygous mutant alleles (GG) of rs35389625 showed significantly increased WMHv (14.93±10.15) than GA (7.94±8.48) and AA (5.09±5.85) carriers. Both rs10815506 and rs35389625 also predicted a subset of high and low WMHv group (OR=2.81, p=0.005; OR=2.42, p=0.016, respectively). No significant interaction between the top SNPs at KDM4C and other risk factors was identified in their association with WMHv. We also conducted a candidate-gene analysis by including several known SNPs, gathered from a reported meta-analysis for WMH. The frequency of MTHFR677 cytosine/thymine (rs1801133) showed difference between lower and upper quantile groups with OR=2.18 for T allele (p=0.030), the direction of which was consistent with previous studies. Conclusion: This study provides the first evidence that genetic variants at KDM4C are associated with WMH in AIS patients.

GWAS Indicates the Presence of Rare Immunogenetic Polymorphisms as Possible Predisposition Factors in Aplastic Anemia.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1093-1093
Author(s):  
Bartlomiej P Przychodzen ◽  
Monika Jasek ◽  
Sandra P Smieszek ◽  
Ron Paquette ◽  
Rainer Richter ◽  
...  
Keyword(s):  
Aplastic Anemia ◽  
Genetic Variants ◽  
Large Scale ◽  
Disease Risk ◽  
Conflicts Of Interest ◽  
New Paradigm ◽  
Genetic Traits ◽  
Network Analyses ◽  
Low Prevalence ◽  
The Impact

Abstract Abstract 1093 Poster Board I-115 While immune mechanisms are involved in the pathogenesis of idiopathic aplastic anemia (AA), due to the impact of exogenous factors and the low prevalence of AA, this disease is not easily amenable to genetic studies. With the advent of whole genome scanning (WGS) technologies such as single nucleotide polymorphism arrays (SNP-A), large scale investigations in various disorders have been conducted. A systems level understanding of particular disease can allows for identification of candidate genetic variants as prognostic and diagnostic markers. We have applied 6.0 SNP-A containing 924644 SNP probes to conduct a comprehensive GWAS in AA with the aim of identifying low prevalence genetic variants that contribute to the pathogenesis of this condition and contribute to individual disease risk. We studied 124 AA patients and significant cohort of 2230 controls that increase detection power using SNP-A. After exclusion of SNP's with call rate of <95% and those with violation of Hardy Weinberg equilibrium (p<.01), 809.802 SNPs (87.5% of initial set) were passed for further investigation. Single allele χ2 statistics for all autosomal markers were performed. 1935 SNP's pointing towards genes with minor allele frequency (MAF) <10% and p<.001 after Bonferroni correction (more stringent than False Discovery Rate) were selected. Of great interest was the top scoring non synonymous SNP (1/38) rs1028180 located in BLZF1 (OR 6.62) involved in cell proliferation and growth. It was represented by singular marker (p<1×10–4) occurring at a heterozygous frequency of 15% vs. 3.5% in controls, and a homozygous frequency of 3.7% vs. 0% in controls. A total of 1 non-synonymous and 3 strongest intronic SNPs were prioritized for final investigation. These included rs9566991, rs1773557 and rs1495963 and directed to informative genes TNFSF11 (OR 6.24), CD247 (OR 3.52) and IL12RB2 (OR 7.04), respectively. Remarkably, several informative LD blocks were identified represented by multiple markers pointing to the presence of informative polymorphisms in the corresponding regions. TNFSF1 gene was represented by marker rs9566991 (p<1×10–3) occurring at the heterozygous frequency of 15.4% vs. 2.7% in controls. The corresponding MAF was 7.6% vs. 1.3%. A second potential locus identified in our study (CD247) was represented by rs1773557 marker (p<1×10–20) occurring at a heterozygous frequency of 19.6% vs. 5.9% in controls, and in homozygous frequency of 0% vs. 0% in controls. Other SNPs including rs1737501, rs1737502 pointed to the same locus. IL12RB2 was represented by a singular marker rs1495963 (p<1×10–6) occurring at the heterozygous frequency of 24% vs. allelic frequency of 3.2% in controls. MAF were 12% versus 1.9%. Another potential loci marked by rs17131583 was TGFBR3. Analysis targeting individual SNP has been the primary focus of GWAS but such an approach offers only limited understanding of the complex diseases as not an individual SNP, and rather a joint action of several SNPs results in particular outcomes. Consequently, in study of AA, we applied the network gene association analysis as a new paradigm incorporating both “operator OR” and “operator AND” thereby allowing for dependence and independence testing. Consequently, the proposed paradigm may lead to identification of meaningful pathways. We performed a simulation study, where genotypes were randomly drawn including homozygous reference, heterozygous and homozygous variant for each SNP Si = 1, 50 where the MAF of SNP is chosen uniformly at random. Of great interest was a pair consisting of rs1737501 CD247 and rs1495963 IL12RB2 both in heterozygous variant, involving operator AND at p<1×10–23. It was reported with occurrence of 12.2% in patients and 0.005% in controls giving a specificity score of 99.995%. In addition to the described pair, SNP in strong LD within CD247 (rs1737502) was scored again together with rs1495963. Functionally, both genes are involved in regulation response. Another pair rs16908086 and rs1773557 that pointed together to CD247 and MRVI2 created a pair with occurrence 21% versus and 3% in controls. In sum, our study constituted the first network analyses of predisposing factors and complex genetic traits enriched in informative loci in immunoregulatory genes. Rare polymorphic variants of these genes may constitute risk factors for development of AA. Disclosures No relevant conflicts of interest to declare.

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