EQTL Analysis Identifies Novel Associations Between Genotype and Gene Expression in the Human Intestine (Expression)
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE40292 | GEO | 2012/12/01
SECONDARY ACCESSION(S): PRJNA173647
REPOSITORIES: GEO
Similar Datasets
Project description:Genome-wide association studies (GWAS) have been pivotal to increasing our understanding of intestinal disease. However, the mode by which genetic variation results in phenotypic change remains largely unknown, with many associated polymorphisms likely to modulate gene expression. Analyses of expression quantitative trait loci (eQTL) to date indicate that as many as 50% of these are tissue specific. Here we report a comprehensive eQTL scan of intestinal tissue.
2012-12-01 | GSE41238 | GEO
Project description:Genome-wide association studies (GWAS) have been pivotal to increasing our understanding of intestinal disease. However, the mode by which genetic variation results in phenotypic change remains largely unknown, with many associated polymorphisms likely to modulate gene expression. Analyses of expression quantitative trait loci (eQTL) to date indicate that as many as 50% of these are tissue specific. Here we report a comprehensive eQTL scan of intestinal tissue. Subjects who had undergone ileal pouch anal anastomosis and closure of ileostomy at least one year prior to recruitment were prospectively enrolled at Mount Sinai Hospital in Toronto. Endoscopically and histologically normal tissue biopsies from the afferent limb of these individuals were obtained and preserved in RNAlater. Total RNA was extracted with the QIAGEN miRNeasy Kit and mRNA analysis was performed on Affymetrix Human Gene 1.0 ST arrays. DNA was obtained from whole-blood samples from the same individuals and genotyped using the Illumina beadchips. Cis- and trans-eQTL analyses were carried out on 173 subjects encompassing the expression levels of 19,047 unique autosomal genes listed in the NCBI database and over 580K dbSNPs (Call Rate ≥ 95%; MAF ≥ 5%; Hardy–Weinberg equilibrium (HWE) χ2 p-values ≥ 10-6). This work was done in a custom software pipeline and the Kruskal-Wallis test was used to compare expression values across different genotypes. False discovery rate correction for multiple testing was applied at an alpha level of 5%. This Series includes the Affymetrix data.
2012-12-01 | E-GEOD-40292 | biostudies-arrayexpress
Project description:Genome-wide association studies (GWAS) have been pivotal to increasing our understanding of intestinal disease. However, the mode by which genetic variation results in phenotypic change remains largely unknown, with many associated polymorphisms likely to modulate gene expression. Analyses of expression quantitative trait loci (eQTL) to date indicate that as many as 50% of these are tissue specific. Here we report a comprehensive eQTL scan of intestinal tissue. Subjects who had undergone ileal pouch anal anastomosis and closure of ileostomy at least one year prior to recruitment were prospectively enrolled at Mount Sinai Hospital in Toronto. Endoscopically and histologically normal tissue biopsies from the afferent limb of these individuals were obtained and preserved in RNAlater. Total RNA was extracted with the QIAGEN miRNeasy Kit and mRNA analysis was performed on Affymetrix Human Gene 1.0 ST arrays. DNA was obtained from whole-blood samples from the same individuals and genotyped using the Illumina beadchips. Cis- and trans-eQTL analyses were carried out on 173 subjects encompassing the expression levels of 19,047 unique autosomal genes listed in the NCBI database and over 580K dbSNPs (Call Rate ? 95%; MAF ? 5%; Hardy–Weinberg equilibrium (HWE) ?2 p-values ? 10-6). This work was done in a custom software pipeline and the Kruskal-Wallis test was used to compare expression values across different genotypes. False discovery rate correction for multiple testing was applied at an alpha level of 5%.
2012-12-01 | E-GEOD-41238 | biostudies-arrayexpress
Project description:A genome-wide eQTL analysis was performed in whole blood samples collected from 76 Japanese subjects. RNA microarray analysis was performed for 3 independent samples that were genotyped in a genome-wide scan. The correlations between the genotypes of 534,404 autosomal single nucleotide polymorphisms (SNPs) and the expression levels of 30,465 probes were examined for each sample. The SNP-probe pairs with combined correlation coefficients of all 3 samples corresponding to P < 3.10 × 10-12 (i.e., Bonferroni-corrected P < 0.05) were considered significant. SNP-probe pairs with a high likelihood of cross-hybridization and SNP-in-probe effects were excluded to exclude false positive results. We identified 102 cis-acting and 5 trans-acting eQTL regions. The cis-eQTL regions were widely distributed both upstream and downstream of the gene, as well as within the gene.
2012-11-27 | GSE42487 | GEO
Project description:Genome-wide association studies (GWAS) have identified over 300 loci associated with the inflammatory bowel diseases (IBD), but putative causal genes for most are unknown. We conducted the largest disease-focused expression quantitative trait loci (eQTL) analysis using colon tissue from 252 IBD patients to determine genetic effects on gene expression and potential contribution to IBD. Combined with two non-IBD colon eQTL studies, we identified 194 potential target genes for 108 GWAS loci. eQTL in IBD tissue were enriched for IBD GWAS loci colocalizations, provided novel evidence for IBD-associated genes such as ABO and TNFRSF14, and identified additional target genes compared to non-IBD tissue eQTL. IBD-associated eQTL unique to diseased tissue had distinct regulatory and functional characteristics with increased effect sizes. Together, these highlight the importance of eQTL studies in diseased tissue for understanding functional consequences of genetic variants, and elucidating molecular mechanisms and regulation of key genes involved in IBD.
2024-10-16 | GSE279302 | GEO
Project description:Background: Cases where genotype-phenotype relationships depend on environmental factors have been quantified for many complex diseases. Such genotype-environment interactions (GEI or GxE) may also affect expression Quantitative Trait Loci (eQTL) present in tissues critical for the manifestation of disease. To assess this hypothesis, we performed an analysis of eQTL-GEI resulting from an individual's smoking environment in the lung small airway epithelium (SAE). While the SAE is challenging to sample, this is the cell population that shows the first signs of smoking related stress and gene expression in the SAE appears to play a role in mediating smoking effects on lung disease. Results: We used expression microarrays to assay the SAE transcriptome for a small sample of African-American individuals and we analyzed SNPs genotyped genome-wide to identify GEI affecting eQTL. While a genome-wide trans- analysis identified few instances of GEI after a multiple test correction, an analysis of cis-genotypes identified a small but significant number of GEI affecting lung SAE gene expression. We determined that significant cases of eQTL-GEI were not driven by outliers and we were also able to find corroborative evidence for a few of these eQTL-GEI in a small, independent sample of individuals of European ancestry. Conclusion: Given that the power of GEI tests is low compared to tests of genotype association and that the total sample size of our study was small, including only 61 African American individuals in our focal population, the identification of significant GEI in our study implies that there may be considerable genotype-specific effects on eQTL due to smoking environment. We discuss individual cases of GEI of interest for lung disease, such as SDC1 and ZAK, as well as the broader implications of our results for the analysis of eQTL and for genome-wide association analysis of complex diseases.
2024-06-05 | GSE23087 | GEO
Project description:African Americans (AAs) are disproportionately affected by metabolic diseases and adverse drug events, with limited publicly available genomic and transcriptomic data to advance the knowledge of the molecular underpinnings or genetic associations to these diseases or drug response phenotypes. To fill this gap, we obtained 60 primary hepatocyte cultures from AA liver donors for genome-wide mapping of expression quantitative trait loci (eQTL) using LAMatrix. We identified 277 eGenes and 19,770 eQTLs, of which 67 eGenes and 7,415 eQTLs are not observed in the Genotype-Tissue Expression Project (GTEx) liver eQTL analysis. Of the eGenes found in GTEx only 25 share the same lead eQTL. These AA-specific eQTLs are less correlated to GTEx eQTL in effect sizes and have larger Fst values compared to eQTLs found in both cohorts (overlapping eQTLs). We assessed the overlap between GWAS variants and their tagging variants with AA hepatocyte eQTLs and demonstrated that AA hepatocyte eQTLs can decrease the number of potential causal variants at GWAS loci. Additionally, we identified 75,002 exon QTLs of which 48.8% are not eQTLs in AA hepatocytes. Our analysis provides the first comprehensive characterization of AA hepatocyte eQTLs and highlights the unique discoveries that are made possible due to the increased genetic diversity within the African ancestry genome.
2020-03-27 | GSE147628 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below.
2012-12-01 | GSE41269 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2012-12-01 | E-GEOD-41269 | biostudies-arrayexpress
Project description:A QTL analysis between inbred mouse strains MRL/MpJ and SM/J was performed to identify genetic loci influencing high-density lipoprotein (HDL) cholesterol and triglycerides (TG) at eight weeks of age in F2 mice fed a chow diet. In order to narrow down lists of candidate genes, expression levels from liver tissue were used to test for differential expression among parental and F1 strains and to scan for eQTL in F2 animals. We provide evidence for Mppe1 (Chr 18) as an HDL QTL candidate gene and Cyp2d26 (Chr 15) as a TG QTL candidate gene.
2011-11-28 | GSE25322 | GEO