title: A Novel Approach for Pathway Analysis of GWAS Data Highlights Role of BMP Signaling and Muscle Cell Differentiation in Colorectal Cancer Susceptibility.
abstract: Genome-wide association studies (GWAS) have revolutionized the field of gene mapping. As the GWAS field matures, it is becoming clear that for many complex traits, a proportion of the missing heritability is attributable to common variants of individually small effect. Detecting these small effects individually can be difficult, and statistical power would be increased if relevant variants could be grouped together for testing. Here, we propose a VEGAS2Pathway approach that aggregates association strength of individual markers into pre-specified biological pathways. It accounts for gene size and linkage disequilibrium between markers using simulations from the multivariate normal distribution. Pathway size is taken into account via a resampling approach. Importantly, since the approach only requires summary data, the method can easily be applied in all GWASs, including meta-analysis, singleton-based, family-based, and DNA-pooling-based designs. This approach is implemented in a user-friendly web page https://vegas2.qimrberghofer.edu.au and a command line tool. The web implementation uses gene-sets from the gene ontology (GO), curated gene-sets from MSigDB (containing canonical pathways and gene-sets from BIOCARTA, REACTOME, KEGG databases), PANTHER, and pathway commons databases, enabling analysis of a wide range of complex traits. We applied this method on a colorectal cancer GWAS meta-analysis data set (10,934 cases, 12,328 controls) from the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO). We report statistically significant enrichment of association signal for the 'BMP signaling' and 'muscle cell differentiation' pathways, suggesting a possible role for these pathways onto the risk of colorectal cancer.
authors.affiliation: Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO) and the Colorectal Cancer Family Registry (CCFR),and Statistical Genetics,QIMR Berghofer Medical Research Institute,Brisbane,Queensland,Australia.
authors.forename: Aniket
authors.initials: A
authors.lastname: Mishra
authors.affiliation: Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO) and the Colorectal Cancer Family Registry (CCFR),and Statistical Genetics,QIMR Berghofer Medical Research Institute,Brisbane,Queensland,Australia.
authors.forename: Stuart
authors.initials: S
authors.lastname: MacGregor
mesh_terms: D019485:Bone Morphogenetic Proteins / Q000235:genetics* / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics*; D002874:Chromosome Mapping; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology; D016208:Databases, Factual; D005786:Gene Expression Regulation; D020022:Genetic Predisposition to Disease; D055106:Genome-Wide Association Study; D006801:Humans; D015810:Linkage Disequilibrium; D032342:Muscle Cells / Q000166:cytology / Q000378:metabolism; D020641:Polymorphism, Single Nucleotide
chemical_list: D019485:Bone Morphogenetic Proteins
keywords: GWAS; VEGAS; VEGAS2Pathway; colorectal cancer; pathway analysis