Identify relationships between genesets
library(RITANdata)
library(RITAN)A feature of RITAN is the ability to account for false-discovery rates across resources. However, the relationships among genesets is not always obvious. That is, two resources may each have a term that is highly similar if not identical to the other. Ideally, you would pick one of these terms to use, prior to analysis. The function geneset_overlap() helps with this process.
# Show the fraction of genes common to multiple disease-gene relationships
o <- geneset_overlap( geneset_list$DisGeNet )
plot(density(c(o)), main='', xlab='Fraction Shared Genes', ylab='Prob()')
diag(o) <- NA # ignore self-overlap
i <- which( o > 0.8, arr.ind = TRUE )
mat <- o[ unique(i[,1]), unique(i[,2]) ]
heatmap( mat, col = rev(gray(seq(0,1,length.out = 15))),
cexRow=.7, cexCol=0.7, margins = c(7,7) )
# Show the fraction of genes common between disease-gene relationships and GO-Slim
o <- geneset_overlap( geneset_list$DisGeNet, geneset_list$GO_slim_generic )
o <- o[ , !( colnames(o) %in% c('biological_process', 'molecular_function', 'cellular_component')) ] # remove the root of each sub-ontology
plot(density(c(o)), main='', xlab='Fraction Shared Genes', ylab='Prob()')
i <- which( o > 0.95, arr.ind = TRUE )
mat <- o[ unique(i[,1]), unique(i[,2]) ]
heatmap( mat, col = rev(gray(seq(0,1,length.out = 15))),
cexRow=.7, cexCol=0.7, margins = c(7,7) )
The overlapping genesets can themselves be highly informative. For instance, perhaps the diseases known to involve genes responsible for chromosome organization is of great interest to you. You can combine the available resources in RITAN to rapidly identify this intersection of genesets.
rownames(o)[ o[ , "chromosome_organization" ] > 0.66 ]## [1] "Coffin-Siris syndrome"
## [2] "Leukemia, Myeloid"
## [3] "Leukemia, Megakaryoblastic, of Down Syndrome"
## [4] "Colorectal Neoplasms, Hereditary Nonpolyposis"
## [5] "Malignant neoplasm breast"Or, perhaps the genes themselves for diseases related to cell motility are of interest as a new geneset.
d <- rownames(o)[ o[ , "cell_motility" ] > 0.66 ]
str(d)## chr [1:20] "Kartagener Syndrome" "Thromboembolism" ...new_geneset <- intersect( unique(unlist(geneset_list$DisGeNet[d])),
unique(unlist(geneset_list$GO_slim_generic$cell_motility)) )
str(new_geneset)## chr [1:86] "CCDC40" "DNAH5" "DNAI1" "DRC1" "DYX1C1" "F2" "F7" "GAS6" ...