AffiXcan-package {AffiXcan} | R Documentation |
Impute a GReX (Genetically Regulated Expression) for a set of genes in a sample of individuals, using a method based on the Total Binding Affinity (TBA) score. Statistical models to impute GReX can be trained on a training dataset where the real total expression values are known.
For every gene a linear regression model can be fitted on a training set of individuals where the real total expression values, the Total Binding Affinity (TBA) values for a set of genomic regions, and the covariates of the population genetic structure, are known. AffiXcan performs a principal component analysis (PCA) on the TBA values to fit a linear model using the formula: GReX ~ PC1 + PC2 + PC3 + ... + COV1 + COV2 + ... . Associations between the expressed genes and the regulatory regions, on which the TBA values have to be computed, are needed. TBA can be computed using "vcf_rider" software (see references)
Alessandro Lussana <alessandro.lussana@protonmail.com> Maintainer: Alessandro Lussana <alessandro.lussana@protonmail.com>
https://github.com/vodkatad/vcf_rider
trainingTbaPaths <- system.file("extdata","training.tba.toydata.rds", package="AffiXcan") data(exprMatrix) data(regionAssoc) data(trainingCovariates) assay <- "values" training <- affiXcanTrain(exprMatrix=exprMatrix, assay=assay, tbaPaths=trainingTbaPaths, regionAssoc=regionAssoc, cov=trainingCovariates, varExplained=80, scale=TRUE) testingTbaPaths <- system.file("extdata","testing.tba.toydata.rds", package="AffiXcan") exprmatrix <- affiXcanImpute(tbaPaths=testingTbaPaths, affiXcanTraining=training, scale=TRUE)