With Xg* the matrix of PCs, Y the phenotype and W an optional matrix of covariates the model can thus be written as Y=α0g1→+Xg*αg+Wβg+εg, where the parameter vector α g represents the genetic effect, β g the effect of the optional covariates, α 0g the intercept and ε g the vector of residuals. The F-test uses the null-hypothesis H 0: αg=0→of no effect of gene g on the phenotype Y, conditional on all covariates.
