Two-stage regression procedure. In the first stage, phenotype is regressed on
covariates to obtain residuals. In the second stage, INT-transformed
residuals are regressed on genotype and adjustments for population structure.
Offset applied during rank-normalization. See rankNormal.
Value
A numeric vector of p-values assessing the null hypothesis of no
genotypic effect. P-values are estimated using the Wald statistic, and
correspond to the rows of G.