General regression model: A “model‐free” association test for quantitative traits allowing to test for the underlying genetic model

Most genome‐wide association studies used genetic‐model‐based tests assuming an additive mode of inheritance, leading to underpowered association tests in case of departure from additivity. The general regression model (GRM) association test proposed by Fisher and Wilson in 1980 makes no assumption on the genetic model. Interestingly, it also allows formal testing of the underlying genetic model. We conducted a simulation study of quantitative...