The use of the trend test induces an ascertainment bias in favor of additive effects. A natural alternative is to use the test with 2 degrees of freedom that compares the general model with the null model, which we refer to as the general test. There are merits, but also disadvantages, to using this test (see Discussion). Since GWAS are typically analyzed with the trend test, here we focused only on results from simulations based on that test.
