Trait Variables Use this field to specify binary trait variables to be tested for with the marker variables. Note: If the Dominant, Recessive, or MAX tests are selected on the Options tab, the trait variables must be numeric with values 0 and 1. To Specify One or More Trait Variables: Specify the Input SAS Data Set. All of the variables in the specified data set are displayed in the Available Variables field. Examine the list of available variables. Highlight the desired variables. Click to add the highlighted variable to the Trait Variables field, as shown below: