Use this field to specify additional variables across the meta-analysis that contain chromosome identifiers.This field is used only when one or more of the data sets selected, after the first, uses a variable with another name for the Chromosome Variable . All variable names for the 2 nd through the last data set must be specified here.
For example, to specify the additional chromosome variables Chr_1 and Chr_2 , type Chr_1 Chr_2 in the text box, as shown below: