I recently got involved into a project that involves calculation of genetic risk scores (GRS) for a set of important SNPs. My question is about weighted GRS and it is as follows,
PredictABEL calculates weighted GRS as sum of allele counts weighted with beta coefficients. Does it matter whether or not the beta coefficients are standardized (resulted from standardized variables)?
Some suggest rescaling weighted GRS by multiplying GRS with number_of_SNPs/sum_of_beta_coefficients to make it comparable to unweighted GRS. Could someone help me understand how and when that is beneficial?
I would appreciate any help on this!