How to calculate Polygenic Risk Score from Summary Results with Z-Score only

Question

[AnnaStieber]

I have summary results from a large GWAS. The information given in this summary statistics is the following columns:

Chromosome, Position, Markername, Effect_allele, Other_allele, P-value , Zscore.

If i understood it correctly, the Z-score is the standardized effect measure (effect/StdError). Is there a way to create a PRS based on this Zscore instead of based on the original effect-estimates? Or do i have to estimate the beta from the Zscore in any way (by using allele frequency,..)? Has anyone done this before? All advice is appreciated!

Answer 1

[Sam]

You can use the z-score for PRS calculation as long as your target and base are from the same population.