How to find Standard Error (SE) values when not provided in GWAS summary stats?

Hi everyone!

I’m trying to do a fixed effect meta-analysis on a couple of GWASes based on p-values, Standard error and effect estimates (Beta) using METAL genetics software. For one of my GWAS studies SE is not reported explicitly in the summary stats, I have Q-test value and I^2 value for heterogeneity in addition to Beta and p value. I was wondering how I could find SE from Q-value. I do not know the sample size or the degrees of freedom.

Another on of my studies mentions T-score in addition to number of samples, p-values and beta. How can I estimate SE based on Tscore?
I read somewhere that SE can be estimated using T-scores and beta by the following formula:
SE=abs(beta/sqrt(t-score))
But wasn’t able to confirm the validity of such formula since T-score can also be negative and can’t take square root of that. How could one apply that formula?

Any advice would help!

Thanks!