Hi,

I am using a post-gwas analysis tools to test genetic overlap between different traits based on summary level data, and it requires the effect size(beta) and SE.

So for summary stats that has the Z score measures, beta and SE are estimated by using the following formula that was published in a large scale study on Alzheimers.

```
SE~=sqrt(VP/(ES×2pq))
Beta=SE×Z
```

where:

- VP: phenotypic variance approximated to 1;
- ES: effective sample size
- pq: allele frequencies (p allele, q allele)
- Z: Z scores

The summary stats that I currently have access to does not have allele frequency information.

head of the summary stats:

```
> Chr Pos MarkerName EffectAllele OtherAllele Z P.value TotalSampleSize
> 1 744055 rs3131000 a g -1.60 0.10 23546
```

Is there a way to calculate the Betas and SE without contacting the study, with just relying on the information that is currently publicly available.

Hi, Would it be possible to send the link of the Alzheimers paper you found the equation in please?

I am somewhat pressed for time but it's not 100% clear which data-points you have. Please take a look here and see if you can work back from the Z-score calculation: A: SNP dataset and Z Score

Do you have the allele tallies?