Hardy-Weinberg Equilibrium Quality Control

Question

[sarvism]

Hi,

In determining the P threshold for Hardy-Weinberg Equilibrium in a trio/family based GWAS, which is better to use as the reference for determining the P value: cases or parents? Or if siblings are available, would this be better? As cases, parents and siblings share some but not all possible problematic and/or associated SNPs (to a varying degree), which one would be best?

Thanks.