normality assumption for GWAS QT

Hi

Planning to perform GWAS on quantitative trait using linear reg in plink. From my basic knowledge of statistics, i know that the assumption of normality (residuals) should be only approximately true. But i have seen so many papers on GWAS transforming the data for normalization. My personal view is that ” no real data set is perfectly normal”. So do i need to transform my data with the following plot ? So far i have received mixed feedbacks from my group members (some say it’s ok to go ahead with linear reg, while others want the data transformed)

TIA