What limits does genomic testing have as a historical source

The limits of genomic testing are connected with tracking the possibilities of developing a certain disease. It used to be believed that genes were the most importan responsible factors for causing self-immune diseases, but now it has been prooved that the environment, bad habits and nourishing, among other factors, play a more important role in that aspect.

i just did something on this guy a few days a go give me two minutes to find it in my notes.