Associations between genetics and traits (such as diseases, height, etc) are already very common in science. One of the main problems is that you need extremely

Associations between genetics and traits (such as diseases, height, etc) are already very common in science. One of the main problems is that you need extremely large sample sizes to see any effect. These kind of studies are called genome-wide association studies. Many common traits need hundreds of thousands of individuals if the genetic link is suspected to be weak (which is the case for most common diseases), making such studies extremely expensive, not to mention time-consuming.