Small variations in our DNA can correlate with differences in the way individuals respond to a medication or in their risk for getting a disease. Often, these variations occur within the DNA letters that make up the protein-coding portion of a gene, influencing how the protein works.
Changing the protein-coding sequence isn't the only way to affect a gene, though. Changing the level of gene expression—thus increasing or decreasing the amount of RNA or protein that is made from it—can influence biological processes just as dramatically.
A major focus in genetic science is to examine how differences in gene expression correlate with drug response or disease risk. Learn more about personalized medicine in Precision Medicine