Applied to the study of the human genome, a goal of GWAS is to locate chromosome regions that are likely to contain genes influencing the risk of disease. Specific genes can be identified in these regions, and particular mutant alleles that increase disease risk can be sequenced. To date, the identification of alleles that increase disease risk has occasionally led to a new therapeutic strategy, but more often the identification of disease alleles is the only outcome.

From a physician's point of view, what is the value of being able to identify alleles that increase the risk of a particular disease?