Genome-Wide Association Studies: Can They Predict Human Disease?

More than 100 large genome-wide association studies have been conducted for scores of human diseases. The foundational concepts, benefits, and limitations of these studies have been admirably summarized in a recent review article.

Because genetic variance at one DNA locus can indicate the probability of genetic variation at adjacent loci, investigators conducting genome-wide association studies usually enroll several thousand affected individuals and target 500,000 DNA markers. By identifying common disease — common variants (rather than single gene mutations) — researchers hope to predict disease risk and to identify important biochemical disease-related pathways. Genetic variability can affect gene expression, protein production, and speci…