Researchers have used a new technique to identify networks of genes linked to obesity in both mice and humans. The procedure is more comprehensive than the traditional method of hunting for genes associated with disease, and is already being used to identify new drug targets. Over the past year, a flurry of studies have revealed genetic variations associated with disease. These ‘genome-wide association studies’ have been used to find variants associated with everything from heart disease to diabetes.
Traditionally, single genes are linked with particular diseases by locating genetic variants present in people who have the disease and identifying the part of a chromosome associated with that disease. Then researchers have to track down the gene on the chromosome, without knowing what it does or why it would be involved. The new approach looks at changes in expression of already-known genes, and finds networks of genes associated with disease, rather than single switches. “Instead of the simple ‘turn the light on or off’ analogy, we would view this as a network of these switches,” says Schadt.