Washington, D.C. ? Scientists have found clusters of new gene variants that raise the risk of Type 2 diabetes – and how the researchers did it is as important as what they found.

In one of the largest studies yet of human genetic variability, the scientists tested the DNA of more than 32,000 people in five countries to pin down spots that harbor genetic risk factors for this complicated killer.

This type of research – called a “genome-wide association” study – promises to usher in a new era of genetics. Most breakthroughs so far have come from finding a mutation in a single gene that causes illness. But some of the world’s most common killers, such as heart disease and diabetes, are caused by complex interactions among numerous genes and modern lifestyles – and teasing out the genetic culprits until now has been almost impossible.

The work, by three international research teams that shared their findings, was published online Thursday by the journal Science.