Just a year ago, science understood little about the genetic origins of common conditions such as diabetes and cancers of the lung, breast and prostate. These were known to be affected by inheritance, but with the exception of rare mutations with catastrophic effects, the genetic mechanisms responsible remained elusive. The picture has changed decisively, as was highlighted this week by the discovery of six new genes that affect type 2 diabetes, and the first genetic variant linked to lung cancer. These are only the latest chapters in a story that is transforming medicine. In the past 12 months, close to 100 common genetic variants have been linked to major diseases, using a new gene-hunting technique called whole-genome association. Such knowledge is providing unprecedented insights into the molecular pathways of disease, which should help with the design of new therapies. Some of these could be aimed at patients with particular genetic profiles, in whom they are most likely to work. Another prospect is genetic screening, allowing people to assess their disease risk, with a view to lowering it through drugs, diet or exercise. It is not hard to see why this ‘new genetics’ has caused so much […]