A new gene chip designed specifically for type 2 diabetes could help resolve a troubling finding plaguing studies of complex human diseases. While scientists have identified a number of genetic variations that raise the risk for developing different diseases, including diabetes, heart disease, and Alzheimer’s, these variants account for only a small portion of the overall risk. In type 2 diabetes, for example, variants identified so far account for only about 9 percent of the genetic risk, said Michael Erdos of the National Human Genome Research Institute at the First Annual Consumer Genetics Conference today in Boston. The rest of the risk likely lies in rarer genetic variations undetectable in existing studies, which have analyzed hundreds to thousands of patients.
Erdos’s group and others are now designing a specialized gene chip for diabetes research, dubbed the metabochip. It will include 50,000 genetic markers, all of those identified to date in genetic association studies, both large and small, of type 2 diabetes, as well as some rare variations found in less than 0.5 percent of the population. Scientists plan to study 200,000 people with diabetes, a number that is about an order of magnitude greater than previous studies. The Wellcome Trust Case Control Consortium, which is the largest genome-wide association study I know of, has analyzed approximately 20,000 patients and controls. The research should help resolve the question of whether larger gene-chip studies can identify the remaining genetic risk factors.
Other scientists are developing new tests for clinical use. Scott Weiss, director of respiratory, environmental, and genetic epidemiology at Harvard Medical School, is working on two new genetic tests for asthmatics. His team has already identified a number of genetic markers that can predict whether a patient with asthma is likely to require hospitalization, and the researchers are working on a test to determine which asthmatic kids taking oral steroids are at risk for stunted growth.
Don’t settle for half the story.
Get paywall-free access to technology news for the here and now.