Today at the World Parkinson Congress (WPC) in Glasgow, Scotland, researchers reported a significant development that suggests that the genetic makeup of a person with Parkinson’s may determine how well they will respond to drugs such as caffeine. This is one of the first genome wide association studies (GWAS) that looked at genetic and environmental interactions.
The investigators scanned the complete genetic code (genome) of 4000 people, about half of whom had Parkinson’s disease, for nearly 1 million markers. They then collected data on the amount of caffeinated coffee the subjects drank over their lifetimes.
Previous studies have shown that caffeine may decrease a person’s risk of developing Parkinson’s. Preliminary findings from this new study suggest that subjects who carry a version of the gene GRIN2A benefited the most from coffee.
The new findings may help researchers identify patients who are likely to respond to drugs that target the same physiological pathways as caffeine. Such drugs are currently being investigated as new treatments for Parkinson’s
“Dr. Payami’s work shows the potential of using genetic and epidemiological approaches to identify new risk factors for Parkinson’s disease,” said Margaret Sutherland, Ph.D., a program director at NINDS. “The next challenge will be to validate that the coffee and GRIN2A association can be replicated in a larger group of patients.”
Dr Kieran Breen, Director of Research and Development at Parkinson’s UK, said: “We are excited by these initial findings. However, more work needs to be done to expand and better understand this study so that in the future we may be better able to target drugs to specific people with Parkinson’s. But for today, patients should not change their caffeine consumption.”
Researchers are hopeful that new drugs, without caffeine’s stimulant and diuretic effects, will prove helpful to patients. In clinical trials, however, such drugs have failed to meet the threshold for effectiveness and regulatory approval.
“The new results suggest the possibility of screening patients for their genetic makeup to determine if they are likely to benefit from drugs that target the brain cells affected by caffeine. Such screening could be done at the outset of clinical trials, and could also become part of routine practice,” said the lead researcher Haydeh Payami, Ph.D., an investigator at the New York State Department of Health Wadsworth Center in Albany. Her work was funded in part by the National Institute of Neurological Disorders and Stroke (NINDS), a part of the U.S. National Institutes of Health, and by the Michael J. Fox Foundation for Parkinson’s Research Edmond J. Safra Global Genetics Consortia initiative.
Parkinson’s disease attacks parts of the brain that are needed to control movement. Common symptoms include involuntary shaking, slow movement, stiff muscles and impaired balance, all which worsen as the disease progresses. A drug called L-dopa can control symptoms, but causes troubling side effects and does not slow progression of the disease.
Ted Dawson M.D., Ph.D., Chair of the Program Committee at the WPC said: “It is truly significant that these preliminary findings were announced at the World Parkinson Congress, a unique international, interdisciplinary forum designed to showcase the latest developments in the world of Parkinson’s disease, featuring a network of scientists, clinicians, patients, caregivers and allied health professionals from 66 countries.”