Since Parkinson's disease was first discovered over 200 years ago, little progress has been made in determining the cause of the disease. Now, in the largest study of its kind, researchers from the Mayo Clinic have discovered that genetics may play a small but significant role in determining one's risk for the disease.
The study found that genes play as much as a 3 percent role in one's overall risk for developing Parkinson's disease. With this new information, further research on the role of these genes may lead to better treatments or even a cure.
"This is an important step forward," said Dr. Demetrius Maraganore, lead study investigator, "Because the contribution of common genetic risk factors to the development of Parkinson's has long been suspected."
The researchers compiled genetic information from almost 2,700 patients with Parkinson's disease and compared it with that of healthy men and women of the same age. They found that in many of the Parkinson's patients, there was one segment of DNA that was a bit longer than in the healthy patients. This section of DNA promotes the expression of another gene, alpha-synuclein. So, in Parkinson's patients this gene is "overexpressed," or turned on more than in a person without Parkinson's disease.
While it is not yet known how this genetic defect leads to Parkinson's, the researchers were able to determine that people with the extra-long DNA segment have a 1.5 greater risk for Parkinson's disease than someone who doesn't.
Parkinson's disease affects around 1 million people in the United States and causes the deterioration of brain cells. This can cause symptoms of uncontrollable shaking, stiffness, imbalance and uncoordinated movements. There are a few treatments that are available to reduce these symptoms, but, in general, their impact is short-lived.
With this new information, however, researchers can turn their attention to the alpha-synuclein gene.
"Our findings support the development of therapies that reduce alpha-synuclein gene expression," said Maraganore. "Such therapies have the potential to prevent or delay the onset of Parkinson's disease or to halt or slow its progression."