"The picture that is emerging of Parkinson's disease is one in which genetic risk factors, passed down through the population for hundreds or thousands of years, add up to substantial susceptibility within a single individual, and, with some possible environmental influences, can result in disease," said Mayo Clinic neuroscientist Owen Ross, first author of the study..

"These types of mutations are important because the goal of this research is to be able to screen people who are most at risk because of their genetic profiles, and design therapies that interfere with the disease process," Ross said.

Dr. Kristoffer Haugarvoll, a Norwegian visiting physician at the Mayo Clinic, said: "Parkinson's disease is fascinating to study because we can now roughly trace when and where mutations occur, and how they travel through offspring and in populations. It also shows us disease that appears to be the same in the majority of patients can originate from different genetic mutations …"

The research is reported in the journal Annals of Neurology.