The 23andme clinical trial for Parkinsons just requires you to provide a saliva sample via a kit that they will send you. Send it in and you should get a great DNA report and even a family history / ancestry report (I am waiting on mine).
The more people who enroll in this research, the more powerful it becomes, and the more likely it is that we can find a cure for Parkinson's. Again, it's free to those with PD (normally it's $199).... more info at: