The purpose of this trial is to study genetic and other risk factors that may be important in the development of Parkinson's disease.

The The Parkinson's Research: The Organized Genetics Initiative, also known as PROGENI, is a multi-center study involving 2000 people throughout North America who are affected, or possibly affected, with Parkinson's disease (PD). The goal of the initiative is to study the genetic and other risk factors which may be important in the development of PD.

In order to better understand the genetic factors leading to PD, researchers will study families having 2 or more members diagnosed with PD. Using DNA samples from each participant, researchers hope to identify genes that may cause a person to be at higher risk for developing PD.

Each participant in the study will be asked to complete a family history questionnaire, providing information about the history of PD in the family. Participants also will be asked to discuss the symptoms they have experienced and their responses to PD medications. This information will be used by study personnel to determine further eligibility for the study. Those eligible for further participation will be asked to undergo a study visit at the site closest to their residence, during which they will be asked to complete questionnaires regarding PD symptoms, medical history, places of residence, occupations, mood, mental status, and activity level. A blood sample will be drawn for DNA extraction. The study visit will take about 2 hours.

Inclusion Criteria:

• To be eligible to participate in this study participants must be diagnosed with or have symptoms of PD. In addition, they must also have a family history of PD in other relatives.

Exclusion Criteria:

• Subjects cannot have participated in any other genetic research project for Parkinson's disease.

families having 2 or more members diagnosed with PD