Cell Studies of Parkinson's Disease

This study will examine and compare blood samples from healthy volunteers and patients with Parkinson's disease to identify abnormalities associated with Parkinson's disease. Disease symptoms include slowness of movement, hand or leg shaking, and stiffness. Some patients have difficulty with balance. Information from this study may provide information on how Parkinson's disease affects the brain and body, and may help lead to a test for earlier diagnosis. Healthy volunteers and patients with Parkinson's disease who are 18 years of age or older may enroll in this study. Participants will undergo the following procedures: * Physical examination, including evaluation of strength, feeling, coordination, and balance * Blood drawing: 150 milliliters (about 10 tablespoons) of blood will be drawn * Personal and family medical history * Consent to access medical records for research purposes Blood samples will be examined for: * Genetic analysis * Study of specific proteins and lipids * Study of mitochondria (parts of cells that make energy)