Genetic linkage studies will include all available, informative family members, while gene sequence analysis will be performed on affected individuals and spousal controls. In the event that we identify a mutation of clear pathogenicity in one of the known Parkinson's genes, we will contact all participating family members to notify them of the discovery of the gene that causes PD in their family and offer them individual counseling and testing in a CLIA approved lab. To assess any impact caused by the offer and subsequent pursuit of genetic testing we will be administering a questionnaire assessing psychological well-being prior to and following testing.