Genetic Polymorphism and Parkinson's Disease in Taiwanese

Inclusion Criteria: * Clinical diagnosis of Parkinson's disease (case subjects are diagnosed by the presence of at least three of the five following primary signs: rest tremor, bradykinesia, rigidity, impaired postural refluxes, and the presence of a sustained L-dopa response.) * Healthy volunteers without Parkinson's disease Exclusion Criteria: * Cases showing atypical features, including multiple system atrophy and progressive supranuclear gaze palsy, or secondary causes of Parkinsonism, such as neuroleptic drugs, infection, tumor, previous cerebrovascular accident and known toxins