Inclusion Criteria:  Diagnosis of Parkinson's disease according to UK PD brain bak criteria OR diagnosis of parkinsonian syndrome: multiple system atrophy, progressive supranuclear palsy, dementia with Lewy body, or corticobasal syndrom OR Subjects at risk of PD defined as :  No symptom or diagnosis of Parkinson's disease nor parkinsonian syndrome, and relative to a patient with a diagosis of PD or parkinsonian syndrome, or carrier of a known mutation responsible for a genetic form of PD or patient with a diagnosis of idiopathic REEM sleep disorder or prodromal form of PD as defined by MDS criteria (Berg et al., 2015)  AND for all participants  Affiliated to social security Age > 10 years  Exclusion Criteria:  Subject under legal protection Subject who do not consent to the research for the optional skin biopsy only: clinically significant coagulation abnormalities or anticoagulant treatment