Epidemiological clues for the etiology of Parkinson's disease.
D004198:Disease Susceptibility; D004200:Diseases in Twins; D004812:Epidemiologic Methods; D006801:Humans; D010300:Parkinson Disease / Q000453:epidemiology / Q000209:etiology* / Q000235:genetics; D010375:Pedigree; D010551:Personality; D012306:Risk