Familial occurrence of Parkinson's disease in a community-based case-control study

Purpose: To study the occurrence of Parkinson's disease (PD) in the relativ es of parkinsonian patients (n = 119), and of their matched controls (n = 2 38). Scope: More patients reported a positive family history of PD in their firs t degree relatives, compared to their controls (OR 2.7, 95% CI 1.3-5.9), an d the incidence of PD among those relatives was also significantly higher ( OR 1.4, 95% CI 1.1-1.8). Conclusions: Familial occurrence of PD is not necessarily a sign of genetic mechanisms in the etiology of PD. Shared environment with common risk fact ors might be even more important. (C) 2001 Elsevier Science Ltd. All rights reserved.