ENVIRONMENTAL AND GENETIC RISK-FACTORS IN PARKINSONS-DISEASE - A CASE-CONTROL STUDY IN SOUTHERN ITALY

To clarify the role of heredity and of some environmental risk factors in the etiology of idiopathic Parkinson's disease, we performed a cas e-control study in two regions of southern Italy, Campania and Molise. We selected two controls for each parkinsonian patient, the patient's spouse and a sex- and age-matched neurological control. One hundred s ixteen consecutive outpatients with Parkinson's disease (77 men, 39 wo men; mean age +/- SD = 62.5 +/- 9.9) and the same number of spouses an d neurological controls were interviewed about five environmental risk factors (cigarette smoking, well-water drinking, head trauma with los s of consciousness, strict diets, general anesthesia) and two genetic risk factors (family history of Parkinson's disease or of essential tr emor). Well-water drinking and family history of Parkinson's disease o r essential tremor showed a positive association with Parkinson's dise ase; smoking showed a negative association. The most relevant risk fac tor was history of familial Parkinson's disease (odds ratio = 14.6; 95 % confidence interval = 7.2 - 29.6); 33% of our patients had at least one affected relative. We also showed a unilateral distribution of anc estral secondary cases on the paternal or on the maternal side, which suggests a dominant inheritance. Clinical and epidemiologic features o f cases with familial Parkinson's disease showed no peculiarity. The s tudy suggests a strong role of the genetic factors in the etiology of Parkinson's disease.