Familial influence on parkinsonism in a rural area of Turkey (Kizilcaboluk-Denizli): a community-based case-control study.

This population-based study on parkinsonism in a genetically isolated community from a rural area of Turkey aimed to provide a selective evaluation of environmental and heritable risk factors. An increased prevalence of parkinsonism (4.1%) was detected in the village of Kizilcaboluk for people 65 years of age and older. This study included 36 patients with parkinsonism living in Kizilcaboluk and three times that number of age- and sex-matched people serving as controls. A questionnaire including demographic data, family history, education, occupation, data on exposures to pesticides, smoking, alcohol intake, and head trauma was administered. We found a significant association of parkinsonism cases with a positive family history in first-degree relatives (odds ratio OR], 7.48; 95% confidence interval CI], 2.52-22.17; P < 0.0001) and with pesticide exposure (OR, 2.96; 95% CI, 1.31-6.69; P = 0.015) compared to the control subjects. The value of genetically isolated populations for the identification of genetic risk factors for common and complex disorders has gained much attention recently because the genetic make-up of these populations is likely to be less complex than that of the general population and our findings should prompt investigations to the nature of a familial aggregation of parkinsonism in this population.