Identifying Risk Factors in PD
The first step to a better understanding of Parkinsonís disease and other movement disorders is to identify and describe the shared characteristics of people who have these types of disease.
- Environmental Factors
- In the early 1980s, interest in environmental causes of Parkinsonís disease was ignited by the description of a cluster of parkinsonism produced by the chemical,1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), which causes symptoms of Parkinsonís disease in humans and experimental animals. Following this, scientists have investigated numerous associations between environmental exposures and Parkinsonís disease.
- Genetic Factors
- When persons with Parkinsonís disease (cases) are compared to those without the disease (controls), cases report more family members with the disease than do controls. However, studies in populations of twinsówho are either genetically similar or even identicalódo not support a major genetic effect for the development of Parkinsonís disease.
In a small percentage of individuals, however, Parkinsonís disease has been associated with mutations in certain genes.
- Combined factors (gene-environment interactions)
- In general, genetic and physical states probably affect each personís likelihood of developing Parkinsonís disease differently, making them more or less vulnerable to certain common exposures, such as pesticides or solvents.