Gene Works with Pesticides to Up Parkinson's Risk
In the body, many pesticides are broken down and made less toxic by an enzyme called cytochrome P450 D6 (CYP2D6). A certain variant in the CYP2D6 gene has been shown to produce an enzyme that is less effective at breaking down pesticides. As a result, people with this variant may be more susceptible to pesticides that might cause Parkinson's disease.
The findings, which are reported in the Annals of Neurology, are based on a study of 247 Parkinson's disease patients and 676 healthy subjects enrolled in the French health insurance organization for farmers and related job classes. DNA from subjects in both groups was tested for the CYP2D6 variant.
Consistent with previous reports, Dr. Alexis Elbaz, from Hopital de la Salpetriere in Paris, and colleagues found that pesticide exposure increased the risk of Parkinson's disease, even in people without the gene variant. No elevated risk of Parkinson's disease was seen in people not exposed to pesticides, even if they had the variant.
The highest Parkinson's disease risk occurred in pesticide-exposed subjects who had no normal copies of CYP2D6, only variants, the authors note. Compared with other exposed patients, such patients were 2.4-times more likely to have Parkinson's disease.
"Larger studies and laboratory data may help to elucidate which pesticides are metabolized through (the CYP2D6) pathway and have an effect on the risk of Parkinson's disease," the investigators conclude.