Parkinson’s disease is a movement disorder that gradually worsens over time. As the disease progresses, people may have trouble walking, talking, and performing simple tasks. The exact cause of Parkinson’s disease is not known, but people with one or more close relatives with the disease are at increased risk of developing it. And some studies have found that certain genetic mutations are more common in people with Parkinson’s disease.

A new study in the January 26, 2006 issue of the New England Journal of Medicine looked for gene mutations in a group of Ashkenazi (Eastern European) Jews. The researchers found that a single mutation was closely linked to Parkinson’s disease in the Ashkenazi Jewish population.

About the Study

This study included 120 unrelated Ashkenazi Jews with Parkinson’s disease and 317 Ashkenazi Jews without Parkinson’s disease (the controls). Researchers collected cells from blood samples or cheek swabs from all the participants, and performed DNA testing to determine whether the participants carried certain genetic mutations. The gene the researchers focused on was the LRRK2 gene, which is mutated in about 1% of Parkinson’s disease patients of European descent.

The LRRK2 G2019S mutation (the most common LRRK2 mutation) was detected in 18.3% of the participants with Parkinson’s disease and 1.3% of the control group. The mutation was more common in the participants with Parkinson’s disease who had a family history of the disease, with 29.7% of those participants carrying the mutation, compared with 13.3% of those who did not have a family history.

How Does This Affect You?

This study suggests that genetics probably plays a major role in the development of Parkinson’s disease in the Ashkenazi Jewish population. It is becoming increasingly clear that a person’s genetics has an important influence over his or her risk of developing Parkinson’s disease.

Outside of a research environment, genetic testing is not currently available for Parkinson’s disease, but should it be? By testing for certain gene mutations, physicians may be able to determine whether a person is at increased risk for this often devastating disease, or even detect it in its early stages. But since there is not yet a way to prevent or cure Parkinson’s disease, the worry and anxiety associated with genetic testing may outweigh the benefits.