The study found 14 percent of the people with Parkinson's disease carried mutations in the glucocerebrosidase (GBA) gene compared to only five percent of people without the disease. The gene abnormality was found in 22 percent of people who were diagnosed with Parkinson's disease before age 50 compared to 10 percent of the people with disease onset after age 50.
Mutations in the GBA gene cause Gaucher's disease, which is a rare disorder that prevents organs, such as the spleen and brain, from working properly due to the build-up of a fatty substance called glucocerebroside.
"Our results confirm that GBA mutations are risk factors for Parkinson's disease and may lead to getting the disease at a younger age," said study author Lorraine N. Clark, PhD, and coauthor Karen Marder, MD, MPH, with Columbia University's Taub Institute for Research on Alzheimer's Disease and the Aging Brain, and Departments of Pathology and Neurology, in New York.
"We found those people with GBA mutations developed Parkinson's disease nearly two years earlier than people without the gene abnormality," N. Clark added.
The study also looked at how Jewish ancestry affected the likelihood of getting Parkinson's disease at an earlier age since some studies have found people with Jewish ancestry are more likely to have GBA mutations.
Of those with Parkinson's disease, researchers found the gene abnormality in 17 percent of the participants with Jewish ancestry compared to only eight percent of those without Jewish ancestry, suggesting that it may be an important risk factor in people with Jewish ancestry.
The study is published in the September 18, 2007, issue of Neurology, the medical journal of the American Academy of Neurology.