This big study looked at more than sixty-seven thousand people from many different countries. It compared those who carry one copy of a specific gene change called GBA1 L444P with those who do not carry this change. The goal was to see how this gene affects the risk of developing Parkinson's disease.
The results showed a very clear difference between the two groups. People with the gene change had about nine times higher chance of developing Parkinson's disease than people without it. This difference was seen across many different groups of people from around the world.
However, the study noted that some smaller groups had less clear results because there were not enough people in those specific categories. Despite this, the main message is strong: having this gene change makes a person much more likely to develop Parkinson's disease. This information is very useful for genetic counselors and doctors talking with families about their health risks.