A National Institutes of Health-funded study shows that cells from patients with different types of Parkinson disease have unique drug responses, a finding that suggests that personalized medicine for the disease is possible.
For this study, researchers collected skin cells from patients with genetically inherited forms of Parkinson disease and reprogrammed those cells into neurons. They found that neurons derived from people with distinct types of the disease showed common signs of distress and vulnerability—in particular, abnormalities in the cellular energy factories known as mitochondria. At the same time, the cells' responses to different treatments depended on the type of Parkinson disease that each patient had.
Most cases of Parkinson disease are sporadic, meaning that the cause is unknown. However, genetics plays a strong role. There are 17 regions of the genome with common variations that affect the risk of developing Parkinson disease. Researchers also have identified 9 genes that, when mutated, can cause the disease.
These results hint that induced pluripotent stem (iPS) cell technology could help define subgroups of patients for clinical trials. To date, interventional trials for Parkinson disease have not focused on specific groups of patients or forms of the disease, because there have been few clues to point investigators toward individualized treatments. Although the current study focused on genetic forms of the disease, iPS cell technology also could be used to define disease mechanisms and the most promising treatments for sporadic Parkinson disease.