Study Rationale:
Biomarkers, or objective measures, of Parkinson's disease (PD) could help identify individuals at risk of PD and predict disease progression. According to recent studies, changes in DNA, such as hydroxymethylation -- the attachment of chemical hydroxymethyl -- can serve as PD biomarkers. It is also known that DNA changes in mitochondria -- powerhouses of the cells -- can affect the risk of Parkinson's and other diseases.
Hypothesis:
In this study, we aim to identify PD biomarkers in mitochondria. These will represent biological changes in mitochondrial DNA (mtDNA), miniature DNA inside each of the mitochondria. These changes could aid in diagnosis and prognosis by serving as a signal of disease or informing about disease progression, respectively. In addition, this study will investigate whether diagnostic or prognostic biomarkers of Parkinson's are influenced by the environment.
Study Design:
The study will compare mtDNA of 180 people with PD with that of 360 healthy volunteers. The attachment of chemical methyl to mtDNA (methylation) will be evaluated in both groups of participants, and differences in methylation between the groups will be identified. We will also investigate whether these differences in methylation change as the disease progresses. This investigation will involve two small subgroups of participants: 10 people with the fastest and 10 people with the slowest disease progression.
Impact on Diagnosis/Treatment of Parkinson's disease:
Firstly, biomarkers based on mtDNA methylation will aid in early diagnosis of PD. These biomarkers will also make possible the use of interventions specific to the course of disease (personalized therapy). Lastly, the discovery of changes in mtDNA associated with Parkinson's, such as methylation, will open avenues for development of new treatment strategies, since changes in methylation are largely reversible.
Next Steps for Development:
Identified biomarkers will need to be confirmed before they enter clinical practice. This will be achieved through additional retrospective and prospective studies, including clinical trials.