Platelet Biomarkers Identify Progression Signals in Parkinson's Disease

Parkinson's disease can begin relatively early and may progress to dementia in some patients. Monitoring disease progression remains challenging because accessible molecular markers are still being investigated. Platelets may provide a blood-based window into changes in gene activity associated with the disease. 

Researchers at the Germans Trias i Pujol Research Institute (IGTP; Barcelona, Spain) identified platelet gene-expression changes associated with disease progression in a rare case of early-onset Parkinson's disease. The study focused on platelets as an accessible blood component for investigating potential biomarkers and compared gene activity in platelets with that in whole blood. Changes associated with disease progression were more pronounced in platelets.

The study involved a patient with early-onset Parkinson's disease who rapidly progressed to dementia and carried a triplication of a genomic region containing SNCA, the gene encoding alpha-synuclein. The genetic alteration arose de novo and spanned a 2.41-megabase region containing 21 genes. Longitudinal follow-up allowed the researchers to compare gene expression at age 41, during early disease, with expression at age 44, after dementia had developed.

The analysis identified progression-associated changes in genes involved in mitochondrial function, protein synthesis, and regulation of inflammation. To determine whether similar patterns occurred in other forms of the disease, the researchers analyzed selected genes in an independent cohort of 15 patients with early-onset sporadic Parkinson's disease and 18 healthy individuals.

In platelet samples from these patients, reduced expression of an SNCA RNA variant and YWHAB, together with increased expression of MMRN1 and two protein synthesis-related genes, mirrored findings from the genetic case and remained statistically significant after correction for multiple comparisons. No significant differences in the analyzed genes were detected in whole blood.

The study was published online in Movement Disorders on October 14, 2026. Collaborating institutions included IGTP, Hospital Germans Trias, the Universitat Autònoma de Barcelona, and the Josep Carreras Leukaemia Research Institute. The findings provide a basis for further research into platelets as a source of blood biomarkers, while noting that the longitudinal component was limited to one patient at two disease stages and did not validate biomarker utility for progression.

“The relevance of this study extends beyond this rare genetic alteration. Some of the molecular signals identified are also present in patients with early-onset sporadic Parkinson's disease. This suggests that studying rare cases can help us understand shared mechanisms and open up new avenues for investigating disease progression,” said Susanna Jiménez, first author of the article.

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Germans Trias i Pujol Research Institute