Toward Personalized Medicine in Parkinson's Disease: A Scoping Review of Biomarkers, Genetics, and Treatment Stratification.

Personalized medicine is transforming Parkinson's disease (PD) care by tailoring therapies to patients' genetic, biomarker, and clinical profiles. Given PD's heterogeneity, this strategy offers new possibilities for disease-modifying interventions beyond symptom management. A systematic search of PubMed and EBSCO MegaFILE was conducted following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) 2020 guidelines. Studies addressed genetic profiling, biomarker discovery, individualized therapeutic strategies, or experimental/computational models relevant to personalized PD care. Twenty studies were included. Major themes identified were the use of genetic markers such as LRRK2 and GBA mutations for patient stratification; advances in alpha-synuclein and other biomarkers for early diagnosis, though standardization remains a barrier; the application of patient-derived induced pluripotent stem cell (iPSC) models and brain organoids to test genotype-specific therapies; and the integration of multi-omics and machine learning to refine disease subtyping and drug discovery. Challenges included limited access to genetic testing, a lack of validated biomarkers, and barriers to clinical translation. Personalized medicine in PD is progressing rapidly, but significant barriers remain before it can be fully integrated into routine care. Future priorities include validating biomarkers, expanding pharmacogenetic infrastructure, and translating biologically informed strategies into clinical practice.