Multiple studies advance understanding of Parkinson's disease biology and diagnostics. Research into genetic variant severity and polygenic backgrounds informs penetrance and progression risk for GBA1 carriers. A task-based fNIRS study identifies neural bases for cognitive impairments in early Parkinson’s with mild cognitive impairment. Detection of volatile organic compounds emerges as a promising non-invasive strategy for monitoring and diagnosing Parkinson’s disease. These findings offer potential pathways for improved patient stratification and monitoring.