This lecture explores the genetic factors underlying Parkinson's disease, focusing on a-synuclein, Parkin, and PINK1. It covers the role of a-synuclein in protein aggregation, the impact of Parkin and PINK1 mutations on mitochondrial quality control, and the link between glucocerebrosidase mutations and Parkinson's. The discussion includes the importance of gene dosage, the formation of Lewy bodies, and the potential therapeutic approaches targeting a-synuclein. The lecture also delves into the classification of genes associated with Parkinson's, the impact of toxins on the disease, and the potential link between exposure to pathogens and Parkinson's.