For example, genetic risk factors for PD particularly affect genes involved in the autophagy and lysosomal pathway, which is responsible for protein clearance and degradation.194,196,197 α-Synuclein aggregates are cleared by lysosomal degradation,198 suggesting that PD pathogenesis involves an aberrant accumulation of misfolded α-synuclein. This evidence concerns the gene SNCA and Parkinson disease.