An interesting study that examined the pathology of cortical and striatal a-synucelin in patients with PD, Parkinson’s disease dementia (PDD), and dementia with Lewy bodies (DLB) and reported that patients with PDD and DLB had greater pathology for cortical and striatal α -synuclein than did patients with PD [8], suggesting a direct association between α -synuclein and dementia. The gene discussed is SNCA; the disease is Parkinson disease.