While the relationship between the spread of Lewy pathology and clinical progression of PD has been outlined by Braak and his colleagues 13,44, only about half of people with clinical PD have a distribution of Lewy pathology that exhibits the classic pattern of Braak staging, and those with genetic forms of disease can be even more distinct from this pattern of synuclein deposition 45. Here, SNCA is linked to Parkinson disease.