The reconstruction with the highest resolution, 2.2 Å for case 1 of PDD, showed density for main-chain oxygen atoms (Extended Data Figure 3c), establishing that α-synuclein filaments with the Lewy fold have a right-handed twist, in contrast to the left-handed twist observed for α-synuclein filaments with the MSA fold (6). Here, SNCA is linked to multiple system atrophy.