This distribution, however, is not strict: nfvPPA can be due to FTLD-TDP (type A or B) and AD [18–20], svPPA to tau or Alzheimer-type deposits [17, 18], and lvPPA to TDP-43 (type A) or alpha-synuclein deposits (dementia with Lewy bodies (DLB)) [17, 21]. This evidence concerns the gene SNCA and Lewy body dementia.