SNCA and Parkinson disease: We also identified a robust association between Parkinson’s disease and SNCA (rTWAS Z and joint Z = 13.9, rTWAS P and joint P = 3.8 x 10-44, rTWAS Bonferroni P = 3.1 x 10-40, PIP = 1.0), which encodes alpha-synuclein, the protein that makes up Lewy bodies, i.e., aggregates of protein that develop inside nerve cells that appear to contribute to neurodegeneration and are often seen in brain autopsies of individuals with Parkinson’s disease (Chen et al., 2020).