Our goal was to use GWAS results to identify relevant tissues and cell types. Our primary focus was human phenotypes whose etiopathology is based in the central nervous system. We thus obtained 18 sets of GWAS summary statistics from European samples for brain-related complex traits. These were selected because they had at least one genome-wide significant association (as of 2018; e.g., Parkinson’s disease, schizophrenia, and IQ). For comparison, we included GWAS summary statistics for 8 diseases and traits with large sample sizes whose etiopathology is not rooted in the central nervous system (e.g., type 2 diabetes). The selection of these conditions allowed contrasts of tissues and cells highlighted by our primary interest in brain phenotypes with non-brain traits. For Parkinson’s disease, we meta-analyzed summary statistics from a published GWAS 19 (9,581 cases, 33,245 controls) with self-reported Parkinson’s disease from 23andMe (12,657 cases, 941,588 controls) after finding a high genetic correlation (rg) 20 between the samples (rg=0.87, s.e=0.068). In this new meta-analysis, we identified 61 independent loci associated with Parkinson’s disease (49 reported previously 18 and 12 novel) (Figure S1).
