Imputation was performed with EAGLE2 (ref. 42) to pre-phase each chromosome and Minimac3 (ref. 43) to impute genotypes with 1000 Genomes Project phase 3 data44 as the reference panel. Subjects with no demographic information or whose genotypic and phenotypic sex did not match were removed. We also removed one subject randomly from each pair of related individuals (kinship coefficient threshold = 0.0884). A greedy algorithm was implemented for network-like relationships among three or more individuals, leaving 331,736 subjects for subsequent analyses.
