We performed association analyses of SNPs on the X chromosome in our two largest cohorts, UKB (N = 329,358) and 23andMe (N = 365,536). The UKB analyses were conducted in a sample of conventionally unrelated European-ancestry individuals, yielding a smaller sample size than the autosomal UKB analyses (Supplementary Table 26). Imputed genotypes for the X chromosome were not included in the data officially released by UKB. We therefore imputed the data ourselves using the 1000 Genomes Project41 as our reference panel.
