Genotype data were obtained using three different Illumina single nucleotide polygmorphism (SNP) genotyping platforms (317K, HumanCNV370-Quadv3,Human CNV370v1 and Human610-Quad). Standard quality control procedures were applied as outlined previously36, including checks for ancestry outliers, Hardy–Weinberg equilibrium (p<10−6), Mendelian errors, call rate, genotypic missingness (>5%), individual missingness (>5%) and minor allele frequency (<0.01). Individuals were pruned on relatedness, removing one individual from each pair with relatedness greater than 0.05, as determined from genetic data. The final sample therefore comprised 2,082 ‘unrelated’ individuals (see Table 1 for sample details).
