Peripheral blood samples were either genotyped using the Illumina (Illumina, San Diego, USA) HumanHap300, HumanHap370 or 610 Quad platform. Genotyping was performed according to standard protocols from Illumina. Although the different genotype oligonucleotide arrays differ, they share 294,757 SNPs, to which the analysis was confined. In addition, SNPs with a minor allele frequency of <5%, or a call-rate <95%, or deviating from Hardy-Weinberg equilibrium (exact p-value <0.001) were excluded, resulting in 289,044 SNPs for further analysis. Genotype calling for each SNP was performed by a previously described algorithm [51].
