The ALSPAC sample was genotyped on the Illumina HumanHap550 quad SNP genotyping platform by the Wellcome Trust Sanger Institute (Cambridge, UK) and Laboratory Corporation of America (Burlington, NC, US). Samples were subjected to quality control filters as previously described (Edwards et al., 2015). Data were imputed using a phased version of the 1000 Genomes reference panel (Phase 1, Version 3), using Impute V2.2.2 and all reference haplotypes to maximize imputation quality.
