Although most of the cases included in the published anorexia nervosa GWASs were included in this analysis, many of the controls used in previous GWAS could not be used for subsequent analyses. To summarize, our analysis includes the CHOP/PFCG data (7) plus cases from 12 of the 15 strata included in the GCAN/WTCCC3 analysis of anorexia nervosa (6). Three datasets (Italy-North, Sweden, and Poland) in Boraska et al. were dropped from our analysis because appropriately matched controls could not be found and/or where case plus control numbers were < 100. After removing these three datasets and combining the US and Canadian cases, we included 11 GCAN/WTCCC3-based datasets plus the CHOP/PFCG dataset in our analyses. For the nine datasets requiring new controls, we first evaluated diverse control datasets from Psychiatric Genomics Consortium (PGC) collaborators for potentially suitable controls based on geographic location and Illumina genotyping. We then performed quality control (QC) steps (below, and with additional details in the Supplementary Text), using visual inspection of principal components plots (comparing cases to controls) as well as QQ and Manhattan plots (for evidence
