Meta-analysis of SNPs common to all four GWAS ( N = 6661818 and N = 6496414 for all AML and cytogenetically normal AML, respectively) also revealed additional borderline significant susceptibility loci at 1p31.1 (rs10789158, CACHD1 , P = 2.25 × 10 −7 ) for all AML and at 7q33 (rs17773014, AKR1B1 , P = 4.09 × 10 −7 ) for cytogenetically normal AML, both with consistent direction and magnitude of effect across all four studies (Figs. 1 and 2 ).
Quantile-quantile plots of observed versus expected P values (minor allele frequency (MAF) >0.01) for all AML cases and cytogenetically normal AML cases showed minimal inflation of test statistics across all three GWAS after adjustment for nominally significant principal components in each GWAS ( λ GC = 1.021, 1.025, and 1.055 for all AML in GWAS1, GWAS2, and GWAS3, respectively; λ GC = 1.006, 1.011, and 1.025 for cytogenetically normal in GWAS1, GWAS2, and GWAS3, respectively) (Supplementary Figs. 6 – 7 ), minimizing the possibility of hidden population stratification and cryptic relatedness.