SNPs in ABO and the surrounding region that were most strongly associated with positive functional assay status from (A) meta-analysis of association with functional assay-positive status and (B) fine-mapping of association in PAINTOR. (A) P values were generated using a random-effects meta-analysis of logistic regressions adjusted for age, sex, and principal components 1-3 in an additive model for combined discovery and replication cohorts. P values on the −log₁₀ scale are plotted on the left vertical axis, and the chromosomal position is plotted along the horizontal axis along with the gene names and size of flanking region. The significance threshold of 5 × 10⁻⁸ is indicated by the black horizontal line. Pairwise LD (r²) with this SNP is indicated by dot color as described in the legend in the upper left corner. The right vertical axis indicates the regional recombination rate (cM/Mb), which is overlaid in blue. (B) PAINTOR posterior probabilities based on the association of sequenced ABO SNPs in combined discovery and replication cohorts with functional annotations from FANTOM5, GENCODE, and Transcription Factor Binding Site datasets. Posterior probabilities values on the log₁₀ scale are plotted on the left vertical axis, and the chromosomal position is plotted along the horizontal axis along with ABO exonic/intronic regions. Z Scores for association with functional assay-positive status are indicated by dot color as described in the legend in the upper right corner.