Genetic variation in antigen-controlling genes compared with array content. Tracks (1 to 5) from outside to inside: (1) representations of HPA (blue)- and RBC antigen (red)–encoding genes; box length equates to the number of amino acids in the protein. RBC and HPA system names are annotated next to gene labels; (2 and 3) coding variants included on the UK Biobank (UKBB) v2 (brown) and UKBB (dark blue) array, respectively; (4) all coding variants with consequences in the gnomAD database (green); (5) antigen-encoding variants in the ISBT and IPD-HPA databases (red). Bar length for tracks 2 to 5 represents gnomAD alternate allele frequency.