HLA sampling (A) is much more widespread than that of the 1,000 Genomes Project (B), which represents the current reference panel of human genomewide diversity.

A. Circles represent the populations that were HLA typed. Colors and size of the circles correspond to the number of common alleles observed in each population (scales in the bottom left corner). B. Circles represent the region of origin for each of the 26 populations of the 1,000 Genomes Project. Each population has a color that corresponds to the associated geographical region: Europe (blue), Africa (yellow), Americas (red), South Asia (purple), and East Asia (green). A-B. Maps were generated using the ggplot2 package in R [16] and the world database.