Figure 1.

(a) Amino acid sequences of the most common subtypes of HLA-DR8. The amino acid sequences of the extracellular domains of the alleles of the DRB1*08 group are compared, and indicate amino acid identity in a specific position with the allele DRB1*08:01. (b,c) Distribution of alleles of the HLA-DRB1*08 was inferred from 224 population samples, indicated by the plotted points. (d) Distinguishing nucleotide substitutions of common subtypes of HLA-DR8 of Native Americans and Africans. The graphical representations were obtained using PyPop software from a compilation of a meta-analytic review [19]. The coloured regions indicate interpolated allele frequency; grey areas are too far from a sampled population to permit meaningful frequency estimation. Only non-migrant populations were used to generate these maps. Frequency maps for all alleles at all loci are available at http://www.pypop.org/popdata/. Adapted from Solberg et al. [20].