The distribution of the five inferred CYP3A5 haplotypes across the dataset. The size of each circle is proportional to the number of individuals sampled from a given population (see Additional file 1 Table S1). The allele combinations at all three loci are given in the key. The alleles in brackets define the inferred haplotype. N.B. the recombinant CYP3A5 haplotype 5: *3/*6, is observed at low frequency in the dataset.