Activating KIR show much greater variation in their presence/absence in different populations. For example KIR2DS1 has four populations with greater than 80% frequency (Australia Aborigines, Brazil Amazon, Brazil Rodonia Province Karitiana and Papua New Guinea Nasioi) but three African populations with < 10%; Central Africa Republic Bagandu Biaka, Ghana and Nigeria Enugu Ibo. Similarly, KIR2DS2 has high frequencies (> 70%) in nine populations (e.g. Australia Aborigines, South Africa San and Xhosa and populations from India) but very low frequencies in Japan

(8·5–16·0%), South Korea (16·9%) and China (17·3%). In some of the South American Amerindian populations KIR2DS3 is absent – Argentina Salta Wichis, Mexico Tarahumaras, Venezuela Bari CHIR-99021 mw and Venezuela Yucpa.53,54 The frequency of this gene is also low Selleck LY294002 in Japan and China. The KIR2DS4 gene is present in seven populations at 100% – either from Africa or African Americans in USA. However, it has also low frequencies – Costa Rica (31%), Australia Aborigines (52%), Taiwan (59·4%). Selection against having KIR3DS1 has been reported

in African populations25 with KIR3DS1 present in San (2·2%), Xhosa (4·0%), Nigeria (3·4% and 6·3%), Senegal (4·0%), Kenya (0·7%), Ghana (4·9%), Central Africa Republic Bagandu Biaka (2·9%). Global phenotype frequencies of KIR3DS1 are shown as an example of how the data can be represented (Fig. 6). Obviously there is a close inverted correspondence between the frequencies of KIR3DL1 and KIR3DS1 in an individual population. A very small percentage of individuals (0·34%) are negative for both KIR3DL1 and KIR3DS1. Such extensive diversity between modern populations may indicate that geographically distinct diseases have exerted recent, or perhaps ongoing, selection on KIR

repertoires. The differences in frequencies therefore make the choice of controls for disease studies very important for all populations. We linked the published data by analysing all populations submitted to the website that had data for 13 KIR genes (excluding KIR2DP1 and KIR3DP1).55 ID-8 The 56 populations analysed, using neighbour-joining dendrograms and correspondence analysis, grouped with a few exceptions according to a geographical gradient. Subsequently, we selected 38 of the 56 populations that we considered to be well defined in the anthropological sense. We found that based on KIR haplotype B genes (i.e. genes mainly encoding activating KIR) the populations were related to geography like a good anthropological marker such as HLA or Y chromosome. However, the results based on the KIR haplotype A (i.e. genes mainly encoding inhibitory KIR) did not show such a correlation.56 There has been an increase in the number of known alleles from 87 in the first KIR nomenclature report in 2002 to 335 in the latest release on the IPD-KIR database, where the sequence of all KIR alleles is kept.