HLA-DQ8

DQB1*0305 gene product reacts slightly more intensely with DQ8 than DQ7 its generally rare in Europe and North America, except in a few indigenous populations.DQ8 β-chains combine with α-chains, encoded by genetically linked HLA-DQA1 alleles, to form the cis-haplotype isoforms.There are 3 places where haplotype frequency is elevated, Central and South America, NE Pacific Rim, and Northern Europe.Studies on Epstein Barr Virus[21] and other proteins suggest both proteins are acidic (meaning peptides with increased negative charge) peptide presenters (see DQ8 for an illustration of the presentation process) and may have been adaptive for certain hunting and gathering lifestyles, possibly coastal foragers.There is a modern hiatus of DQ8 in the Alaska-Eastern Siberian region and it is unclear whether this is due to replacement, selection, or the mode in which first Americans arrived (i.e. strictly maritime route).The Cook Island DQ8 had only one associated DR haplotype suggesting diversity limiting introduction into the region, either via the TW-(Japan/Korea/China) route or through the west, for example the Bunun have high DRB1*0403.There are many common markers found in France, Germans, Danes, Swedes, Tibetans, Amur River, Japanese and Koreans that are potential indicators of this bilateral spread.The path of DQ8 spread to the New World is enigmatic, certainly Japan and Amur River are potent sources, but other displaced populations cannot be ruled out.If the mode of travel was through the Beringia corridor as proposed by archaeologist, the very low frequency of DQ8 at present is a very unusual find with regard to evidence for complete displacement elsewhere in the World.Most of American cultivars were domesticated south of the Rio Grande (exceptions are Caddo rice and Texas varigated squash, etc.).DQ8 is also found in many indigenous peoples of Asia, it was detected early on in the Bedoin population of Arabia where DQ2.5 is frequently absent, and in these instances DQ8 is solely associated HLA in coeliac disease.