HLA B7-DR15-DQ6

HLA B7-DR15-DQ6 is a multigene haplotype that covers a majority of the human major histocompatibility complex on chromosome 6. A multigene haplotype is set of inherited alleles covering several genes, or gene-alleles, common multigene haplotypes are generally the result of descent by common ancestry (share a recent common ancestor for that segment of the chromosome). Chromosomal recombination fragments multigene haplotypes as the distance to that ancestor increases in number of generations.

HLA B7-DR15-DQ6 is a representation(by serotype) of a common HLA haplotype found in Western Eurasia. The haplotype can be written in an extended form covering the major histocompatibility loci as follows:

HLA Cw*0702 : B*0702 : DRB1*1501 : DQA1*0102 : DQB1*0602

The older literature may describe this haplotype in two different ways. One B7-DR2-DQ6 derives from the fact that DR15 is a split antigen of the DR2 broad antigen serotype. The other B7-DR2-DQ1 stems from the fact that DQ1 is an alpha chain serotype that is now covered by the beta chain type DQ5 and DQ6 (DQ1 pairs with DQ5 and DQ6 by cis-haplotype pairing).

There are two major subhaplotypes one that is preceded on its telomeric side by HLA A*0301 and the other by HLA A*0201. The A*0301 bearing haplotype (HLA A3-B7-DR15-DQ6) is described as the longest known multgene haplotype in humans.