Analysis of the 14 bp insertion and deletion polymorphism in human leukocyte antigen-G gene in two Chinese ethnic populations.

The biological significance of human leukocyte antigen-G (HLA-G) is now beyond its initial concepts on the fetal-maternal immune regulation. HLA-G in various pathophysical conditions has been investigated, such as autoimmunity, tumor, inflammation and transplantation. HLA-G has also been postulated as a chemotherapy response marker both in protein and in genetic contexts. In the current study, a total of 640 Chinese Han and 258 Chinese She ethnic minority populations had been genotyped for the 14 bp insertion (+14 bp) and deletion (-14 bp) polymorphism in the HLA-G gene. Significant difference was observed for both the +14 bp/+14 bp (15.2% in the Han and 6.6% in the She; P = 0.00048, P(c) = 0.00097) and -14 bp/-14 bp (34.5% in the Han and 50.4% in the She; P = 1.05 x 10(-5), P(c) = 2.1 x 10(-5)) genotypes between the two populations, and similar significance was found for both +14 bp (40.3% in the Han and 28.1% in the She) and -14 bp allele distributions (P = 1.2 x 10(-6), P(c) = 2.4 x 10(-6)). Furthermore, frequencies of the 14 bp genotype and alleles both in the Chinese Han and in the Chinese She populations were compared with other ethnic populations. Data showed that dramatic variations between different ethnic populations were also observed for this polymorphism. In summary, our results indicate that heterogeneity of the 14 bp polymorphism in the HLA-G gene among different ethnic populations is possibly the result of evolution.