Distribution of HLA-G 14-bp insertion/deletion polymorphism in six Chinese ethnic groups

Recently, a 14-bp insertion/deletion polymorphism (+14 bp/-14 bp) in exon 8 of the Human leucocyte antigen-G (HLA-G) gene has been studied extensively because this polymorphism has been associated with HLA-G mRNA stability and could influence HLA-G mRNA expression. We investigated the distribution of the 14-bp insertion/deletion polymorphism in six different Chinese ethnic groups (Bulang, Wa, Hani, Jinuo, Maonan and Zhuang), which originated from three major ancient tribes (Di-Qiang, Baipu and Baiyue) in China. Comparison of the 14-bp insertion frequency in the six groups with other Chinese groups showed marked variation among the three ancient tribes, Di-Qing (0.490-0.534), Baipu (0.470-0.609) and Baiyue (0.280-0.344). Furthermore, the frequencies of the 14-bp insertion were similar in groups that came from the same ancient tribe, which indicated that the individuals who share the 14-bp insertion have the most probably inherited the 14-bp element from a common ancestor. In addition, an intra-tribal comparison of the 14-bp insertion/deletion frequencies between the descendants of the ancient ancestral tribes suggests that population histories or some environmental effects, such as founder effect or isolation, might also influence the distribution.