中国壮族和裕固族群体HLA Ⅰ类区域Alu插入多态性及其与HLA-A位点的相关性

近年来研究发现:位于HLAⅠ类基因区域的Alu插入是研究不同群体HLAⅠ类基因区域祖先单倍型和HLAⅠ类基因多样性产生、进化和重组的理想工具。文章对中国壮族和裕固族群体HLAⅠ类基因区域5个Alu插入多态性(AluMICB、AluTF、AluHJ、AluHG和AluHF)进行研究,结合HLA基因分型数据,分析壮族、裕固族、哈尼族、布朗族和傣族5个民族群体中Alu插入与HLA-A等位基因的关系。研究结果显示:(1)壮族和裕固族人群中5个Alu插入频率范围分别为1.5%~35.8%和9.2~34.8%,AluMICB、AluTF和AluHF插入频率在这两个群体中有统计学差异(P<0.05);(2)在5个研究的群体中,AluHG插入与HLA-A*02的不同亚型关联;AluHJ插入与HLA-A*2402在5个群体中都关联,但AluHJ与HLA-A*1101和HLA-A*2407只在布朗族中关联。表明不同群体HLAⅠ类基因区域内Alu插入具有各自的特征,且Alu插入与不同的HLA-A等位基因相关联。这种Alu插入及其与HLA-A的关联特征可作为研究群体中HLAⅠ类基因和单倍型系谱变化的重要遗传标记。

Polymorphic Alu insertions and their associations with HLA I alleles in Yugu and Zhuang ethnic populations

Many studies have show that the structurally polymorphic Alu insertion within HLA class I region are useful tools for investigating the origin, evolution and recombination of HLA class I progenitor haplotypes and gene diversity in different ethnic populations. In the present study, we determined the frequencies of HLA-Alus (i.e., AluMICB, AluTF, AluHJ, AluHG, and AluHF) in Zhuang and Yugu ethnic populations at first. Then, combined with HLA genotyping data, we studied associations between HLA-Alus and HLA-A alleles in Zhuang, Yugu, Bulang, Dai, and Hani ethnic populations. Our results showed that (1) the frequencies of five HLA-Alus were 1.5%~35.8% and 9.2%~34.8% in Zhuang and Yugu, respectively; and (2) the results of association between HLA-A alleles and HLA-Alu showed strong association between AluHG insertion and HLA-A 02 subtypes in all populations, association between AluHJ insertion and HLA-A 2402 in all populations, and association between AluHJ insertion and HLA-A 1101, -A 2407 in Bulang. The present study suggested that the distribution of HLA-Alus as well as the associations between HLA-Alus and HLA class I alleles are variable in different ethnic populations. HLA Alus alone or together with the HLA class I alleles are informative genetic markers for the identification of HLA class I allele and variation of haplotype lineages in different populations.