广东人群PP2A-Aα亚基基因5′-侧翼区单体型分析

Genetic variants of haplotypes in the 5′-flanking region of protein phosphatase 2A-Aα gene in Cantonese,China

目的探讨蛋白磷酸酶2A(PP2A)-Aα亚基基因启动子区多态性的人群单体型分布特征。方法采用Haploview软件分析部分广东汉族人群PPP2R1A基因5′-侧翼区筛查到的7个多态性位点的遗传学特征、连锁不平衡(LD)、标签(tag)SNP和单体型(域)分布。结果各多态性位点基因型频率均符合H-W平衡(P>0.05);各位点在该人群的杂合度(π)不同,且在-568G>A和+87T>C与HapMap中的不同人群存在明显差异(P<0.05);-1039G>T(+Ins)与+87T>C和+108A>G、-568G>A与-241-/G位点之间呈强LD,+87T>C与+108A>G之间为完全LD;构建该人群中的5种单体型(H1～H5),频率分布为野生单体型(H1)53%、其余4种变异单体型(H2～H5)为44%;得到两个单体型域,筛选出-1039G>T(+Ins)、-512G>A、-241-/G、+107-/C为4个tag SNP,并确定了2个单体型域内标签SNPs(htSNP)及其分别代表的单体型。结论首次确定并报道中国广东汉族健康人群PPP2R1A基因5′-侧翼区的标签SNP和单体型(域)分布。

Objective To investigate the linkage disequilibrium（LD） and haplotype distribution of genetic variants in the 5′-flanking region of PP2A-Aα subunit gene（PPP2R1A） in Guangdong Han population.Methods HaploView software was used to analyze the genetic characteristics,the LD and the tag of seven single nucleotide polymorphisms（SNP） previously identified by DNA sequencing in the 5′-flanking region of PPP2R1A.Results All the allele frequencies were in the Hardy-Weinberg equilibrium（P〉0.05）.The population heterozygosities（π） of 6 SNPs were over 0.15,while a novel-512G〉A SNP site was 0.05.The results showed that these polymorphisms had high LD between-1039G〉T and ＋87T〉C,-1039G〉T and ＋108A〉G,-568G〉A and-241-/G in the population.Complete LD was found between ＋87T〉C and ＋108A〉G.Five major haplotypes were established,while wild type haplotype was 53%.Tag SNPs were confirmed for four polymorphisms,including-1039GT（＋Ins）,-512G〉A,-241-/G and ＋107-/C.Two haplotype blocks were constructed,and their representative haplotypes were constructed with-512G〉A and ＋108A〉G as haplotype tag SNP（htSNP）.Conclusion The tag SNPs and the haplotypes of genovariants in 5′-flanking region of PPP2R1A were identified for general Guangdong Han Chinese population.These results provide a basis for the further functional analysis of promoter haplotypes.