中文摘要：

目的：探讨蛋白磷酸酶2A-Aα亚基基因PPP2RIA启动子区的遗传多态性在中国南方汉族人群中的分布特征。方法：随机选取部分广东汉族人群,获取全血基因组DNA。PCR扩增获得PPP2RIA基因5′-侧翼区的目的片段产物直接再测序,筛查并确证潜在的基因多态性位点,采用HaploView软件进行该人群多态性等位基因分布频率的分析、并与HapMap结果进行分布特征比较。结果：PCR扩增和成功测序63例健康人（126条染色体）PPP2RIA基因-1 844～＋201nt的目的片段,序列比对发现该人群中6个已知多态性位点及其人群最小等位基因频率分别为-1 039 G〉T（＋Ins）（rs10414793,但其中T等位基因型含有29个碱基片段的插入）（8.73%）、-568 G〉A（rs1864007）（25.40%）、-241 -/G（rsl 1453459）（26.90%）、＋87 T〉C（rs13344984）（7.94%）、＋107 -/C（rs3833207）（30.16%）和＋108 A〉G（rs1 7554825）（7.94%）;且其中2个位点在该人群中的分布与HapMap公布的国外人群数据存在不同（P〈0.05）;同时,该人群中还发现-512 G〉A（2.38%）的潜在新多态性位点。结论：筛查PPP2RIA基因5′-侧翼区在中国广东汉族人群中多态性位点的等位基因分布,为进一步开展多态性功能性分析提供基础。

英文摘要：

OBJECTIVE：To investigate the distribution of potential genetic polymorphisms in the promoter region of the protein phosphatase 2A-Aαsubunit gene（PPP2R1A） in Guangdong Han population.METHODS：Genomic DNA samples were obtained from randomly selected healthy Cantonese subjects.Direct resequencing was applied to identify and to confirm the polymorphism sites in the 5＇-flanking region of PPP2R1A.Allele frequencies of the potential genetic variants in the studied population were analyzed by HaploView Software and compared with HapMap data. RESULTS：63 DNA samples（126 chromosomes） from the subjects（all Han Chinese） were completely re-sequenced with the PCR amplicons of target gene locus at（-1 844）-（＋201） nt fraction.Six single nucleotide polymorphism（SNP） sites（with the MAF）,-1 039 G〉T（＋Ins）（rs10414793）（8.73%）,-568 G〉A（rs1864007）（25.40%）,-241 -/G（rs11453459）（26.90%）, ＋87 T〉C（rs13344984）（7.94%）,＋107 -/C（rs3833207）（30.16%） and ＋108 A〉G（rs17554825）（7.94%）,were confirmed.The frequencies of 2 polymorphism sites in our study were different from other foreign populations reported in HapMap data （P〈0.05）.Meanwhile,a noval potential SNP site,-512G〉A（2.38%）,was identified in the current study. CONCLUSION：The PPP2R1A gene polymorphisms in 5＇-flanking region and their allele frequencies were identified for the first time and reported in the general Guangdong Han population of Southern China.It provides the basis for further functional analysis of these polymorphism sites.