Data from: Influences of APOA5 variants on plasma triglyceride levels in Uyghur population

Objective: Single nucleotide polymorphisms (SNPs) in apolipoprotein A5 (APOA5) gene are associated with triglyceride (TG) levels. However, the minor allele frequencies and linkage disequilibriums (LDs) of the SNPs in addition to their effects on TG levels vary greatly between Caucasians and East Asians. The distributions of the SNPs/haplotypes and their associations with TG levels in Uyghur population, an admixture population of Caucasians and East Asians, have not been reported to date. Here, we performed a cross-sectional study to address these. Methods: Genotyping of four SNPs in APOA5 (rs662799, rs3135506, rs2075291, and rs2266788) was performed in 1174 unrelated Uyghur subjects. SNP/haplotype and TG association analyses were conducted. Results: The frequencies of the SNPs in Uyghurs were in between those in Caucasians and East Asians. The LD between rs662799 and rs2266788 in Uyghurs was stronger than that in East Asians but weaker than that in Caucasians, and the four SNPs resulted in four haplotypes (TGGT, CGGC, TCGT, and CGTT arranged in the order of rs662799, rs3135506, rs2075291, and rs2266788) representing 99.2% of the population. All the four SNPs were significantly associated with TG levels. Compared with non-carriers, carriers of rs662799-C, rs3135506-C, rs2075291-T, and rs2266788-C alleles had 16.0%, 15.1%, 17.1%, and 12.4% higher TG levels, respectively. When haplotype TGGT was defined as the reference, the haplotypes CGGC, TCGT, and CGTT resulted in 16.1%, 19.0%, and 19.8% higher TG levels, respectively. The proportions of variance in TG explained by APOA5 locus were 2.5%, 0.3%, 0.4%, and 1.9% for single SNP rs662799, rs3135506, rs2075291, and rs2266788, respectively, and 3.0% for the haplotypes constructed by them. Conclusions: The association profiles between the SNPs and haplotypes at APOA5 locus and TG levels in this admixture population differed from those in Caucasians and East Asians. The functions of these SNPs and haplotypes need to be elucidated comprehensively.

研究目的：载脂蛋白A5（apolipoprotein A5, APOA5）基因的单核苷酸多态性（single nucleotide polymorphisms, SNPs）与甘油三酯（triglyceride, TG）水平相关。然而，不同人群中上述单核苷酸多态性的次要等位基因频率、连锁不平衡（linkage disequilibrium, LD）特征及其对甘油三酯水平的影响存在显著差异，高加索人群与东亚人群之间的差异尤为突出。维吾尔族人群作为高加索与东亚人群的混合血统群体，其载脂蛋白A5基因单核苷酸多态性/单体型的分布特征及其与甘油三酯水平的关联研究迄今尚未见报道。本研究通过横断面研究对此展开探讨。
研究方法：本研究纳入1174名无亲缘关系的维吾尔族受试者，对载脂蛋白A5基因的4个单核苷酸多态性位点（rs662799、rs3135506、rs2075291及rs2266788）进行基因分型，并开展单核苷酸多态性/单体型与甘油三酯水平的关联分析。
研究结果：维吾尔族人群中4个单核苷酸多态性位点的等位基因频率介于高加索人群与东亚人群之间。维吾尔族人群中rs662799与rs2266788之间的连锁不平衡强度高于东亚人群，但低于高加索人群；4个单核苷酸多态性位点共构成4种单体型（按rs662799、rs3135506、rs2075291及rs2266788的顺序排列分别为TGGT、CGGC、TCGT及CGTT），覆盖了99.2%的研究人群。4个单核苷酸多态性位点均与甘油三酯水平存在显著关联：与非携带者相比，携带rs662799-C、rs3135506-C、rs2075291-T及rs2266788-C等位基因的受试者甘油三酯水平分别升高16.0%、15.1%、17.1%及12.4%。以单体型TGGT作为参照组时，单体型CGGC、TCGT及CGTT对应的甘油三酯水平分别升高16.1%、19.0%及19.8%。载脂蛋白A5基因位点对甘油三酯水平的方差解释率方面，单个位点rs662799、rs3135506、rs2075291及rs2266788分别为2.5%、0.3%、0.4%及1.9%，基于上述位点构建的单体型整体方差解释率为3.0%。
研究结论：本研究纳入的混合血统人群中，载脂蛋白A5基因位点的单核苷酸多态性、单体型与甘油三酯水平的关联特征与高加索人群及东亚人群均存在差异，上述单核苷酸多态性及单体型的具体功能仍需全面阐明。