中国汉族高度近视患者与正常人CTNND2基因单核苷酸多态性的病例对照研究

摘要

背景 高度近视是致盲的主要原因之一,迄今尚未找到明确的致病基因,最近报道了一个新加坡人高度近视新的易感位点,CTNND2基因的两个单核苷酸多态性(SNPs)(rs12716080和rs6885224)位点,但其与汉族高度近视的发病是否有关尚不清楚.目的 研究CTNND2基因SNPs位点与中国汉族高度近视发病的相关性.方法 采用病例对照关联研究设计方法.收集933例高度近视患者(高度近视组)和年龄及性别匹配的1227名屈光状态和眼轴长度在正常范围的正常对照者(正常对照组)的外周血各5 ml,并提取基因DNA,用聚合酶链反应(PCR)法扩增目的DNA,采用单碱基延伸(SNaPshot)法进行DNA纯化.选取CTNND2基因的4个标签SNPs,包括已有报道的rs12716080位点和rs6885224位点,分析其与高度近视的相关性.结果 CTNND2基因4个标签SNPs,rs6885224、rs12716080、rs917012、rs16901340的基因型均符合Hardy-Weinberg平衡(HWE) (P=0.181、0.085、0.732、0.313、0.264、0.663、0.084、0.196),高度近视组和正常对照组rs12716080、rs917012、rs6885224、rs16901340 SNPs的基因型频率相比差异均无统计学意义(P=0.654、0.406、0.828、0.403),其等位基因频率在高度近视组与正常对照组间差异均无统计学意义(P=0.377、0.209、0.743、0.198).通过Haploview单体型分析发现,rg12716080和rs917012位于同一个连锁不平衡区域,高度近视组与正常对照组单体型TA的频率(0.784 vs.0.719)和GA的频率(0.087 vs.0.136)比较差异均有统计学意义(x2=6.115,P=0.013；x2 =6.634,P=0.010),而两组间单体型GG的频率比较差异无统计学意义(0.123vs.0.143,x2 =0.889,P=0.346).结论 CTNND2基因rs12716080、rs917012、rs6885224、rs16901340 SNPs与高度近视不相关,但rs12716080位点和rs917012位点的单体型与高度近视相关.%Background High myopia is one of leading causes of blindness,so far the pathogenesis remains unclear.Two single-nucleotide polymorphisms (SNPs) of rs6885224 and rs12716080 in CTNND2 gene were recently found to be associated with high myopia in Singaporean Chinese.But whether these SNPs are related with the pathogenesis of high myopia in Han Chinese is worth studying, Objective This study was to investigate the relationship between the genetic variations of the CTNND2 gene and high myopia in Han Chinese. Methods A case-controlled association study was designed.Nine hundred and thirty-three individuals with high myopia and 1227age- and gender-matched normal subjects were included in this study.The 5 ml of periphery blood was obtained from all subjects for the extraction of genomic DNA.The target DNA was amplified using PCR and purified by the SNaPshot method.Four SNPs rs12716080,rs917012,rs6885224 and rs16901340 in the CTNND2 gene were genotyped.This study was approved by the Ethic Committee of Sichuan Provincial People Hospital.Written informed consent was obtained from each subject before his/her enrollment. Results The frequencies of the genotypes rs6885224,rs12716080,rs917012,rs16901340 SNPs were in Hardy-Weinberg equilibrium (HWE) ( P=0.181,0.085,0.732,0.313,0.264,0.663,0.084,0.196).There were no significant differences in genotypes frequency distribution ( in turn P =0.654,0.406,0.828,0.403 ) and allele frequency distribution of the CTNND2 gene ( in turn P =0.377,0.209,0.743,0.198) between the high myopia group and normal control group.The haplotypes (TA and GA)frequencies of rs12716080 and rs917012 in the high myopia group were significantly different from those of the normal control group(TA:0.784 vs.0.719;GA:0.087 vs.0.136) (x2 =6.115,P=0.013 ;x2 =6.634,P=0.010),but those of GG were similar between the high myopia group and normal control group ( 0.123 vs.0.143,x2 =0.889,P =0.346). Conclusions The SNPs rs12716080,rs917012,rs6885224 and rs16901340 in CTNND2 gene were not responsible for high myopia,however,the haplotypes of rs12716080 and rs917012 are susceptible for high myopia in Han Chinese.