Yip Shea Ping, Leung Kim Hung, Fung Wai Yan, Ng Po Wah, Sham Pak Chung, Yap Maurice K H
Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong SAR, China.
Mol Vis. 2011 Mar 26;17:810-21.
We examined the relationship between high myopia and common polymorphisms in four candidate genes: collagen, type XI, alpha 1 (COL11A1); collagen, type XVIII, alpha 1 (COL18A1); fibrillin 1 (FBN1); and procollagen-lysine 1,2-oxoglutarate 5-dioxygenase 1 (PLOD1). These genes were selected because rare pathogenic mutations in these genes cause disease syndromes that have myopia, usually high myopia, as one of the common presenting features.
This study recruited 600 unrelated Han Chinese subjects including 300 cases with high myopia (spherical equivalent or SE≤-8.00 diopters) and 300 controls (SE within ±1.00 diopter). A total of 66 tag single nucleotide polymorphisms (SNPs) were selected for study from these four candidate genes. The study adopted a DNA pooling strategy with an initial screen of DNA pools to identify putatively positive SNPs and then confirmed the "positive" SNPs by genotyping individual samples forming the original DNA pools. DNA pools were each constructed by mixing equal amounts of DNA from 50 individuals with the same phenotype status. Six case pools were prepared from 300 cases and six control pools from 300 controls. Allele frequencies of DNA pools were estimated by analyzing the primer-extended products with denaturing high performance liquid chromatography and compared between case pools and control pools with nested ANOVA.
In the first stage, 60 SNPs from the 4 candidate genes were successfully screened using the DNA pooling approach. Of these, 6 SNPs showed a statistical significant difference in estimated allele frequencies between case pools and controls at p<0.10. In the second stage, these "positive" SNPs were followed up by individual genotyping, but failed to be confirmed via standard single-marker and haplotype analyses.
Common polymorphisms in these four candidate genes (COL11A1, COL18A1, FBN1 and PLOD1) were unlikely to play important roles in the genetic susceptibility to high myopia.
我们研究了高度近视与四个候选基因的常见多态性之间的关系，这四个基因分别是：Ⅺ型胶原α1链（COL11A1）、ⅩⅧ型胶原α1链（COL18A1）、原纤蛋白1（FBN1）和原胶原赖氨酸1,2 - 酮戊二酸5 - 双加氧酶1（PLOD1）。选择这些基因是因为这些基因中的罕见致病突变会导致以近视（通常为高度近视）作为常见表现特征之一的疾病综合征。
本研究招募了600名无血缘关系的汉族受试者，其中包括300例高度近视患者（球镜等效度或SE≤ - 8.00屈光度）和300名对照者（SE在±1.00屈光度范围内）。从这四个候选基因中总共选择了66个标签单核苷酸多态性（SNP）进行研究。该研究采用DNA池策略，首先对DNA池进行初步筛选以鉴定可能呈阳性的SNP，然后通过对构成原始DNA池的个体样本进行基因分型来确认“阳性”SNP。每个DNA池通过将来自50名具有相同表型状态个体的等量DNA混合构建而成。从300例患者中制备了6个病例池，从300名对照者中制备了6个对照池。通过变性高效液相色谱分析引物延伸产物来估计DNA池的等位基因频率，并使用嵌套方差分析比较病例池和对照池之间的等位基因频率。
在第一阶段，使用DNA池方法成功筛选了来自4个候选基因的60个SNP。其中，6个SNP在病例池和对照池之间估计的等位基因频率上显示出统计学显著差异（p<0.10）。在第二阶段，对这些“阳性”SNP进行个体基因分型随访，但通过标准单标记和单倍型分析未能得到确认。
这四个候选基因（COL11A1、COL18A1、FBN1和PLOD1）中的常见多态性不太可能在高度近视的遗传易感性中起重要作用。
