ABSTRACT

Background: Primary open-angle glaucoma (POAG) is a multifactorial disease that affects 65.5 million people worldwide. In addition to the genetic variants already established as indicators of greater risk for POAG, the apolipoprotein (APOE) gene has been studied in some populations, with controversial results. The aim of this study is to investigate the frequency of the genetic variants of APOE in the Brazilian population, and to evaluate the association between these polymorphisms and the risk of POAG.

Methods: APOE variants (rs429358; rs7412) were genotyped in 402 POAG patients and 401 controls. We evaluated the association between APOE genetic variants and the risk for POAG, as well as the correlation between the requirement of glaucoma surgery and the APOE polymorphisms.

Results: Among the three APOE gene isoforms, we found a low frequency of APOE alleles ε2 (7.34%) and ε4 (11.76%), but a high frequency of ε3 (80.88%) in our population. When compared to ε3ε3 reference genotype, ε2 allele-carriers (OR = 1.516; p-value = 0.04) and ε2ε3 genotype (OR = 1.655; p-value = 0.02) were associated with a greater risk for POAG. An additive genetic model confirmed the influence of the ε2 allele in the risk of POAG in this sample of the Brazilian population (OR = 1.502; p-value = 0.04). There was no significant association between the analyzed genotypes and the requirement or number of glaucoma surgeries (p > .05).

Conclusion: Brazilian individuals carrying the APOEε2 allele may be at an increased risk for the development of POAG.

摘要

背景：原发性开角型青光眼（POAG）是一种多因素疾病，全球范围内有6550万人受到影响。除了已经确立的遗传变异作为增加POAG风险的指标外，载脂蛋白（APOE）基因已经在一些人群中进行了研究，结果颇具争议。这项研究的目的是调查巴西人口中APOE遗传变异的频率，并评估这些多态性与POAG风险之间的关联。

方法：对402例POAG患者和401例对照组的APOE基因（rs429358； rs7412）进行基因分型。我们评估了APOE基因变异与POAG风险之间的关联，以及青光眼手术的需求与APOE多态性之间的相关性。

结果：在这三种APOE基因同工型中，我们在人群中发现APOE等位基因ε2（7.34％）和ε4（11.76％）的频率较低，但是ε3等位基因的频率较高（80.88％）。与ε3ε3参考基因型相比，ε2等位基因携带者（OR = 1.516；p值= 0.04）和ε2ε3基因型（OR = 1.655；p值= 0.02）与POAG风险更高。一个加性遗传模型证实了该巴西人群样本中ε2等位基因对POAG风险的影响（OR = 1.502；p值= 0.04）。在分析的基因型与青光眼手术的需求或数量之间没有显着关联（p > .05）。

结论：巴西携带个人APOE ε2等位基因可能是在为开角型青光眼的风险增加。