Lam Ching Yan, Fan Bao Jian, Wang Dan Yi, Tam Pancy Oi Sin, Yung Tham Clement Chee, Leung Dexter Yu Lung, Ping Fan Dorothy Shu, Chiu Lam Dennis Shun, Pang Chi Pui
Department of Ophthalmology and Visual Sciences, Chinese University of Hong Kong, Kowloon, Hong Kong.
J Glaucoma. 2006 Jun;15(3):218-22. doi: 10.1097/01.ijg.0000212217.19804.a7.
To evaluate the role of apolipoprotein E (APOE) polymorphisms in primary open angle glaucoma (POAG).
A cohort of 400 unrelated Chinese POAG patients was examined, including 294 cases of high tension glaucoma (HTG) and 106 with normal tension glaucoma (NTG). Also studied were 300 unrelated Chinese control subjects. The genotypes of the APOE polymorphisms in exon 4 and in the promoter at positions -491, -427, and -219 were determined by polymerase chain reaction and restriction endonuclease analysis. Frequencies of the genotypes were compared between patients and controls by chi test or Fisher exact test. The association of APOE polymorphisms with POAG phenotypes including age at diagnosis, intraocular pressure (IOP) at diagnosis, highest IOP, cup-disc ratio, and visual field score was investigated by the Kruskal-Wallis test.
No significant difference was detected in the frequencies of APOE promoter polymorphisms between POAG patients and control subjects (P>0.0125). For the exon 4 polymorphism, when compared with control subjects, the frequency of epsilon 4 carriers was significantly lower in patients with NTG (P=0.008; odds ratio=0.36, 95% confidence interval=0.17, 0.79) but not in HTG (P=0.07). Compared with -219TT, the -219G carriers had a significant higher age at diagnosis (P=0.0046). No significant association was found between other APOE polymorphisms and POAG phenotypes (P>0.07).
Our findings suggest that the APOE epsilon 4 allele confers a protective effect against NTG, whereas the APOE promoter polymorphisms do not contribute to POAG risk. However, the APOE -219G carriers tended to have later-onset POAG.
评估载脂蛋白E（APOE）基因多态性在原发性开角型青光眼（POAG）中的作用。
对400例无亲缘关系的中国POAG患者进行研究，其中包括294例高眼压性青光眼（HTG）和106例正常眼压性青光眼（NTG）。还对300例无亲缘关系的中国对照者进行了研究。通过聚合酶链反应和限制性内切酶分析确定第4外显子以及启动子区-491、-427和-219位点APOE基因多态性的基因型。采用卡方检验或Fisher精确检验比较患者与对照者之间基因型的频率。通过Kruskal-Wallis检验研究APOE基因多态性与POAG表型（包括诊断年龄、诊断时眼压（IOP）、最高眼压、杯盘比和视野评分）之间的关联。
POAG患者与对照者之间APOE启动子区基因多态性的频率未检测到显著差异（P>0.0125）。对于第4外显子多态性，与对照者相比，NTG患者中ε4等位基因携带者的频率显著降低（P=0.008；优势比=0.36，95%置信区间=0.17，0.79），但HTG患者中未降低（P=0.07）。与-219TT相比，-219G携带者的诊断年龄显著更高（P=0.0046）。未发现其他APOE基因多态性与POAG表型之间存在显著关联（P>0.07）。
我们的研究结果表明，APOEε4等位基因对NTG具有保护作用，而APOE启动子区基因多态性与POAG风险无关。然而，APOE -219G携带者的POAG发病年龄往往较晚。
