Genetic Variant Near PLXDC2 Influences the Risk of Primary Open-angle Glaucoma by Increasing Intraocular Pressure in the Japanese Population.

Purpose: The purpose of this study is to assess the association between the genetic variants that were previously reported to be associated with primary open-angle glaucoma (POAG) in the Japanese population and the phenotypic features.

Methods: A total of 661 Japanese patients including 417 patients with POAG [normal tension glaucoma (NTG), n=210; high tension glaucoma (HTG), n=207] and 244 control subjects without glaucoma were analyzed for 3 genetic variants: rs547984 (near gene: ZP4), rs7081455 (PLXDC2), and rs7961953 (TMTC2). The allele frequency differences between POAG (NTG or HTG) patients and control subjects were estimated. The association between these genetic variants and the phenotypic features, including the maximum intraocular pressure (IOP) and the vertical cup-to-disc ratio, was evaluated.

Results: There was a significant difference in the rs7081455 (PLXDC2) allele frequencies between the POAG (P=0.0050) patients and the control subjects. An almost 1.5 increase in the risk of POAG (P=0.0042, odds ratio 1.52) was found with a G allele of rs7081455 (PLXDC2). The maximum IOP [23.5±10.3 mm Hg (mean±SD)] in patients with the GG genotype of rs7081455 (PLXDC2) was significantly higher (P=0.0037) than that (19.9±7.4 mm Hg) in patients with the TT genotype.

Conclusions: The genetic variant near the PLXDC2 gene was found to influence the risk of POAG by increasing IOP in the Japanese population.