A Multi-Locus Genetic Risk Score for Primary Open-Angle Glaucoma (POAG) Variants Is Associated with POAG Risk in a Mediterranean Population: Inverse Correlations with Plasma Vitamin C and E Concentrations.

Vicente Zanon-Moreno,Eva Asensio-Marquez,Carolina Ortega-Azorin,Jose Ordovas,Jose Garcia-Medina,Maria Pinazo-Duran,Oscar Coltell,Dolores Corella

doi:10.3390/ijms18112302

Abstract

Primary open-angle glaucoma (POAG) is a leading cause of blindness worldwide. The genetics of POAG are complex, and population-specific effects have been reported. Although many polymorphisms associated with POAG risk have been reported, few studies have analyzed their additive effects. We investigated, in a southern European Mediterranean population, the association between relevant POAG polymorphisms, identified by initial genome-wide association studies (GWASs) and POAG risk, both separately and as an aggregated multi-locus genetic risk score (GRS). Also, bearing in mind that oxidative stress is a factor increasingly recognized in the pathogenesis of POAG, we analyzed the potential association of the GRS with plasma concentrations of antioxidant vitamins (C and E). We carried out a case–control study including 391 POAG cases and 383 healthy controls, and analyzed four genetic polymorphisms (rs4656461-TMCO1, rs4236601-CAV1/CAV2, rs2157719-CDKN2B-AS1 and rs3088440-CDKN2A). An unweighted GRS including the four non-linked polymorphisms was constructed. A strong association between the GRS and POAG risk was found. When three categories of the GRS were considered, subjects in the top category of the GRS were 2.92 (95% confidence interval (CI): 1.79–4.77) times more likely to have POAG compared with participants in the bottom category (p < 0.001). Moreover, the GRS was inversely correlated with plasma vitamin C (p = 0.002) and vitamin E (p = 0.001) concentrations, even after additional adjustment for POAG status. In conclusion, we have found a strong association between the GRS and POAG risk in this Mediterranean population. While the additional correlation found between GRS and low levels of vitamins C and E does not indicated a causal relationship, it does suggest the need for new and deeper research into the effects of oxidative stress as a potential mechanism for those associations.

Highlights

Primary open-angle glaucoma (POAG) is the most common form of glaucoma
In a southern European Mediterranean population, the association between relevant POAG polymorphisms, identified by initial genome-wide association studies (GWASs) and POAG risk, both separately and as an aggregated multi-locus genetic risk score (GRS)
Bearing in mind that oxidative stress is a factor increasingly recognized in the pathogenesis of POAG, we analyzed the potential association of the GRS with plasma concentrations of antioxidant vitamins (C and E)

Summary

Introduction

Primary open-angle glaucoma (POAG) is the most common form of glaucoma. It is a form of optic neuropathy characterized by high intraocular pressure (IOP), an alteration of the optic nerve head, and a loss of visual field [1]. POAG is one of the main causes of blindness worldwide, and currently has no cure. One of the most important risk factors for POAG is IOP. POAG is a multifactorial disease that involves both genetic and environmental factors (including diet), so the development of the glaucomatous disease is determined by the individual effect of each of these factors, and by the joint effect of the interaction between all of them [3,4]

Objectives

Methods

Findings

Conclusion