Polymorphic markers of the G1639A form of VKORC1 involved in the development of retinal vessel occlusion

Retinal vessel occlusion (RVO) is an eye disease that leads to decreased visual acuity, ultimately resulting in blindness. It is observed in 1%-2% of individuals above the age of 40 years. The etiology of RVO still remains unclear. However, the most widely recognized risk factors include age, hypertension, hyperlipidemia, atherosclerosis, cardiovascular diseases, and diabetes. The number of patients with RVO among the young population has increased in recent years; hence, more attention has been focused on the genetic factors. Polymorphisms in the genes encoding proteins involved in the vitamin K cycle are among the genetic factors that may influence RVO. According to literature, the G1639A polymorphism in the vitamin K epoxide reductase complex subunit 1 (vKoRc1) is a possible risk factor for RVO.

Purpose. To estimate the association between carriers of the G1639A form of vKoRc1 and the development of venous RVO (VRVO) and arterial RVO (ARVO).

Materials and methods. The study included 126 patients aged between 40 and 80 years, mean age 61.5 years. Genotyping for the presence of the G1639A polymorphism of vKoRc1 was performed using polymerase chain reaction, and statistical analysis was performed using the Instat program.

Results. The GG genotype of G1639A was found to be significantly more common in patients with VRVO or ARVO than in those of the control group (VRVO, 42.6%; ARVO, 60%; control group, 32%; p = 0.0449 for VRVO, and p = 0.0925 for ARVO). However, the AA genotype was significantly less common in patients with VRVO or ARVO than in those of the control group (VRVO, 9.8%; ARVO, 6.7%; control group, 28%; p = 0.0238 for VRVO and p = 0.1593 for ARVO, RR 2.015, 95% confidence interval 1.011-4.16).

Conclusions. Our study demonstrates that the GG genotypic form of the G1639A polymorphism of VKORC1 is associated with the development of VRVO and possibly ARVO. However, the AA genotypic form of this polymorphism is not closely associated with the development of VRVO or ARVO.