Relative leukocyte telomere length and ZNF676, CTC1 gene polymorphisms associations with myopia and its degree

Abstract

Introduction: Myopia is a refractive error that occurs when light rays enter the eye parallel to the optical axis and are directed in front of the retina [1]. Myopia is usually caused by an enlarged intraocular chamber, an elongated eyeball, or excessive power of the lens [2]. Telomeres are structures of nucleoproteins located at the ends of each chromosome that maintain the stability of the genome [3]. When telomeres bind to proteins of the shelter in complex, the ends of eukaryotic chromosomes are covered and protected from degradation and inter chromosomal fusion [4]. ZNF676 and CTC1 genes and their products are involved in important cell cycle mechanisms that regulate telomere length, control telomerase, protect telomeres from shortening, and affect the cell cycle [5, 6]. Aim: To determine associations between relative leukocyte telomere length and ZNF676, CTC1 gene polymorphisms with myopia and its degree. Materials and methods: The study included 134 patients with myopia and 165 ophthalmologically healthy subjects. DNA was extracted from peripheral venous blood by the salting-out method. Genotyping of ZNF676 rs412658 and CTC1 rs3027234 and measurement of relative leukocyte telomere length (RLTL) were performed using a real-time polymerase chain reaction method (RT-PCR). The data obtained were statistically analyzed using the software program IBM SPSS Statistics 27.0. Results: We found that males with CTC1 rs3027234 CC genotype had statistically significantly longer leukocyte telomeres than females with CC genotype, relative leukocyte telomere length median (IQR) for women and men, respectively: 0.476 (0.509) vs. 0.708 (0.544), p = 0.041. Evaluation of the genotype and allele distributions of the polymorphisms in the individuals showed that each ZNF676 rs412658 T allele was associated with 2 times decreased odds of moderate myopia development (OR = 0.508; 95% CI: 0.260-0.992; p = 0.047). Conclusion: CTC1 rs3027234 CC may be considered as a protective genotype for telomere shortening in men. ZNF676 rs412658 T allele might be regarded as a protective allele from myopia.