Association between GJD2 and RASGFR1 genes, fetal origins and myopia in Lithuanian twin population

Abstract

Background: Myopia is a common eye condition that affects approximately one in four individuals in Western populations. Gap junction delta-2 GJD2) and Ras-specific guanine nucleotide-releasing factor1 (RASGRF1) genes are involved in synaptic transmission and play an important role in the transmission and processing of visual signals. This study aimed to find associations between GJD2, RASGRF1 genes, fetal origins and myopia. Methods: A total of 379 twin pairs (211 monozygotic and 168 dizygotic) age 15-58 were investigated by ophthalmologist. Myopia was found in 240, emetropia in 148 and hyperopia in 70 twins. Two single nucleotide polymorphisms (SNPs) GJD2 rs634990 and RASGFR1 rs8027411 genes were assessed using TaqMan assays. The Applied Biosystems 7900HT Real-Time Polymerase Chain Reaction System were used to detect the SNPs. Results: We found, that myopia statistically significantly higher developed to the twins, whose birth weight was 800-1400, compared with the control group. In twins with myopia the RASGRF1 GT genotype carriers had significantly lower gestational age in comparison with the TT genotype carriers (p=0.004). The significant association between the combinations of GJD2 and RASGRF1 and myopia were found in men. The odds ratio of having myopia was statistically significant in the combinations of the GJD2 genotype CC and RASGRF1 genotype GG (OR=0.152, p=0.05) and GJD2 genotype CT and RASGRF1 genotype GT (OR=0.227; p=0.001). Conclusions: The lower weight of birth and gestations age can increase the risk of developing in myopia. Twins with two or one minor alleles in GJD2 and RASGRF1 genes have a greater chance of myopia development.