Association of CX36 Protein Encoding Gene GJD2 with Refractive Errors.

Purpose: This study aimed to evaluate the associations of GJD2 (rs634990, rs524952) and RASGRF1 (rs8027411, rs4778879, rs28412916) gene polymorphisms with refractive errors. Methods: The study included 373 subjects with refractive errors (48 myopia, 239 myopia with astigmatism, 14 hyperopia, and 72 hyperopia with astigmatism patients) and 104 ophthalmologically healthy subjects in the control group. A quantitative real-time polymerase chain reaction (qPCR) method was chosen for genotyping. Statistical calculations and analysis of results were performed with IBM SPSS Statistics 27 software. Results: The correlations in monozygotic (MZ) twin pairs were higher compared to DZ pairs, indicating genetic effects on hyperopia and astigmatism. The heritability (h2) of hyperopia and astigmatism was 0.654 for the right eye and 0.492 for the left eye. The GJD2 rs634990 TT genotype increased the incidence of hyperopia with astigmatism by 2.4-fold and the CT genotype decreased the incidence of hyperopia with astigmatism by 0.51-fold (p < 0.05). The GJD2 rs524952 AT genotype reduced the incidence of hyperopia with astigmatism by 0.53-fold (p < 0.05). Haplotype analysis of SNPs in the GJD2 gene revealed two statistically significant haplotypes: ACTAGG for rs634990 and TTTAGA for rs524952, which statistically significantly reduced the incidence of hyperopia and hyperopia with astigmatism by 0.41-fold (95% CI: 0.220−0.765) and 0.383-fold (95% CI: 0.199−0.737), respectively (p < 0.05). It was also found that, in the presence of haplotypes ACTAGG for rs634990 and TATAGA for rs524952, the possibility of hyperopia was reduced by 0.4-fold (p < 0.05). Conclusions: the heritability of hyperopia and hyperopia with astigmatism was 0.654−0.492, according to different eyes in patients between 20 and 40 years. The GJD2 rs634990 was identified as an SNP, which has significant associations with the co-occurrence of hyperopia and astigmatism. Patients with the GJD2 gene rs634990 TT genotype were found to have a 2.4-fold higher risk of develop hyperopia with astigmatism.

Independent association of whole blood miR-328 expression and polymorphism at 3'UTR of the PAX6 gene with myopia.

PURPOSE: This study aimed to find associations between miR-328 expression in whole blood, polymorphism at 3'UTR of the PAX6 gene (paired box homeotic gene 6) and myopia. METHODS: We evaluated 451 individuals (142 individuals with low, 49 with moderate and 13 with high-degree myopia, and 247 healthy individuals). DNA and RNA were extracted from peripheral blood samples. Expression of miR-328 was assessed and genotyping of single-nucleotide polymorphisms (SNPs) of the PAX6 (rs662702) performed using the Applied Biosystems 7900HT Real-Time Polymerase Chain Reaction System. RESULTS: Moderate and high degree myopia showed significant differences between TT and CT genotypes of the PAX6 gene (p < 0.001). In the myopia group, 71.4% of the subjects had the TT genotype and 28.6% had the CT genotype; meanwhile in the control group, 97.1% had the TT genotype and 2.9% had the CT genotype. The odds ratio of having moderate and/or high degree myopia for individuals with the CT genotype was 13.6 (2.865-64.55) 95% CI versus TT genotype (p = 0.001). MiR-328 results showed that ∆Ct values differed statistically significantly between the myopia and control groups. Patients with myopia in the peripheral blood cells had a higher expression of miR-328 than controls (p < 0.05). CONCLUSIONS: Significant differences were detected between the PAX6 gene (rs662702) TT and CT genotypes in moderate and high degree myopia; the risk C allele increased the risk for myopia. The expression level of miR-328 in peripheral blood cells was higher in patients with myopia than controls. We did not find the association between expression of mir-328 in the peripheral blood cells and PAX6 gene (rs662702) polymorphism comparing myopia and control groups.

Heritability of myopia and its relation with GDJ2 and RASGRF1 genes in Lithuania.

BACKGROUND: This study aimed to assess heritability of myopia in Lithuania and evaluate both genes GJD2 (Gap Junction Protein, Delta 2) and RASGRF1 (RAS protein-specific guanine nucleotide-releasing factor 1) relation with myopia. METHODS: In this study Lithuanian twin population aged between 18 and 40 (n = 460) were examined. Single-nucleotide polymorphisms of the RASGRF1 (rs8027411) and GJD2 (rs634990) genes were assessed by real-time polymerase chain reaction method. RESULTS: Intrapair correlations for spherical equivalent in all twin pairs were significantly higher in MZ twin pairs r = 0.539 (p < 0.001, 95% CI 0.353-0.684) than in DZ twin pairs r = 0.203 (p < 0.01, 95% CI 0.0633-0.442) in myopia group. Correlations for spherical equivalent in emmetropia group were not significant in MZ twin pairs r = 0.091 (p > 0.05, 95% CI -0.215-0.381) and in DZ twin pairs r = - 0.220 (p > 0.05, 95% CI -0.587-0.222). The odds ratio (95% CI) were 2.7 (1.018-7.460) for combinations of genotypes of rs634990 CC and rs8027411 GT (p = 0.046). CONCLUSIONS: Our studies have shown that the heritability of myopia makes 67.2% in Lithuania. Persons with combinations of genotypes rs634990 CC and rs8027411 GT have 2.7 times higher odds to have myopia.