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

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.

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.

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).

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.