A novel G26A variation in 5' half of TGIF1 gene associates with high myopia in ethnic Kashmiri population from India.

This study aims to look at novel variations in TGIF1 gene and explores their potential association with high myopia in an ethnic population from Kashmir (India). Genomic DNA was genotyped for polymorphic variations, and allele frequencies were tested for the Hardy-Weinberg disequilibrium in 240 ethnic Kashmiri cases with high myopia with a spherical equivalent of >-6 diopters (D) and compared with emmetropic controls with spherical equivalent within -0.5D in one or both eyes represented by a sample size of 228. In this study, we found a novel sequence variation G26A (GAT to AAT) in 5' half of TGIF1 gene (p. aspartic acid >asparagine) at a frequency of 62% (148/240, ≤ 0.0001). Variation appears to associate with high myopia significantly ( ≤ 0.001) as it happens to be present only in high myopia affected individuals. Further, it shows statistical significance for its association with gender and the degree of myopia ( ≤ 0.05). In addition, predictions show that variation likely has an impact on the structure and functional properties of the protein. The assessment of the I-TASSER protein structure showed higher energy for a wild-type protein (-5820.186 kJ/mol) as compared to mutant protein (-6595.593 kJ/mol).