Genome-wide association study of quantitative ocular traits, including axial length and central corneal thickness, identifies loci for refractive error in the Korean population.

Abstract

Background: The eye is a sensory organ that receives light and generates visual information. Refractive errors, which are influenced by both genetic and environmental factors, are a major cause of visual impairment. In particular, the high prevalence of myopia in some East Asian countries has become an increasing public health concern.

Objective: To gain insights into the genetic basis of refractive error, this study aimed to identify genetic associations for axial length (AL) and central corneal thickness (CCT), two quantitative ocular traits that contribute to refractive error.

Methods: We conducted genome-wide association (GWA) analyses of 649 Korean individuals using the Korea Biobank Array (KBA) chip to identify genetic variants associated with AL and CCT. After SNP imputation, a total of 9,408,715 common SNPs were included in the association analysis. Additionally, 97,434 rare variants were analyzed using q.emmax test. Gene-based analyses were further performed to detect genes significantly associated with these ocular traits.

Results: The GWA analyses identified 10 common variants (minor allele frequency [MAF] ≥ 1%) significantly associated with AL and 2 with CCT (P < 5 × 10⁻⁸). Analyses of rare variants (MAF < 1%) further detected 7 associations with AL and 2 with CCT. In addition, gene-based analysis identified MROH1 as significantly associated with AL.

Conclusion: This study identified novel genetic associations influencing AL and CCT in the Korean population. These findings provide new insights into the genetic architecture of refractive error and may contribute to improving eye health through the prediction of genetic predisposition to refractive errors.