Abstract
Purpose :
To identify genetic variations associated with axial length (AL), an endophenotype of myopia, in children.
Methods :
Totally 2,875 children aged between 6 and 9 years were recruited from the Hong Kong Children Eye Study. Genomic DNA was extracted from buccal swab samples. Six single-nucleotide polymorphism (SNPs) that were identified in previous genome-wide association studies (GWAS) of AL in adults were genotyped in 1,062 children (Stage 1). SNPs showing association with AL were further tested in another 1,813 children (Stage 2). Linear regression was utilized to fit an additive model for AL, adjusted for age, gender and height. Associations of the SNPs with refractive error (RE) were also evaluated by fitting a linear regression model for mean spherical equivalent, adjusted for age and gender.
Results :
In stage 1, SNPs rs10453441 and rs12144790, but not rs9811920, rs11073058, rs12321, rs4373767, were associated with AL (P= 0.024 and 0.043, respectively). In Stage 2, the association of rs10453441 (β=0.12, P=1.1x10-5) and rs12144790 (β=0.058, P=0.037) with AL were replicated, both achieving an enhanced, significant association in the pooled cohort (β=0.108, P=2.7x10-6; β=0.069, P=0.0023, respectively). None of the tested SNPs was associated with RE.
Conclusions :
Only SNPs rs10453441 and rs12144790 out of 6 SNPs associated with AL in adults were significantly associated with AL in children, with comparable effect sizes to that in adults. Our data suggests that the genetic profiles of AL could be different between children and adults. Different gene variants may exert their effects on AL differently in childhood as compared to adulthood.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.