Identification of loci involved in childhood visual acuity and associations with cognitive skill and educational attainment

Background: Visual acuity (VA) significantly contributes to quality of life. Deficits are associated with reading difficulties (RD), which can have detrimental effects on education outcomes. In adults, it has been observed that vision defects such as myopia are associated with higher educational attainment (EA). This is almost certainly the result of gene-environment correlation (rGE) through pro-longed reading and screen time as well as time indoors. However, the cause/effect relationship of this pattern along developmental trajectories is not entirely clear.

Methods: We examined associations between distance VA, socioeconomic status (SES), cognitive measures, and neurodevelopmental conditions in a longitudinal cohort of British children (ALSPAC, n = 6,807, M age = 11.8). We performed the first genome-wide association study (GWAS, n = 5,571) on VA and tested for genetic associations with relevant phenotypes using polygenic scores (PGS) and genetic correlation analyses.

Results: VA was associated with higher SES and better cognitive performance on a range of tests including reading skill, while VA was reduced in individuals with RD compared to controls. We identify genetic associations at the NPLOC4 locus and highlight other genes involved in sensory function. In line with positive genetic correlations between VA and cognitive measures, EA PGS were positively associated with VA, while there was a less robust negative association with myopia PGS.

Conclusions: Our results suggest that individuals with higher PGS for educational attainment, but not myopia, have increased VA in childhood. Better VA is associated with a range of positive outcomes, including cognitive abilities. In turn, environmental exposures linked to higher EA might have detrimental effects on vision offsetting the initial genetic advantage.