Abstract
Purpose :
Myopia (MYP), commonly referred to as nearsightedness, is one of the most common causes of visual disability throughout the world. It affects more people worldwide than any other chronic condition. The prevalence of myopia in the general population has been reported to be about 10-25%, however it is much higher in Asia. There is compelling evidence that both environmental and genetic factors are involved in the etiology of myopia, although the environmental changes that are responsible for the increased incidence and the mechanism through which they act are unknown. This is despite the fact that many factors can potentially trigger changes in epigenetic state. We hypothesize that epigenetic modifications are a contributory factor to MYP. Epigenetic changes can modify the activation of certain genes, while sparing the gene sequence.
Methods :
We conducted a genome-wide DNA methylation analysis using an Illumina Infinium 450k human methylation assay in a cohort of 24 young children, ages 9-12 with isolated, nonsyndromic Myopia and an equal number of ethnic and age matched normal controls. The degrees of myopia ranged from -7 to 15 D with the majority having 9.0 D.
Results :
The study identified significantly altered CpG methylation at 2445 sites in 450 genes in MYP subjects in comparison to normal controls. Gene Ontology analysis of MYP identified biological processes and functions for these genes including cell differentiation, protein binding and integral membrane proteins. Consistent with prior clinical data, eight pathways including type 1 diabetes pathway were found to be overexpressed in the myopic group. A significant epigenetic change in the COL1A1 gene known to be involved in Myopia was also observed.
Conclusions :
Profound differences in CpG methylation sites were observed in hundreds genes in myopia individuals, thus raising the possibility of molecular screening markers for this disorder. Using epigenetic analysis we were able to identify genes significantly involved in the pathogenesis of MYP.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.