Abstract
Purpose :
Vogt-Koyanagi-Harada (VKH) syndrome is a rare multisystemic autoimmune disease caused by the interplay of genetic and environmental factors. Although associations between several genetic variants and VKH syndrome have been identified, little is known about epigenetic changes related to VKH syndrome. The present study aims to identify VKH-associated methylated sites.
Methods :
A two-stage epigenome-wide association study (EWAS) was performed in 160 VKH syndrome patients and 160 healthy controls. In the first stage, we typed the whole-blood DNA samples of 60 VKH syndrome patients and 60 healthy controls with the Infinium Human Methylation 450k array. After quality control, methylation levels were tested for association with VKH syndrome. Nine sites in this primary cohort were tested in a second replication cohort of 160 VKH syndrome patients and 160 healthy controls using pyrosequencing. Real-time PCR was performed to examine the association of methylation at VKH syndrome-associated sites with the gene expression.
Results :
Our results showed that significant association between methylation at nine probes across five different genes and VKH syndrome (p<10-8). We also observed a significant inverse correlation between these methylation site and expression of the genes they located.
Conclusions :
In conclusion, this is the first genome-wide DNA methylation profiling study on VKH syndrome to date, and we identified that regulation of DNA methylation of BTNL2, NOTCH4, RIBC2, TNXB, and AGPAT2 genes might contribute to VKH syndrome.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.