Abstract
Purpose :
Behçet's disease (BD) is a chronic systemic inflammatory disorder characterized by recurrent ocular symptoms, oral and genital ulcers, and skin lesions. The etiology of BD is still uncertain, but currently some external environmental factors are thought to trigger BD in individuals with a particular genetic background. It is well established that BD is strongly associated with the human leukocyte antigen (HLA) class I allele, HLA-B*51, in many different ethnic groups. The purpose of this study was to identify loci/genes specifically associated with ocular involvement in BD using a genome-wide association study (GWAS).
Methods :
We used previous GWAS data with a Japanese population (612 BD patients and 740 healthy controls) using Affymetrix GeneChip Human Mapping 500K Array Set (500,568 SNPs) (Nat Genet 2010;42(8):703-6.). After sample and SNP quality control, a total of 309,362 autosomal SNPs from 611 patients (including 432 patients with ocular involvement) and 737 controls were used for statistical analyses to identify susceptibility loci for ocular BD.
Results :
We identified 30 loci showing significant associations with ocular BD (P < 0.00001, OR ≥ 1.40) but not non-ocular BD (P > 0.05, OR < 1.1). The HLA class I region (6p21.3) showed the most significant association (ocular BD: P = 6.3 × 10-15, OR = 2.44; non-ocular BD: P = 0.77, OR = 0.93). Outside the HLA region, the 9q33.3 locus had the strongest association signal (ocular BD: P = 5.8 × 10-7, OR = 2.08; non-ocular BD: P = 0.45, OR = 0.86). The second strongest association was observed on 7p12.3 (ocular BD: P = 8.6 × 10-7, OR = 1.55; non-ocular BD: P = 0.85, OR = 1.03) and 1q32.1 (ocular BD: P = 8.8 × 10-7, OR = 1.59; non-ocular BD: P = 0.82, OR = 0.97).
Conclusions :
Preliminary results of the ongoing study point out to risk loci for ocular BD. To confirm the findings, future validation studies with other independent populations are needed.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.