Association of ATG5 Gene Polymorphisms With Behçet's Disease and ATG10 Gene Polymorphisms With VKH Syndrome in a Chinese Han Population

PURPOSE: This study was conducted to explore the association of autophagy-related genes (ATGs) single nucleotide polymorphisms (SNPs) with Behçet's disease (BD) and Vogt-Koyanagi-Harada (VKH) syndrome in a Chinese Han population.

METHODS: A two-stage association study was carried out in 940 BD, 1061 VKH, and 2007 healthy controls. Genotyping for genetic variants of 10 autophagy family genes (ATG5, ATG7, ATG10, ATG16L1, IRGM, LKKR2, ATG2A, DAP, ULK1, and TSC1) was performed using PCR-restriction fragment length polymorphism (PCR-RFLP) or TaqMan SNP assays. Gene expression was quantified by real-time PCR.

RESULTS: In the cohort of BD patients, we observed that the TT genotype of rs573775/ATG5 decreased susceptibility to BD (Pc = 8.35 × 10-6, OR = 0.490). In the case of VKH patients, the AC genotype of rs4703863/ATG10 increased susceptibility to VKH syndrome (Pc = 9.94 × 10-5, OR = 1.444), whereas the A allele and AA genotype of rs4703863 (Pc = 7.06 × 10-5, OR = 0.745; Pc = 6.34 × 10-6, OR = 0.669, respectively) acted as protective factors for VKH. Functional experiments showed an increased ATG5 expression by LPS stimulated PBMCs in TT cases of rs573775 compared with controls. The level of ATG5 mRNA in active BD patients not receiving immunosuppression was significantly higher than that in healthy controls.

CONCLUSIONS: This study demonstrated an association of ATG5 rs573775 with BD and ATG10 rs4703863 with VKH syndrome in a Chinese Han population. Furthermore, a variant of the ATG5 gene was shown to be correlated with ATG5 expression.