Identification of TIE2 as a susceptibility gene for neovascular age-related macular degeneration and polypoidal choroidal vasculopathy.

PURPOSE: The endothelial and cell-specific angiopoietin-Tie pathway plays an important regulatory role in angiogenesis. In this study, we investigated the associations of the TIE2 (tyrosine kinase, endothelial, TEK) gene with neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy (PCV), using haplotype-tagging single-nucleotide polymorphisms (SNPs) analysis. METHODS: This study involved totally 2343 subjects, including a Hong Kong Chinese cohort (214 nAMD patients, 236 PCV patients and 433 control subjects), a Shantou Chinese cohort (189 nAMD patients, 187 PCV patients and 531 control subjects) and an Osaka Japanese cohort (192 nAMD patients, 204 PCV patients and 157 control subjects). Thirty haplotype-tagging SNPs in TIE2 were genotyped in the Hong Kong cohort using TaqMan technology. Two SNPs (rs625767 and rs2273717) showing association in the Hong Kong cohort were genotyped in the Shantou and Osaka cohorts. The SNP-disease association of individual and pooled cohorts were analysed. RESULTS: Two SNPs (rs625767 and rs2273717) showed suggestive association with both nAMD and PCV in the Hong Kong cohort. In the meta-analysis involving all the three cohorts, rs625767 showed significant associations with nAMD (p=0.01; OR=0.82, 95% CI 0.70 to 0.96; I2=0%), PCV (p=0.02; OR=0.83, 95% CI 0.71 to 0.97; I2=27%) and pooled nAMD and PCV (p=0.002; OR=0.82, 95% CI 0.72 to 0.93; I2=0%), with low inter-cohort heterogeneities. CONCLUSION: This study revealed TIE2 as a novel susceptibility gene for nAMD and PCV in Japanese and Chinese. Further studies in other populations are warranted to confirm its role.