Objective: To detect the single nucleotide polymorphism (SNP) of trabecular meshwork-induced glucocorticoid response protein (TIGR) gene and to investigate the association between SNP and primary open-angle glaucoma (POAG) in Chinese Han population.
Methods: High throughput conformation sensitive gel electrophoresis (HTCSGE) and fluorescent labeling automated sequencing method were used to screen and identify the SNPs of TIGR in 82 unrelated patients with POAG. Restriction endonuclease analysis was used to detect the SNPs of TIGR in 150 sex-and age-matched unrelated control subjects without POAG. The frequencies of genotypes and alleles of each SNP between the two groups were compared by chi-square test.
Results: A total of six SNPs were identified in TIGR gene with a length of 2172 bp, including all coding regions and part of promoter, introns and 3'UTR region: 1-83(G --> A), G12R, R46X, R76K, IVS2 + 35(A --> G), and T353I. Significant differences were found in frequencies of the genotype TC and the allele T of T353I between POAG patients and control subjects. The frequency of heterozygote TC was 12.20% in POAG patients, significantly higher than that in control subjects (3.33%, kappa(2) = 6.885, P = 0.009, OR = 4.028, OR95% CI = 1.327 approximately 12.223). The frequency of the allele T was 6.10% in POAG patients, significantly higher than that in control subjects (1.67%, kappa(2) = 6.655, P = 0.010). No significant difference was found between the two groups in frequencies of genotypes and alleles of the other SNPs.
Conclusion: The T353I polymorphism of TIGR gene is associated with POAG in Chinese Han population.