Angiotensin-converting enzyme gene polymorphisms and nonarteritic anterior ischemic optic neuropathy risk

Aims: This study was aimed to investigate the association between angiotensin-converting enzyme gene (ACE) polymorphisms (rs4291, rs4309, rs4343, rs4646994) and nonarteritic anterior ischemic optic neuropathy (NAION) risk. Methods: The method of polymerase chain reaction (PCR) was used to perform the genotyping of ACE polymorphisms between the case and control groups. The χ2 test was conduct to detect Hardy-Weinberg equilibrium (HWE) as well as the distribution differences of genotypes, allele, haplotypes in ACE polymorphisms between two groups. The linkage disequilibrium (LD) and haplotype were analyzed to identify the combined function of ACE polymorphisms. Odds ratio (OR) with 95% confidence interval (95% CI) was calculated to assess the association strength. Results: In four polymorphisms of ACE gene, the distributions of not only genotyes but alleles in rs4309 had the significant differences between the case and control groups (P=0.01, 0, respectively). Similarly, rs4646994, a common insertion/deletion mutation in ACE, the genotypes and alleles also showed the obvious frequency differences between two study groups (P=0.04, 0.01). There was the LD among rs4291, rs4309, rs4343 and A-C-A, T-C-G haplotypes significantly increased the susceptibility of individuals to NAION (OR=1.85, 95% CI=1.05-3.26; OR=4.09, 95% CI=1.83-9.11). Conclusion: ACE rs4309, rs4646994 polymorphisms may be associated with the occurrence of NAION in Chinese Han population and A-C-A, T-C-G haplotypes are also the risk factors for NAION.