Objective: To determine whether ACE insertion/deletion (I/D) polymorphism is associated with the ossification of the posterior longitudinal ligament (OPLL) of the spine in the Korean population.
Methods: A case-control study was conducted to investigate the association between I/D polymorphism of the angiotensin I converting enzyme (peptidyl-dipeptidase A) 1 (ACE) gene and OPLL. The 95 OPLL patients and 274 control subjects were recruited. Polymerase chain reaction for the genotyping of ACE I/D polymorphism was performed. The difference between the OPLL patients and the control subjects was compared using the contingency χ(2) test and the logistic regression analysis. For statistical analysis, SPSS, SNPStats, SNPAnalyzer, and Helixtree programs were used.
Results: The genotype and allele frequencies of ACE I/D polymorphism showed significant differences between the OPLL patients and the control subjects (genotype, p<0.001; allele, p=0.009). The frequencies of D/D genotype and D allele in the OPLL group were higher than those in the control group. In logistic regression analysis, ACE I/D polymorphism was associated with OPLL (dominant model; p=0.002; odd ratio, 2.20; 95% confidence interval, 1.33-3.65).
Conclusion: These results suggest that the deletion polymorphism of the ACE gene may be a risk factor for the development of OPLL in the Korean population.
Keywords: Angiotension converting enzyme; Genetic association analysis; Genetic polymorphism; Ossification of the posterior longitudinal ligament.