ABSTRACT
Objective This study aimed to investigate whether the copy numbers of the CCL3L1 (Chemokine C-C-Motif Ligand 3 Like Protein 1) gene were associated with susceptibility to ankylosing spondylitis (AS). Methods A total of 806 Chinese individuals including 405 AS patients and 401 healthy controls were enrolled. The CCL3L1 gene copy number was measured by a custom-by-design Multiplex AccuCopyTM Kit based on a multiplex fluorescence competitive polymerase chain reaction (PCR) principle, and 50 samples were randomly selected using the fluorescent quantitative PCR method to verify copy number. Main statistical method was t test, chi-square test and logistic regression model. Results There were no statistically significant differences between the case group and control group in age and gender ( t=1.77, P=0.076, χ2=1.14, P=0.289). The copy number of CCL3L1 gene ranged from 0 to 13 in both AS patients and the controls. After copy numbers were classified into 3 categories by 3, we did not find significant difference between the two groups ( χ2=0.591, P=0.669). And regression analyses also did not support the hypothesis that CCL3L1 gene copy number variation (CNV) could be an impact factor to the severity or function indexes of AS patients ( χ2=0.341, P=0.804 and χ2=0.472, P=0.774, respectively). Conclusion We suggest that the copy number of the CCL3L1 gene does not have a role in the susceptibility and the severity or function to AS.