Study Design. Case-control study.
Objective. This study is to replicate the association between the promoter polymorphisms of matrix metalloproteinase (MMP)-3 (−1171 5A/6A rs3025058) and interleukin (IL)-6 genes (−174G/C rs1800795) and adolescent idiopathic scoliosis (AIS) in a Chinese Han population.
Summary of Background Data. Recently, promoter polymorphisms in MMP-3 and IL-6 have been reported to be associated with AIS. Such genetic association, if confirmed by replication in other samples, would point to a primary degenerative defect in the disc or nucleus pulposus and inflammation as the key pathogenic mechanisms of AIS.
Methods. A total of 487 Chinese girls with AIS and 494 healthy age-matched adolescent girls were recruited consecutively during a 3-year period. The same genotyping technique as the original report was used to detect promoter polymorphisms of the MMP-3 and IL-6 genes. Statistical analysis of genotype frequencies between AIS patients and normal controls were performed by χ2 test.
Results. In this association study of the MMP-3 polymorphism and the risk of scoliosis, no significant difference was found between cases and controls, both in term of allelic association (6A: 81.2% in cases vs. 81.8% in controls, 5A: 18.8% in cases vs. 18.2% in controls, P = 0.745) or genotype association (6A/6A: 65.9% in cases vs. 66.2% in controls, 5A/6A: 30.6% in cases vs. 31.2% in controls, and 5A/5A: 3.5% in cases vs. 2.6% in controls; P = 0.733). Among AIS patients, the maximal Cobb angles were also not different among MMP-3 genotypes (6A/6A: 31.1° ± 9.7°, 5A/6A: 29.1° ± 10.5°, and 5A/5A: 29.4° ± 11.2°; P = 0.392). As for IL-6 polymorphism, −174G/C polymorphism was not found in the Chinese AIS patients, and all 100 AIS patients and 100 normal controls were found to carry the G/G wild type.
Conclusion. This study did not find any significant association of promoter polymorphisms of the MMP-3 (−1171 5A/6A rs3025058) and IL-6 gene (−174G/C rs1800795) with AIS. The results indicate that the MMP-3 promoter polymorphism is not associated with AIS in the Chinese population. Further studies, however, are needed to rule out the potential association with other promoter polymorphisms in IL-6.
This study was a genetic association study of the promoter polymorphism of matrix metalloproteinase (MMP)-3 gene and interleukin (IL)-6 gene with adolescent idiopathic scoliosis (AIS) in a Chinese Han population. The results indicate that the MMP-3 promoter polymorphism is not associated with AIS in the Chinese population. On the other hand, a potential association with other promoter polymorphisms in IL-6 cannot be excluded.
From the *Spine Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, People's Republic of China; †The Joint Scoliosis Research Center of the Chinese University of Hong Kong and Nanjing University, Nanjing, People's Republic of China; and Departments of ‡Chemical Pathology, and §Orthopaedics and Traumatology, Chinese University of Hong Kong, Hong Kong, People's Republic of China.
Acknowledgment date: March 27, 2009. Revision date: September 14, 2009. Acceptance date: September 15, 2009.
The manuscript submitted does not contain information about medical device(s)/drug(s).
No funds were received in support of this work. No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this manuscript.
The first two authors contributed equally to this work.
Address correspondence and reprint request to Yong Qiu, MD, Spine Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, People's Republic of China; E-mail: firstname.lastname@example.org