Lack of Association Between the Promoter Polymorphisms of MMP-3 and IL-6 Genes and Adolescent Idiopathic Scoliosis: A Case-Control Study in a Chinese Han Population

• Published in: Spine (Philadelphia, Pa. 1976) Vol. 35; no. 18; pp. 1701 - 1705
• Main Authors: ZHEN LIU, TANG, Nelson L. S, CAO, Xing-Bin, LIU, Wen-Jun, QIU, Xu-Sheng, CHENG, Jack C. Y, YONG QIU
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD Lippincott Williams & Wilkins 15-08-2010
• Subjects: Adolescent; Asian Continental Ancestry Group - genetics; Biological and medical sciences; Case-Control Studies; Cerebrospinal fluid. Meninges. Spinal cord; Child; China - ethnology; Female; Genetic Predisposition to Disease - ethnology; Genetic Predisposition to Disease - genetics; Humans; Interleukin-6 - genetics; Matrix Metalloproteinase 3 - genetics; Medical sciences; Nervous system (semeiology, syndromes); Neurology; Polymorphism, Genetic - genetics; Promoter Regions, Genetic - genetics; Scoliosis - enzymology; Scoliosis - genetics; Scoliosis - metabolism; Tumors of the nervous system. Phacomatoses; Young Adult; China; Human; Nervous system diseases; Deformation; Vertebral canal; Spine; Cytokine; Diseases of the osteoarticular system; Idiopathic; Spine disease; Case control study; occurrence; IL-6; Osteoarticular system; Interleukin 6; Scoliosis; Central nervous system disease; Adolescent; MMP-3; Chinese; Spinal cord disease; Polymorphism; adolescent idiopathic scoliosis; curve severity
• ISSN: 0362-2436; 1528-1159
• DOI: 10.1097/BRS.0b013e3181c6ba13

Case-control study.
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.
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.
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 chi test.
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 degrees +/- 9.7 degrees, 5A/6A: 29.1 degrees +/- 10.5 degrees, and 5A/5A: 29.4 degrees +/- 11.2 degrees; 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.
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.