Association Between IL-6 and MMP3 Common Genetic Polymorphisms and Idiopathic Scoliosis in Bulgarian Patients: A Case-control Study.

STUDY DESIGN: A case-control study was performed on 105 patients with idiopathic scoliosis (IS) and 210 unrelated gender-matched controls from Bulgarian population. OBJECTIVE: Investigation of the association between common genetic polymorphisms of IL-6 and MMP3 genes and the etiology and progression of IS among Bulgarian patients. SUMMARY OF BACKGROUND DATA: The IL-6 and MMP3 genes have been considered as candidate genes of IS in Caucasian population. METHODS: Molecular detection of the promoter polymorphisms of IL-6 and MMP3 was performed by polymerase chain reaction followed by restriction fragment length polymorphism. The statistical analysis was performed by χ test with a value of P < 0.05 as statistically significant. The combinatorial effect of the candidate genes was also examined. RESULTS: This case-control study revealed statistically significant association between the IL-6 (rs1800795) functional polymorphism and susceptibility to IS (χ = 16.055; P < 0.0001). In addition, a significant association between IL-6 (rs1800795) and curve severity was detected (χ = 16.87; P < 0.0001). No genotype or allele of MMP3 (rs3025058) was found to be correlated to the onset or progression of IS (P > 0.05). One IL-6-MMP3 genotype combination was associated with the susceptibility to IS. CONCLUSION: IL-6 gene could be considered as a susceptibility and modifying factor of IS. The identification of molecular markers with diagnostic and prognostic value could be useful for early detection of children at risk for the development of IS and for prognosis of the risk for a rapid deformity progression. That would facilitate the therapy decisions and early stage treatment of the patient with the least invasive procedures. LEVEL OF EVIDENCE: 4.