Study design: A genetic association study of the transforming growth factor beta 1 (TGFB1) gene with adolescent idiopathic scoliosis (AIS) in Russian population.
Objective: To determine whether common genetic polymorphisms C-509T (rs1800469) and Arg25Pro (rs1800471) of the TGFB1 gene are associated with susceptibility to AIS.
Summary of background data: An importance of growth factors for the pathogenesis of AIS has been demonstrated by the findings of abnormal expression of these proteins in the spine and surrounding tissues in patients with AIS. However, no studies have been performed to investigate the relationship between genetic polymorphisms of the TGFB1 gene and susceptibility to AIS.
Methods: A total of 600 unrelated adolescents from Central Russia (Moscow) were recruited in this study, including 300 patients with AIS and 300 age- and sex-matched healthy adolescents. The polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism.
Results: The allele -509T and genotype -509TT of the TGFB1 gene were significantly associated with the increased risk of idiopathic scoliosis in both females and males (P < 0.01). Logistic regression analysis has revealed a recessive model of the genetic association between polymorphism C-509T of the TGFB1 gene and AIS. Moreover, we found sexual dimorphisms in the relationships of SNP C-509T of the TGFB1 gene with both the age of disease onset and curve severity: the polymorphism was found to determine both an early onset of scoliosis and the severity of curvature in females but not in males (P < 0.05).
Conclusion: This study, for the first time, highlights the importance of TGFB1 gene for the development and progress of AIS. We hypothesize several mechanisms by which the TGFB1 gene may contribute to spinal deformity in patients with AIS.