The TGFB1 gene is associated with curve severity but not with the development of adolescent idiopathic scoliosis: a replication study in the Chinese population

Background: The transforming growth factor beta-1 (TGFB1) gene was recently reported to be a new susceptible gene of adolescent idiopathic scoliosis (AIS) in Russian population. This study aimed to replicate the relationship between the TGFB1 gene and the susceptibility of AIS in a Chinese population, and to further describe its association with the curve severity. Methods: A total of 1251 female AIS patients and 994 age-matched healthy controls were included in this study. The rs1800469 of TGFB1 gene was genotyped for all participants using the PCR-based Invader assay. The differences of genotype and allele distributions between AIS patients and healthy controls were assessed using the Chi-square test. One-way ANOVA test was used to compare the mean Cobb angles among patients with different genotypes. Results: There was no significant difference in terms of the genotype and the allele frequency between the patients and the controls. The mean Cobb angle was 34.7 +/- 11.9 degrees (range 25-61 degrees). Case-only analysis showed that rs1800469 was significantly associated with the curve severity. Patients with genotype TT had remarkably higher curve magnitude (39.1 +/- 12.8 degrees) than those with genotype CT (34.8 +/- 11.1 degrees) or CC (32.1 +/- 10.6 degrees). Conclusions: The TGFB1 gene may not be a predisposition gene of AIS in the Chinese population. However, it can play a role in the curve progression of AIS. Replication studies in other ethnic groups are warranted to understand the implication of TGFB1 gene in AIS.