OBJECTIVETo investigate the association between the tissue inhibitor of metalloproteinase-2 (TIMP-2) gene polymorphisms with the predisposition and disease severity of thoracic adolescent idiopathic scoliosis (AIS).

METHODSThree hundred and fifty-four female thoracic AIS patients treated from January 2007 to March 2009 and 210 healthy female who underwent health examination during March 2005 to June 2006 as normal controls were recruited in this study. One SNP-418G/C (rs8179090) in the promoter region were selected for TIMP-2 gene. PCR- RFLP was used for genotyping.

RESULTSNo significant differences of genotype and allele frequency distribution were found between AIS patients and normal controls (P > 0.05). In AIS patients, the frequency of C allele of the patients with the body mass index (BMI) < 17 kg/m(2) was significantly higher than those with the BMI > or = 17 kg/m(2) (P < 0.05), and the frequency of C allele of cases with the major Cobb angle > or = 40 degrees was significantly higher than that with Cobb angle < 40 degrees (P < 0.05). Among the patients who reached skeletal maturity without any interference of natural history, significantly higher average maximum Cobb angle was found in patients with GC and CC genotype compare with those with GG genotype.

CONCLUSIONSThe SNP-418G/C (rs8179090) in the promoter region of TIMP-2 gene may be associated with abnormal growth pattern and curve progression of thoracic AIS. TIMP-2 gene is a disease-modifier gene of thoracic AIS.