Association between the ESR1 -351A>G single nucleotide polymorphism (rs9340799) and adolescent idiopathic scoliosis: a systematic review and meta-analysis.

Purpose: A single nucleotide polymorphism in the promoter region of the estrogen receptor alpha gene (ESR1), rs9340799, has been linked with adolescent idiopathic scoliosis (AIS) in several association studies with limited sample size and inconsistent findings. A systematic review can provide a comprehensive appraisal of literature evidence and a meta-analysis can obtain a more precise estimate of any association. The purpose of the present study was to assess and synthesize the currently available evidence on the association between rs9340799 and AIS by conducting a systematic review and meta-analysis.
Methods: This review followed the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines. PubMed (MEDLINE), EMBASE, Scopus and HuGE Literature Finder databases were systematically searched to identify relevant studies following a sensitive strategy. Summary odds ratios and corresponding 95% confidence intervals (95 % CI) were estimated using the fixed-effect inverse variance model for allelic (G vs. A) and genotypic comparisons.
Results: Meta-analysis of four studies (n = 1,827 AIS cases and n = 1,253 controls) found a non-significant association between rs9340799 and AIS (allelic odds ratio 1.09, 95 % CI 0.96-1.23, p = 0.17).
Conclusions: When examined in isolation, the rs9340799 polymorphism does not appear to be a likely susceptibility variant for AIS predisposition. However, rs9340799 may be associated with AIS severity, progression and treatment; further investigation is necessary to confirm these potential associations.