Single Nucleotide Polymorphisms and Adolescent Idiopathic Scoliosis: A Systematic Review and Meta-analysis of the Literature.

STUDY DESIGN: Meta-analysis.

OBJECTIVE: To determine the single nucleotide polymorphisms that are related to adult idiopathic scoliosis.

SUMMARY AND BACKGROUND DATA: Adolescent Idiopathic Scoliosis (AIS) is considered one of the most prevalent spinal diseases. Even though the cause of AIS is yet to be determined, family history and gender have shown conclusive associations. Multiple studies have indicated that AIS is more prevalent in families where at least one other first-degree relative is similarly affected, indicating a possible genetic etiology to AIS.

METHODS: Articles were collected from 3 different search engines and then processed in 2 stages for final article selection for quantitative analysis. 5 different genetic models were represented to show association between the different single nucleotide polymorphisms (SNP) and AIS. The Hardy-Weinberg Equilibrium was examined using Fisher's exact test, with significance set at P<0.05. The final analysis's papers' quality was evaluated using the Newcastle Ottawa Scale. Kappa-inter rater agreement was calculated to evaluate agreement between authors.

RESULTS: The final analysis comprised 43 publications, 19412 cases, 22005 controls, and 25 distinct genes. LBX1 rs11190870 T>C and MATN-1 SNPs were associated with an increased risk of AIS in one or all of the five genetic models. IGF-1, Estrogen Receptor alfa (ERα), and MTNR1B, SNPs were not associated to AIS in all five genetic models. Newcastle Ottawa Scale showed good quality for the selected articles. Cohen's k=0.741 and Kappa inter-rater agreement of 84% showed that the writers were in strong agreement.

CONCLUSIONS: There appears to be associations between AIS and genetic SNP. Further larger studies should be conducted to validate the results.