Association of COL9A3 trp3 polymorphism with intervertebral disk degeneration: a meta-analysis

Abstract

Background: Intervertebral disk degeneration (IDD) is a common musculoskeletal disease associated with genetic factors. COL9A3 gene encodes the α3 (IX) chain of type IX collagen that is part of the interior structure of the disc. Mutations in COL9A3 gene sequence, leading to an Arg103Trp substitution in its 3 chain (the Trp3 allele at rs61734651 site), respectively, have been found to be connected with IDD occurrence in several studies. However, those studies have showed conflict results. Thus, a meta-analysis has been performed to assess the associations between the COL9A3 trp3 polymorphism and IDD.

Methods: Data were gathered from the following four electronic databases: PubMed, Web of Science (WOS), Embase and Cochrane library up to January 01, 2018. The pooled odds ratio (polled ORs) and 95% confidence interval (CI) were calculated to evaluate the strength of relationship between the COL9A3 trp3 polymorphism and IDD.

Results: Eleven eligible studies with 1631 cases of IDD and 1366 controls were included in this meta-analysis. The results indicated that the COL9A3 trp3 polymorphism was not associated with IDD (trp3 positive versus trp3 negative: OR = 1.31, 95%CI = 0.78-2.21, P = 0.309). Furthermore, the Egger's test and the Begg funnel plot did not show any evidence of publication bias.

Conclusions: Our results suggest that the COL9A3 trp3 polymorphism might not be associated with IDD. Nor did we find any relationship in subgroup analyses stratified by gender and ethnicity. Future researches with larger samples are required to verify this outcome.

Keywords: COL9A3; Intervertebral disk degeneration; Meta-analysis; Single nucleotide polymorphism; trp3.

Fig. 1

Flow diagram for the selection of studies

Fig. 2

Forest plot of the association between COL9A3 trp3 polymorphisms and IDD (trp3 positive versus trp3 negative) for: (a) overall analysis and subgroup analyses stratified by (b) gender, (c) ethnicity

Fig. 3

Sensitivity analysis for confirmation of the stability of the pooled results

Fig. 4

Begg funnel plot for the identification of potential missing studies