Promoter Polymorphism (-308G/A) of Tumor Necrosis Factor-Alpha () Gene and Asthma Risk: An Updated Meta-Analysis.

The relationship between the promoter polymorphism (-308G/A) of the tumor necrosis factor-alpha () gene and the susceptibility to asthma has been tested in several studies. However, the results have been inconsistent. Therefore, we performed an updated meta-analysis to evaluate the relationship between this promoter polymorphism of the gene and the risk of asthma. Fifty case-control studies were included in this meta-analysis which provided 17,937 controls and 9961 asthma patients. The pooled -value, odds ratio (OR), and 95% confidence interval (95% CI) were used to investigate the strength of the association of this polymorphism of the gene with the risk of asthma. The meta-analysis was carried out by Comprehensive Meta-Analysis software. The results of our meta-analysis revealed that the polymorphism (-308, G/A) was strongly associated with the risk of asthma ( < 0.05 in the allelic, dominant, and recessive models, respectively). In further analyses, based on age group and ethnicity, we observed this association for all subpopulations examined ( < 0.05 in allelic, dominant, and recessive models, respectively). This large-scale meta-analysis supports a strong association between the gene promoter polymorphism (-308G/A) and the development to asthma in both children and adults.