Association of 231G>A polymorphism of endothelin type A receptor gene with migraine: A meta-analysis

Background/aims: Vascular dysfunction is implied in migraine. Endothelin type A receptor (EDNRA) is a receptor for endothelin-1, a potent vasoconstrictor. Several studies have investigated the association between EDNRA -231G > A SNP and migraine, but showed conflicting results. This study aimed to evaluate the association between EDNRA -231A allele and migraine by meta-analysis. Methods: Relevant databases were searched to identify eligible studies published in English from 2000 to 2012. Data were extracted using standardized forms. The association was assessed by relative risk (RR) with 95% confidence intervals (CIs) using a fixed or random effects model to determine the strength of the genetic association. Results: Three studies comprising 440 migraineurs, 222 subjects with tension-type headaches (TTHs) and 1323 controls were included in the meta-analysis. A significant difference was found between migraineurs and controls with AA genotype vs. AG+GG, and pooled RR with fixed effect was 4.04 (95% CI 1.173, 1.585; p = 0.000, I-2 = 15.1%). However, there was no statistically significant difference between TTH and controls (p = 0.774). Conclusions: This meta-analysis provides evidence suggesting a significant association between EDNRA - 231G > A polymorphism and migraine. (C) 2012 Elsevier B.V. All rights reserved.