In a meta-analysis of all studies concerning COMT rs4680 and risk of migraine, carriers of the AA genotype versus carriers of GG + GA genotypes had 24% decreased migraine risk (AA vs. GG + GA: OR = 0.76, 95% CI = 0.60–0.97, PHet > 0.642, I2 = 0). Here, COMT is linked to migraine disorder.