Sixteen of the patients were carriers of the risk allele rs2274316 ( MEF2D), which confers increased risk of MO and may regulate PACAP38 expression, and 16 were non-carriers.
Conclusion Migraine response to PACAP38 infusion in migraine without aura patients is not associated with high family load or the risk allele of rs2274316 ( MEF2D).
We also demonstrated that the currently known single nucleotide polymorphisms conferring risk of migraine without aura have no additive effect on calcitonin gene-related peptide induced migraine-like attacks.
We herein investigated the role of polymorphisms in calcitonin gene-related peptide (CGRP)-related genes looking at the association of rs3781719 (T > C) in the calcitonin gene-related polypeptide-alpha (CALCA) gene and of rs3754701 (T > A) and rs7590387 (C > G) at the receptor activity modifying 1 (RAMP1) locus with triptan response in patients with migraine without aura (MwoA).
Studies eligible for this meta-analysis were searched in the PubMed, Embase, and CNKI by using the keywords "tumor necrosis factor", "TNF", "252A>G", "rs909253", "polymorphism", "polymorphisms", "variant", "SNP", combined with "migraine" or "migraine with aura (MA)" or "migraine without aura (MO)".
Subgroup analyses suggested that the A allele of the TNFα -308G > A variant more than doubles the risk for migraine among populations with a heterogeneous ethnic background, which was driven by associations for migraine without aura (additive model: pooled OR = 2.87, 95% CI 1.86-4.43).
In conclusion, the present results indicate the possible contribution of TNF-alpha and IL-1beta gene polymorphisms to migraine headache generation in MwoA patients.