Replication study of the insulin receptor gene in migraine with aura.

We performed the first replication study for the reported association of the insulin receptor gene (INSR) with migraine with aura (MA). Two of 35 SNPs (rs1052371 and rs2860174) reached borderline significance (best uncorrected allelic p value of 0.052 for rs2860174) in stage 1 of our study (270 MA patients, 280 controls). As rs2860174 was 1 of the 5 SNPs with prior evidence of association, we also genotyped this SNP in our stage 2 sample (679 MA patients, 368 controls), and it was nonsignificant (allelic p value 0.478). The combined analysis of our samples showed just a nonsignificant trend for rs2860174 (p=0.1). However, the joint analysis of our study and the initial study reporting an association-including 1278 Caucasian MA patients and 1337 Caucasian controls altogether-displayed a significant allelic p value of 0.005. In conclusion, further association studies for rs2860174 with even larger numbers of individuals are required to exclude or confirm definitely a small effect of this SNP on migraine susceptibility.