Family-based association analysis of functional VNTR polymorphisms in the dopamine transporter gene in migraine with and without aura.

Because of the role of dopamine in triggering migraine attacks, genes of the dopamine system are candidates for involvement in migraine. We examined three VNTR polymorphisms in the dopamine transporter, the 5'UTR VNTR, the intron 8 VNTR and the intron 14 VNTR, in a sample of 205 family trios. We used the transmission disequilibirium test (TDT) to examine the transmission of these three markers and their haplotypes to offspring affected by migraine. We found no significant transmission distortion of any marker. Likewise haplotypes of the three markers did not show significant overall or individual association with migraine. Finally we examined migraine with and without aura, and likewise found no association between dopamine transporter VNTRs or their haplotypes and either classification of the disease. We conclude that functional genetic variation in the dopamine transporter does not act as a significant risk factor for migraine.