A genetic association study of migraine with dopamine receptor 4, dopamine transporter and dopamine-beta-hydroxylase genes.

We assessed the role of some dopamine metabolism genes in the genetic susceptibility to migraine. We performed an association study using three functional polymorphisms: a 48-base-pair (bp) tandem repeat in the D4 dopamine receptor gene ( DRD4), a 40-bp tandem repeat in the dopamine transporter gene ( DAT) and a dinucleotide repeat in the dopamine beta-hydroxylase ( DBH) gene. Allelic and genotypic frequencies for each polymorphism were assayed in two migraine populations (93 individuals with migraine with aura (MA) and 101 with migraine without aura (MO)) and were compared with those in a control group (117 individuals). No significant differences were found between control and migraine groups for DAT and DBH polymorphisms. Instead, the distribution of alleles for the DRD4 gene in the MO group was significantly different from those in both MA and control groups, with the shortest and longest alleles being less frequent in MO. Our data indicate that MO, but not MA, shows significant genetic association with DRD4.