No associations between five polymorphisms in COMT gene and migraine.

OBJECTIVES

The pathophysiology of migraine headaches is not clearly understood yet. The dopaminergic system has been hypothesized to be involved in migraine pathogenesis. The aim of this study was to investigate catechol-O-methyltransferase (COMT) polymorphisms and chronic headaches. We analyzed five single nucleotide polymorphisms (SNPs) in COMT.

MATERIALS & METHODS: The study population consisted of 71 patients with migraine with aura, 152 patients with migraine without aura, 86 patients with tension-type headache, and 191 healthy controls. The selected polymorphic markers included one causing His62His (rs4633) and two non-synonymous SNPs, Ala72Ser and Val158Met (rs6267, rs4680 respectively). Two other non-polymorphic SNPs (rs6270, rs740602) were examined.

RESULTS

We found no significant differences in any genotypes, allele frequencies, or haplotypes among the patient groups and controls.

CONCLUSIONS

Our results indicate that the five polymorphisms in COMT have no association with migraineurs in Western Japan. The possibility that segments elsewhere in the gene may contain a mutation responsible for modifying the expression of COMT or the activity of the enzyme is important. We cannot conclusively exclude the entire COMT gene from being involved in migraine pathogenesis.