Abstract

Background
Following the first clinical and pharmacological suggestion of altered dopaminergic neu- rotransmission in migraine, recent genetic association studies have addressed the possible genetic role of the dopaminergic system in migraine. COMT(Catechol-O-methyltransferase) is an enzyme which play a crucial role in the metabolism of dopamine. This genetic polymorphism is associated with 3～4 fold variation of enzymatic activity. So change in their activity could participated in migraine pathogenesis and its clinical phenotype. Objectives: We assessed the role of the COMT enzyme polymorphism in the genetic susceptibility to migraine and their phenotypical expression in Korean population. Methods: The 77 migraine without aura and 94 healthy volunteers were included in the study. The analysis of COMT polymorphism was performed using PCR. After amplifying COMT genes by PCR and assessed genotype and allele by restriction fragment length polymorphism(RFLP). Results: Result of chi-square statistical analysis indicated that the genotype frequency and allele distri- bution was not different between migraine without aura and control group. Compared to individuals with H/H genotype, migraineurs with L allele showed more severe pain intensity(p=0.001) and over represen- ted the associated nausea/vomiting symptom during migraine attack(94% vs 75%: p=0.031) compared those without L allele. Conclusion: Altered dopaminergic activity due to polymorphism of COMT gene may be one of the mechanisms involved in the contribution to the pain intensity of attack and dopamine related symptom although this polymorphism does not appear to be involved in a genetic predisposition to development of migraine without aura.