Linking migraine frequency with family history of migraine.

Background Migraine is a complex genetic disorder that is brought about by multiple genetic and environmental factors. We aimed to assess whether migraine frequency is associated with genetic susceptibility. Methods We investigated in 2829 migraine patients (14% males) whether migraine frequency' (measured as the number of migraine days per month) was related to genetic load' (measured as the number of parents affected with migraine) using a validated web-based questionnaire. In addition, we investigated associations with age-at-onset, migraine subtype, use of acute headache medication, and comorbid depression. Results We found an association between the number of migraine days per month and family history of migraine for males (p=0.03), but not for females (p=0.97). This association was confirmed in a linear regression analysis. Also, a lower age-at-onset (p<0.001), having migraine with aura (p=0.03), and a high number of medication days (p=0.006) were associated with a stronger family history of migraine, whereas lifetime depression (p=0.13) was not. Discussion Migraine frequency, as measured by the number of migraine days per month, seems associated with a genetic predisposition only in males. A stronger family history of migraine was also associated with a lower age-at-onset, a higher number of medication days, and migraine with aura. Our findings suggest that specific clinical features of migraine seem more determined by genetic factors.