title: Evidence of a genetic factor in migraine with aura: a population-based Danish twin study.
abstract: We studied the genetic influence on cause of migraine with aura (MA) by analyzing a twin population. The twin sample consisted of 2,026 monozygotic (MZ) twins and 3,334 same-sex dizygotic (DZ) twins, born from 1953 to 1960, from the population-based New Danish Twin Register. A validated questionnaire was used to screen for migraine, the response rate being 87%, and similar among MZ and DZ twins. All twin pairs with at least 1 twin with possible MA were interviewed by a physician experienced in headache diagnoses. The answers from the questionnaire as well as the zygosity of the twins were blinded for the interviewer. A total of 211 twin pairs were identified, of whom 77 pairs were MZ and 134 pairs were DZ. The lifetime prevalence of MA was 7% and with a male-to-female ratio of 1:1.1. The pairwise concordance rates were significantly higher in MZ (34%) than in DZ twin pairs (12%), emphasizing the importance of genetic factors in MA. However, environmental factors are also important, as the pairwise concordance rate was less than 100% in MZ twin pairs. The recurrence risk of MA was 50% in MZ and 21% in DZ twin pairs. In nontwin siblings, the recurrence risk of MA is 27%, which is similar to the recurrence risk in DZ twins. This indicates that MA is not developed due to specific environmental factors shared by the twins.
authors.affiliation: Department of Neurology, Glostrup Hospital, University of Copenhagen, Denmark.
authors.forename: V
authors.initials: V
authors.lastname: Ulrich
authors.forename: M
authors.initials: M
authors.lastname: Gervil
authors.forename: K O
authors.initials: KO
authors.lastname: Kyvik
authors.forename: J
authors.initials: J
authors.lastname: Olesen
authors.forename: M B
authors.initials: MB
authors.lastname: Russell
mesh_terms: D000328:Adult; D017677:Age Distribution; D003718:Denmark / Q000453:epidemiology; D004200:Diseases in Twins / Q000453:epidemiology* / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D008881:Migraine Disorders / Q000453:epidemiology* / Q000235:genetics*; D012042:Registries