Background and purpose
Genetic factors contribute to the aetiology of the prevalent form of migraine without aura (MO) and migraine with typical aura (MTA). Due to the complex inheritance of MO and MTA, the genetic background is still not fully established. In a population-based genome-wide association study by Chasman et al. (Nat Genet 2011: 43: 695–698), three common variants were found to confer risk of migraine at a genome-wide significant level (P < 5 × 10−8). We aimed to evaluate the top association single nucleotide polymorphisms (SNPs) from the discovery set by Chasman et al. in a primarily clinic-based Danish and Icelandic cohort.