Etiology of primary headaches: the importance of genes and environment

Results from twin studies show that genes play an important role for susceptibility to migraine. The propensity for migraine to run in some families but not in others arises predominantly from alleles shared by family members and not the shared family environment, and that environmental influences on migraine are unique to the affected family member. The main genetic and environmental architecture for the other two major primary headaches, tension-type and cluster, remains to be elucidated. This review focuses on recent advances in twin studies of primary headaches and the future prospects are outlined.