a1 Dept of Biological Psychology,Vrije Universiteit,Amsterdam,The Netherlands. EJCM.Mulder@psy.vu.nl
a2 Dept of Biological Psychology,Vrije Universiteit,Amsterdam,The Netherlands.
a3 University of Southern Denmark, Odense & Dept of Neurology, Odense University Hospital, Denmark.
a4 Helsinki University Central Hospital, Finland.
a5 Dept of Public Health, University of Helsinki & Dept of Mental of Health, National Public Health Institute, Helsinki, Finland.
a6 Karolinska Institutet Stockholm, Sweden.
a7 The Queensland Institute of Medical Research, Brisbane, Australia.
a8 The Queensland Institute of Medical Research, Brisbane, Australia.
a9 Twin Research and Genetic Epidemiology Unit, St Thomas' Hospital, London, UK.
a10 Twin Research and Genetic Epidemiology Unit, St Thomas' Hospital, London, UK.
a11 Dept of Biological Psychology,Vrije Universiteit,Amsterdam,The Netherlands.
a12 The Finnish Genome Center and the Department of Clinical Chemistry, University of Helsinki, Helsinki, Finland.
Migraine is a common neurovascular brain disorder that is manifested in recurrent episodes of disabling headache. The aim of the present study was to compare the prevalence and heritability of migraine across six of the countries that participate in GenomEUtwin project including a total number of 29,717 twin pairs. Migraine was assessed by questionnaires that differed between most countries. It was most prevalent in Danish and Dutch females (32% and 34%, respectively), whereas the lowest prevalence was found in the younger and older Finnish cohorts (13% and 10%, respectively). The estimated genetic variance (heritability) was significant and the same between sexes in all countries. Heritability ranged from 34% to 57%, with lowest estimates in Australia, and highest estimates in the older cohort of Finland, the Netherlands, and Denmark. There was some indication that part of the genetic variance was non-additive, but this was significant in Sweden only. In addition to genetic factors, environmental effects that are non-shared between members of a twin pair contributed to the liability of migraine. After migraine definitions are homogenized among the participating countries, the GenomEUtwin project will provide a powerful resource to identify the genes involved in migraine.
c1 Address for correspondence: Elles J. Mulder, Dept of Biological Psychology, FPP, Vrije Universiteit. Van der Boechorststraat 1, Room 1F-58, 1081 BT, Amsterdam, the Netherlands.