An international team of researchers has succeeded in finding a genetic link to migraine susceptibility in two diverse populations - 210 migraine families from Finland and Australia. The findings of this EU-funded study were recently published in the American Journal of Human Genetics. Migraine typically causes episodes of severe or moderate headache that can last from 4 to 72 hours. In addition to the throbbing, often unilateral pain, migraine triggers a heightened sensitivity to noise and lights, and brings on gastrointestinal troubles like nausea and vomiting. Around 15% of the world's population suffers from migraines and it places a huge burden on healthcare. In Europe, some 41 million people are affected, costing the EU some €10 billion each year. A major difficulty faced by researchers investigating the genetic causes of migraines is the wide range of symptoms experienced by migraine sufferers. Previous studies have reported links between migraine and a number of points on the genome, but none were ever consistently replicated. 'To address this problem, we developed a new analysis technique concentrating on different symptoms of migraine,' said Professor Aarno Palotie from the University of Helsinki, Finland, and the Wellcome Trust Sanger Institute, Cambridge, UK. In the study, one gene locus was identified on chromosome 10q23. The researchers said that this discovery strongly indicated a genetic linkage in both populations studied, as well as in the replication study. The locus was showed particularly strong links to migraine in female migraine sufferers. An interesting feature of this study is that while Finland and Australia are genetically distant, the researchers were able to tie together previous research that offered strong evidence for identifying the region that is easily affected. 'In a further analysis, two independent previous studies, one Finnish and one Australian, had detected the same locus, but in those studies the level of evidence had been just below significance, and thus the connection had so far been missed,' explained Dr Verneri Antilla, a Postdoctoral Fellow at the Wellcome Trust Sanger Institute, and a member of Palotie's group. The researchers were able to link this locus to migraine in 4,000 migraine sufferers or their close relatives. 'All these findings depended on the newly discovered aspect of migraine genetics: different types of pain, such as pain that pulsates or pain that is unilateral, are more closely linked to specific genetic loci than general pain,' Professor Palotie commented. The results from this study should help stimulate further work on unravelling the mystery behind migraine pathways and uncovering targets for future treatments. According to Professor Palotie and Dr Antilla, applying new analysis strategies for detecting the locus helped forge subsequent association studies. A total of nine research institutes from four countries participated in the study. In addition to the University of Helsinki and the Sanger Institute, participants were Helsinki University Central Hospital, Folkhälsan Research Center and National Public Health Institute, (Finland); Queensland Institute of Medical Research (Australia); and Columbia University, National Institute of Mental Health, the Broad Institute of MIT and Harvard, (USA).