Millions of migraine sufferers are being offered new hope after scientists identified a gene that causes the condition.
Researchers scanned the genomes of more than 50,000 people and found those who suffered from the severe headaches had a mutation on a section of DNA known as chromosome eight.
The mutation appears to stop the clearing of a substance called glutamate, a major brain neurotransmitter which becomes toxic when allowed to build up in high levels.
The gene, called EAAT2, has previously been linked with epilepsy, schizophrenia and mood and anxiety disorders.
Professor Christian Kubisch, of the University of Ulm in Germany, said: "This research opens the door for new studies to look in depth at the biology of the disease and how this alteration in particular may exert its effect."
Around six million people in the UK suffer migraines, with one in four having to endure the most acute aura variety, which can last up to 72 hours and cause visual disturbances, dizziness and nausea. Twice as many women as men are affected. It is thefirst time a genetic risk factor has been discovered and the researchers, whose findings are published in Nature Genetics, believe it will open the door for new therapies to prevent attacks.
Dr Aarno Palotie, chair of the International Headache Genetics Consortium at the Wellcome Trust Sanger Institute, Cambridge, said: "This discovery opens new doors to understand common human diseases."
The researchers compared the genomes of more than 3000 migraine sufferers from Finland, Germany and the Netherlands with those of more than 10,000 "nonmigrainers" to spot differences in their DNA.
