A revolutionary way of screening the entire human genome for the genetic signposts of disease has produced its latest success — the first inherited link to common migraine and a possible reason for extreme headaches.
The technique, which scans all 23 pairs of human chromosomes in a single sweep, has found the first genetic risk factor that predisposes someone to the common form of migraine, which affects one in six women and one in 12 men.
The discovery has led to a new possible cause of migraine by alerting scientists to DNA defects involved in the build-up of a substance in the nerves of sufferers that could be the trigger for their migraines.
Scientists believe the findings could lead to a better understanding, as well as new treatments, for the chronic and debilitating condition which is estimated to be one of the most costly brain-related disorders in society, causing countless lost working days.
Scanning the entire blueprint of human DNA by Genome-Wide Association Studies (GWAS) has had a profound effect on the understanding of a range of other medical conditions, from heart disease and obesity to bipolar disorder and testicular cancer.
The study of migraine, published in the journal Nature Genetics, was an archetypal example of the new approach of medical genetics using the GWAS technique. Scientists analysed the genomes of 5,000 people who suffer from migraines and compared their DNA to that of unaffected people to see if there were any significant differences.
“This is the first time we have been able to peer into the genomes of many thousands of people and find genetic clues to understand common migraine,” said Dr Aarno Palotie, chair of the international headache genetics consortium at the Wellcome Trust Sanger Institute in Cambridge.
“Studies of this kind are possible only through large-scale international collaboration so that we could pick out this genetic variant. This discovery opens new doors to understanding common human diseases,” he added.
The scientists behind the migraine study scanned the entire genomes of 50,000 people in total, a huge undertaking that was only possible because of the availability of relatively cheap commercial GWAS kits that can be used to screen all of a person's 46 chromosomes in a single sweep.
The insight that this approach has given scientists could only be dreamed of 10 or 15 years ago.
”I think it has revolutionised the way we can tackle these diseases. We've identified new pathways to disease and new causes we did not know before,” Dr Palotie said.