A new study suggests that migraines are mostly caused by problems with the blood supply system, and the findings could help inform future research and treatments for the disorder.
The research, published by the International Headache Genetics Consortium (IHGC), could help resolve a question doctors have long wrestled with: whether migraines are primarily a vascular (related to blood supply) or neurological (related to the nervous system) problem.
The IHGC pulled in data from 22 different genome-wide association studies, covering almost 60,000 migraine cases in total, with groups from more than 12 countries helping with the research. All up, 38 genomic regions were linked with migraines, 28 for the first time.
While these genes are only newly associated with migraines, they have also been linked to vascular disease, smooth muscle contraction, regulation of vascular tone, and arterial functioning. The finding suggest vascular and muscle problems play a large role in migraines.
"In this latest, large-scale study, tens of new genetic risk factors were discovered," said the leader of the IHGC, Aarno Palotie. "Because all of these variants modify the disease risk only slightly, the effect could only be seen when this large amount of samples became available."
"These genetic findings are the first concrete step towards developing personalised, evidence-based treatments for this very complex disease," added another of the team, John-Anker Zwart from the Oslo University Hospital in Norway. "We doctors have known for a long time that migraine patients differ from each other and the drugs that work for some patients are completely inefficient for others."
While previous studies have found significant links between brain tissue genes and migraines, that wasn't the case here – possibly because there weren't enough tissue samples included in the new research, the team acknowledges.
The scientists also uncovered some evidence that migraines may be linked to the ion channels of the nervous system, which help transmit neural signals, and this is one potential area for further study.
The team shared data between various international biological databases to help identify the links between migraines and certain genomes, and the researchers were keen to emphasise the benefits of working together.
"We simply can't overstate the importance of international collaboration when studying genetics of complex, common diseases," said Palotie, who is also a research director at the University of Helsinki.
Ultimately the hope is that the research, and further studies that build on it, will lead to more effective and more personalised treatments for people who experience migraines. With around 1 in 7 people worldwide experiencing the painful disorder, those treatments can't come soon enough.
The findings are published in Nature Genetics.