The mutations are rare, but lead researcher Louis Ptáček, professor of neurology at the University of California, San Francisco, says the study moves scientists 'one step closer to understanding the molecular pathway to pain in migraine'.
Migraine is common, affecting one in four women and one in 12 men in the UK. Yet the condition is not well understood and, Professor Ptáček says, ‘the need for better treatments is huge'.
The mutations are in a gene called casein kinase I delta (CKIdelta), which has many functions, including helping control the body’s internal clock. CKIdelta mutations cause an unusual sleep pattern of early sleep times and early rising. Work on two families with this sleep disorder suggested to researchers that CKIdelta mutations were also associated with migraines.
They investigated this link using mice carrying one of the CKIdelta mutations. 'Obviously, we can’t measure headache in a mouse', Professor Ptáček explained, 'but there are other things that go along with migraine that we can measure'.
Like people who experience migraines, the mutant mice were more sensitive to touch and heat. The mice also showed a change in electrical brain waves that may be connected with the visual patterns that some people experience before a migraine attack.
The finding may contribute to understanding of the links between migraine and sleep disturbance.
'Disruptions of sleep are very well known to be a migraine trigger', co-author Professor Andrew Charles of the University of California, Los Angeles told National Public Radio (NPR) in the US. 'And many migraine patients will tell you that their migraine attack will only end if they're able to get to sleep'.
One of the study's co-authors, Dr Emily Bates from Brigham Young University, told NPR that she was inspired to become a geneticist as a teenager because of her own experience with migraine.
'I know so well how frustrating and really demoralizing it can be to get a migraine', she said. 'But I think once we understand the mechanism we can design better drugs'.
The study was published in the journal Science Translational Medicine.