Canadian and British researchers have found that some people may have a genetic predisposition to migraines, a condition that's notoriously difficult to treat. Here, a quick guide:

What did the study conclude?
When comparing the DNA of migraine sufferers, researchers at the University of Montreal and the University of Oxford found a gene mutation common to the members of a large family who are all vulnerable to migraines with auras — a type of migraine whose sufferers experience abnormal "visual disturbances" or see spots. "When we tested everyone in the family, all those who suffered from migraines also had the mutation," says the study's lead author, Ron Lafreniere.

What does the genetic abnormality do?
The mutation interferes with the production of a protein called TRESK in the KCNK18 gene. This protein has an important role in "nerve cell communication" and "helps to regulate the sensitivity threshold of pain centres in the brain." Migraines, says Dr. Zameel Cader, one of the researchers, "seem to depend on how excitable our nerves are in specific parts of the brain."

Has anything like this been found before?
Previous studies have linked DNA to an increased risk of migraines, but this is the first to link migraines to a specific gene.

How many people suffer from migraine headaches worldwide?
Roughly one in five women, and one in ten men. According to the World Health Organization, migraines are one of the leading causes of disability.

What does this mean for migraine treatment?
Now that researchers have found that some migraine sufferers have the defective gene, "what we want to do is find a drug that will activate the gene," says Cader. The study's findings "give us a real opportunity to find a new way to fight migraines and improve the quality of life for those suffering." One day, says Dr. Richard Besser, ABC News' Senior Health and Medical Editor, a doctor may be able to tell a patient, "'You have a defect in this particular gene. I know this particular treatment is going to work for you.'"

Sources: BBC News, NHS, Medical News Today, ABC News