Headaches are a pain — literally. But while most people see them as a temporary nuisance, many others find them extremely debilitating. For the 8% of men and 17% of women who suffer from migraine headaches, these long, recurring episodes can include more than just throbbing pain: vomiting, chills, sensitivity to light or sound, or trouble concentrating are just a few of the possible symptoms. Some people experience a set of symptoms prior to their migraine attacks known as “aura” but for others the attacks come without warning.
Because the condition is complex and manifests differently in each person, the biological causes of migraine have been difficult to determine. New research, however, is implicating common genetic variants which may help to elucidate the biological underpinnings of the disease.
In a study published this week in Nature Genetics, a team of scientists from the International Headache Genetics Consortium (IHGC) identified a genetic variant associated with migraine susceptibility. The researchers compared almost 6,000 migraine sufferers to more than 50,000 people who did not suffer from migraines, all of European ancestry, and found that the less common variant was associated with about 1.2 times higher odds of migraine headache.
Although the SNP is not located within any known genes, it is found in a region of the genome that contains genes involved in the regulation of a neurotransmitter called glutamate. When the IHGC team looked at the nearby genes, they observed that was significantly correlated with the expression levels of MTDH. MTDH regulates another gene that encodes a protein that transports glutamate in the brain. Previous research has suggested that an imbalance in glutamate levels may contribute to the development of migraines, in addition to other neurological disorders, but the exact mechanisms are still unknown. More studies are needed to confirm and elaborate on the IHGC’s findings.