(SALT LAKE CITY)—In an unprecedented international study, researchers from Europe and the United States have shown that individuals carrying a particular genetic variant in the PHACTR1 gene are at reduced risk of sustaining cervical artery dissection, a major cause of stroke in young and middle-aged adults.
Cervical artery dissection is caused by a tear in an artery supplying the brain (carotid or vertebral) that can lead to blood clotting within the artery, potentially causing occlusion of downstream vessels and brain infarction (stroke). The disease is relatively uncommon in the general population, but it is an important cause of stroke in people under 50.
Researchers in the international CADISP (Cervical Artery Dissections and Ischemic Stroke Patients) consortium wanted to identify genes that predisposed people to cervical artery dissection, so they screened the entire genome of 1,400 patients with the disease and 14,400 patients without it. The results of their research were published online in Nature Genetics (www.nature.com/ng/) on Nov. 24, 2014.
"Understanding the mechanisms by which this region of the genome appears to influence key vascular functions could have major applications for the treatment of these severe and disabling conditions," says study co-author Jennifer Majersik, M.D., associate professor of neurology at the University of Utah School of Medicine and director of the University of Utah Stroke Center. "More research is clearly needed to nail down the underlying mechanisms."
Minor neck trauma such as lifting weights or sustaining whiplash injury in a roller-coaster, recent infection, migraine, and hypertension are predisposing factors for cervical artery dissection, but the underlying mechanisms are largely unknown and many times no risk factors or precipitating traumas can be found. Several lines of evidence suggest that genetic risk factors could contribute to the occurrence of the disease. Investigating the genes influencing the risk of cervical artery dissection is important to better understand its mechanisms and improve prevention strategies.
Cervical artery dissection is one of the most common causes of stroke in younger patients seen at University of Utah Health Care. In 2009-10, when this international study was beginning, Majersik contacted nearly 100 patients previously treated for dissection by physicians in the University of Utah Stroke Center. Forty of them responded and came back to the Clinical Neurosciences Center to have their blood drawn for this important genetic study.
"I am grateful that so many of our patients were willing to come back to our center to assist in this study, says Majersik, who is a member of the International Stroke Genetic Consortium. "I think many of them were motivated by the desire to contribute to their neurologist's understanding of the disease and a hope that that knowledge would improve the lives of their family and community members,"
With them, she is now participating in another similar international collaboration – this time to determine the genetic determinants of cerebral venous thrombosis, another common cause of stroke in the young. "It is only through these large international consortia that questions such as these—the genetics of rare but devastating forms of stroke—can be answered," Majersik says.
