A new study has identified a genetic variant as a factor in developing coronary artery disease (CAD), according to research from the Broad Institute of MIT and Harvard.
Each year, more than 735,000 Americans suffer a heart attack, according to the Centers for Disease Control. Coronary artery disease is the primary cause of heart attack.
Uncovering Chromosomal Causes of Coronary Artery Disease
Cardiologists at the Broad Institute have found that a variant on chromosome 6p24 is common among patients with CAD. The study also found that this variant is present in people with other vascular diseases, such as cervical artery dissection, fibromuscular dysplasia, high blood pressure and migraine headaches.
The study used the genetic information of 200,000 people found in CARDIOGRAMplusC4D, a collaborative consortium of genetic studies used by researchers to identify genetic variants that cause CAD and heart attacks.
Authors of the study also used information collected from the 1000 Genomes Project, the world’s largest catalog of genetic variants.
The Massachusetts researchers sifted through the information in these two databases looking for the presence of a particular single Nucleo peptide rs9349379. Researchers believe variances in rs9349379 are responsible for the change found in 6p24.
Although Broad Institute researchers do not yet know exactly how the chromosomes connect to cause CAD, they do know the consequence of this connection.
A Cause for Concern
The variance found in 6p24 increases activity in endothelin-1 (EDN-1), a gene that causes the arteries to narrow, a condition known as vasoconstriction. Researchers also connected this change in the gene to the development of atherosclerosis, or hardening of the arteries.
Vasoconstriction and atherosclerosis are two contributing factors to the occurrence of heart attack and stroke.
Atherosclerosis is characterized by the buildup of plaque on the inside walls of the arteries. This plaque, made up of cholesterol, calcium and other substances, hardens and calcifies over time.
Any artery in the body can be affected by atherosclerosis, including the peripheral arteries, which deliver blood and oxygen to the limbs, stomach, kidneys, neck and head,
The results of the Broad Institute study are exciting to physicians like Dr. Michael Budler.
"Identifying causes of cardiovascular disease and other types of vascular diseases vastly improves prevention and patient outcomes," Budler said.
Budler is an interventional radiologist in Grand Island, Nebraska, and treats patients with complications caused by atherosclerosis of their peripheral arteries.
Peripheral Artery Disease
"When arteries harden or become constricted, blood flow to the peripheral areas of the body is reduced, and in some cases, completely cut off," Budler said.
Over time, reduced blood flow leads to complications such as tissue death, organ failure, heart attack or stroke.
PAD patients often report that their legs feel tired, weak or heavy. Other symptoms include tingling or numbness in the extremities, thinning of skin and loss of hair on the legs, and wounds or skin ulcers that do not heal.
Some PAD patients report occasional cramping in the legs or buttocks, a condition known as intermittent claudication. Only 20 percent of PAD patients report intermittent claudication as a symptom.
The CDC estimates that 8.5 million Americans have PAD. One in 20 patients with PAD is over the age of 50.
The risk of developing PAD is greater for patients with conditions like high cholesterol, high blood pressure and diabetes.
Like CAD, genetics are a contributing factor for the development of PAD. Smoking, excessive alcohol consumption and obesity increase the risk of developing the condition.
Budler uses the same procedures to treat PAD and CAD. The treatments, vascular stenting and angioplasty, are designed to increase the blood flow through the artery, which improves tissue health, lowers blood pressure and reduces the risk of heart attack.
Cell Press. (2017, July 27). Five vascular diseases linked to one common genetic variant. ScienceDaily. Retrieved August 14, 2017.
Centers for Disease Control. Peripheral Artery Disease (PAD) Fact Sheet. 16 June 2016.