Genetic basis for painful peripheral artery disease

Peripheral artery disease image showing ‘furring up’ of arteries 

Peripheral vascular disease (PVD) can affect the arteries, the veins or the lymph vessels. The most common and important type of PVD is peripheral artery disease, which affects about 8 million Americans.  It becomes more common as a person gets older, and by age 65, about 12 to 20 % of the population has it. Diagnosis is critical, as people with peripheral artery disease have a four to five times higher risk of heart attack or stroke. 

Peripheral Artery Disease (PAD) results from fatty deposits (plaque) that build up in the arteries outside the heart (peripheral arteries); mainly the arteries supplying the legs and feet. This buildup narrows or blocks a person’s arteries and reduces the amount of blood and oxygen delivered to their leg muscles and feet. The iliac, femoral, popliteal and tibial arteries are commonly affected.  the main symptoms are leg pain that won’t go away when exercising;  foot or toe wounds that won’t heal quickly, lower temperature in the affected leg and at worst gangrene.

Researchers from Duke University Medical Center, funded by NIH took two strains of mice with surgically-induced blocked blood flow that mimicked human response to PAD. One strain recovered well, showing restored blood flow and little tissue death; the other had greater tissue loss and poor recovery of normal blood flow. On further investigation, the scientists isolated a small area on chromosome 7 which appeared to give protection from PAD.

Dr. Brian Annex, professor of medicine and director of vascular medicine at Duke, says the study stemmed directly from his clinical experience. “Over and over, I’d see two patients show up at the same time. They would be the same sex, same age, have identical risk factors and have similar blockages in their arteries. One of them would experience very slow progression of the disease, while the other would face limb loss or death within six months. I just knew there just had to be a genetic basis for it.”

“Essentially, we now have a field of about 20 genes that we think may be involved in shaping the way peripheral artery disease develops,” says Annex. “At this point, we are not certain which ones are playing an active role, however. Still, we feel strongly that our discovery opens a new wave of investigation that may one day yield novel prevention strategies or treatments.”

Elaine Warburton www.geneticsandhealth.com