Plaque build-up caused by atherosclerosis increases the risk of blood clots, heart attack, and stroke. Blockages of plaque can occur in different areas of the body. PAD, a circulatory disorder in which blockages occur in the peripheral arteries, is one manifestation of atherosclerosis. Individuals with PAD experience reduced blood flow to the legs, which may cause leg pain while walking. Coronary artery disease (CAD), in which plaque builds up in arteries leading to the heart, is another atherosclerosis-related condition. Individuals with PAD and CAD have similar atherosclerosis risk factors, but it remains unknown why some individuals develop one disease and not the other. Genetic differences may influence where atherosclerosis develops. The goal of the study is to identify genetic variations that may cause inherited differences in plaque distribution.