For long it was thought that elevated homocysteine was associated with cardiovascular diseases. That could lead to coronary artery disease, heart attacks, strokes, clots in veins causing DVT and PE, and pregnancy complications, among others. But in 2010 the American Heart Association declared that elevated homocysteine levels were not considered to be a major risk factor for cardiovascular disease. Subsequently, in 2013, the American College of Obstetricians and Gynecologists recommended that fasting homocysteine levels should not be ordered as part of workup for VTE. Homocysteine is a breakdown product of methionine that can be recycled by the human body with the help of the enzyme methylene tetrahydrofolate reductase to reuse in building proteins. A mutation of the methylene tetrahydrofolate reductase gene (C677T) impairs its ability to process folate that may lead to elevated homocysteine levels. An elevated homocysteine level is not a clotting disorder and should not be included in thrombophilia testing panels.