Hyperhomocysteinemia presenting as exclusive small vessel coronary artery disease (CAD) in a young.

We present an extremely rare case of a 26-year-old young male, an engineering student and a staunch vegetarian from early childhood without conventional cardiac risk factors, with hyperhomocysteinemia presenting as acute lateral wall ST elevation myocardial infarction with angiographic evidence of focal critical occlusion of the first diagonal branch. Although homocysteinemia and its association with coronary artery disease is well known, hyperhomocysteinemia with very high level of plasma homocysteine (>100 mmol/l) presenting as an exclusive small vessel coronary artery disease like involving only diagonal branch sparing major coronary vessels has not yet been described in the literature. Our case is unique and the first description of an exclusive small vessel coronary artery disease sparing major coronary vessels in the presence of paradoxically very high-level serum homocysteine (in a young male without conventional cardiac risk factors). Vegetarians should be encouraged to take Vitamin B6 rich food like potatoes, bananas, and garbanzo beans to decrease the likelihood of having severe coronary artery disease secondary to hyperhomocysteinemia.