How common is coronary heart disease among children, and what are the major risk factors?

Extremely rare: The only two conditions I am aware of where this is present is: the kawasaki disease where coronary aneurysms can affect some, & progeria, the rare premature aging disease. Rarely the coronary arteries can be located in the wrong place as a congenital defect, but it is a stretch to compare it with cad. Risks are the same as for adults.