Familial hypercholesterolaemia affects up to 10 million people worldwide. Importantly, the presence of this condition can cause atherosclerotic lesions to appear even in ... 11-year-old children! [1] And the consequences can be serious, including heart attack, aneurysm or stroke. An excessively high cholesterol level in a child is a worrying symptom, which may be associated precisely with familial hypercholesterolaemia.