Familial hypercholesterolemia (FH) is a common life-threatening genetic condition that causes high cholesterol. Untreated, FH leads to early heart attacks and heart disease. People with FH have a high amount of low-density lipoprotein (LDL) or “bad cholesterol” due to a mutation in one of the genes that control the way cholesterol is cleared by the body. As a result, cholesterol accumulates in the bloodstream and can ultimately build up in the walls of the arteries. Cholesterol build-up in the artery wall is called hardening of the arteries, or atherosclerosis, and can lead to problems such as heart attacks and strokes in young adults and even children.
People with familial hypercholesterolemia have a high risk of developing a form of heart disease called coronary artery disease at a young age. This condition occurs when excess cholesterol in the bloodstream is deposited on the inner walls of blood vessels, particularly the arteries that supply blood to the heart (coronary arteries). The abnormal buildup of cholesterol forms clumps (plaques) that narrow and harden artery walls. As the plaques get bigger, they can clog the arteries and restrict the flow of blood to the heart. The buildup of plaques in coronary arteries causes a form of chest pain called angina and greatly increases a person's risk of having a heart attack.