Familial hypercholesterolemia (FH) is an inherited condition that results in high levels of total cholesterol and LDL (low-density lipoprotein) cholesterol. Cholesterol is a waxy substance found in cells that can be dangerous when it builds up on artery walls, causing atherosclerosis and the risk of heart attacks at an early age in those affected. Familial hypercholesterolemia is also known as Type II hyperlipoprotinemia.
As the most common form of inherited high cholesterol, FH affects about 1 in every 500 individuals. Compared to cases of non-genetic hypercholesterolemia, FH is much more severe. People who have the familial version will have much higher cholesterol levels.