Harvard Heart Letter
New insights about an inherited form of high cholesterol
Although uncommon, this genetic condition is responsible for most heart attacks that occur at a young age. About one in 250 people has a genetic mutation that causes dangerously high cholesterol levels. Known as familial hypercholesterolemia, or FH, this condition can raise levels of harmful LDL cholesterol as high as 350 milligrams per deciliter (mg/dL)ómore than three times higher than the desirable level of less than 100 mg/dL.