When very high cholesterol runs in the family

Ongoing efforts seek to better identify and treat familial hypercholesterolemia, a leading cause of early heart attacks.

Some 35 million Americans have cholesterol values that put them at high risk for heart disease. The vast majority likely have dozens of different genetic mutations, each of which raises cholesterol by a little bit. Coupled with an unhealthy diet and not enough exercise, cholesterol creeps up slowly over time in these people.

But a small minority — about one of every 250 adults — have a genetic condition called familial hypercholesterolemia (FH). Most have a mutation in one of three key genes that provide instructions that help remove excess "bad" LDL cholesterol from the bloodstream. When one of these genes doesn't operate properly, LDL cholesterol levels can skyrocket as high as 350 milligrams per deciliter (mg/dL) — more than three times higher than the desirable level of less than 100 mg/dL. Their total cholesterol levels (which includes LDL cholesterol plus other lipids) may reach 500 mg/dL or higher.

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