The latest thinking on inherited high cholesterol

Nearly one-third of American adults have high levels of harmful low-density lipoprotein (LDL) cholesterol circulating in their blood, doubling their risk of heart disease compared with people at normal levels. Most of these people likely carry dozens of different genetic mutations, each nudging LDL up a little. Over time, combined with a less-than-ideal diet and too little exercise, their LDL levels slowly creep upward.

But what about very high LDL? "About 5% of the population have LDL values of 190 or higher, and their risk of heart disease is five times higher than people with near-optimal LDL," says a cardiologist at a major teaching hospital. Within this group, an important minority has familial hypercholesterolemia (FH), a genetic condition affecting about one in 250 adults.