Health screening and genetic tests might identify more than 1 million U.S. adults who carry a gene for familial hypercholesterolemia, a common genetic disorder that causes elevated low-density lipoprotein (LDL) cholesterol, known as "bad cholesterol," which may lead to premature heart attack or death, according to new research published today in the Journal of the American Heart Association, an open access, peer-reviewed journal of the American Heart Association.