Gene Tests Could Spot 1 Million Americans at Risk of High Cholesterol

May 18, 2022
By Robert Preidt HealthDay Reporter

A combination of genetic testing and health screenings could identify more than 1 million U.S. adults with an inherited risk for a cholesterol disorder that increases their risk for premature heart attack and death, according to a new study.

About 1 in 250 Americans may have at least one gene for familial hypercholesterolemia, which can cause elevated levels of low-density lipoprotein (LDL) cholesterol, often called "bad cholesterol."

"Currently, most individuals aren't diagnosed with familial hypercholesterolemia until they are in their 50s," said lead author Brandon Bellows, an assistant professor of medical sciences at Columbia University. "If a young adult is identified to have familial hypercholesterolemia, they would likely benefit from earlier and more aggressive treatment to prevent heart attack and stroke."

Among folks with one gene for the disorder, the average age for a first heart attack if the condition is not treated is 50 years for men and 60 for women. That compares to 66 years for men and 72 for women in the general population.

Those with two genes (one from each parent) for familial hypercholesterolemia have far higher levels of bad cholesterol and heart disease, and it begins during childhood or their teens, according to the researchers.

The study was published May 18 in the Journal of the American Heart Association.

The American Heart Association (AHA) recommends that everyone 20 and older have their cholesterol and other heart risk factors checked every four to six years if their risk remains low. But screening for familial hypercholesterolemia screening is not standard.

Genetic testing is available but may not be affordable. The AHA says genetic testing for cardiovascular diseases should typically be limited to people with a confirmed or suspected diagnosis of a condition and to those with a known disease-causing gene in their family.

This study examined the impact of screening for familial hypercholesterolemia using risk factors such as cholesterol levels and early heart disease in a person or close family member (parent, sibling or child), both with and without genetic testing.

Using health records and genetic test results from about 50,000 40- to 69-year-olds in the United Kingdom, researchers estimated the percentage who had a familial hypercholesterolemia gene.

They then used the relationships found in the U.K. data to estimate the rate in nearly 40,000 U.S. adults 20 and older with no genetic test results.

The researchers concluded that screening alone would identify 3.7 familial hypercholesterolemia cases for every 1,000 U.S. adults. Genetic testing would identify 3.8 cases per 1,000.

When both clinical criteria and genetic testing were combined, 6.6 cases per 1,000 adults screened would be identified, the study found.

Among younger Americans ages 20 to 39, screening alone would identify 1.3 cases per 1,000. Adding genetic testing would bring the rate to 4.2 per 1,000, researchers said.

"We need to do more to support familial hypercholesterolemia screening programs," Bellows said in a journal news release.

Screening should include both clinical factors and genetic testing, he said.

"Individuals with high cholesterol levels or with a family member that had a heart attack at a young age should undergo genetic testing for familial hypercholesterolemia," Bellows said. "Early diagnosis and treatment of familial hypercholesterolemia are the best ways to reduce the risk of early heart attack or stroke."

More information

The U.S. Genetic and Rare Disease Information Center has more on familial hypercholesterolemia.

SOURCE: Journal of the American Heart Association, news release, May 18, 2022

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