Genes Archive

Direct-to-consumer genetic tests can screen for rare heart conditions that arise from variants in a single gene (such as cardiomyopathies) as well as common conditions influenced by many thousands of gene variants (such as coronary artery disease). But because the results are not definitive, they can be challenging to interpret.

People with a family history of heart disease and high LDL cholesterol should consult their doctor about lowering their LDL levels to less than 70 milligrams per deciliter, which often means taking a statin, eating a healthier diet and exercising regularly.

A 2025 study addressed the role of genes versus lifestyle habits and life circumstances in influencing a person's health. Researchers found that genes seemed to have a stronger influence than lifestyle and life circumstances for some diseases, including dementia, macular degeneration, and certain cancers. For other diseases, such as atherosclerosis involving arteries of the heart and brain, rheumatoid arthritis, and diseases of the lung, heart, and liver, lifestyle and life circumstances had a stronger influence than genes.

About 5% of Americans have low-density lipoprotein (LDL) values of 190 mg/dL or higher. Their risk of heart disease is five times higher than people with near-optimal values (less than 130 mg/dL). Some have familial hypercholesterolemia, a genetic condition that can lead to LDL values up to 350 mg/dL (or even higher in some cases). Known as FH, it's a common cause of early heart attacks.

Clinical trials are under way using gene therapy to treat inherited cardiovascular conditions, including familial hypercholesterolemia (one form of abnormally high cholesterol), hypertrophic cardiomyopathy (a type of heart muscle disease), and transthyretin amyloid cardiomyopathy (a form of heart failure resulting from amyloid deposits). But challenges remain in developing and delivering these therapies.

Lynch syndrome is an inherited condition that predisposes people to colorectal, uterine, ovarian, and other forms of cancer. Genetic testing can pinpoint Lynch syndrome, and genetic counseling is also recommended. People with Lynch syndrome need frequent cancer screenings and should watch for symptoms. Women with Lynch syndrome are also advised to undergo risk-reducing surgery that removes the ovaries, fallopian tubes, and uterus between ages 35 and 40, unless a woman is planning another pregnancy.

Some doctors feel it's unlikely that editing people's genes will help prevent them from getting Alzheimer's disease. It's not just because attempts to edit genes inside the cells of living animals are in their infancy. It's also because most cases of Alzheimer's disease occur in older adults, and those cases do not appear to be caused just by a few defective genes. Lifestyle—particularly exercise, diet, and the amount of high-quality sleep—affects the risk of developing Alzheimer's at least as much as genes.

A polygenic risk score for heart disease is based on an analysis of more than three million common DNA variants and is expressed as a percentile. People can have zero, one, or two copies of any variant, each of which may either raise or lower the risk of coronary artery disease. Many of these variants occur in genes known to affect heart disease, such as those related to cholesterol, blood pressure, and blood clotting. Others aren't well understood and may provide targets for future research, potentially fueling new drug discovery efforts. For now, the potential benefits of this test are greatest for people under 50.