Familial hypercholesterolemia affects the way the body processes cholesterol. As a result, people with familial hypercholesterolemia have a higher risk of heart disease and a greater risk of early heart attack.

The genetic changes that cause familial hypercholesterolemia are inherited. The condition is present from birth, but symptoms may not appear until adulthood.

People who inherit the condition from both parents usually develop symptoms in childhood. If this rare and more severe variety is left untreated, death often occurs before age 20.

Treatments for both types of familial hypercholesterolemia include a variety of medications and healthy-lifestyle behaviors.

Adults and children who have familial hypercholesterolemia have very high levels of low-density lipoprotein (LDL) cholesterol in their blood. LDL cholesterol is known as "bad" cholesterol because it can build up in the walls of the arteries, making them hard and narrow.

This excess cholesterol is sometimes deposited in certain portions of the skin, some tendons and around the iris of the eyes:

• Skin. The most common spots for cholesterol deposits to occur is on the hands, elbows and knees. They also can occur in the skin around the eyes.
• Tendons. Cholesterol deposits may thicken the Achilles tendon, along with some tendons in the hands.
• Eyes. High cholesterol levels can cause corneal arcus, a white or gray ring around the iris of the eye. This happens most commonly in older people, but it can occur in younger people who have familial hypercholesterolemia.

Familial hypercholesterolemia is caused by a gene alteration that's passed down from one or both parents. People who have this condition are born with it. This change prevents the body from ridding itself of the type of cholesterol that can build up in the arteries and cause heart disease.

The risk of familial hypercholesterolemia is higher if one or both of your parents have the gene alteration that causes it. Most people who have the condition receive one affected gene. But in rare cases, a child can get the affected gene from both parents. This can cause a more severe form of the condition.

Familial hypercholesterolemia may be more common in certain populations, including:

• Ashkenazi Jews
• Some Lebanese groups
• French Canadians

People who have familial hypercholesterolemia have a higher risk of heart disease and death at a younger age. Heart attacks may occur before age 50 in men and age 60 in women. The rarer and more severe variety of the condition, if undiagnosed or untreated, can cause death before age 20.

A detailed family history is an important key to diagnosing familial hypercholesterolemia. Doctors will be interested to know if your siblings, parents, aunts, uncles or grandparents ever had high cholesterol levels or heart disease — especially during childhood.

During the physical exam, doctors usually check for cholesterol deposits that may occur in the skin around the hands, knees, elbows and eyes. Tendons in the heel and hand may be thickened, and a gray or white ring may develop around the iris of the eye.

Cholesterol tests

The National Heart, Lung, and Blood Institute recommends that a person's first cholesterol screening should occur between the ages of 9 and 11, and then be repeated every five years after that. Earlier or more-frequent screenings may be suggested for families with a history of childhood heart disease.

In the United States, cholesterol levels are measured in milligrams (mg) of cholesterol per deciliter (dL) of blood. In Canada and many European countries, cholesterol levels are measured in millimoles per liter (mmol/L).

Adults who have familial hypercholesterolemia usually have LDL cholesterol levels over 190 mg/dL (4.9 mmol/L). Children who have the disorder often have LDL cholesterol levels over 160 mg/dL (4.1 mmol/L). In severe cases, LDL cholesterol levels can be over 500 mg/dL (13 mmol/L).

LDL cholesterol is also known as bad cholesterol because it can build up in the walls of the arteries, making them hard and narrow. This can increase the risk of heart attacks.

Genetic testing

A genetic test can confirm familial hypercholesterolemia, but it's not always necessary. However, a genetic test can help determine whether other family members also may be at risk.

If one parent has familial hypercholesterolemia, each child has a 50% chance of inheriting it. Inheriting the altered gene from both parents can result in a rarer and more severe form of the disease.

If you are diagnosed with familial hypercholesterolemia, doctors usually recommend that your first-degree relatives — such as siblings, parents and children — be checked for the disorder. This will allow treatment to begin early, if needed.

Familial hypercholesterolemia treatment focuses on reducing the extremely high levels of LDL (bad) cholesterol. This helps lower the risk of heart attack and death.

Medications

Most people with familial hypercholesteremia will need to take more than one medication to control their LDL cholesterol levels. Options include:

• Statins. These drugs block a substance the liver needs to make cholesterol. Examples include atorvastatin (Lipitor), fluvastatin (Lescol XL), lovastatin (Altoprev), pitavastatin (Livalo), pravastatin, rosuvastatin (Crestor) and simvastatin (Zocor).
• Ezetimibe (Zetia). This drug limits the absorption of cholesterol contained in the food you eat. If statins don't reduce cholesterol enough, doctors often suggest adding ezetimibe.
• PCSK9 inhibitors. These newer drugs — alirocumab (Praluent) and evolocumab (Repatha) — help the liver absorb more LDL cholesterol, which lowers the amount of cholesterol circulating in the blood. They're injected under the skin every few weeks and are very expensive.

Other treatments

In severe cases, people with familial hypercholesterolemia may also need to periodically undergo a procedure that filters the excess cholesterol from their blood. Some may need liver transplants.

Healthy-lifestyle habits also can help reduce the risk of heart disease, and some may lower your cholesterol:

• Lose extra pounds. Losing weight can help lower cholesterol.
• Eat a heart-healthy diet. Focus on plant-based foods, including fruits, vegetables and whole grains. Limit saturated fats and trans fats.
• Exercise regularly. With your doctor's OK, work up to at least 30 minutes of moderate-intensity exercise five times a week.
• Don't smoke. If you smoke, find a way to quit.