What is familial hypercholesterolemia?
People with a genetic condition called familial hypercholesterolemia (FH) have very high levels of low-density lipoprotein (LDL) cholesterol, which is the “bad” cholesterol that can block your arteries. A healthy LDL level is less than 100 mg/dL (milligrams per deciliter), but people with familial hypercholesterolemia can have an LDL of 160mg/dL to 400 mg/dL or higher.
Without treatment, people who have this disorder are at a higher risk of getting coronary artery disease early. This can lead to heart attacks and other cardiovascular issues at a much younger age than for people who don’t have FH.
How common is familial hypercholesterolemia?
About 1 in 250 people have familial hypercholesterolemia. Only 1 in 160,000 to 250,000 people have the more severe type, which you inherit from both parents instead of one. However, FH is much more common (from 1 out of 67 people to 1 out of 100 people) among specific populations in Lebanon, South Africa and Lithuania.
Most people — 90% — who have FH don’t know they have it.
What does familial hypercholesterolemia do to your body?
Atherosclerosis, or plaque collecting in your arteries, is a common problem in people who have FH. This can lead to:
- Coronary artery disease.
- Cerebrovascular disease.
- Aortic aneurysm.
- Peripheral artery disease.
- Xanthomas (skin bumps from cholesterol accumulating on the Achilles tendon, elbow, knee or hand tendons).
- Xanthelasmas (yellow cholesterol around the eyelids).
- Corneal arcus (white ring around your eye’s cornea).
These issues can start in childhood for people who have homozygous FH.
Symptoms and Causes
What are the symptoms?
Symptoms of familial hypercholesterolemia may not be obvious until you have coronary artery disease. People with familial hypercholesterolemia need treatment much earlier than that because their LDL level starts out high even as a newborn.
Familial hypercholesterolemia symptoms, linked to atherosclerosis, include:
- Chest pain.
- Heart attack at a younger age.
- Sudden death.
- Stroke or symptoms similar to a stroke.
- Calf cramps.
What causes familial hypercholesterolemia?
Familial hypercholesterolemia is a disease you inherit or get from one or both of your parents. In people with this genetic issue, a specific protein (LDL receptor) that gets LDL out of your blood doesn’t work well or there isn’t enough of it.
The cholesterol buildup in your arteries is like what would happen if you didn’t take your trash out of your house on a regular basis. It would just keep piling up until you couldn’t find a path through it. When cholesterol fills your arteries, your blood can’t get through.
Familial hypercholesterolemia types
- If you get altered DNA from one parent, it’s called heterozygous familial hypercholesterolemia. This is the more common of the two types.
- If you get it from both of your parents, which is rare, it’s called homozygous familial hypercholesterolemia. This is more severe than the heterozygous type. Teens with this kind can have coronary artery disease.
Chances of passing familial hypercholesterolemia to your child
|Parent A’s status||Parent B’s status||Chance of child inheriting FH|
|Has heterozygous FH||Doesn’t have FH||50% heterozygous, 50% no FH|
|Has homozygous FH||Has homozygous FH||100% homozygous|
|Has heterozygous FH||Has heterozygous FH||25% homozygous, 50% heterozygous, 25% no FH|
|Has heterozygous FH||Has homozygous FH||50% heterozygous, 50% homozygous|
|Has homozygous FH||Doesn’t have FH||100% heterozygous|
Although most people with familial hypercholesterolemia will have a variant on one of three specific genes, researchers are still discovering more. If you’re in the 20% to 30% of people who appear to have familial hypercholesterolemia but test negative for it, you could still have it from a genetic variant researchers haven’t found yet.
Diagnosis and Tests
How is familial hypercholesterolemia diagnosed?
Your healthcare provider can make a familial hypercholesterolemia diagnosis based on:
- Unusually high LDL levels.
- A history of coronary artery disease in your family or yourself at a young age.
- Symptoms linked to atherosclerosis at a younger age than usual.
- DNA test results.
What tests will be done to diagnose familial hypercholesterolemia?
Two tests can help your provider make a familial hypercholesterolemia diagnosis.
- Your provider will want to do a lipid panel blood test to measure your cholesterol. Children with familial hypercholesterolemia can have LDL levels higher than 160 mg/dL. Adults can have LDL of 190 mg/dL or higher. In people with the severe form, homozygous familial hypercholesterolemia, LDL can be higher than 400 mg/dL. For all ages, a healthy LDL level is less than 100 mg/dL.
- A DNA test can find problems with one of the three genes that can cause FH.
After you get an FH diagnosis, you may need to see your provider regularly to check on your cardiovascular health.
Management and Treatment
How is familial hypercholesterolemia treated?
Your provider will want to cut down your LDL level by 50%. To do this, people with both types of familial hypercholesterolemia need medications. If you have homozygous FH, you also may need multiple medications (statins and PCSK9 inhibitors) or — in people with severe FH — LDL apheresis (blood filtering like dialysis). Getting a liver transplant is a rare option.
What can’t I eat with this condition?
If you have familial hypercholesterolemia, your top goal is to cut down your LDL level. Ways to achieve this — before or in addition to taking medicine — include:
- Eating less saturated fat.
- Not eating trans fats.
- Eating less cholesterol.
- Getting protein from vegetables, fish, lean poultry and low-fat dairy foods.
- Eating more soluble fiber.
- Eating lots of vegetables, nuts, legumes, fruit and whole grains.
- Not eating egg yolks.
What medications are used?
If you have the more severe form of FH, you’ll need more aggressive treatment.
Heterozygous familial hypercholesterolemia treatment
Medications for heterozygous FH include:
- Statins (even for children as young as 8 years old).
- PCSK9 inhibitors (like alirocumab or evolocumab).
- Bile acid sequestrants.
- Nicotinic acid.
- Bempedoic acid.
Side effects of the treatment
Any medication can have side effects, but the benefits usually make the cholesterol-lowering drugs worth taking. Statins, the medicine providers prescribe most often for FH, can give some people muscle aches. About 5% to 10% of people, mostly in the older adult population, have this issue. One in 10,000 people taking statins can get rhabdomyolysis (severe muscle injury).
Homozygous familial hypercholesterolemia treatment
Medicines for homozygous FH include:
- PCSK9 inhibitors.
- Evinacumab-dgnb injection.
How can I reduce my risk?
Although you can’t prevent an inherited disease like familial hypercholesterolemia, you can reduce your risk of atherosclerosis. You can change your diet, exercise and take any medicines your provider prescribes.
Outlook / Prognosis
What can I expect if I have familial hypercholesterolemia?
People with familial hypercholesterolemia have a much higher risk of atherosclerosis, which can cause heart attacks and strokes. Without treatment, people who have FH have 20 times the risk of coronary artery disease. The chances of getting coronary artery disease go up even more if you use tobacco products, have diabetes or have other risk factors for cardiovascular disease.
How long familial hypercholesterolemia lasts
Since FH is a condition you inherit from your parents, it’s a part of your DNA for life.
Outlook for familial hypercholesterolemia
Once you know you have FH, your provider can treat you for it with medications and help you prevent cardiovascular disease. You can most likely have a normal life expectancy if you know your risk at a younger age and get treatment. Getting treatment for familial hypercholesterolemia early brings down your risk of heart disease by 80%.
Because it’s important to know you’re at a higher risk when you’re younger, your family can take care of each other by sharing information. When someone in your family has FH, telling other relatives will allow them to get checked for it. You can start screening a child at age 2 if they have a high risk of FH.
How do I take care of myself?
If you have familial hypercholesterolemia, you can lower your risk of cardiovascular problems in these ways:
- Take medicines your provider prescribes.
- Eat foods that are low in cholesterol and saturated and trans fats.
- Eat foods that have unsaturated fat.
- Be at a healthy weight.
When should I see my healthcare provider?
Regular appointments with your healthcare provider are crucial to make sure your medication is working. Contact your provider if you’re having trouble with side effects from your medicine. They may be able to switch you to a different medicine.
When should I go to the ER?
Get help immediately if you have chest pain/pressure or another symptom of a heart attack or stroke.
What questions should I ask my doctor?
- What type of familial hypercholesterolemia do I have?
- How often do I need to have imaging or checkups?
- Who in my family should get tested?
A note from Cleveland Clinic
Familial hypercholesterolemia puts you at a much higher risk of heart disease at a younger age, but early treatment can bring down your risk by 80%. Be sure to keep your appointments with your healthcare provider and take the medicines they prescribe for you. Eating a diet low in saturated and trans fats can help, as well as exercising and addressing other risk factors for heart disease.
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