Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is a common genetic disorder that gives you very high levels of low-density lipoprotein (LDL) cholesterol. LDL is the “bad” cholesterol that can lead to cholesterol plaque buildup in your arteries. Over time, this can cause heart attacks, strokes or peripheral artery disease.

A healthy LDL level is less than 100 mg/dL (milligrams per deciliter). If you have familial hypercholesterolemia, your LDL may be 160 mg/dL or higher. Without treatment for this disorder, you’re at a higher risk of getting coronary artery disease before age 30. This can lead to heart and blood vessel problems at a much younger age than for people who don’t have FH.

Most people who have FH don’t know they have it. But once you know you have FH, you should start treatment right away. Medicines (as well as healthy foods and physical activity) can lower your LDL level.

Types of this condition

There are two familial hypercholesterolemia types. The difference between them is whether one or both biological parents give you the genetic variant (change) that causes FH:

• Heterozygous familial hypercholesterolemia is the type you have if one of your parents gives you the FH variant. This is the more common of the two types.
• Homozygous familial hypercholesterolemia is the type you have if you get the variant from both of your parents. This is rare and more severe than the heterozygous type. Only 1 in 250,000 to 360,000 FH cases are this type.

Causes of familial hypercholesterolemia

FH is a genetic disorder you inherit, or get, from one or both of your biological parents. In most people with this genetic issue, a specific protein (LDL receptor) that filters LDL out of your blood doesn’t work well, or there isn’t enough of it.

Most people with familial hypercholesterolemia will have a variant on one of four specific genes (APOB, LDLR, PCSK9 or APOE). But researchers are still finding more. If you appear to have familial hypercholesterolemia, but test negative for it, you may have gotten it from a genetic variant that researchers haven’t identified yet.

Risk factors

You may be at risk of having FH if you have a biological parent with the variant. FH is an autosomal dominant genetic disorder, which means it only takes one parent to pass it on.

Complications of this condition

Early treatment greatly reduces your risk of complications.

It’s common for people who have FH to have atherosclerosis, or plaque (atheroma) collecting in their arteries. This can lead to:

• Aortic aneurysm (stretched out wall of your largest artery)
• Peripheral artery disease (plaque buildup in arteries in your legs and arms)
• Coronary artery disease (narrow or blocked heart arteries)
• Aortic stenosis (narrow aortic valve)
• Stroke from a lack of blood flow to your brain
• Sudden death

How doctors diagnose this condition

A provider can use a lipid panel or a DNA test to make an FH diagnosis.

A lipid panel blood test measures your cholesterol levels, including your LDL 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.

A DNA test can find problems with one of the genes researchers know can cause FH. If you have familial hypercholesterolemia, your biological siblings, parents and children should get a test. You can start screening a child at age 2 if they have a high risk of FH.

Your healthcare provider can make an FH 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
• Abnormal skin findings, like bumps on your elbows or around your eyelids
• DNA test results

How is it treated?

Familial hypercholesterolemia treatment may include one or more medications to reduce your LDL level as low as possible. People with severe FH may need periodic blood filtering (LDL apheresis) or — rarely — a liver transplant.

Medicines to treat FH

When should I see my healthcare provider?

After you get an FH diagnosis, you can expect to see your provider regularly to check on your heart and blood vessel health. Regular visits 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 one.

Get help right away, call 911 or emergency services if you have chest pain, shortness of breath or another symptom of a heart attack or stroke.

What can I expect if I have this condition?

With familial hypercholesterolemia, you have a much higher risk of atherosclerosis, which can cause heart attacks and stroke. Without treatment for FH, you have a much higher risk of coronary artery disease compared to someone without FH. The chances of getting coronary artery disease go up even more if you use tobacco products or have diabetes or other risk factors for cardiovascular disease.

Without early treatment, heart disease can start before age 10 for people who have homozygous FH. People with the heterozygous type may develop heart disease at age 30 without treatment. For either type, this can lead to a heart attack by age 50 or 60 (depending on your sex).

As FH is a condition you inherit from your parents, it’s a part of your DNA all your life. You’ll need lifelong treatment.

Healthcare providers don’t have a cure for familial hypercholesterolemia. But once you know you have FH, your provider can treat you for it and help you prevent cardiovascular disease. With early treatment for FH, the outlook (prognosis) is excellent.

Life expectancy

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 cuts down your risk of heart disease by more than half. Without treatment, people with the rare type of FH may not live to be 30.