Many people with familial hypercholesterolemia (FH) are young and appear otherwise healthy, yet their arteries may tell a different story. With FH, the body can’t keep up with cholesterol levels. As a result, high levels of bad cholesterol may have been in their bodies – often unchecked – since they were born.

Over time, this can damage the blood vessels and block the arteries that supply the heart and brain. Cholesterol can also build up in the eyes, the skin, the liver and the tendons. Finding and treating FH early is critical.

If someone doesn’t know they have FH, the condition is often first suspected after someone has had a heart attack or stroke at a very early age, often before age 50.

The risk for problems is even higher in people who have other risk factors such as smoking or diabetes.

Familial hypercholesterolemia, or FH, runs in families (a genetic condition). It happens when there is a change in one of several genes in the body.

There are two types of FH:

Heterozygous FH (HeFH) is more common. People with HeFH have one FH gene from one parent.

Homozygous FH (HoFH) is less common. People with HoFH inherit two FH genes, one from each parent. In this case, both parents have FH. This is much more serious and needs early detection in childhood.

People with HoFH can have LDL cholesterol levels more than 4 times higher than normal, which raises their risk of heart disease even more. Events can happen at younger ages, even in childhood. HoFH is harder to treat.

With both types of FH, treatment to lower LDL cholesterol is important to prevent heart attacks, stroke and related death.

Familial hypercholesterolemia (FH) is an inherited, or genetic, condition. The main risk factor is having a parent with the condition. This usually arises as a concern because a parent or aunts and uncles have had a cardiovascular event when they were young, usually before age 50.

In general, if one of your parents has FH, you have a 50/50 chance of having it. In the same way if you have FH, each of your children has a 50/50 chance of being born with it.

Detecting FH early and starting treatment is important to lower LDL cholesterol and prevent heart attacks, stroke and related death. That’s why it is important to find out who else in the family may have FH or be at risk for it.

Anyone can have FH, but it seems to be more common in French Canadians, Ashkenazi Jews, South Africans and Christian Lebanese.

What are the signs and symptoms of familial hypercholesterolemia (FH)?

The main red flags are having:

• Very high levels of LDL-cholesterol (over 190 mg/dL) that don’t improve much with exercise, healthy eating or certain medications

• A family history of very high cholesterol or family members who developed heart disease, had a heart attack or died at young ages

For some people with FH, a heart attack , stroke or dying suddenly and at a young age may be the first sign. That’s because high cholesterol itself typically doesn’t cause signs or symptoms. Over time, as more cholesterol builds in the blood vessels, it can narrow or block arteries limiting blood flow.

	Heterozygous FH (more common, one FH gene)	Homozygous FH (less common, two FH genes)
Typical LDL Levels	Over 190 mg/dL for adults Over 160 mg/dL for children	Over 400 mg/dL

Other signs of FH may include:

• Evidence of cholesterol buildup in the heart’s arteries, such as seen in a coronary artery calcium (CAC) scan or other early detection test.
• Peripheral artery disease, which is when cholesterol builds up in arteries in the legs, which may result in discomfort or pain upon walking that usually subsides when resting
• Carotid artery disease, which is a narrowing of the blood vessels in the neck that carry blood from the heart to the brain
• Nodules or raised bumps on your skin or tendons (called xanthomas)
• Bumps on your upper or lower eyelids (called xanthelasma)
• White, blueish or yellowish cholesterol deposits that form a ring around the cornea of the eye

A diagnosis of familial hypercholesterolemia (FH) is usually based on:

• A simple blood test to measure the amount of cholesterol in your blood. LDL-cholesterol is much higher among people with FH.
  

  	Heterozygous FH (more common, one FH gene)	Homozygous FH (less common, two FH genes)
  Typical LDL Levels	Over 190 mg/dL for adults Over 160 mg/dL for children	Over 400 mg/dL

• A thorough family history. FH runs in families. Your care team will want to know if a close relative has FH, very high LDL cholesterol, or has died from heart or blood vessel disease at an early age.
• A physical exam, to look for any physical signs, including cholesterol deposits or bumps under the skin or around the eyes.
• Genetic testing may be used to confirm that someone has FH. Testing looks for gene changes, or variants, that have been linked to FH.If you have a gene variant, you can test to see if other family members also have the same one. In some cases, it’s not possible to find the variant that is causing FH because it hasn’t been discovered yet. A genetic counselor can help answer questions and give advice about testing.

If you have FH, you may be referred to a preventive cardiologist, endocrinologist or lipidologist — a doctor who specializes in treating high cholesterol or lipid disorders.

There are many imaging tests that can look for early development of atherosclerosis (plaque buildup in the arteries) including calcium scoring and CT scans that may help guide your diagnosis or plan.

When Should Screening for FH Begin?

Two types of screening approaches can be used to find FH: universal and cascade. The American Academy of Pediatrics, for example, recommends that all children have their cholesterol levels checked by ages 9 to 11 years old. This universal screening approach can identify children with high LDL cholesterol levels that are caused by genetics or lifestyle habits given the growing number of children who are overweight.

If you have FH, “family tracing” or “cascade screening” with lipid and/or genetic testing can help identify other first-degree family members who might be affected.

If there is suspected or confirmed FH in a parent, consider screening children starting at age 2. If both parents have FH, consider screening their children at birth.

Early and stepped-up treatment for familial hypercholesterolemia (FH) is needed to lower LDL cholesterol and, in turn, lower the chance of a heart attack, stroke or early cardiovascular death.

Without treatment, LDL cholesterol levels and risks to the heart and brain will be very high. So treatment for FH is lifelong. A first step is to cut LDL cholesterol by at least half. Overall, the main goal is to get your LDL below 100 mg/dL if you have FH and no other risk factors. If you have other risk factors, then the goal will be to get LDL to under 70 mg/dL.

People with homozygous familial hypercholesterolemia (HoFH) will need even more intense therapy.

A healthy diet, regular exercise, weight loss and not smoking are known to lower cholesterol and carry a host of other health benefits. While these changes are essential for good health, lifestyle changes alone often aren’t enough with FH and need to be coupled with medications and other therapies.

Your health care team will advise you on what approach would be best for you. Treatment will likely include a combination of the following:

• • Medications, depending on your type of FH and which medications have already been tried
    • High-intensity statins, which block an enzyme needed to produce cholesterol in the liver
    • Ezetimibe, which blocks cholesterol from being absorbed in the gut
    • Bile acid sequestrants, which help remove cholesterol from the body
    • PCSK9 inhibitors (alirocumab or evolocumab) work by helping the body get rid of LDL cholesterol from the blood by blocking a protein in the liver called proprotein convertase subtilisin kexin 9, or PCSK9
    • Bempedoic acid, an adenosine triphosphate-citrate lyase inhibitor that helps stop cholesterol production in your liver, or a combination of bempedoic acid and ezetimibe
    • Lomitapide inhibits the microsomal triglyceride transfer protein (MTP) to lower production in the liver and release of LDL cholesterol in the blood
    • Evinacumab, an angiopoietin-like 3 (ANGPTL-3) inhibitor, allows faster breakdown of fats that lead to high cholesterol in the blood
    • Inclisiran blocks production of the PCSK9 protein in the liver

• • Lifestyle changes to help medication therapy
    • Eating foods that are low in saturated fats, trans fats and cholesterol, and high in fiber, especially whole grains, beans, and fresh fruits and vegetables
    • Being physically active most days of the week – even regular walking helps and not sitting for long periods of time
    • Losing weight, if needed
    • Not smoking or using tobacco
    • Managing other conditions, such as high blood pressure or diabetes

• •   Lipoprotein apheresis is a nonsurgical therapy that filters the blood through a machine to remove LDL cholesterol. It’s often done every 2-3 weeks and is considered when cholesterol-lowering medications are not enough or are not well tolerated.

•   Ongoing monitoring to keep your numbers on track – In the early stages of getting your cholesterol under control, you may see your health care team more often. But when your levels are stable, you may need only one or two visits a year.

Clinical trials involving other treatments are underway. For example, gene therapy is being studied and could one day potentially cure this disorder.

It’s important to prepare for your health visits to make sure any questions you have are answered. Remember to mention any changes in how you feel – especially any chest pain, shortness of breath, or concerns about the medications you are taking.

It may help to write down a list of questions ahead of time. Some helpful ones might include:

• What type of FH do I have?
• How much damage has already been done to my heart/blood vessels? How likely am I to have a heart attack or stroke?
• Can we review the medications I am taking to help lower my cholesterol and how each one works? Will I be taking these medications for the rest of my life?
• How can I best manage side effects?
• Are there other health conditions that can also raise my cholesterol?
• I’ve heard there is a therapy that removes LDL cholesterol from the blood. How does it work? Is it safe?
• How often should I have my cholesterol checked?
• What is lipoprotein(a) and how does that factor in?
• Are there other tests I will need?
• Should I see a genetic counselor? If so, who would you recommend?
• At what point should I talk with my kids about FH or get them tested?
• How is FH treated in children?
• If I have FH and want to get pregnant, do my medications need to be adjusted or stopped?