Familial Hypercholesterolemia

A common genetic cause of high cholesterol, risks, and resources for support.

What is Familial Hypercholesterolemia?

Familial hypercholesterolemia, or FH, is a common genetic condition that is passed down through families. People with FH have a high cholesterol and an increased risk of heart disease.

About 1 in 250 people have a genetic variation that causes FH. Based on this estimate, around 31,000 people in Washington are at risk for heart disease related to FH. Many people may not know their risk.

That’s why developing strategies to identify people who have FH is a public health priority.

What Is Cholesterol, and Why Does It Matter for My Health?

Cholesterol is important for your body's normal structure and function. It builds and repairs cells, helps you digest food, and make hormones.

But high cholesterol levels can cause problems. This is especially true for low-density lipoprotein cholesterol (LDL), or “bad” cholesterol.

Extra cholesterol can combine with other materials to form plaques that stick to blood vessel walls. Plaque deposits narrow the vessels and make it harder for blood to flow. This puts stress on the heart and other organs.

Learn more about cholesterol.

What Causes Plaque to Build Up in Blood Vessels?

Different factors cause plaque to build up in blood vessels. This often happens due to a combination of things like:

  • Diet high in animal fats
  • Smoking
  • Not getting enough physical activity
  • Diabetes
  • Older age

Sometimes, high cholesterol levels run in families. In these cases, it’s passed down due to gene changes.

How Do Genes Affect Cholesterol?

Genes serve as instructions for the body. Some genes tell the body how to process and remove LDL from your bloodstream. These include:

  • LDLR
  • APOB
  • PSCK9
  • LDLRAP

We each have 2 copies of every gene in our bodies, inheriting 1 from each parent. Most people with FH have a variation (mutation) in 1 of these genes. It’s like a spelling difference in the body’s instruction manual.

In rare cases, a person may inherit a mutation from both parents. This less common type of FH is called homozygous FH. It causes higher cholesterol levels and more serious health risks.

What Does FH Do to the Body?

Both forms of FH prevent the body from removing LDL from the bloodstream. Over time, it leads to high cholesterol levels, unless it’s not caught early and treated.

Could My Personal or Family Health History Point to FH?

Yes. Certain patterns in your or family health history may suggest the possibility of FH.

Talk to your provider if you or a family member has a history of any of the following:

  • High cholesterol levels
    • LDL cholesterol higher than190 mg/dL (or 4.9 mmol/L) in adults
    • LDL cholesterol higher than 160 mg/dL (or 4.9 mmol/L) in children

Your provider can help you understand your cholesterol numbers and what they might mean.

  • Heart disease at a young age
    • Before age 55 in people assigned male at birth
    • Before age 65 in people assigned female at birth
  • Coronary artery disease (heart disease) that blocks blood vessels, including:
    • Heart attacks
    • Procedures to open blocked arteries
    • Stroke
    • Peripheral vascular disease (blocked blood flow to the legs)
  • Signs of high cholesterol in the body
    • Xanthomas: lumps or bumps of cholesterol in hands, elbows, knees, or tendons
    • Xanthelasmas: yellowish, waxy spots around the eyes
    • Corneal arcus: white, gray, or blue ring around the colored part of the eye
      • More likely to be linked to FH if it happens before age 45
  • Genetic test results
    • A positive genetic test result in an FH gene (LDLR, APOB, PSCK9, and LDLRAP)

Want to learn more? Please visit the Family Health History webpage for more information and resources.

What Can I Do To Understand My Risk for FH?

If you’re concerned about your personal or family health history, start by talking to your health care provider. You can use this checklist and a doctor discussion guide to get started.

Here’s what to expect:

  • Health care providers typically start with tests to check your cholesterol levels.
  • They may also calculate your 10-year risk of a heart event, like a heart attack or stroke to recommend preventive management and next steps.
  • If your cholesterol is high, your provider may recommend:
    • Eating a heart healthy diet
    • Exercising regularly
    • Lifestyle changes
    • Taking medications, such as statins

How is FH Diagnosed?

FH can be diagnosed in 2 ways:

  • Through a clinical assessment, using standard criteria
  • Through genetic testing

If your clinical findings or family health history suggest that you may have FH, your health care provider will likely refer you to a genetic specialist for more evaluation.

What Happens in Genetic Testing?

Genetic testing is often best managed by genetic specialists. They can:

  • Help clarify your risk and educate you on genetic test options
  • Make sure that the testing criteria are met
  • Order the appropriate tests
  • Provide an overview of the benefits, limitations, and key factors
  • Help determine if genetic testing is the right choice

Important note: Even if your genetic test is negative, FH may still be present.

Need help finding a genetic provider in Washington? Use the Genetic Clinic directory to find a genetic specialist in your area. Your provider may need to submit a referral.

I Have FH. What Should I Do Next?

If you’ve been diagnosed with FH, there are steps you can take to keep your LDL levels at a safe level and manage your risk of heart disease.

Your provider can help create a personalized care plan that may include:

Testing Your Family Members

In addition to preventive care to manage your FH risk, your health care provider may also recommend testing your family members. The process where relative are told about an FH diagnosis and offered genetic testing is called cascade screening.

FH is usually passed down dominantly, here’s how the risk works:

  • A child with 1 parent who has FH is at 50% risk of inheriting it
  • First degree relatives (parents, siblings, children) are at a 50% risk
  • Second-degree relatives (half-siblings, aunts, uncles, grandparents) are at a 25% risk

A cascade screening works best when it’s guided by genetic providers.

If you don’t know your family health history or don’t want to pursue genetic testing, that is OK.

Talk to your provider about ways to understand and manage your risk of high cholesterol and heart disease:

  • Talk to your provider about high cholesterol screening and heart disease screening
  • Use population-based calculators to assess your chances

Resources For Patients

Resources For Providers

Use personal and family health history risk assessment tools to identify people with FH before symptoms appear.

Key Steps Include

  • Use family health history in routine care.
  • Consider referring patients to a genetic provider for genetic risk assessment or a lipid specialist if LDL levels stay high after six months of medication.
  • Encourage cascade screening for people and families diagnosed with genetic FH.

Provider Resources