Familial hypercholesterolemia (FH) is an inherited condition that can cause a person to have high levels of ‘bad’ cholesterol. FH can mean that a person is at a higher risk of conditions such as heart disease.

Cholesterol is a waxy substance that the body uses to make cells, vitamins, and hormones. A person’s liver produces all the cholesterol their body requires. A person can also take in cholesterol from food.

A certain amount of cholesterol in the body is necessary for normal function. However, too much ‘bad’ cholesterol can cause problems. A person with FH has high levels of ‘bad’ cholesterol due to a genetic defect.

Read on to learn more about FH, including its symptoms, causes, and treatments.

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FH is a genetic condition that causes a person to have high low-density lipoprotein (LDL) cholesterol. LDL is what many people refer to as ‘bad’ cholesterol.

The American Heart Association (AHA) notes that about 1.3 million people are living with FH in the United States. However, only around 10% of people with FH know they have it.

There are two forms of FH that a person can have:

  • Heterozygous FH: If one parent passes on a mutated FH gene, a person will have heterozygous FH.
  • Homozygous FH: Homozygous is a rarer, more severe form of FH. Homozygous FH occurs when both parents pass on the mutated gene for FH.

Many people who have FH experience no symptoms at all. If a person does have symptoms of FH, these can include:

  • chest pain
  • cholesterol deposits, which are small bumps, on the Achilles tendon, hand, knee, or elbow tendons, or around the eyes
  • yellow areas around the eyes
  • a white arc near the iris of the eye

If a person notices any of these symptoms, they may already have very high LDL cholesterol levels. A person with signs of FH should speak with their healthcare professional as soon as possible.

FH occurs due to a mutation in a person’s genes. This mutation affects how a person’s body removes cholesterol. If the body cannot remove cholesterol effectively, its levels will increase within the bloodstream.

According to the FH Foundation, most people with FH have a mutation on one of the following genes:

  • LDLR gene
  • APOB gene
  • PCSK9 gene

Currently, researchers are aware of over 2,000 gene mutations that are responsible for FH developing.

Having a parent or parents with FH makes a person more likely to have it. A person with a parent who has FH has a 50% chance of also having it. Anyone who has a family member with FH should arrange to get a test to check for it.

Research indicates that people with Lebanese, Afrikaans, French Canadian, or Ashkenazi Jewish backgrounds are more likely to be carriers of FH genes.

To diagnose FH, doctors usually use a combination of a physical examination, laboratory tests, and family history.

A physician may examine a person for signs of FH, such as cholesterol deposits or yellow areas around the eyes. A person’s doctor may also ask about a family history of early heart attacks or heart disease. Heart attack or heart disease before the age of 60 in female relatives and 50 in male relatives can indicate FH.

When diagnosing FH, a doctor may order blood tests to check a person’s LDL levels. An LDL cholesterol level of 190 milligrams per deciliter (mg/dL) of blood in adults and 160 mg/dL in children can indicate FH. If a person has FH, they should also have their children tested for it.

Doctors use genetic testing to diagnose FH. Genetic testing looks for mutations in the genes that can cause FH. The CDC notes that genetic testing can locate FH-causing genes in around 60–80% of people with the condition.

According to the Centers for Disease Control and Prevention (CDC), early diagnosis and treatment of FH can reduce the chances of developing coronary heart disease by 80%.

Certain lifestyle changes can help to lower a person’s LDL cholesterol levels, such as:

  • eating foods low in saturated fat, trans fats, sodium, and sugar
  • exercising
  • abstaining from smoking
  • limiting alcohol use
  • checking cholesterol levels

However, in people with FH, lifestyle changes alone are not enough to lower LDL cholesterol to a healthy level.

Cholesterol-lowering medications, such as statins, can help to reduce LDL cholesterol levels in people with FH. The CDC states that a person with FH will often have to take more than one cholesterol-lowering medication.

Other medications for FH include:

  • cholesterol absorption inhibitor, a drug that reduces cholesterol absorption
  • bile acid sequestrants, which help remove cholesterol from the bloodstream
  • PCSK9 inhibitors, which help the liver to remove cholesterol
  • bempedoic acid, which reduces the liver’s cholesterol production

Advanced treatments

A person with FH may require advanced treatments in addition to lifestyle changes and medications. Advanced treatments for FH include:

  • Lipoprotein apheresis: This is a non-surgical procedure that filters LDL cholesterol from a person’s blood plasma. The treatment needs to be frequent as LDL cholesterol levels build over time.
  • Lomitapide: This is a medication that blocks microsomal triglyceride transfer protein (MTP) activity. MTP helps in the creation of lipoproteins within the liver. By blocking MTP activity, lomitapide helps lower LDL cholesterol levels.
  • Liver transplant: This is generally only used for very young patients with blocked arteries. In a liver transplant operation, a person has their liver replaced with one that does not contain FH-causing genes.

If a person has FH, they are more likely to develop additional problems.

High LDL cholesterol due to FH can lead to plaque buildup within the arteries. Plaque is a fatty substance made from cholesterol, fat, calcium, and other waste products.

When plaque deposits build up within a person’s arteries, they can become blocked. Blocked arteries can cause serious conditions, such as heart disease or stroke.

The outlook for a person with FH can depend on how early they receive their diagnosis and if they receive treatment.

Although there is no cure for FH, a person who receives their diagnosis and begins treatment early has an excellent outlook.

According to the AHA, a person with untreated FH is 20 times more likely to develop heart disease. A person with FH is also likely to have heart disease 10–20 years earlier if they are male or 20–30 years earlier if they are female.

The AHA also notes that 50% of males with untreated FH have heart attacks or angina before turning 50.

Additionally, around 30% of females with untreated FH will have a heart attack before turning 60.

A person with untreated homozygous FH is unlikely to live into their 20s.

If a person has the gene for FH, there is no way to prevent it. However, a person can take steps to ensure they receive a diagnosis and begin a treatment plan early.

The CDC recommends that an adult has their cholesterol levels checked every 4–6 years. A person with a family history of heart disease or high cholesterol should check their cholesterol levels more regularly.

The CDC also suggests that children and young adults have their cholesterol levels checked between 9–11 years old and 17–21 years old.

FH is a genetic condition that causes a person to have high LDL cholesterol levels.

High LDL cholesterol levels can cause conditions such as heart disease or stroke.

A person who has a parent or parents with FH has a 50% chance of developing it themselves. If a person notices any signs of symptoms of FH, they should see their doctor immediately. If a person has FH, they should also get their children tested for it.

Although there is no cure for FH, medications, treatments, and lifestyle changes can help lower a person’s LDL cholesterol levels. With early diagnosis and appropriate treatments, a person with FH has an excellent outlook.