Familial hypercholesterolaemia (or familial hyperlipidaemia) is an inherited (genetic) condition in which affected members of a family have high levels of LDL cholesterol, the so-called ‘bad’ cholesterol, in their blood.
Too much LDL cholesterol in the blood can cause deposits of fats to build up in the walls of the arteries (atherosclerosis). People with familial hypercholesterolaemia have high cholesterol from birth and are at high risk of developing atherosclerosis at a young age.
Atherosclerosis is the process behind several conditions, including:
- coronary heart disease (which can result in angina and heart attack);
- cerebrovascular disease (which can cause stroke); and
- peripheral artery disease (which causes poor circulation in the legs).
Many people with familial hypercholesterolaemia don’t know they have it. This is because high cholesterol levels by themselves often don’t cause any symptoms.
When cholesterol levels are extremely high, cholesterol can accumulate in certain areas, such as:
- the skin and tissue underneath the skin, causing visible fatty growths known as xanthomas (often seen over tendons in the hands and feet and the Achilles tendon); and
- around the corneas in the eyes, which appears as a white or grey ring (called arcus cornealis or corneal arcus).
Symptoms of premature (early-onset) coronary heart disease, cerebrovascular disease or peripheral artery disease may be the first sign of familial hypercholesterolaemia. These conditions are defined as premature when they occur in men younger than 55 years and women younger than 60 years.
Some families carry genes that lead to high levels of LDL cholesterol. The abnormal genes mean the body has trouble clearing LDL cholesterol from the blood.
Familial hypercholesterolaemia affects about one in 500 people. Children of affected people have a 50 per cent chance of having the condition.
Tests and diagnosis
Your doctor will ask about your medical history, including a family history and perform a physical examination. People with familial hypercholesterolaemia usually have a strong personal or family history of early-onset of diseases caused by atherosclerosis.
Other conditions that can cause high cholesterol levels (such as thyroid or kidney problems) need to be ruled out before a diagnosis of familial hypercholesterolaemia can be made.
- A blood cholesterol test can be used to detect abnormal cholesterol levels. In people with familial hypercholesterolaemia, LDL levels are generally very high for their age.
- Genetic tests may be performed to confirm the diagnosis and help in the identification of other affected family members.
Treatment for familial hypercholesterolaemia
If you have familial hypercholesterolaemia, treatment will be directed at lowering your cholesterol and reducing your risk of coronary artery disease and stroke.
You will almost certainly be prescribed cholesterol-lowering medicine(s).
Cholesterol-lowering medicines include:
- ezetimibe (often used where statins are not suitable, or in addition to statins);
- cholestyramine and colestipol (which can be used where statins are not suitable, or in addition to statins);
- nicotinic acid (sometimes used in addition to other cholesterol-lowering medicines); and
People with very high LDL cholesterol levels usually need to take a combination of medicines to effectively lower their cholesterol levels.
Your doctor will also advise you to take some of the following lifestyle steps.
- Stop smoking if you are a smoker.
- Lose weight, if you are overweight, or maintain a healthy weight if you are not overweight.
- Diet: eat a healthy, balanced diet that is low in saturated and trans fats. Replace foods containing saturated fats with foods that contain unsaturated fats.
- Increase your intake of fibre with foods such as fruits, vegetables, beans and peas. Soluble fibre, called so because it dissolves in water, is found in oat bran and psyllium husk, and is very helpful in lowering blood cholesterol.
- Eat foods shown to have cholesterol-lowering properties, such as tree nuts; olive oil; and foods supplemented with sterols or stanols (such as cholesterol-lowering margarines, yoghurt or breakfast cereals).
- Limit alcohol to no more than 2 standard drinks per day.
- Exercise regularly. Regular physical activity can improve cholesterol levels and lower your risk of coronary heart disease.
Regular monitoring of your cholesterol levels, and for evidence of blood vessel disease, is important.
When to see your doctor
See your doctor for a blood test to check your cholesterol level if you have:
- a close relative who has very high LDL cholesterol levels;
- a family history of early-onset coronary heart disease, stroke or peripheral artery disease; or
- symptoms that suggest you may have high cholesterol or coronary artery disease.
The good news for people with familial hyperlipidaemia is that with medication and a careful lifestyle, the risk of coronary artery disease can be reduced considerably.