Familial hypercholesterolaemia
Familial hypercholesterolaemia 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 of this type of cholesterol in the blood causes deposits of fats to build up in the walls of the arteries. This build-up can eventually lead to narrowing of the arteries which slows down blood flow. If a clot forms, the narrowed artery can become blocked. If this happens in the coronary arteries (the ones that supply the heart with blood) a heart attack may result.
There are many different types of familial hyperlipidaemia, some relatively common and some extremely rare. They have slightly different patterns of lipid abnormality, but the common findings are elevated cholesterol or triglycerides, or both.
What causes familial hypercholesterolaemia?
Although high blood cholesterol is most often caused by lifestyle factors such as eating too much saturated fat and being overweight, there can also be an inherited component: if you have close relatives with high cholesterol levels, there is a good chance that you may also have high cholesterol. This is because 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.
People who are affected by familial hypercholesterolaemia are at a very high risk of developing coronary artery disease and dying prematurely from heart attack. This is especially true of men: about 85 per cent of men with the condition have had a heart attack by the age of 60 years. For women, the higher risk of heart attack tends to become apparent about 10 years later.
What are the symptoms?
The disease often causes no symptoms but if cholesterol levels are extremely high, fat deposits can accumulate in the tendons and skin, causing visible fatty growths known as xanthomas. Sometimes people may notice cholesterol deposits around the eyelids (xanthelasmas).
How is familial hypercholesterolaemia diagnosed?
Many people with familial hypercholesterolaemia don’t know they have it. This is because high cholesterol levels by themselves don’t cause any symptoms and can be diagnosed only with a blood test. This means that many people with the condition may feel otherwise well and may not be diagnosed until later in life. This is often bad news for them: by that time they may already have advanced coronary artery disease.
Screening tests are often performed in people with a family history of heart attacks at a young age.
What treatment is available?
If you have familial hypercholesterolaemia, treatment will be directed at reducing your risk of coronary artery disease. You will almost certainly be prescribed cholesterol-lowering medication, and in addition your doctor will also probably advise you to take some of the following steps.
- Stop smoking immediately, if you are a smoker.
- Lose weight, if you are overweight, or maintain a healthy weight if you are not overweight.
- Eat a diet that is extremely low in fat. The more fats you eat, particularly animal and dairy fat, the higher your risk of heart disease.
- Exercise regularly. Regular exercise can lower LDL (‘bad’) cholesterol levels.
- 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.
If you have a close relative who has high cholesterol levels it makes sense to see your doctor now for a simple blood test to see if you are at risk. The good news is that with medication and a careful lifestyle, the risk of an early death from coronary artery disease can be reduced considerably.
Last Reviewed: 25 March 2009
- 1. MedlinePlus. A service of the US National Library of Medicine and the National Institutes of Health. Medical Encyclopedia: Familial hypercholesterolemia [updated 2008, Sep 12; accessed 2009, May 14]. Available from: http://www.nlm.nih.gov/medlineplus/ency/article/000392.htm
