Have I got FH?
If you or your doctor think you might have FH, there are a number of tests they can do to get a better idea of what’s going on.
Your doctor will:
- ask you more questions about health problems in your family
- arrange for you to have a blood test called a lipid profile, which looks at the amounts of different fats in your blood
- do a physical examination to check for the physical signs of FH.
Getting tested
Your doctor can then make a clinical diagnosis using a set of guidelines called the Simon Broome criteria or the Dutch Lipid Clinical Network criteria.
Your doctor should refer you to a specialist in a lipid clinic for tests and treatment and for confirmation of the diagnosis of FH. These are centres run by specialists in blood fats and diseases of the heart and blood vessels.
You should be offered genetic testing if there is a very strong likelihood that you have the condition. This is a specialist test that tries to identify a gene alteration that is causing the condition.
Why get tested for FH?
Getting a diagnosis means you can get the right treatment and make healthy changes to your lifestyle to lower your cholesterol and help prevent heart disease and other serious illnesses. It also means that members of your family can get tested and start treatment if they need it. If you have children, they should get tested too.
Your family tree
FH is passed from parent to child in the genes, and it’s usually possible to trace FH back through several generations.
Talk to your GP about illnesses in your family to see if your high cholesterol could be due to FH. If you go to a lipid clinic, you can also help your specialist draw a family tree.
Drawing a family tree helps your doctor to find out if your high cholesterol is caused by FH, and it means they can see if there is anyone else in your family who might have FH. The family tree is known as a pedigree.
It’s possible to have two altered genes – if you have two parents with FH and you inherit the altered gene from both parents. This is very rare. This is called compound heterozygous or homozygous FH.
What do I need to know about my family history?
To draw your family tree, your doctor will ask you:
- if any of your blood relatives have high cholesterol
- if they have had a heart attack or heart disease
- how old they were when they were first diagnosed with heart disease
- if they had angina, which is pain in the chest caused by heart disease, and how old they were when it started
- how old they were when they had their first heart attack or needed treatment
- if they died from heart disease and how old they were.
Physical signs of FH
There are a few physical signs and symptoms your doctor will look for if they think you might have FH. They are easy to miss, so you might have these signs and not notice.
If you don’t have these signs, it’s possible you still have FH, as not everyone with FH has them.
- swollen tendons on the knuckles of your hands and your Achilles tendon at the back of your ankle (tendon xanthoma). These can look like small fatty lumps
- raised, pale, yellowish patches around your eyes and on your eyelids (xanthelasma)
- a white arc shape or ring around the edge of the iris, the coloured part of the eye (corneal arcus).
Blood tests
If your doctor thinks you have FH, you have probably already had a cholesterol test. You might have your cholesterol tested again, this time to look at all the different types of fats, known as lipids, in your blood. This is called a lipid profile, or a full fasting lipid profile.
Your doctor may also arrange for your blood to be tested for other things, such as blood sugar to check for diabetes, and signs of how well your liver and kidneys are working.
Genetic testing
There are different types of FH, as it can be caused by alterations in different genes. Genetic testing means your doctor can find out if you definitely have FH and which type you have – as the tests can find the specific gene involved.