If you have symptoms of Huntington's disease, your GP will refer you to a clinician with specialist expertise in the condition if they feel your symptoms need further investigation.

Many areas have Huntington's disease management clinics with a range of specialists.

The specialist will ask about your symptoms, such as whether you have had recent emotional problems, to see if it is likely you have Huntington's disease and to rule out similar conditions.

They may also test a number of physical functions, such as your reflexes, eye movements, balance, walking, general movements and strength. All of these can be affected by Huntington's disease.

Confirming the diagnosis

If you are showing symptoms of Huntington's disease and it is known to run in your family, or if your doctor strongly suspects you have the disease, genetic testing can confirm the diagnosis.

It is important to realise the diagnosis is based on the doctor recognising a combination of a number of factors – neurological examination, family history and genetic testing. It is possible to have the gene change and still be healthy.

Read more information about genetic testing.

Taking a genetic test

The children of someone with Huntington's disease can take a genetic test after the age of 18 to see if they have inherited the disease. If they have inherited the faulty gene, they will develop Huntington's but it is not possible to work out at what age.

You can ask your GP or neurologist to arrange an appointment for you at a regional genetic clinic. You will have some counselling, then two blood samples will be taken. Your DNA is extracted from the blood sample and analysed to see if you have inherited the faulty gene.

You may have to wait two to four weeks for the test results.

Having a brain scan

In the early stages of Huntington's disease there may be no specific changes on the brain scan. A doctor may use a brain scan at any stage of the illness if there are concerns that there may be other problems in addition to Huntington's disease.

A brain scan may involve a CT scan or an MRI scan.

Getting tested in pregnancy

If you are pregnant and already known to have the Huntington's disease gene, it is possible to have a direct test on the pregnancy at 11 weeks. This needs careful consideration and can be discussed with a genetic counselling team.

If one half of a couple is at risk of Huntington's disease but does not want to find out if they have the disease, and the couple would like to have children free of risk, more complex indirect genetic testing is needed. This needs to be discussed with the genetic clinic. One option is preimplantation genetic diagnosis.

Preimplantation genetic diagnosis

Preimplantation genetic diagnosis can be used when one partner is known to have the faulty gene. This is a direct test.

It involves having in vitro fertilisation (IVF) treatment, then genetically testing the embryo in a laboratory to see if it has the faulty gene. The embryo will only be placed inside the woman if it does not have the faulty gene.

The procedure is also an option for couples where one partner has a 50% risk and does not want to be tested. An embryo that is not at 50% risk will be placed inside the woman.

Preimplantation genetic diagnosis is not a straightforward procedure, and raises a number of issues that need to be considered in detail. For more information, read the Human Fertilisation and Embryology Authority's (HFEA) guidance on the procedure.

Should I get tested?

Not everyone wants to know if they have inherited the disease. It is a personal choice.

Some people say they would rather not know because they want to enjoy their life and they may die of other causes before the disease develops.

Most people have approximately 40 years of a normal healthy life before the disease develops.

Less than one in five people at risk of Huntington's disease choose to have the genetic test.

If you are considering genetic testing, it is strongly recommended you speak to a genetic counsellor first. Your GP will be able to refer you.

You can also read more information about genetic testing on the HDA website.