A test to look for the genetic change that causes Huntington's disease can be used to diagnose the condition or check if you or your child will develop it later in life.

If you have a history of Huntington's disease in your family (especially if a parent or grandparent had it), you can have a test to see if you'll also get it.

It's up to you to decide if you want to have the test. Lots of people at risk of Huntington's disease decide they'd rather not know until any symptoms appear.

If you do want to know, ask your GP for a referral to a genetic counsellor. You'll have several appointments with the counsellor. It's only done once all the benefits and risks have been explained.

The test involves checking a sample of your blood for the genetic fault that causes the condition. It can take a few weeks to get the result.

The Huntington's Disease Association has more information about genetic testing for Huntington's disease.

Speak to your GP if you're planning a pregnancy and:

• you have a family history of Huntington's disease
• a test has shown you have the genetic fault that causes the condition

This might mean your child is at risk of developing Huntington's disease.

Your GP can refer you to a genetic counsellor to discuss your options.

These may include:

• having a child with a donor egg or sperm
• adopting a child
• having a test during pregnancy (chorionic villus sampling) to see if your baby will get Huntington's disease
• pre-implantation genetic diagnosis – where eggs are fertilised in a laboratory and tested to make sure they don't have the Huntington's disease gene, before being implanted into the womb

If you have symptoms of Huntington's disease, your GP may refer you to a specialist for tests.

The specialist will ask about your symptoms to see if it's likely you have Huntington's disease and rule out similar conditions.

They may examine you and test things like your thinking, balance and walking ability. Sometimes you might also have a brain scan.

A blood test to check for the Huntington's disease gene can confirm if you have the condition.