Huntington's disease

Huntington’s disease is a condition that damages the nerve cells in your brain. It’s usually passed down from a biological parent and slowly gets worse. Over time, it changes the way you move, think, and feel. There’s no cure yet, but treatment can help you to manage the symptoms.

About Huntington’s disease

Huntington’s disease is known as a genetic, inherited disease. This means that if one of your biological parents carries the faulty gene that causes Huntington’s disease, there’s a 50 per cent chance they could pass it on to you. For more information on this, see our Causes section below.

It’s a progressive condition, which means your symptoms gradually become worse over time. It slowly damages the parts of your brain that help to control movement, thinking, mood, and memory. So, you might twitch or fidget uncontrollably, feel angry or upset, begin to act differently, have difficulty remembering things, or making decisions.

Anyone can get Huntington’s disease, but it happens to about 6 out of every 100,000 people with European backgrounds. There’s no cure for Huntington’s disease yet, but scientists are working hard to understand it better and find treatments. Most people with the condition live for 15 to 20 years after their diagnosis, but it’s possible to live longer.

Types of Huntington’s disease

There are two types of Huntington’s disease:

Adult onset Huntington’s disease

This is the most common type of Huntington’s disease. The symptoms usually start between the ages of 30 and 50, though they can sometimes appear earlier or later. If you have this type, you’re likely to notice changes in your movement, thinking, and emotions that gradually get worse over time.

Early onset (Juvenile) Huntington’s disease

This is a rare form of Huntington’s disease that happens in children and teenagers, before you turn 20. The symptoms can include movement problems, learning difficulties, and behavioural changes. Early onset tends to progress faster than adult onset.

Huntington’s disease cause

Huntington’s disease is caused by a problem with one of your genes, called the huntingtin (HTT) gene. It’s usually passed down (inherited) from one of your biological parents. If one of your parents has this gene, there’s a 1 in 2 chance you could also develop the condition.

Genes are like instruction manuals that live inside your cells and tell them what proteins to make. The huntingtin gene makes a protein called huntingtin. This protein helps the nerve cells in your brain to work properly.

But if you have Huntington’s disease, this gene is faulty. It contains more code and is longer than it’s supposed to be. This means it creates an incorrect version of the huntingtin protein. Over time, this can damage the nerve cells in the areas of your brain that are responsible for movement, thinking, memory, and decision-making.

The faulty Huntington’s disease gene usually gets longer with each generation, and the longer it is, the earlier your symptoms may start.

Sometimes, you can get Huntington’s disease even if no one in your family had it before, but this is rare.

Symptoms of Huntington’s disease

If you have the Huntington’s disease gene, you might not have any symptoms for many years. The symptoms can start at any time, but usually begin between the ages of 30 and 50. They affect everyone differently, and gradually get worse as time goes on.

In the early stages of Huntington’s disease, you might start to twitch or jerk without meaning to, or notice changes to your mood or focus. But you’ll probably still be able to carry out daily tasks on your own. Over time, you might find that things like walking, speaking, swallowing, doing household chores, driving, and working start to become more difficult. Towards the end stages of Huntington’s disease, you’ll need full-time care to help you complete everyday tasks.

The most common symptoms of Huntington’s disease include:

Physical changes such as:

• jerky, fidgety, or twitching movements that you can’t control (chorea)
• trouble with balance, coordination, and walking, making you more likely to fall over
• difficulty swallowing, which makes it harder to eat and maintain a healthy weight
• problems with your speech, making it difficult to talk and communicate
• struggling with everyday tasks, such as holding a pen or doing buttons up
• difficulty moving around, making your movement feel slow, stiff, or rigid
• peeing without meaning to (urinary incontinence )

Cognitive changes such as:

• trouble with your focus and concentration
• struggling to make decisions
• difficulty remembering things
• finding it hard to learn new information

Emotional changes including:

• suddenly feeling angry, sad, or frustrated more often than usual
• feeling anxious or depressed
• changes to your behaviour, personality, and how you interact with others
• losing interest in the things you used to love
• obsessive thoughts or behaviours
• not taking care of yourself and your personal hygiene

Diagnosis of Huntington’s disease

Make an appointment to see a GP if you have a family history of Huntington’s disease and think you might have symptoms or want to know if you’re also going to get it. They can refer you for a blood test to see if you have the faulty gene that causes Huntington’s disease. Your diagnosis could include the following steps.

Seeing a GP

Your GP will ask you about your symptoms and any family history of Huntington’s disease. If they suspect you might have the Huntington’s disease gene, they’ll refer you to a doctor who specialises in brain and nerve health, called a neurologist. Or they might send you to a clinic that specialises in Huntington’s disease, for further tests.

Seeing a neurologist

Your neurologist will examine you and check your movements, coordination, and reflexes. They might also ask about your mood, mental health, and memory, because Huntington’s disease can affect these areas.

Brain imaging tests

Sometimes, your neurologist might recommend you have an MRI scan or a CT scan so they can get a closer look at any changes inside your brain, but this isn’t always needed.

Genetic counselling

The only way to confirm if you have Huntington’s disease is through a blood test that checks for the faulty Huntington’s disease gene. This is known as genetic testing. But if you’re thinking about finding out if you have Huntington’s disease, you’ll need to have a number of sessions with a genetic counsellor first. A genetic counsellor is a specially trained healthcare professional who can help you understand genetic conditions. They’ll go through all the pros and cons with you, so you can decide if genetic testing is the right choice for you.

Blood tests

If you decide to go ahead with genetic testing, there are two types of blood test that can confirm whether or not you have the faulty gene that causes Huntington’s disease.

• Diagnostic testing. This is a blood test to confirm whether or not you currently have Huntington’s disease. It looks for the faulty gene that causes Huntington’s disease, and is done if you’ve already started to get symptoms.
• Predictive testing. This is a blood test to find out if you have the faulty gene that causes Huntington’s disease before any symptoms appear. You might decide to have this test if you already know that Huntington’s disease runs in your family, and want to find out if you’ll get it in future. But you can’t have this test until you’re 18 and it can’t tell you when your symptoms might start.

Understanding your chance of developing Huntington’s disease in the future can help you to make informed decisions about your health and plan ahead. But having a predictive test is a big decision and the result could be very upsetting, so you might prefer not to know until you start to have symptoms.

Self-help for Huntington’s disease

If you have Huntington’s disease, it’s important to take good care of your health, especially as your symptoms get worse. There are some things you can do that will help you live as well as possible.

• Eat a nutritious diet. As your condition gets worse, you might struggle to swallow, lose your appetite, and lose weight. Try to follow a nutritious Mediterranean diet and eat high-calorie and high-protein foods to help keep your weight up.
• Stay as active as you can. Keeping physically active at all stages of your condition can help support your balance, energy levels, mood, and mental health.
• Keep your vaccinations up-to-date. You’re more likely to catch infections as your condition progresses. So remember to keep your flu and pneumonia vaccinations updated.
• Join a support group. Connecting with people who understand what you’re going through can be really helpful. In the UK, the Huntington’s Disease Association can provide you, your family, and carers with emotional support and advice.
• Make plans for your future. During the end stages of Huntington’s disease you’ll need full-time care. You might also struggle to make important decisions. So try to plan ahead, research care services, make financial decisions, and think about any wishes you might have.
• Let the DVLA know. You must inform the Driver and Vehicle Licensing Authority (DVLA) if you’ve been diagnosed with Huntington’s disease. They might contact your doctor for more details, or ask you to take a driving assessment.

Prevention of Huntington’s disease

If you have the gene for Huntington’s disease, there’s no way to cure the condition or stop it getting worse over time. But treating your symptoms can help to make you more comfortable.

If you or your partner has the Huntington’s gene, there’s a chance you could pass the gene on to any children you have. So, if you’re thinking about starting a family, talk to a genetic counsellor about genetic testing.

You might be able to have a procedure called pre-implantation genetic testing (PGT). This involves creating embryos through in vitro fertilisation (IVF) and testing them for the Huntington’s gene. Only the healthy embryos that don’t carry the gene will be placed in your uterus. This means your baby won’t have the faulty gene and develop Huntington’s disease. This procedure has the same risks as IVF, and your specialist can help you understand everything you need to know.