Huntington's disease is an inherited condition that damages certain nerve cells in the brain.
This brain damage gets progressively worse over time and can affect movement, cognition (perception, awareness, thinking, judgement) and behaviour.
Early features can include personality changes, mood swings, fidgety movements, irritability and altered behaviour, although these are often overlooked and attributed to something else.
Huntington's disease was originally called Huntington's chorea ("chorea" is the Greek word for dancing). This is because the involuntary movements associated with the condition can look like jerky dancing. However, "disease" is now the preferred term, because the condition involves a lot more than just abnormal movements.
Huntington's disease is caused by an inherited faulty gene. However, in around 3% of cases, there's no family history of the condition, normally because the parents died at a young age.
Diagnosing Huntington's disease
If you have symptoms of Huntington's disease, your GP will refer you to a specialist clinician (usually a neurologist) if they feel your symptoms need further investigation.
The specialist will ask about your symptoms to assess how likely it is that you have Huntington's disease and to rule out similar conditions.
They may also test a number of physical functions, such as your eye movements, balance, control, movement and walking. Your speech and cognition may also be tested. All of these can be affected by Huntington's disease.
Genetic testing can be used to confirm the diagnosis.
Treating Huntington's disease
There's no cure for Huntington's disease and its progress can't be reversed or slowed down.
As the condition progresses, it may put a strain on family and relationships. Treatments for Huntington's disease aim to improve any mood disturbance; this is done to maintain skills used in daily living that can deteriorate over time.
Medication can help manage some of the symptoms, such as irritability or excessive movement. Therapies such as speech and language therapy and occupational therapy can help with communication and day-to-day living.
Support is also available for the family of a person with Huntington's disease. This includes, for example, testing family members who don't have any of the condition's features (manifest) to see whether they carry the gene, or help with choosing a suitable care home in advanced cases.
Huntington's disease usually progresses and gets worse over a 10-25 year period from when it first appears, before the person eventually dies from it. During the condition's later stages, the person will be totally dependent and need full nursing care.
Death is usually from a secondary cause, such as heart failure, pneumonia or another infection.
Who's affected by Huntington's disease?
Both men and women with a family history of Huntington's disease can inherit the condition. Symptoms usually start to appear during adulthood.
Juvenile (children's) Huntington's disease develops before the age of 20. Only 5-10% of people with Huntington's disease develop it at a very young age, and the pattern of features may be different.
It was previously thought that 4-6 people in a population of 100,000 were affected by Huntington's disease. However, UK research carried out in 2012 found the actual figure for those affected by the condition to be about 12 people per 100,000.
It's thought that the number of people who have the Huntington's gene and are not yet affected is about twice that of those who have symptoms.
Research is underway to find disease-modifying medication and new treatments for the features of Huntington's disease.
Exciting progress has been made in identifying potential ways of slowing down or halting the condition by "switching off" the faulty gene that causes Huntington's disease.
See our page on clinical trials for Huntington's disease for details of theclinical trials that are currently running. You can find out more by visiting the European Huntington's Disease Network.
Features of Huntington's disease
The clinical features of Huntington's disease can include psychiatric problems and difficulties with behaviour, feeding, communication and abnormal movements.
People can start to show the features of Huntington's disease at almost any age, but most will develop problems between the ages of 35 and 55.
The condition usually progresses and gets worse for around 10-25 years, until the person eventually dies. Signs and symptoms may vary between individuals and there's no typical pattern.
Early features, such as personality changes, mood swings and unusual behaviour, are often overlooked at first and attributed to something else.
Some people with Huntington's disease may not recognise that they have any problems.
Behavioural changes are often the first features to appear in Huntington's disease and can be the most distressing. These changes often include:
a lack of emotions and not recognising the needs of others in the family
alternating periods of aggression, excitement, depression, apathy, antisocial behaviour and anger
difficulty concentrating on more than one task and handling complex situations
irritability and impulsiveness
A person with Huntington's disease may appear to have a lack of drive, initiative and concentration, making them seem lazy. However, this isn't the case – it's just the way the condition affects the brain. As part of this, they may also develop a lack of interest in hygiene and self care.
The Huntington's Disease Association has more information about the behavioural problems (PDF, 219kb) associated with the condition.
Many people with Huntington's disease have depression. This occurs as part of the condition, not just as a response to the diagnosis.Symptoms of depression include continuous low mood, low self-esteem, a lack of motivation or interest in things, and feelings of hopelessness.
A few people may also develop obsessive behaviours and schizophrenic-like problems, although this is relatively rare.
Studies have shown that people with Huntington's disease are more likely to consider suicide, particularly near the time of diagnosis when the condition is becoming apparent, and when they start to lose their independence.
Huntington's disease affects movement. Early features include slight, uncontrollable movements of the face, and jerking, flicking or fidgety movements of the limbs and body. These move from one area of the body to another and can cause the person to lurch and stumble.
These features are often first seen when the person is walking or resting (sitting in a chair or lying in bed).
As the condition progresses, the uncontrollable movements will become more frequent and extreme. However, over time this may change and in the advanced stages of the condition a person's movements may become slow and their muscles more rigid.
People with Huntington's disease tend to lose weight, despite having a good appetite. They can find eating tiring, frustrating and messy because the mouth and throat muscles don't work properly, due to the loss of motor control. In some cases, this can lead to choking and recurrent chest infections.
Loss of coordination can lead to spilling or dropping food. Swallowing is a problem, so choking on food and drink, particularly thin drinks such as water, can be a common problem.
A referral to a dietitian or a speech and language therapist may be necessary if there are difficulties with swallowing. In some cases, a feeding tube can be inserted.
The Huntington's Disease Association has more information about the eating and swallowing difficulties (PDF, 320kb) associated with the condition.
Communication and cognition (perception, awareness, thinking and judgement) are affected by Huntington's disease.
People with the condition often have difficulty putting thoughts into words and slur their speech. They can understand what's being said, but may not be able to respond or communicate that they understand. However, with time, a person with Huntington's disease will become less responsive, more withdrawn and communicate little.
People with Huntington's disease can have problems with sexual relationships, particularly during the early stages of the condition. This is usually a loss of interest in sex or, less commonly, making inappropriate sexual demands.
The Huntington's Disease Association has more information about sexual problems (PDF, 193kb) associated with the condition.
End of life
In the later stages of Huntington's disease, the person will be totally dependent and need full nursing care.
Death is usually from a secondary cause, such as pneumonia or another infection.
You may find the end of life care guide useful if you're caring for someone who's dying, or if you want to plan your end of life care in advance.
Juvenile Huntington's disease
Juvenile Huntington's disease is an uncommon form of the condition that can occur in people younger than 20 years old. Common signs include:
a rapid decline in school performance
changes in handwriting
problems with movement, such as slowness, stiffness, tremor or muscle twitching (similar to the features of Parkinson's disease)
The cause of Huntington's disease
Huntington's disease is caused by a faulty gene that runs in families.
Genes and chromosomes
Genes are the instructions for making all parts of the human body and brain. They're made up of DNA and packaged onto strands called chromosomes. We have two copies of all our genes, so our chromosomes are in pairs.
Humans have 46 chromosomes (23 pairs). The faulty gene that causes Huntington's disease is found on chromosome number four.
The normal copy of the gene produces a protein called huntingtin, but the faulty gene contains an abnormal region of what are called CAG repeats. This area is larger than normal and produces a mutant form of huntingtin.
Cells in parts of the brain – specifically, the basal ganglia and parts of the cortex – are very sensitive to the effects of the abnormal huntingtin. This makes them function poorly and eventually die.
The brain normally sends messages through the basal ganglia and cortex to control movement and thinking, as well as motivation. If this part of the brain is damaged, it causes problems with control of movement, behaviour and thinking.
It's still unclear exactly how abnormal huntingtin affects the brain cells and why some are more sensitive than others.
Inheriting Huntington's disease
A parent with the Huntington's disease gene has one good copy of the gene and one faulty copy. Their child will inherit one of these genes. Therefore, there's a 50:50 chance that the child will get the faulty gene and develop Huntington's disease.
However, it's very difficult to predict how old the child will be when they develop the condition if they inherit the abnormal gene, unless it contains a very long CAG repeat (>55).
There's also a 50:50 chance that the child with Huntington's disease will pass the faulty gene on to a child they may have in the future. This pattern of inheritance is called "autosomal dominant".
In around 3% of cases of Huntington's disease, there's no obvious family history of the condition. This could be due to adoption or because relatives with the condition died early from other causes. In rare cases, it's due to a new expansion in the gene.
Treating Huntington's disease
There's no cure for Huntington's disease. Its progress can't be reversed or slowed down, although this is the goal of many research projects.
Some of the features of Huntington's disease can be managed with medication and therapies, which may be coordinated by specialist teams.
Therapies, such as speech and language therapy and occupational therapy, can help with communication and day-to-day living.
Regular exercise is also very important. People who are active tend to feel much better physically and mentally than those who don't exercise. Someone with Huntington's disease may have poor coordination, but walking independently, with the use of walking aids if necessary, can make all the difference.
Medication for Huntington's disease
Medicines for Huntington's disease, which can be taken in liquid form in many cases if needed, are described below.
Most of these medications have side effects, such as extreme tiredness. However, it may sometimes be difficult to tell whether these are symptoms of the condition or a result of the medication.
Antidepressants to treat depression
Antidepressants can help improve mood swings and treat depression. They include:
SSRI antidepressants – such as fluoxetine, citalopram and paroxetine
tricyclic antidepressants – such as amitriptyline
other types of antidepressants – including mirtazapine, duloxetine and venlafaxine
Side effects of antidepressants may include:
shaking or trembling
difficulty sleeping (insomnia)
Mood stabilisers to treat irritability or mood swings
Mood stabilisers, particularly carbamazepine, may be considered as a treatment for irritability. Olanzapine can also help, along with sodium valproate and lamotrigine.
The dose of carbamazepine needs to be slowly increased and any side effects monitored. Carbamazepine can't be used during pregnancy.
Medication to suppress involuntary movements
The medications listed below suppress the involuntary movements – or chorea – seen in Huntington's disease. In the UK, antipsychotic medicines are usually preferred.
antipsychotic medication – such as olanzapine, sulpiride, risperidone and quetiapine
tetrabenazine – reduces the amount of dopamine reaching some of the nerve cells in the brain
benzodiazepines – such as clonazepam and diazepam
Antipsychotic medication may also help control delusions and violent outbursts. However, they may have severe side effects, such as:
stiffness and rigidity
Due to the possibility of experiencing these side effects, the lowest possible dose of antipsychotics are normally prescribed in the first instance.
Help and support
If you want to talk to someone about Huntington's disease, theHuntington's Disease Association has a team of advisers who can help. You can call their helpline on 0151 331 5444, or their email address is email@example.com.
Living with Huntington's disease
Help is available to assist people with Huntington's disease in their day-to-day living. This might include physiotherapy, occupational therapy and speech therapy.
Huntington's disease puts a great deal of strain on relationships, and is very stressful and upsetting for the family. It's distressing to see a family member's state of mind deteriorate so much that they may not be like their former self at all.
Daily routines such as getting dressed and eating meals can be frustrating and exhausting. The types of help outlined below aim to ease the strain of the condition by improving skills that may deteriorate.
Help with communication
Speech and language therapy can improve communication skills, memory and teach alternative ways of communicating. It can also help with swallowing problems.
Communication aidscan sometimes be helpful, as they allow communication without the need for talking. For example, you can point to symbols on a chart to indicate your mood or whether you're hungry.
The family of someone with Huntington's disease will need to be patient and supportive. They can try alternative ways of communicating if speech is a problem.
Help with mealtimes
People with Huntington's disease need to have a high-calorie diet. A dietitian can help you work out an appropriate diet plan.
To help with eating and drinking, food should be easy to chew, swallow and digest. It can be cut into small pieces or puréed to prevent choking. Feeding equipment is also available, such as special straws and non-slip mats.
At some point, it may be necessary to use a feeding tube that goes directly into the stomach. If a person with Huntington's disease doesn't want to be artificially fed during the later stages of the condition, they should make their wishes known to their family and doctor. They may want to consider making an advance decision (a living will) or a statement of wishes and preferences.
The Huntington's Disease Association has more information about eating and swallowing (PDF, 320kb). You can also email theRoyal Hospital for Neuro-disability for further information and advice about swallowing difficulties and artificial nutrition. Their telephone number is 020 8780 4500, or you can email them on firstname.lastname@example.org.
An occupational therapist (OT) can help with day-to-day activities. Your home can be adapted by social services to make life easier for a person with Huntington's disease, as they may be at risk of injury from a fall or accidentally starting a fire.
Your shower, bath, chairs and bed may need to be adapted. You may also need to think about wheelchair access.
A physiotherapist can help with mobility and balance by using a range of treatments, including manipulation, massage, exercise, electrotherapy and hydrotherapy. You may be referred to a physiotherapist through your GP or social services.
Electronic assistive technology
The Royal Hospital for Neuro-disability provides an electronic assistive technology (EAT) service. It's made up of a team of healthcare professionals who provide EAT equipment for patients and residents within the hospital, as well as for people with disabilities living in the community or at other hospitals or units.
computers and software
switches and other access devices
powered wheelchair controls
Information about Huntington's disease
The Huntington's Disease Association has a number of useful factsheets that provide advice about a range of topics, including:
diet, eating and swallowing
driving (see below)
seating, equipment and adaptations
information for teenagers
The charity can also help you explore the housing options available when full-time care is needed.
It's also worth finding out what benefits you may be entitled to if you have Huntington’s disease, or if you're looking after someone with it.
You can do this through the Huntington's Disease Association or by contacting the Citizens Advice Bureau (CAB).
A person diagnosed with Huntington's disease who's started to experience clinical features should inform the Driver and Vehicle Licensing Agency (DVLA) because it will affect their ability to drive.
The DVLA will write to your doctor, with your permission, to ask for their opinion about your condition. Based on that information, a decision will be made about whether you can still drive and for how long before another assessment is needed.
There's no need to tell the DVLA if you're carrying the faulty gene but haven't yet developed the features of the condition.