Huntington's disease is an illness caused by a faulty gene in your DNA. If the person develops symptoms of before the age of 20, this is known as Juvenile Huntington’s disease.


As with adult-onset Huntington’s, Juvenile Huntington’s symptoms can vary from one person to another. They mostly affect three main areas:

  • Movement
  • Thinking
  • Behaviour

In some ways, symptoms of Juvenile Huntington’s are similar to those of the adult disease, but there are some key differences.

Children and young people affected by Huntington’s are less likely to experience the involuntary movements, known as chorea, that often characterise the adult illness, and more likely to be affected by muscle contractions and stiffness. Epilepsy is also more common in Juvenile Huntington’s, particularly in younger people and children.

Key facts:

  • Children and young people with Huntington’s can remain undiagnosed for some time, as doctors and specialists may be reluctant to give a diagnosis or refer them for genetic testing before physical symptoms appear.
  • Challenging behaviour tends to be more common in people who develop the disease in their teens, but many young people/children are not affected in this way.
  • Sometimes changes in behaviour or a drop in school performance are often the first noticeable symptoms of Juvenile Huntington’s disease.

What it's like to live with Juvenile Huntington's disease

How to know if it's Juvenile Huntington's disease?

Different types of symptoms generally occur at different stages of the illness. Often the first indication that someone has Juvenile Huntington’s is a change in their thinking or behaviour. For example, they may experience difficulty concentrating and following instructions, and there may be a noticeable drop in their performance at school, college or work. Family members and teachers may not initially interpret these changes as an illness at all.

Not all behavioural changes, however, may be directly caused by the disease. Children of families affected by Huntington’s may also be experiencing disruption and difficulties in their home life, which might also impact their behaviour, or they may be facing other challenges in their lives.

The stages of Juvenile Huntington's disease

Click on the below tabs - each of which will explain in further detail about symptoms in the different stages of Juvenile Huntington's disease.

Early stages

Changes in behaviour or a drop in school performance are sometimes a noticeable symptoms of Juvenile Huntington’s disease.


  • It may become harder to concentrate, learn new things, follow instructions and remember things.
  • It may take longer for them to respond to questions and perform tasks.
  • It might be harder to start things - sometimes this can be misinterpreted as lethargy or laziness.
  • They may feel more frustrated, impatient, irritable or angry than normal.
  • Experiencing stiffness in their limbs. Their movements may slow down and they might stumble or walk unevenly.


These are just a few of the possible symptoms - they may not experience them all or may experience different ones. It is usually the case that the earlier the onset of symptoms, the more rapid they are likely to progress.


Many symptoms can be greatly helped with extra support at home and in class. As Juvenile Huntington’s is so rare, it’s important for parents and carers to work with a child’s school to help them understand the disease and how best to support you. 


Middle stages

Symptoms of the middle stage of the illness often revolve around changes in muscles and movement, although changes in behaviour may also become more significant and challenging too.


  • Muscles are likely to start making involuntary contractions and become stiff and rigid.
  • Movements slow down and arms and legs may become clumsy.
  • Experiencing changes in how they speak as forming words becomes more tricky. Speech therapy and certain equipment can help a lot with this.
  • It may become difficult for you to swallow, making eating difficult. Support from a dietician can help to make sure they keep their weight up.
  • Behaviour may change as feelings of anger, frustration or depression become quite intense. This can be quite challenging for you and those around you. It doesn’t happen to everyone but it’s more likely to happen if they start to develop symptoms in their teens.


Everyone’s journey through Juvenile Huntington’s is unique. Some people may not experience all these symptoms or may experience different ones or experience them at different stages. This means care will need to be tailored to their specific needs and to change and evolve as they do.


Late stages

The nature of Huntington’s is such that gradually, often over a period of many years, the disease progresses until the end of life. In the later stages of the disease more care and support will be needed.


Later on, they may experience difficulties with:

  • weight loss and nutrition
  • speech and swallowing
  • movement and stiffness
  • communication


These are just a few of the possible symptoms - thyey may not experience them all or may experience different ones. It is important to pay attention to the symptoms that are causing the person and their family the greatest difficulty, emotionally or practically, at the time.


Sometimes the psychological and emotional sides of living with the disease are more of a problem than the physical side. It can be mentally difficult to cope with having a serious illness, and extremely frustrating not to be able to do more of the things that they could easily do before.