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

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

• Movement
• Thinking
• Behaviour

However, 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.

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.

For these reasons, because you usually need to be over 18 before you can have the genetic test for Huntington’s, and because Juvenile Huntington’s symptoms can resemble those of other diseases such as Parkinson’s disease, depression or attention deficit disorder (ADD), sometimes the illness can be misdiagnosed or remain undiagnosed for some time. This is particularly true where a family history of the disease is not known.

Key facts:

• Changes in behaviour or a drop in school performance are often the first noticeable symptoms of Juvenile Huntington’s disease.
• 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.

There are many ways that children and young people living with Juvenile Huntington’s can get help and support with their symptoms to help them cope in school and greatly improve their quality of life.