What is Juvenile Huntington Disease? | Huntington Disease Awareness

The month of May is not only Cystic Fibrosis Awareness Month, but also the month where the societies around the globe raise awareness for Huntington Disease. For Huntington Disease Awareness Month 2017, the spotlight is on Juvenile Huntington Disease, a sub-category of HD which affects around 5-10% of those with HD. It is categorised by any patient showing symptoms under the age of 20, and has further complications and different presentations to adult HD. To help raise awareness, we will explain the symptoms, causes and treatments for both HD as a whole, and more specifically JHD, to help bring this little known disease out of the shade and into the light.

What is Huntington Disease (HD)?

Huntington Disease is a genetic brain disorder, caused by a faulty gene on chromosome 4. This causes several issues with the central nervous system, and patients experience a gradual change in their physical abilities and mental health or stability, due to cells in parts of the brain deteriorating and dying. HD is a rare condition, with approximately 30,000 people being affected in the US. The gene is passed on genetically and if just one parent has the HD gene, there is a 50-50% chance the child will have the faulty gene as well. If you have the gene, the symptoms could present at any time, most commonly happening at ages 30-50, but sometimes in younger or older patients.

What is Juvenile Huntington Disease (JHD)?

Patients who have HD symptoms under the age of 20 are diagnosed with Juvenile Huntington Disease (JHD). With only 1500-3000 people in the US suffering from JHD, the disease can feel isolating for both the patients and the parents or families of the patients. JHD is also much harder to diagnose as cognitive symptoms are harder to spot, and indeed the disease is often missed as an option as it is so rare. Where the family history of HD is known, it is important to tell your physician about this, However, in many cases, it is not known that the family carries the faulty gene. JHD symptoms can vary from patient to patient, and they are slightly different to adults suffering with HD.

Symptoms of HD

The main symptoms of HD can be split into cognitive or emotional symptoms, and physical symptoms. The cognitive symptoms are most often the first signs of HD in an adult patient and can include:

• Irritability
• Difficulty in organizing routine
• Difficulty coping effectively with new situations
• Difficulty recalling information
• Taking longer to complete previously simple tasks
• Impaired decision making skills

These cognitive symptoms progress over years, and gradually simple cognitive tasks such as remembering addresses become difficult. Emotional symptoms such as frustration and depression are also extremely common, and as the disease progresses, nerve changes in the brain and cerebral cortex can cause violent, aggressive and antisocial behaviour.

Physical symptoms are present alongside the cognitive symptoms, and tend to get worse in the more intermediate stages of the disease:

• In early stages, small involuntary movements, which progress into jerking and obvious movements
• Impaired speech or slurring
• Difficulty swallowing
• Stumbling and clumsiness, eventually leading to complete lack of independent movement
• Weight loss
• Susceptibility to infections
• Rigidness in later stages of the disease

Although you can’t die from Huntington Disease itself, as symptoms progress, secondary illnesses such as pneumonia cause death, and life expectancy is around 15-25 years after first onset of symptoms.

Juvenile HD symptoms

Unlike adults with HD, cognitive symptoms can be much harder to spot early on in a child suffering with JHD. Physical symptoms are much more likely to raise alarm bells first, and can include:

• Clumsiness, or difficulty walking or balancing
• Rigidness in early stages of the disease, with much less involuntary movements
• Epileptic seizures
• Issues with chewing and swallowing
• Stiff joints and limbs

In addition to this, there are some changes in mood and mental abilities, which often get mistaken for ‘bad behaviour’ or more common juvenile conditions such as ADD or learning disabilities. Frustration and mood swings are common in patients with JHD, as well as:

• Inability to master new tasks
• Loss of tasks previously mastered e.g. reading
• Difficulty in remembering events or information
• Irrational fears

JHD and Puberty

Puberty is usually a difficult time for any child, and this is always escalated when another disease or condition is thrown into the mix. For JHD, puberty can be a difficult time as sexual maturity sets in and is confusing and frightening for patients. Furthermore, restraint over urges and and natural behavioural changes such as mood swings, makes the process a challenge for all those involved. Child psychiatry and/or medication can help with this period of a JHD patient’s life.

Treatment of HD and JHD

There is currently no cure for HD or JHD, and there are also no methods found of slowing the onset of the disease. However, there are several treatments available to alleviate the individual symptoms, and avoiding unnecessary infections is also extremely important. Medications for joint rigidity, epilepsy, depression and mental health can help control and stabilise symptoms.

If you are affected by any of the topics discussed in this blogpost, there are a lot of resources available and people to talk to about HD and JHD, and we have left a list of useful links below. If you are concerned about the symptoms you or a loved one are experiencing, place them into the Isabel Symptom Checker and discuss the results with your doctor.

Useful Links:

HD in USA: http://hdsa.org/

HD in UK: https://www.hda.org.uk

HD in Canada: https://www.huntingtonsociety.ca

Research: http://www.hdlf.org/

Support for young people with JHD: https://en.hdyo.org/