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HD 101

What Is JHD?

Juvenile Huntington's Disease (JHD), sometimes called JoHD (Juvenile onset HD) is recognized when someone under the age of 20 has the symptoms of HD.  

JHD, like adult-onset HD, is characterized by the progressive loss of control over movement, emotion, and thinking. The severity and types of symptoms vary greatly from person to person. Children and young adults with JHD often experience changes in personality, reduced ability to learn, clumsiness, stiffness, and seizures. Once symptoms begin, they tend to progress more rapidly than adult-onset HD.  

Research is ongoing and medications and treatments are available for treating some of the symptoms. Sadly, JHD is incurable right now and the average life span for children and young adults with JHD is about 15 years. 

Symptoms of JHD 

Movement Chorea (involuntary jerky movements) is less common in JHD. Instead, young people tend to become more rigid and stiff. This stiffness can cause clumsiness, difficulty walking, and loss of balance. As the symptoms progress, chewing, swallowing, and speaking become more difficult. Epileptic seizures occur in about 25% of youth with JHD. Seizures almost never occur in adult-onset HD.
Emotion Experiencing loss of independence and ability to do typical activities can cause feelings of frustration, anger, fear, sadness, and grief. Obsessive thoughts or irrational fears can occur. Sometimes negative emotions are expressed in aggressive behavior. Challenging behavior is more common in teens who develop JHD.
Thinking Attention and concentration may decline as the disease progresses. Previously learned skills such as reading, writing, and counting, may become more difficult, and learning new information and accumulating new memories may also become increasingly challenging.

Some of the symptoms can be confused with “bad behavior” or mistaken for attention deficit disorder. 

Stages of JHD 

Early stage Most common changes are changes in behavior and ability to concentrate at school. Sometimes a drop in school performance occurs.
Middle stage Stiffness and clumsiness typically occur along with more significant and challenging changes in behavior. Speaking may become more difficult and speech therapy can be very helpful. Swallowing may also be more challenging, so working with a dietician can greatly help. Therapists can help manage the more challenging behaviors that can come along.
Late stage Weight loss and nutrition can become more serious problems and speech, swallowing, moving, and communicating will become harder.

Puberty and JHD 

Changes in teenagers' bodies naturally bring on sexual urges and desires for more independence. JHD will affect the ability to control some of these natural behaviors. 

Diagnosing JHD 

Diagnosis of JHD is often challenging, particularly when there is no known family history. Early symptoms can easily be confused with non-HD-related emotional and behavioral changes in children and youth. After consulting with a physician, the diagnosis can be confirmed through genetic testing. The CAG repeat expansion for people with JHD is higher than adults with HD and it is more likely to be inherited from the father. 

Predictive genetic testing – testing without the appearance of symptoms, is not available to people under the age of 18. Anyone over the age of 18, can learn more about the predictive testing process here.

Tips for Living with JHD 

  • Stay active in school and regular activities for as long as possible. 
  • Allow for extra rest breaks. Living with JHD makes things harder and can be draining.  
  • Work with teachers to create and adjust individual learning plans as needed. 
  • Educate teachers, counselors, and school administrators to help everyone understand what adjustments and accommodations may need to be made. 
  • Build a comprehensive care team including neurologists, psychiatrists, speech therapists, occupational therapists, social workers, dietitians, physical therapists, and others to meet the young adult’s needs. 
  • Connect with other JHD parents and join support groups. 
  • Everyone in the family is affected by JHD. Seek support including counselors for all family members. 
  • Talk to financial and legal experts to develop a sound plan to support all the needs of the person with JHD. 
  • Enjoy fun activities and celebrate special times.   

Check out HDYO's presentation on living with Juvenile Huntington's Disease. This video may be upsetting/triggering. Please reach out to us for support.