What is Huntington's and Juvenile Huntington's disease?

Huntington's Disease (gene found in 1993), is a hereditary, degenerative, and terminal brain disease for which there is no cure. Huntington's disease is caused by a genetic mutation on chromosome 4.  Huntington's disease abbreviated - HD or Juvenile Huntington's disease — JHD is an autosomal dominant disease. This means that only one parent must have the mutated gene for a child to inherit the disease. Every child of a person with Huntington's disease has a 50/50 chance of inheriting the fatal mutation. Huntington's disease does not skip generations. This disease slowly diminishes the individual's ability to walk, move, talk, and reason.  In advanced stages, the person with HD relies completely on others for their personal care.

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HD affects the lives of entire families — socially, psychologically, and economically, it affects males and females and knows no ethnic or racial boundaries. Many of us within the international community describe the symptoms of JHD/HD as having, ALS, Parkinson’s, Alzheimer's disease, Dementia, Bipolar disorder, and Schizophrenia — all at the same time. Huntington's disease is not a one-size-fits-all disease, and each patient must be individually treated.

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Simply, Huntington's disease is more than a physical disease. Often, the individual with HD might seem to be (or act) "drunk" to the on-looker, due to the physical attributes of the disease. 

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Juvenile Huntington's disease (JHD) affects children before the age of twenty. If the father is the affected parent, his children can show symptoms much earlier in life than the father - (JHD). CAG repeats for JHD patients are much higher than the adult-onset of Huntington’s disease – repeats maybe 50+, 60+, or more. Upwards of 10 percent of known cases of Huntington's disease is the juvenile form. Individuals who suffer from JHD may experience seizures and many other horrific attributes of this disease earlier in life. Diagnosis of JHD usually happens with symptoms manifest before the age of twenty, and in many cases, is often delayed by false diagnoses such as ADHD.

Symptoms of Juvenile Huntington's Disease

The onset and progression of Huntington's disease in younger people is faster than in adults.

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• Stiffness of arms and legs

• Clumsiness of arms and legs

• Slowness in movements (bradykinesia)

• Irregular eye movements

• Trouble chewing/ swallowing/choking

• Speech / Communication problems

• Itching/scratching

• Seizures may occur

• Sleep disturbances

• Decline in cognitive functions (learning ability)

• Changes in behavior

• Obsessive-compulsive behaviors

• Sexual promiscuity

Sadly, the current testing process (genetic blood test) for JHD is often too difficult. Why? The debate among medical professionals is that many youths may have ADHD, depression, juvenile variations of bipolar disorder, mild cerebral palsy, seizure disorders, thyroid disease, and not JHD. In addition, regulations restrict a minor (under age 16) from genetic testing unless a thorough neuro-psychiatric exam takes place. Families with a history of Huntington's disease are battling these challenges. The process to have a child diagnosed with JHD can take years — time families just do not have.

Symptoms of Huntington's Disease

Huntington's disease usually causes movement, cognitive and psychiatric disorders with a wide spectrum of signs and symptoms. Which symptoms appear first varies greatly among affected people. During the course of the disease, some disorders appear to be more dominant or have a greater effect on functional ability.

Movement disorders

The movement disorders associated with Huntington's disease (Chorea), can include both involuntary movements and impairments involuntary movements:

•          Involuntary jerking or writhing movements (chorea)

•          Muscle problems, such as rigidity or muscle contracture (dystonia)

•          Slow or abnormal eye movements

•          Impaired gait, posture, and balance

•          Difficulty with the physical production of speech or swallowing

Impairments of voluntary movements — rather than the involuntary movements — may have a greater impact on a person's ability to work, perform daily activities, communicate, and remain independent.

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Some of the movement symptoms of HD include muscle spasms, tics, rigidity, falling down, difficulty physically producing speech, and, in the later stages of the disease, difficulty swallowing (which can lead to significant weight loss). Uncontrollable movements such as writhing and twisting are also quite common symptoms of HD. Physicians sometimes refer to these uncontrollable movements as “chorea.”

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Cognitive disorders

Cognitive impairments often associated with Huntington's disease include:​

• Difficulty organizing, prioritizing or focusing on tasks

• Lack of flexibility or the tendency to get stuck on a thought, behaviors or action (perseveration)

• Lack of awareness of one's own behaviors and abilities

• Slowness in processing thoughts or ''finding'' words

• Difficulty in learning new information

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Behavioral changes

• Loss of previously learned academic or physical skills

• Rapid, significant drop in overall school performance

• Behavioral problems

Physical changes

• Contracted and rigid muscles that affect gait (especially in young children)

• Changes in fine motor skills that might be noticeable in skills such as handwriting

• Tremors or slight involuntary movements

• Seizures

• Weight loss is common in people with Huntington's disease, especially as the disease progresses.

Psychiatric disorders

The most common psychiatric disorder associated with Huntington's disease is depression. This is not simply a reaction to receiving a diagnosis of Huntington's disease. Instead, depression appears to occur because of injury to the brain and subsequent changes in brain function. Signs and symptoms may include:

•          Feelings of irritability,

•          Aggressiveness

•          Social withdrawal

•          Apathy

•          Insomnia

•          Fatigue and loss of energy

•          Sadness, Frequent thoughts of death, dying or suicide (3-5 times higher than the

general public)

•          Alcohol and drug abuse

•          Lack of impulse control that can result in outbursts, acting without thinking and sexual promiscuity

Other common psychiatric disorders include:

•          Obsessive-compulsive disorder, recurrent, intrusive thoughts, and repetitive behaviors

•          Mania, which can cause elevated mood, overactivity, impulsive behavior and inflated self-esteem

•          Bipolar disorder, or alternating episodes of depression and mania

Please visit the PLOS links for important algorithms for Huntington's and Juvenile Huntington's disease. 

HD affects the whole brain, but certain areas are more vulnerable than others. Pictured above are the basal ganglia - a group of nerves cell clusters, called nuclei. These nuclei play a key role in movement and behavior control and are the parts of the brain most prominently affected in early HD. - HDSA.org