# Huntington's Disease
What is it
Huntington's disease is an inherited disorder that gradually affects the nervous system. It is caused by a fault in a single gene, which leads to the death of certain brain cells. This occurs because a piece of the DNA code repeats itself over and over — more repetitions usually mean a more severe course and earlier onset of symptoms.
The disease is not contagious and occurs in all peoples and cultures. It is rare: in the Netherlands, an estimated 800 to 1,200 people have the diagnosis, although these numbers vary by source. For many families, it is a burdensome condition, because it is inherited and because there is still no cure.
Causes
Huntington's disease is caused by a mutation in the HTT gene. This gene codes for a protein that is present in all body cells, but mainly causes problems in certain brain cells — especially in the basal ganglia, areas that are important for movement, thoughts, and feelings.
The mutation consists of a repeated code sequence (CAG repeats). Everyone has a number of these repeats, but in Huntington's, there are many more than normal. The more repeats, the earlier the disease usually begins and the faster it can progress.
**Inheritance:** This is an autosomal-dominant genetic disorder. This means that if one parent carries the mutation, each child has a 50% chance of inheriting it — regardless of sex. If you have the mutation, you will (almost certainly) develop symptoms at some point in your life.
How the disease progresses
Huntington's disease usually progresses in three phases, although each person is unique. The disease process starts long before symptoms appear: brain cells begin to die, but you don't feel anything yet.
**Premanifest phase:** This is the period before clear symptoms appear. Through genetic testing, one can know that the mutation is present, while someone still feels and functions completely normally. This phase can last years to decades, depending on the number of CAG repeats. Many researchers intensively study this phase, because understanding it can help find treatments that can slow the disease before damage occurs.
**Manifest phase:** Symptoms become visible and affect daily life. This phase is often divided into early, middle, and late stages, although those boundaries are not sharp.
**Late phase:** The disease has progressed to a point where much independence has been lost and intensive care is needed.
The total disease duration is usually 15 to 20 years from the time symptoms appear, but this varies greatly from person to person.
Symptoms by phase
Early phase (manifest period begins)
- **Movements:** Involuntary, uncontrolled movements (chorea) — unwilling grimaces, jerky movements of arms and legs, or smoother but chaotic movements. This can start subtly (like nervous twitches) and gradually become worse.
- **Behavior and mood:** Irritability, mood swings, depression, or anxiety may be noticeable. Some become impulsive or have difficulty with self-control.
- **Cognition:** Loss of concentration, slower thinking, difficulty with planning or multitasking. Memory for facts can remain reasonable, but working memory (holding information while working with it) suffers.
- **Sleep:** Sleep disorders are frequent — difficulty falling asleep, frequent waking, or disrupted day-night rhythm.
Middle phase
- **Movements:** Chorea usually becomes more obvious and bothersome. At the same time, other movement disorders can occur (rigidity, slowness, stiffness) — especially in younger people.
- **Behavior:** Behavioral changes can become more severe. Apathy (lack of initiative) is frequent. Personality can change.
- **Cognition:** Thinking speed decreases, attention becomes difficult, speech and word-finding can stutter.
- **Physical:** Weight loss is common, despite eating well — the disease causes higher energy expenditure. Swallowing difficulties may begin.
- **Functioning:** Work becomes more difficult, social contacts may suffer, shopping or personal care require help.
Late stage
- **Movement:** Chorea may decrease, but movement problems become more severe — rigidity, slowness, difficulty with balance and gait.
- **Cognition:** Severe impairment of thinking, memory and language. Communication becomes very difficult.
- **Physical:** Swallowing difficulties can be severe; nutritional support via feeding tube may be needed. Stiffness, joint contractures, falls.
- **Dependence:** Complete dependence on care for daily functioning — eating, washing, toileting, mobility.
- **Awareness:** Often awareness remains present, which can be emotionally difficult.
What it means for daily life
For the person themselves
Many people with Huntington's deal with loss of independence — step by step. Work often has to stop. Driving becomes unsafe. Personal care requires help. The involuntary movements can feel like a loss of control over your own body in public.
Emotionally there is much to process: the knowledge that the disease is progressing, fear of what is to come, possibly depression or apathy (due to the disease itself, not just psychological). For some, medications that help these symptoms provide relief, for others they do not.
Cognitive changes can be frustrating — not being able to concentrate, not being able to find words, not being able to make plans. For many with Huntington's, self-awareness remains present, which can make this psychologically even more burdensome.
For loved ones
Partners, parents and children often feel helpless. Seeing someone change can be painful. Practical care is needed, which is exhausting. Children of an affected parent fear their own future, especially if they know they have a 50% risk.
Family relationships can become strained by behavioral changes or by the burden of care. Financially, expenses can mount (help, home modifications). Many families feel isolated.
In practice
Safety becomes a focal point: falls, burns in the kitchen, medication errors. The home may need to be adapted. Help from home care, speech therapists, physiotherapists or psychologists may be needed.
Social life often becomes limited — uncertainty about how the disease manifests in public, or simply lack of energy. Friends may distance themselves (consciously or unconsciously).
For children at risk: some choose genetic testing, others do not. This is a very personal choice with psychological consequences.
Outlook
There is currently no cure for Huntington's disease. The disease will without exception progress, although the pace differs from person to person.
**Life expectancy:** People with Huntington's usually have a normal or near-normal life expectancy if they are well cared for, although some complications (such as malnutrition or pneumonia) can lengthen or shorten it. The disease itself is not directly fatal, but complications from advanced stages (malnutrition, aspiration pneumonia from swallowing difficulties, falls) can be.
**Research:** Considerable research is underway into the disease — aimed at understanding what happens in the brain, at markers that can predict how quickly someone becomes ill, and at possible treatments. These studies focus, among other things, on inflammatory processes, protein waste systems in cells and genetic mechanisms. So far, results have been promising at the research level, but have not yet led to full translation into available treatments.
**Symptomatic treatment:** There are medications that can relieve some symptoms — movement disorders, depression, anxiety, sleep problems. This gives people more quality of life, although it does not stop the underlying disease.
**Palliative care:** As the disease progresses, comfort, dignity and quality of life become central. This means pain relief, help with eating and drinking, emotional support.
Frequently asked questions
**Q: Is Huntington's disease hereditary? Can I pass it on to my children?**
A: Yes, it is hereditary. If you are a carrier of the mutation, each of your children has a 50% chance of inheriting it as well. Only carriers of the mutation will ever develop symptoms. Non-carriers will never become ill and cannot pass on the disease.
**Q: Can doctors tell me how quickly my disease will progress?**
A: The number of CAG repeats in your gene provides an indication — generally speaking: more repeats = earlier onset and often faster progression. But this is not absolute; two people with the same test can progress very differently. Your doctor can discuss your situation, but cannot accurately predict what your personal future will be.
**Q: Are there treatments that stop the disease?**
A: Not currently. There are medications that can help with certain symptoms (movement problems, mood disorders). Much research is aimed at slowing the disease, especially in early stages. Some experimental treatments are being investigated, but these are not yet widely available.
**Q: Should I get tested to see if I have the mutation if my parent has it?**
A: This is very personal. Some people want the certainty; others feel mentally better without knowing. It is wise to first talk to a genetic counselor, who can help you think through the advantages and disadvantages of testing.
---
_This information never replaces a doctor's judgment. Always discuss your situation with your own healthcare provider._