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Huntington’s disease: a plain-language guide

trialport plain-language guide to Huntington's Disease
Keith

Huntington’s disease is an inherited brain condition in which nerve cells slowly stop working, causing changes in movement, thinking, mood and behavior, and although there is no treatment yet that slows or stops it, the symptoms can be treated and research is active [1,3,4].

This page provides general information. It does not replace advice from a doctor or another qualified healthcare professional.

Key facts

  • Huntington’s disease is caused by a change in a single gene called HTT, and each child of an affected parent has a 1 in 2, or 50 percent, chance of inheriting that change [1,3,4].
  • Symptoms usually begin between the ages of 30 and 50, and the average survival after symptoms start is 15 to 18 years, with a wide range from about 5 years to more than 25 [3,6].
  • Changes in thinking, mood and behavior often come before the movement symptoms, and families frequently find them the hardest part to live with [5,8].
  • There is no cure and no treatment yet that slows or stops the condition, and medicines, therapies and good nutrition can help a great deal with the symptoms [1,4,11].
  • A blood test can tell an adult who has no symptoms whether they carry the gene change, and it is a genuine choice: in the United Kingdom, more than 80 in every 100 people at risk have not taken that test [10,12].
  • Thoughts of suicide are more common in Huntington’s disease than in the general population, and telling a doctor is the right thing to do rather than something to hide [5,14,15].

On this page

What is Huntington’s disease?

Huntington’s disease affects the brain and changes slowly over many years. It is inherited, meaning it is passed down through families [1,2].

One gene, called HTT, carries the instructions for a protein called huntingtin that brain cells appear to need. In Huntington’s disease part of that gene is too long, so the cell makes a huntingtin protein longer than it should be, and over many years it damages nerve cells [2,7,11].

The damage begins deep in the brain, in two small structures called the caudate nucleus and the putamen, which help control movement, mood and memory, and spreads outward later [3,11].

It is also written Huntington disease, and older texts say Huntington’s chorea [2]. It is not catching, and nothing anyone did caused it.

How common is it?

Huntington’s disease is uncommon and unevenly spread. About 9.7 in every 100,000 people of European ancestry live with it, and figures are far lower in people of East Asian and African ancestry, from 0.1 to 2 in every 100,000, though records there are less complete [3].

These are prevalence figures, how many people have it at one time, and they count people already diagnosed, so the real number is higher [3].

What causes it?

Huntington’s disease is inherited in a pattern called autosomal dominant. Everyone has two copies of the HTT gene, one from each parent, and one altered copy is enough to cause it [2,3]. Each child of an affected parent has a 1 in 2, or 50 percent, chance of inheriting that copy [1,4,7].

Inside the gene, three DNA letters, C, A and G, repeat one after another, and the number of repeats matters [3,7]:

  • 26 or fewer: the usual range. Huntington’s disease will not develop.
  • 27 to 35, an intermediate result: the person is not expected to develop it, and the count can lengthen when passed on, so a child could be affected.
  • 36 to 39, called reduced penetrance: symptoms may or may not appear, and many in this range never develop them.
  • 40 or more: symptoms are expected at some point in a normal lifespan.

Longer counts go with earlier starts, and counts above 55 with childhood or teenage onset [3]. Repeat length explains up to about 70 percent of the difference in when symptoms begin, so it is a guide and cannot predict the year for one person [3]. The count can also grow between generations, called anticipation, which happens far more often when the gene comes from the father [2,3].

What are the symptoms?

Symptoms vary a lot, even within one family. Movement is what most people expect, and it is usually not what comes first: thinking and behavior often change earlier, and families describe those as the hardest part [5,8].

  • Thinking. Thought becomes slower, and planning, organizing and holding attention get harder [3].
  • Mood and behavior. Depression affects around 40 in every 100 people and can begin before any movement changes, and irritability, anxiety and loss of drive are common [3,5].
  • Movement. Chorea, jerky movement of the limbs, face or trunk that cannot be held back, is present in most people, worsens with stress and stops during sleep. Stiffness and slowness often replace it later, and weight loss and trouble with speech and swallowing follow [3,5].

Juvenile Huntington’s disease means symptoms before the age of 20, in fewer than 10 in every 100 people with Huntington’s [9]. School performance and behavior usually change first, stiffness is more common than chorea, and 30 to 50 in every 100 of these children have seizures [2,9].

When to seek urgent help. Thoughts of suicide are more common in Huntington’s disease than in the general population. Among 2,094 people studied, 13 in every 100 had such thoughts at the time and 28 in every 100 had had them before [14]. Risk is highest around diagnosis, and again when the condition starts to affect everyday independence [3]. This is a reason to tell a doctor or someone you trust rather than something to hide, and guidance says it should be asked about at every stage [5]. If you or someone near you is thinking about suicide, contact emergency services, a crisis line or a doctor now. Also seek urgent help for choking, a fall causing injury or a first seizure [3,4].

How is it diagnosed?

The same blood test is used in two very different situations.

When someone already has symptoms. A family doctor refers the person to a neurologist, a brain and nerve specialist. Diagnosis comes from the person’s history, an examination and the family history, and the blood test counting the repeats confirms it [1,3,4]. A brain scan can support it, not answer it alone [3,4]. Diagnosis is often delayed, since early mood and thinking changes have many other causes [8].

When someone is well and wants to know. This is predictive testing, normally offered to adults from the age of 18 [1]. It always comes with genetic counseling before and after, and that exists for good reasons. The talks beforehand cover why the person wants to know, what a result either way would mean, effects on insurance and work, and how their mood is [3]. Testing is not done if mental health problems are not being managed first [3].

Testing is a choice, not an expectation. The Huntington’s Disease Association says plainly that the test being available does not mean anyone must or should have it [10]. The NHS notes that some people choose not to be tested, particularly while nothing can prevent the condition [1]. Of 9,407 predictive tests in the United Kingdom from 1993 to 2014, take-up among people at 50 percent risk was about 17.4 percent, so more than 80 in every 100 at-risk people had not tested [12]. Neither choice is the responsible one.

A worldwide review of 4,527 people tested found 44, just under 1 in 100, had a suicide, suicide attempt or psychiatric admission afterwards, and all five who died by suicide already had signs of the condition [13].

How is it treated?

There is no cure, and no treatment yet slows or stops it. A great deal can still be done for the symptoms [1,4,11].

Chorea. Medicine is considered when the movements cause distress, not because they are visible [5]. Tetrabenazine is one first-line option, and second-generation antipsychotics are often preferred where mood, behavior or psychosis also need treating [5]. Deutetrabenazine and valbenazine work in a similar way [3,4]. All of them can cause or worsen depression, sedation, restlessness and stiffness, sometimes worse than the chorea itself [3,5]. In the United States the valbenazine label carries the strongest form of warning about depression and suicidal thoughts in Huntington’s disease [15].

Availability differs by country. The United States approved tetrabenazine in 2008, deutetrabenazine in 2017 and valbenazine for chorea in Huntington’s in 2023 [15,16,17]. In the European Union deutetrabenazine was authorized in 2026 for a different movement condition, not for chorea in Huntington’s [18].

Mood and behavior. SSRI antidepressants come first for depression, anxiety and irritability, and antipsychotics are used for aggression or psychosis [5]. No medicine improves the thinking changes [11].

Therapies and everyday care. Physiotherapy helps movement and balance, occupational therapy supports daily activities, and speech and language therapy helps with speech and swallowing. Early referral to a dietitian matters, since keeping weight up usually needs high-calorie, high-protein food [1,5]. They work best as one team around a care plan [1,3].

Living with Huntington’s disease

Care usually comes from a specialist team, reached through a clinic or a specialist adviser [1,6]. The condition also affects a whole family. Each child of an affected parent has a 50 percent chance of inheriting the gene change, and brothers and sisters carry the same chance [3]. Adult relatives can ask for genetic counseling whether or not they want a test, and children in an affected family often need their own support [3].

Several options exist for people thinking about having children, each a decision for the people involved. Testing during pregnancy is possible, as is pre-implantation genetic testing, where embryos created through IVF are tested before one is used. Arrangements also exist that let a couple test an embryo without the at-risk parent learning their own result [3,4]. These talks are easiest before a pregnancy [3].

Work, driving, money and care planning come up over time. Average survival after symptoms begin is 15 to 18 years, ranging from about 5 to over 25 [1,3].

Thinking about a clinical trial?

Clinical trials test whether a treatment works and whether it is safe. Studies exist for people with symptoms and for people who carry the gene change and are still well. It helps to decide in steps.

1. Understand what the study is asking

  • what the researchers want to learn, and what the treatment is compared with
  • how long it lasts, often one to three years, sometimes with follow-up for five years or more
  • what visits and tests are involved, usually movement, thinking and mood testing, blood tests and brain scans, and sometimes a sample of the fluid around the spine
  • how it is given, which may be tablets, an injection into the fluid around the spine, or a one-time brain operation, and what recovery would involve
  • the travel each visit needs, the possible benefits and risks, and what happens when the study ends

2. Consider possible medical suitability

Every trial has rules about who can take part, called eligibility criteria. For a Huntington’s disease study these often include a genetic result confirming a repeat count above a set number, commonly 40 or more; an age range; a particular stage on a standard scale of daily function; a stable dose of medicines for chorea or mood, or in some studies none of those medicines at all; and no other health problem that makes the tests unsafe.

trialport’s medifit helps people consider information related to possible medical suitability. It does not diagnose a condition, confirm eligibility or replace formal screening by the study team.

Explore Huntington’s disease clinical trials through trialport

3. Consider whether participation fits your life

A study can look right on paper and still be hard in practice:

  • how many visits there are, how long each takes, and how you would get there
  • work, school, and caring for others, including another affected family member
  • how you feel about a study involving repeated spinal injections or brain surgery
  • whether you want to learn more about your own genetic result than you currently know
  • how you and the people close to you would feel if the treatment turned out not to work, and who you want to talk it through with

trialport’s readifit helps people reflect on their understanding, motivation, time, routines, support, emotions and practical arrangements.

4. Ask questions before deciding

  • Why is this study being done, and what is already known about the treatment?
  • What exactly would I need to do, and how often?
  • Could I receive a placebo, a dummy treatment with no active medicine, used so results can be compared fairly? How likely is that, and could it mean an imitation operation?
  • Would I have to change, pause or start any of my current medicines, and who decides?
  • What are the known risks of the treatment and of the procedure that delivers it?
  • What will you tell me about my own results, including my genetic result?
  • Can I leave after joining, and what happens to my care then?
  • Are travel costs covered, and could I keep the treatment afterward?

Taking part is voluntary. A person can ask questions, speak with people they trust and choose not to participate.

Search for clinical trials at app.trialport.com.

Current research

Most research tries to lower the amount of altered huntingtin the brain makes, by interfering with the gene’s message before the protein is built [3,4]. The picture mixes setbacks with encouraging signs, and nothing below is approved.

  • Two well-known programs did not work as hoped. A late-stage study of tominersen, injected into the fluid around the spine, was stopped in 2021 because the balance of benefit and risk was unfavorable, and a smaller study of a lower dose continues [20]. Pridopidine, taken by mouth, failed in a study of 499 people, and European regulators recommended refusing a license in 2025 before the company withdrew it [19,20].
  • One gene therapy has produced the most encouraging results so far. AMT-130 is given once, through brain surgery. At three years, people on the higher dose declined more slowly on a combined measure of movement, thinking and daily function than a matched group from an existing natural-history study [20]. Two cautions belong with that: the comparison was not against people given a placebo in the same study, and only twelve people per dose had reached three years [3,20]. In June 2026 the United States regulator said those data could support an application for accelerated approval [21].
  • Other approaches are in earlier testing, including tablets that lower huntingtin [3,20].

Study status checked: 3 August 2026. Research moves quickly, so this will date. For current information, search at app.trialport.com.

Support and further information

In the United Kingdom the Huntington’s Disease Association runs a helpline, regional specialist advisers and local branches [6]. In the United States the Huntington’s Disease Society of America funds research, runs a helpline and lists specialist centers [11]. The European Huntington Association links groups in 32 countries [24]. The Huntington Society of Canada, Huntington’s Victoria in Australia and the Huntington’s Disease Association of New Zealand support those countries [25,26,27]. The Huntington’s Disease Youth Organization writes separately for young people of different ages [28].

The NHS and NINDS pages are reliable starting points [1,4]. Coverage is thin across much of Africa, Asia, the Middle East and South America.

Well-known people connected with Huntington’s disease

The folk singer Woody Guthrie was diagnosed in 1952, after several wrong diagnoses, and died in 1967 at 55. His wife Marjorie Guthrie founded the organization that became the Huntington’s Disease Society of America [22].

The British former news correspondent Charles Sabine learned in 2006 that he carries the gene change, twelve years after his father was diagnosed. He chose to speak publicly, and campaigns against the secrecy around it [23].

Neither experience predicts anyone else’s, and both men chose for themselves what to make public.

Questions people often ask

Is there a cure for Huntington’s disease?
No, and no treatment yet slows or stops it. Medicines, therapies and good nutrition help with the symptoms, and research on the underlying cause is active [1,4].

If my parent has Huntington’s disease, will I get it?
Each child has a 1 in 2, or 50 percent, chance of inheriting the gene change, and not inheriting it means it cannot pass to your own children [1,3,4].

Should I have the predictive test?
There is no right answer. It is offered to adults with counseling before and after, and many at-risk people decide not to test: more than 80 in every 100 in the United Kingdom have not [10,12]. A genetic counselor helps you think it through without pushing you either way [1].

Can Huntington’s disease skip a generation?
Not really, though it can look that way if a parent died before symptoms began, was misdiagnosed or carried a borderline count that later grew [3].

How long do people live after symptoms start?
On average 15 to 18 years, ranging from about 5 to more than 25, and the pattern differs from person to person [1,3].

Are the mood and personality changes part of the condition?
Yes. Depression, irritability, anxiety and loss of drive come from changes in the brain, not from a lack of effort, they often start before any movement symptoms, and they can be treated [3,5,8].

Sources

  1. National Health Service (NHS). Huntington’s disease. Page last reviewed 13 March 2025. https://www.nhs.uk/conditions/huntingtons-disease/ Accessed 3 August 2026.
  2. MedlinePlus Genetics, National Library of Medicine. Huntington’s disease. https://medlineplus.gov/genetics/condition/huntingtons-disease/ Accessed 3 August 2026.
  3. Caldeira Brás I, Dawson J, Kay C, Caron NS, Hayden MR. Huntington Disease. In: Adam MP, Feldman J, Mirzaa GM, et al, editors. GeneReviews. Seattle: University of Washington; 1993 to 2026. Comprehensive update posted 12 February 2026. https://www.ncbi.nlm.nih.gov/books/NBK1305/ Accessed 3 August 2026.
  4. National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health. Huntington’s Disease. Last reviewed 23 July 2026. https://www.ninds.nih.gov/health-information/disorders/huntingtons-disease Accessed 3 August 2026.
  5. Bachoud-Lévi AC, Ferreira J, Massart R, Youssov K, Rosser A, Busse M, Craufurd D, Reilmann R, De Michele G, Rae D, Squitieri F, Seppi K, Perrine C, Scherer-Gagou C, Audrey O, Verny C, Burgunder JM. International Guidelines for the Treatment of Huntington’s Disease. Frontiers in Neurology. 2019;10:710. doi:10.3389/fneur.2019.00710. Commissioned by the European Huntington’s Disease Network. Full text read at https://pmc.ncbi.nlm.nih.gov/articles/PMC6618900/ Accessed 3 August 2026.
  6. Huntington’s Disease Association (United Kingdom). What is Huntington’s disease? https://www.hda.org.uk/information-and-support/huntingtons-disease/what-is-huntingtons-disease/ Accessed 3 August 2026.
  7. Huntington’s Disease Association (United Kingdom). What causes Huntington’s disease. https://www.hda.org.uk/information-and-support/huntingtons-disease/what-causes-huntingtons-disease/ Accessed 3 August 2026.
  8. Huntington’s Disease Association (United Kingdom). Huntington’s disease symptoms. https://www.hda.org.uk/information-and-support/huntingtons-disease/huntingtons-disease-symptoms/ Accessed 3 August 2026.
  9. Huntington’s Disease Association (United Kingdom). Juvenile Huntington’s disease. https://www.hda.org.uk/information-and-support/huntingtons-disease/juvenile-huntingtons-disease/ Accessed 3 August 2026.
  10. Huntington’s Disease Association (United Kingdom). Genetic testing. https://www.hda.org.uk/information-and-support/getting-help/genetic-testing/ Accessed 3 August 2026.
  11. Huntington’s Disease Society of America. Overview of Huntington’s Disease. https://hdsa.org/what-is-hd/overview-of-huntingtons-disease/ Accessed 3 August 2026.
  12. Baig SS, Strong M, Rosser E, Taverner NV, Glew R, Miedzybrodzka Z, Clarke A, Craufurd D, UK Huntington’s Disease Prediction Consortium, Quarrell OW. 22 Years of predictive testing for Huntington’s disease: the experience of the UK Huntington’s Prediction Consortium. European Journal of Human Genetics. 2016;24(10):1396-1402. doi:10.1038/ejhg.2016.36. Full text read at https://pmc.ncbi.nlm.nih.gov/articles/PMC5027682/ Accessed 3 August 2026.
  13. Almqvist EW, Bloch M, Brinkman R, Craufurd D, Hayden MR. A worldwide study of the frequency of suicide, suicide attempts, or psychiatric hospitalization after predictive testing for Huntington disease. American Journal of Human Genetics. 1999;64(5):1293-1304. doi:10.1086/302374. Published abstract read at https://pmc.ncbi.nlm.nih.gov/articles/PMC1377865/ Accessed 3 August 2026.
  14. Rodríguez Santana I, Frank SA, Mestre TA, Arnesen A, Hamilton JL, Hubberstey H, Winkelmann M, Hernandez-Jimenez E, Frimpter J, Dolmetsch R, Ali TM. Suicidal Ideation and Sleep Disturbances Among People With Huntington Disease: Evidence From the HDBOI Study. Neurology: Clinical Practice. 2025;15(3):e200461. doi:10.1212/CPJ.0000000000200461. Full text read at https://pmc.ncbi.nlm.nih.gov/articles/PMC11962051/ Accessed 3 August 2026.
  15. United States Food and Drug Administration. INGREZZA (valbenazine) capsules: highlights of prescribing information, including boxed warning on depression and suicidal ideation and behavior in patients with Huntington’s disease. Efficacy supplement approved 18 August 2023. https://www.accessdata.fda.gov/drugsatfda_docs/label/2023/209241s026lbl.pdf Accessed 3 August 2026.
  16. United States Food and Drug Administration. Drugs@FDA record for XENAZINE (tetrabenazine), new drug application 021894, original approval 15 August 2008. https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=021894 Accessed 3 August 2026.
  17. United States Food and Drug Administration. Drugs@FDA record for AUSTEDO (deutetrabenazine), new drug application 208082, original approval 3 April 2017. https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=208082 Accessed 3 August 2026.
  18. European Medicines Agency. Austedo (deutetrabenazine): medicine overview. Marketing authorization valid throughout the European Union from 8 January 2026, for moderate to severe tardive dyskinesia. https://www.ema.europa.eu/en/medicines/human/EPAR/austedo Accessed 3 August 2026.
  19. European Medicines Agency. Nurzigma (pridopidine): withdrawal of the marketing authorization application, 7 November 2025, following the July 2025 recommendation to refuse. Reference EMA/358840/2025. https://www.ema.europa.eu/en/medicines/human/EPAR/nurzigma Accessed 3 August 2026.
  20. Farag M, Tabrizi SJ, Wild EJ. Huntington’s disease clinical trials update: October 2025. Journal of Huntington’s Disease. 2026;15(1):156-166. doi:10.1177/18796397251399751. Full text read at https://pmc.ncbi.nlm.nih.gov/articles/PMC12847458/ Accessed 3 August 2026.
  21. uniQure N.V. uniQure Announces Plan for BLA Submission for AMT-130 in Huntington’s Disease. Company announcement, 17 June 2026, published by the Huntington’s Disease Society of America. https://hdsa.org/wp-content/uploads/2026/06/PR_TypeB-Update_June-2026_06.17.26_Final-1.pdf Accessed 3 August 2026.
  22. Huntington’s Disease Society of America. HDSA History. https://hdsa.org/about-hdsa/hdsa-history/ Accessed 3 August 2026.
  23. Bunting E, for the Huntington’s Disease Association (United Kingdom). Transforming adversity into advocacy: Charles Sabine OBE. Guest blog. https://www.hda.org.uk/transforming-adversity-into-advocacy/ Accessed 3 August 2026.
  24. European Huntington Association. Umbrella organization for Huntington’s disease associations from 32 countries. https://eurohuntington.org/ Accessed 3 August 2026.
  25. Huntington Society of Canada. https://www.huntingtonsociety.ca/ Accessed 3 August 2026.
  26. Huntington’s Victoria (Australia). https://www.huntingtonsvic.org.au/ Accessed 3 August 2026.
  27. Huntington’s Disease Association of New Zealand. https://www.huntingtons.org.nz/ Accessed 3 August 2026.
  28. Huntington’s Disease Youth Organization (HDYO). https://hdyo.org/ Accessed 3 August 2026.
  29. National Library of Medicine, Clinical Table Search Service. ICD-10-CM code G10, Huntington’s disease. https://clinicaltables.nlm.nih.gov/apidoc/icd10cm/v3/doc.html Accessed 3 August 2026.

Review information

Written by: trialport editorial team
Reviewed by: Keith Berelowitz, Founder and CEO, trialport
Reviewed on: 3 August 2026
Next review due: 3 August 2027
References last checked: 3 August 2026