Huntington disease

Last reviewed: 25 Aug 2023
Last updated: 22 Nov 2022



History and exam

Key diagnostic factors

  • positive family history of Huntington disease
  • known expansion of the CAG repeat length at the N-terminal end of the huntingtin gene
  • impaired work or school performance
  • personality change
  • irritability and impulsivity
  • chorea
  • twitching or restlessness
  • loss of coordination
  • deficit in fine motor coordination
  • slowed rapid (saccadic) eye movements
  • motor impersistence
  • impaired tandem walking
More key diagnostic factors

Other diagnostic factors

  • concentration impairment/task anxiety or apathy
  • cognitive decline relative to spouse/siblings
  • changes in personal habits/hygiene
  • disinhibition or unusually anxious behavior
  • depression, obsessions, and compulsions
Other diagnostic factors

Risk factors

  • expansion of the CAG repeat length at the N-terminal end of the huntingtin gene
  • other genetic factors
  • family history
More risk factors

Diagnostic investigations

1st investigations to order

  • no initial tests
More 1st investigations to order

Investigations to consider

  • CAG repeat testing
  • MRI or CT scan
More investigations to consider

Treatment algorithm


all patients



Mitsuko Nakajima, MD

Clinical Research Fellow

Huntington's Disease Centre

Queen Square

Institute of Neurology

Department of Neurodegenerative Disease

Russell Square House




MN declares no competing interests.


Dr Mitsuko Nakajima would like to gratefully acknowledge Dr Peter McColgan, Dr Sarah Tabrizi, Dr David Craufurd, Dr Marianne Novak, and Dr Francis Walker, previous contributors to this topic.


FW declared that he had no competing interests. MN is an author of a reference cited in this topic. DC has received fees for advisory board membership from Hoffmann-La Roche Ltd. SJT has received grant funding for her research from CHDI Foundation, the BBSRC, Dementia and Neurodegenerative Disease Network UK, European Huntington’s Disease Network, Huntington’s Disease Association of the UK, the Medical Research Council UK, Takeda Pharmaceuticals, the UCL/UCLH Biomedical Research Center, and the Wellcome Trust. SJT has been on advisory boards or had consultancies with F. Hoffmann-La Roche Ltd, Ixico Technologies, Shire Human Genetic Therapies, Takeda Pharmaceuticals International, and TEVA Pharmaceuticals; all honoraria for these consultancies and advisory boards were paid to UCL. Through the offices of UCL Consultants Ltd, a wholly owned subsidiary of UCL, SJT has undertaken consultancy services for F. Hoffmann-La Roche Ltd and GSK. ST is also an author of references cited in this topic PM declared that he had no competing interests.

Peer reviewers

Adrian Priesol, MD, FRCPC


Massachusetts Eye and Ear Infirmary

Harvard Medical School




AP declares that he has no competing interests.

Tiago Mestre, MD, MSc

Resident Neurology

Neurological Clinical Research Unit

Institute of Molecular Medicine




TM declares that he has no competing interests.

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