Rare Hematology News

Advertisement

Disease Profile

Huntington disease

Prevalence
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.

1-9 / 100 000

US Estimated

Europe Estimated

Age of onset

Childhood

ageofonset-childhood.svg

ICD-10

G10

Inheritance

Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.

rnn-autosomaldominant.svg

Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.

no.svg

X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.

no.svg

X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.

no.svg

Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.

no.svg

Not applicable

no.svg

Other names (AKA)

Huntington's chorea; Huntington's disease; HD

Categories

Congenital and Genetic Diseases; Nervous System Diseases

Summary

Huntington disease (HD) is an inherited condition that causes progressive degeneration of neurons in the brain. Signs and symptoms usually develop between ages 35 to 44 years and may include uncontrolled movements, loss of intellectual abilities, and various emotional and psychiatric problems. People with HD usually live for about 15 to 20 years after the condition begins. It is caused by changes (mutations) in the HTT gene and is inherited in an autosomal dominant manner. Treatment is based on the symptoms present in each person and may include various medications.[1][2]

There is also a less common, early-onset form of HD which begins in childhood or adolescence. For more information on this form, please visit GARD's juvenile Huntington disease Web page.

Symptoms

Huntington disease (HD) is a progressive disorder that causes motor, cognitive, and psychiatric signs and symptoms. On average, most people begin developing features of HD between ages 35 and 44. Signs and symptoms vary by stage and may include:[2][3]

Early stage:

  • Behavioral disturbances
  • Clumsiness
  • Moodiness
  • Irritability
  • Paranoia
  • Apathy
  • Anxiety
  • Hallucinations
  • Abnormal eye movements
  • Depression
  • Impaired ability to detect odors

Middle stage:

  • Dystonia
  • Involuntary movements
  • Trouble with balance and walking
  • Chorea with twisting and writhing motions
  • Unsteady gait (style of walking)
  • Slow reaction time
  • General weakness
  • Weight loss
  • Speech difficulties
  • Stubbornness

Late stage:

  • Rigidity (continual tension of the muscles)
  • Bradykinesia (difficulty initiating and continuing movements)
  • Severe chorea
  • Serious weight loss
  • Inability to speak
  • Inability to walk
  • Swallowing problems
  • Inability to care for oneself

There is also a less common, early-onset form of HD which begins in childhood or adolescence. For more information on this form, please visit GARD's juvenile Huntington disease Web page.

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Chorea
0002072
Mental deterioration
Cognitive decline
Cognitive decline, progressive
Intellectual deterioration
Progressive cognitive decline

[ more ]

0001268
30%-79% of people have these symptoms
Abnormal libido
0031845
Abnormality of eye movement
Abnormal eye movement
Abnormal eye movements
Eye movement abnormalities
Eye movement issue

[ more ]

0000496
Abnormality of the sense of smell
Abnormal sense of smell
Smell defect

[ more ]

0004408
Aggressive behavior
Aggression
Aggressive behaviour
Aggressiveness

[ more ]

0000718
Agitation
0000713
Anxiety
Excessive, persistent worry and fear
0000739
Apathy
Lack of feeling, emotion, interest
0000741
Bradykinesia
Slow movements
Slowness of movements

[ more ]

0002067
Bradyphrenia
Slowness of thought
0031843
Clumsiness
0002312
Delusions
0000746
Depressivity
Depression
0000716
Difficulty walking
Difficulty in walking
0002355
Disinhibition
0000734
Dystonia
0001332
Gait imbalance
Abnormality of balance
Abnormality of equilibrium
Imbalanced walk

[ more ]

0002141
Generalized muscle weakness
0003324
Hallucinations
Hallucination
Sensory hallucination

[ more ]

0000738
Hostility
0031473
Hypokinesia
Decreased muscle movement
Decreased spontaneous movement
Decreased spontaneous movements

[ more ]

0002375
Irritability
Irritable
0000737
Memory impairment
Forgetfulness
Memory loss
Memory problems
Poor memory

[ more ]

0002354
Myoclonus
0001336
Obsessive-compulsive behavior
Obsessive compulsive behavior
0000722
Poor fine motor coordination
0007010
Seizure
0001250
Speech articulation difficulties
0009088
Staring gaze
0025401
Weight loss
0001824
5%-29% of people have these symptoms
Abnormal circulating cholesterol concentration
Abnormality of cholesterol metabolism
0003107
Abnormality of the cerebral white matter
0002500
Alcoholism
0030955
Babinski sign
0003487
Caudate atrophy
0002340
Cerebral atrophy
Degeneration of cerebrum
0002059
Choking episodes
0030842
Clonus
0002169
Decreased body mass index
0045082
Degeneration of the striatum
0040140
Excessive daytime somnolence
Excessive daytime sleepiness
More than typical sleepiness during day

[ more ]

0001262
Impaired visuospatial constructive cognition
0010794
Inability to walk
0002540
Insomnia
Difficulty staying or falling asleep
0100785
Mutism
Inability to speak
Muteness

[ more ]

0002300
Oral-pharyngeal dysphagia
0200136
Polyphagia
Voracious appetite
0002591
Rigidity
Muscle rigidity
0002063
Suicidal ideation
0031589
Percent of people who have these symptoms is not available through HPO
Autosomal dominant inheritance
0000006
Cerebellar atrophy
Degeneration of cerebellum
0001272
Dementia
Dementia, progressive
Progressive dementia

[ more ]

0000726
Gait ataxia
Inability to coordinate movements when walking
0002066
Gliosis
0002171
Hyperreflexia
Increased reflexes
0001347
Neuronal loss in central nervous system
Loss of brain cells
0002529
Personality changes
Personality change
0000751

Cause

Huntington disease (HD) is caused by a change (mutation) in the HTT gene. This gene gives instructions for making a protein called huntingtin. The exact function of this protein is unclear, but it appears to be important to nerve cells (neurons) in the brain.[1]

The HTT gene mutation that causes HD involves a DNA segment known as a CAG trinucleotide repeat. This segment is made up of three DNA building blocks that repeat multiple times in a row. The CAG segment in a normal HTT gene repeats about 10 to 35 times. In people with HD, it may repeat from 36 to over 120 times. People with 36 to 39 CAG repeats (an intermediate size) may or may not develop HD, while people with 40 or more repeats almost always develop HD.[1]

Diagnosis

A diagnosis of Huntington disease is typically suspected in people with characteristic signs and symptoms of the condition and a family history consistent with autosomal dominant inheritance. The diagnosis can then be confirmed with genetic testing that identifies a specific type of change (mutation) in the HTT gene.[2]

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.
  • The Division of Neurogenetics at the University of Washington is a tertiary specialty that provides clinical services to adults in the general public as well as training. They have created a booklet entitled, "Huntington Disease: Making an Informed Choice, that can be downloaded at no charge.
  • Orphanet lists international laboratories offering diagnostic testing for this condition.

    Treatment

    Unfortunately, there is currently no cure for Huntington disease (HD). The current goal of treatment is to slow down the course of the disease and help affected people function for as long and as comfortably as possible.[3]

    Current treatment strategies involve the use of various medications to treat specific symptoms such as abnormal movements and behaviors. Depression and suicide are more common among affected people, so caregivers should monitor for associated symptoms and seek help if necessary. As symptoms of the disease worsen, affected people need more assistance, supervision, and care.[3]

    FDA-Approved Treatments

    The medication(s) listed below have been approved by the Food and Drug Administration (FDA) as orphan products for treatment of this condition. Learn more orphan products.

    Organizations

    Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

    Organizations Supporting this Disease

      Social Networking Websites

        Learn more

        These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

        Where to Start

        • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
        • Genetics Home Reference (GHR) contains information on Huntington disease. This website is maintained by the National Library of Medicine.
        • The National Human Genome Research Institute's (NHGRI) website has an information page on this topic. NHGRI is part of the National Institutes of Health and supports research on the structure and function of the human genome and its role in health and disease.
        • The National Institute of Neurological Disorders and Stroke (NINDS) collects and disseminates research information related to neurological disorders. Click on the link to view information on this topic.
        • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

          In-Depth Information

          • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
          • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
          • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
          • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
          • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
          • PubMed is a searchable database of medical literature and lists journal articles that discuss Huntington disease. Click on the link to view a sample search on this topic.

            References

            1. Huntington disease. Genetics Home Reference. June, 2013; https://ghr.nlm.nih.gov/condition/huntington-disease.
            2. Simon C Warby, Rona K Graham, and Michael R Hayden. Huntington Disease. GeneReviews. December 11, 2014; https://www.ncbi.nlm.nih.gov/books/NBK1305/.
            3. Huntington disease. MedlinePlus. May 28, 2013; https://www.nlm.nih.gov/medlineplus/ency/article/000770.htm.
            4. Idan Sharon. Huntington Disease Dementia. Medscape Reference. April 18, 2014; https://emedicine.medscape.com/article/289706-overview.
            5. Fredy J Revilla. Huntington Disease. Medscape Reference. July 9, 2015; https://emedicine.medscape.com/article/1150165-overview.

            Rare Hematology News