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Diseases

Genetic and Rare Diseases Information Center (GARD)

Huntington disease


Other Names for this Disease
  • HD
  • Huntington chorea
  • Huntington's chorea
  • Huntington's disease
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.

Your Question

I have a family history of Huntington's disease.  My mother was diagnosed with it about 5 years ago.  I just needed to know some information about where I can get tested.  Also, how early can they start treatment if I am diagnosed with it?  I'm only 21 years old.  I just thought that maybe the sooner they start the better.

Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

What is Huntington disease?

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.
Last updated: 7/8/2015

How is Huntington disease diagnosed?

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]
Last updated: 7/8/2015

How is Huntington disease inherited?

Huntington disease (HD) is inherited in an autosomal dominant manner.[2] This means that having a change (mutation) in only one of the 2 copies of the responsible gene (the HTT gene) is enough to cause the condition. When a person with HD has children, each child has a 50% (1 in 2) chance to inherit the mutated gene and develop the condition.

Although HD can rarely be caused by a de novo mutation in the HTT gene (a mutation that occurs for the first time and is not inherited from a parent), most people with HD have an affected parent. The family history can sometimes appear negative for various reasons even though a parent carries, or carried, a mutation.[2]

As HD is passed through generations, the size of the trinucleotide repeat often increases. A longer repeat in the HTT gene may cause an earlier onset of symptoms. This phenomenon is called anticipation.[1]
Last updated: 7/8/2015

Is genetic testing available for Huntington disease?

Yes. Testing of adults at risk for Huntington disease (HD) who have no symptoms of the disease is called predictive testing. Whether to have predictive testing requires careful thought, including pre-test and post-test genetic counseling. This is particularly important because there is currently no cure. Furthermore, predictive testing cannot accurately predict the age a person with an HD mutation will develop symptoms, the severity or type of symptoms they will experience, or the future rate of disease progression. A person may want to have predictive testing because they feel they need to know or to inform personal decisions involving having children, finances, and/or career planning. Other people decide they do not want to know whether they will develop HD.[2]

Testing is appropriate to consider in symptomatic people of any age in a family with a confirmed diagnosis of HD. However, testing of asymptomatic people younger than age 18 is not considered appropriate. A main reason is that it takes away the choice of whether the person wants to know, while there is no major benefit to knowing at that age.

People who are interested in learning more about genetic testing for HD should speak with a genetics professional.
Last updated: 7/8/2015

Why might an at-risk asymptomatic adult seek testing for Huntington disease?

If a diagnosis of Huntington disease (HD) is confirmed in a family, asymptomatic adult family members who are at risk of developing the condition may seek testing in order to make personal decisions regarding reproduction, financial matters, and career planning. Others may have different motivations including simply the 'need to know.'[1][2]

Presymptomatic testing for HD usually involves pretest interviews in which the motives for requesting the test, the person's knowledge of Huntington disease, the possible impact of positive and negative test results, and neurologic status are assessed. Those seeking testing should be counseled about possible problems that they may encounter with regard to health, life, and disability insurance coverage; employment and educational discrimination; and changes in social and family interaction. Informed consent should be obtained and records kept confidential. People who are found to carry a Huntington disease-causing gene mutation need arrangements for long-term follow-up and evaluations.[1][2]
Last updated: 7/8/2015

How might Huntington disease be treated?

Unfortunately, there is currently no cure for Huntington disease (HD) and no way to stop the progression of the condition. 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]
Last updated: 7/8/2015

References
Other Names for this Disease
  • HD
  • Huntington chorea
  • Huntington's chorea
  • Huntington's disease
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.