Huntington's disease Dr Rob Hicks Dr Trisha Macnair Huntington's disease is a hereditary disorder that damages the nerve cells of certain areas of the brain.

In this article

What is Huntington's disease Symptoms

Causes and risk factors Treatment and recovery

Advice and support

Huntington's disease (also referred to in more formal medical research as Huntington Disease) is an hereditary neurological disorder of the central nervous system that causes progressive degeneration of cells in the brain, slowly impairing a person's ability to walk, think, talk and reason.

It was first described in 1872 by an American doctor, George Huntington, who studied an extended family in Long Island affected by the condition.

Symptoms develop gradually over months or years. The age at which they first appear is usually between about 30 and 50.

However, in about 5% of cases Huntington's disease becomes apparent before the age of 20 (in this situation, referred to as juvenile-onset Huntington's Disease, it is usually inherited from the father). The onset and rate of progression of the disease tends to follow a pattern within each family.

Symptoms begin with memory loss (especially of recent events) or confusion, changes in personality and mood that may include aggressive and antisocial behaviour, as well as clumsiness or uncontrolled muscle movements (these movements are known as chorea) and rigidity.

As the condition progresses, other symptoms of dementia appear, such as loss of rational thought and poor concentration. Involuntary movements, difficulties with speaking and swallowing, weight loss, seizures, depression and anxiety may also occur.

The disease often progresses slowly, and the affected person may live for 15 to 20 years after the initial diagnosis.

Huntington's disease is caused by a single defective gene on chromosome 4. This leads to damage of the nerve cells in areas of the brain including the basal ganglia and cerebral cortex, and to the gradual onset of physical, mental and emotional changes.

The Huntington's Disease Association estimates between 6,500 and 8,000 people in the UK have the disease.

The tragedy is that by the time symptoms appear, the person has often had a family and may have passed on the gene to their children. Each person whose parent has Huntington's disease has a 50 per cent chance of inheriting the gene, and everyone who inherits the gene will at some stage develop the disease.

In three per cent of cases, there's no family history of Huntington's disease and the genetic fault may be a new mutation.

The disease can't be prevented from developing if someone has the faulty gene. To inherit the illness, the gene only has to come from one parent, making it autosomal dominant.

The gene for Huntington's disease can be detected with a blood test, which is available to those aged over 18, before symptoms begin. This can determine whether someone has the faulty gene and help them in their family planning.

With no cure, many of those at risk decide not to take the test rather than live their life in the shadow of the disease. Genetic testing has also led to fears that those with a family history of the condition will have financial problems, such as getting insurance and mortgages.

There's no cure, but supportive care can ease many symptoms and help a person with Huntington's disease, and their family, lead as normal a life as possible.

Drugs can relieve symptoms of involuntary movements, depression and mood swings. Speech therapy can help improve speech and swallowing problems. A high-calorie diet can help maintain weight and improve symptoms such as involuntary movement and behavioural problems.

Cognitive changes often result in loss of enthusiasm, initiative and organisational skills, which can make multi-tasking difficult. Constant nursing care is needed in the later stages of the disease and support for carers is important, too.

Secondary illnesses, such as pneumonia, are often the cause of death.

There's extensive research into possible treatments for Huntington's disease. One technique is the use of transplants of foetal brain cells, which appear in some cases to repair and rejuvenate the damaged area.

Meanwhile, researchers at the University of Leeds have found that one of the body's naturally occurring proteins is causing some of the disruption that occurs in the brains of those with Huntington's, and its effects may be modified by using drugs that are already being used to help cancer patients. But it is likely to be years, if at all, before these developments result in an effective treatment.

Huntington's Disease Association

Tel: 020 7022 1950
Email: info@hda.org.uk
Website: www.hda.org.uk

Scottish Huntington's Association

Tel: 01505 322245
Email: sha-admin@hdscotland.org
Website: www.hdscotland.org

Huntington's Disease Association of Northern Ireland

Tel: 028 9022 1950
Website: www.hdani.org.uk

This article was last medically reviewed by Dr Trisha Macnair in March 2009.